Association Between Blood Urea Nitrogen to Creatinine Ratio and 90-Day Mortality in Patients with Acute Kidney Injury: a Retrospective Cohort Study

Association Between Blood Urea Nitrogen to Creatinine Ratio and 90-Day Mortality in Patients with Acute Kidney Injury: a Retrospective Cohort Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Association Between Blood Urea Nitrogen to Creatinine Ratio and 90-Day Mortality in Patients with Acute Kidney Injury: a Retrospective Cohort Study Chuankang Zhou, Xiang Li, XiaoFen Ma, YiMing Zhang, Zhanfeng Jiao This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9450994/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract Although blood urea nitrogen (BUN) and serum creatinine (Scr) levels are routinely monitored in clinical practice, the prognostic significance of the blood urea nitrogen to creatinine ratio (BUN/Cr) in patients with acute kidney injury (AKI) remains incompletely elucidated. This study aims to evaluate the association between blood urea nitrogen-to-creatinine ratio (BUN/Cr) and 90-day mortality in critically ill patients with acute kidney injury (AKI) undergoing continuous renal replacement therapy (CRRT). This will assist clinicians in risk stratification, identifying high-risk patients, and implementing individualized clinical interventions.This retrospective observational study included 1,137 critically ill patients with acute kidney injury (AKI) who initiated continuous renal replacement therapy (CRRT). Patients were divided into four groups based on BUN/Cr quartiles: Q1 ( 28.80), with Q1 serving as the reference group. The primary outcome measure was 90-day all-cause mortality. Multivariate Cox regression analysis and Kaplan-Meier curves were employed to evaluate the association between BUN/Cr and in-hospital mortality.In addition, subgroup analyses were performed to assess consistency between groups.Multivariable analysis demonstrated that each standard deviation increase in BUN/Cr was associated with a 1% elevated risk of in-hospital mortality (adjusted HR 1.01, 95% CI 1.01–1.02; p = 0.01). When analyzed categorically, Q3 and Q4 groups exhibited significantly higher mortality risks compared to Q1 (reference group), whereas Q2 showed no significant association with 90-day mortality (p = 0.821).RCS analysis revealed a U-shaped relationship between the BUN/Cr ratio and 28-day mortality (p for non-linearity: 0.023), with an inflection point at 11.3 mg/dL. Mortality risk decreased to the left of the inflection point and increased to the right of it. Subgroup analyses revealed no significant interaction effects (all p-interaction > 0.5). Kaplan-Meier survival curves demonstrated the poorest survival probability in the Q4 cohort.The serum urea nitrogen-to-creatinine ratio (BUN/Cr) serves as a potential biomarker for predicting 90-day in-hospital mortality risk in acute kidney injury (AKI) patients, with elevated BUN/Cr levels demonstrating a dose-dependent association with increased mortality risk. Health sciences/Biomarkers Health sciences/Diseases Health sciences/Medical research Health sciences/Nephrology Health sciences/Risk factors Blood Urea Nitrogen-to-Creatinine Ratio Continuous Renal Replacement Therapy Acute Kidney Injury Prognosis All-Cause Mortality Figures Figure 1 Figure 2 Figure 3 Introduction Acute kidney injury (AKI) affects approximately half of all critically ill patients admitted to intensive care units (ICUs), and is associated with substantially poorer clinical outcomes and heightened healthcare expenditures [ 1 , 2 ]. Continuous renal replacement therapy (CRRT) has been established as the preferred and indispensable modality for managing AKI in critically ill patients, particularly those with hemodynamic instability[ 3 , 4 ]. Despite technological advancements in CRRT techniques, mortality rates among AKI patients receiving CRRT remain alarmingly high, ranging from 40% to 60% [ 3 , 5 , 6 ]. Consequently, the early identification of high-risk AKI patients undergoing CRRT is clinically imperative to facilitate timely therapeutic interventions aimed at mitigating mortality risk. Blood urea nitrogen (BUN), a metabolic byproduct derived from protein catabolism, is primarily excreted via the kidneys. It serves as a conventional biomarker for evaluating renal function, hydration status, and metabolic conditions. For instance, elevated BUN levels typically indicate impaired renal function or dehydration[ 7 ]. However, BUN elevation may also arise from congestive heart failure, gastrointestinal hemorrhage, or excessive protein intake[ 8 ]. Similarly, creatinine (Cr), a breakdown product of skeletal muscle metabolism, represents a reliable indicator of renal function due to its relatively constant production rate and exclusive renal excretion. Patients with chronic kidney disease (CKD) or acute kidney injury (AKI) consistently demonstrate significantly elevated Cr levels [ 9 ]. Given that isolated BUN or Cr measurements are confounded by extraneous physiological variables, the BUN-to-creatinine ratio (BUN/Cr) has gained clinical traction as a more robust diagnostic parameter. This ratio mitigates the impact of individual fluctuations in BUN or Cr levels, thereby providing a more consistent clinical assessment[ 10 ]. Previous investigations have established BUN/Cr as an independent predictor of adverse outcomes in critically ill populations, including those with stroke, non-traumatic intracranial hemorrhage, venous thromboembolism, cerebral infarction, and atrial fibrillation[ 11 – 15 ]. Furthermore, emerging evidence suggests an association between BUN/Cr levels and all-cause mortality in acute pancreatitis patients[ 16 ]. Nevertheless, the prognostic significance of BUN/Cr specifically in AKI patients remains incompletely characterized. Method Study Population This secondary analysis utilized data from a retrospective cohort study[ 17 ], accessed via the DATADRYAD repository ( https://datadryad.org/stash ; DOI: 10.5061/dryad.6v0j9 ). The dataset comprised 1,144 critically ill patients who underwent continuous renal replacement therapy (CRRT) in intensive care units (ICUs) at Severance Hospital, Yonsei University Health System, and Ilsan Hospital, National Health Insurance Service, Korea, between January 2009 and September 2016. Among 2,391patients initially screened for eligibility, inclusion required stage 2 or higher acute kidney injury (AKI) per the Acute Kidney Injury Network (AKIN) criteria[ 18 ], defined as either serum creatinine elevation ≥ 200% from baseline or urine output < 0.5 mL/kg/h for ≥ 12 hours. Exclusion criteria encompassed: age < 18 years, pregnancy/lactation, pre-existing chronic kidney disease (CKD) or dialysis history, prior renal transplantation, postrenal obstruction, and missing serum urea nitrogen or creatinine measurements. Consequently 1137 patients were included in the final analysis (Figue. 1). The original study protocol received ethical approval from the Institutional Review Board of Severance Hospital, Yonsei University Health System (Approval No. 4-2016-1073), adhering to the principles of the Declaration of Helsinki. As the dataset was fully anonymized, waiver of informed consent was granted for this secondary analysis. This figure illustrates the patient inclusion criteria. This secondary analysis evaluated 1,144 patients meeting the inclusion criteria from the original study. Seven patients were excluded due to missing baseline blood urea nitrogen (BUN) or creatinine (Cr) values. The final analysis included 1,137 subjects enrolled in this study. Study Parameters and Endpoints Epidemiological and clinical data, including age, gender body mass index, and comorbidities, were prospectively recorded prior to continuous renal replacement therapy (CRRT) initiation. Biochemical laboratory parameters were collected at CRRT initiation (0-hour), supplemented by age-adjusted Charlson Comorbidity Index (CCI)[ 19 ], Sequential Organ Failure Assessment (SOFA) score[ 20 ], and Acute Physiology and Chronic Health Evaluation II (APACHE II) score. The decision and timing for CRRT implementation were determined by nephrology specialists in the primary study[ 17 ]. Clinical Measurements Demographic characteristics and comorbidity data were extracted from hospital information systems upon intensive care unit (ICU) admission, encompassing age, gender, height, weight, mean arterial pressure (MAP), and documented histories of cerebrovascular disease, heart failure (HF), peripheral vascular disease (PVD), myocardial infarction (MI), diabetes mellitus (DM), hypertension, chronic obstructive pulmonary disease (COPD), and dementia. Dementia was clinically defined as physician-diagnosed Alzheimer's disease or related dementias. Body mass index (BMI) was calculated as weight in kilograms divided by height in meters squared (kg/m²). Baseline laboratory parameters measured at CRRT initiation included serum albumin (ALB), hemoglobin (HGB), blood urea nitrogen (BUN), serum creatinine (SCr), potassium (K⁺), and estimated glomerular filtration rate (eGFR). All assays were performed using standardized automated analyzers according to manufacturer-specified protocols. CRRT Protocol Patients with acute kidney injury (AKI) in the intensive care unit (ICU) underwent nephrologist assessment for continuous renal replacement therapy (CRRT) initiation. Indications for CRRT included oliguria/anuria, life-threatening volume overload, refractory hyperkalemia (serum potassium > 6.5 mmol/L), or profound metabolic acidosis. Vascular access was established via temporary catheterization of the internal jugular, subclavian, or femoral veins. For critically ill AKI patients, regional citrate anticoagulation was preferentially employed using hemofilters with smaller membrane surface areas (1.0–1.4 m²). The prescribed CRRT dose was maintained at 35 mL/kg/h, with the median treatment duration exceeding 24 hours for the initial session. This approach optimizes hemodynamic stability and mitigates circuit-related complications in critically ill populations. Exposure and Outcome Ascertainment The primary variable examined in this study was the serum urea nitrogen-to-creatinine ratio (BUN/Cr). The BUN/Cr ratio was calculated by dividing the serum BUN level (mg/dL) by the serum Cr level (mg/dL).To evaluate its association with adverse outcomes, participants were stratified into quartiles: Q1 ( 28.80). Additionally, BUN/Cr was analyzed as a continuous variable to assess dose-response relationships. The primary outcome was all-cause mortality within 90 days post-CRRT initiation. Mortality events, including both status and dates, were systematically documented through electronic medical records and national death registries, irrespective of follow-up schedules. Statistical Analysis Categorical variables were presented as frequencies and percentages. Continuous variables conforming to normal distribution were expressed as mean ± standard deviation (SD), while non-normally distributed variables were reported as median with interquartile range (IQR). For comparisons of normally distributed continuous variables, one-way analysis of variance (ANOVA) or Student's t-test was used; for non-normally distributed continuous variables, the Kruskal-Wallis test or Mann-Whitney U test was employed. Categorical variables were compared using Pearson's χ² test or Fisher's exact test. The association between blood urea nitrogen/creatinine ratio (BUN/Cr) and mortality was assessed using Kaplan-Meier curves and multivariate Cox proportional hazards regression models. Variables with P < 0.05 in univariate analysis and clinically significant variables were included in the model. Results were expressed as hazard ratios (HR) with 95% confidence intervals (CI). Restricted cubic spline (RCS) analysis explored the nonlinear relationship between BUN/Cr ratio and mortality. Subgroup analyses were performed to evaluate differential effects of BUN/Cr ratio across subgroups. All tests were two-sided with a significance level of 0.05.All analyses were performed using the Free Statistics software version 2.3( http://www.clinicalscientists.cn/freestatistics ). A descriptive study was conducted on all participants. Results Baseline Characteristics Table 1 delineates the baseline clinical profiles and laboratory parameters of the study cohort. The cohort comprised 1,137 patients with a mean age of 63.2 ± 14.4 years, of whom 701 (61.7%) were male. Comorbid conditions included diabetes mellitus in 397 patients (34.0%) and heart failure in 185 patients (16.3%). At continuous renal replacement therapy (CRRT) initiation, the mean serum creatinine level was 2.7 ± 1.6 mg/dL. The median Charlson Comorbidity Index (CCI) was 3.0 (interquartile range [IQR] 2.0–5). Mean Sequential Organ Failure Assessment (SOFA) and Acute Physiology Chronic Health Evaluation II (APACHE II) scores were 12.1 ± 3.5 and 27.3 ± 8.0, respectively. Mean arterial pressure (MAP) measured at CRRT commencement (0-hour) was 77.3 ± 14.6 mmHg. Mechanical ventilation was required in 893 patients (78.6%). The median white blood cell count was 11,700.0/µL (IQR 6,510.0–18,640.0). The cumulative 90-day all-cause mortality rate following CRRT initiation was 71.9%.as illustrated in Table 1 . Table 1 The basic characteristics of the AKI population stratified by quartiles of the BUN/Cr ratio. Variables Total (n = 1137) Q1 (n = 284) Q2 (n = 283) Q3 (n = 285) Q4 (n = 285) P-value Age(years) 63.3 ± 14.4 59.4 ± 15.4 65.7 ± 13.7 64.2 ± 13.9 63.8 ± 13.9 < 0.001 Male Sex (%) 701 (61.7) 194 (68.3) 176 (62.2) 171 (60) 160 (56.1) 0.025 Myocardial infarction (%) 112 ( 9.9) 34 (12) 31 (11) 25 (8.8) 22 (7.7) 0.301 CHF (%) 185 (16.3) 36 (12.7) 46 (16.3) 56 (19.6) 47 (16.5) 0.165 Cerevascular_disease (%) 114 (10.1) 28 (9.9) 32 (11.3) 30 (10.6) 24 (8.5) PVD(%) 45 ( 4.0) 10 (3.5) 11 (3.9) 16 (5.6) 8 (2.8) 0.362 Dementia(%) 42 ( 3.7) 10 (3.5) 10 (3.5) 9 (3.2) 13 (4.6) 0.831 DM (%) 397 (34.9) 103 (36.3) 97 (34.3) 91 (32) 106 (37.2) 0.581 HTN (%) 596 (52.4) 137 (48.2) 152 (53.7) 150 (52.6) 157 (55.1) 0.392 COPD(%) 80 ( 7.0) 15 (5.3) 19 (6.7) 17 (6) 29 (10.2) 0.103 Potassium (mEq/L) 4.7 ± 1.1 4.7 ± 1.2 4.8 ± 1.1 4.7 ± 1.1 4.6 ± 1.0 0.304 CCI 3.0 (2.0, 5.0) 3.0 (2.0, 5.0) 2.0 (1.0, 4.0) 3.0 (2.0, 5.0) 3.0 (2.0, 5.0) 0.043 BMI(kg/m2) 23.8 ± 4.6 24.8 ± 4.5 23.5 ± 3.8 23.9 ± 5.1 22.9 ± 4.7 < 0.001 MAP(mmHg) 77.3 ± 14.6 76.5 ± 15.4 78.7 ± 13.8 77.0 ± 14.6 77.1 ± 14.5 0.307 MV(%) 893 (78.6) 211 (74.3) 226 (79.9) 225 (78.9) 231 (81.3) 0.197 White blood cell (µL) 11700.0 (6510.0, 18640.0) 12290.0 (6760.0, 19305.0) 12070.0 (7730.0, 18720.0) 12280.0 (6755.0, 20570.0) 10520.0 (5085.0, 16150.0) 0.007 Hemoglobin (g/dL) 9.6 ± 2.2 10.0 ± 2.6 9.7 ± 2.1 9.7 ± 2.3 9.1 ± 1.8 < 0.001 BUN (mg/dL) 49.0 (33.0, 73.0) 33.0 (23.0, 47.0) 44.0 (32.0, 60.0) 56.0 (40.0, 77.0) 74.0 (54.0, 95.0) < 0.001 Creatinine (mg/dL) 2.4 (1.6, 3.4) 3.2 (2.1, 4.5) 2.6 (1.9, 3.6) 2.4 (1.6, 3.2) 1.7 (1.2, 2.3) < 0.001 Albumin (g/dL) 2.6 ± 0.6 2.7 ± 0.6 2.6 ± 0.6 2.6 ± 0.6 2.5 ± 0.6 0.016 GFR(ml/min) 26.4 (17.1, 39.1) 19.8 (12.7, 30.8) 23.2 (15.0, 34.3) 25.9 (17.4, 37.3) 37.7 (27.2, 54.7) < 0.001 APACHE II score 27.3 ± 8.0 27.3 ± 8.0 27.0 ± 8.3 27.8 ± 7.9 27.2 ± 7.8 0.705 SOFA score 12.1 ± 3.5 12.2 ± 3.4 11.7 ± 3.7 12.5 ± 3.5 12.0 ± 3.5 0.045 CRRTcause (%) 0.527 Volume overload 160 (14.1) 36 (12.7) 36 (12.7) 39 (13.7) 49 (17.2) Metablic Acidosis 241 (21.2) 68 (23.9) 65 (23) 56 (19.6) 52 (18.2) Hyperkalemia 57 ( 5.0) 16 (5.6) 13 (4.6) 12 (4.2) 16 (5.6) Uremia 114 (10.0) 32 (11.3) 23 (8.1) 25 (8.8) 34 (11.9) Oliguria 291 (25.6) 74 (26.1) 78 (27.6) 74 (26) 65 (22.8) Others 274 (24.1) 58 (20.4) 68 (24) 79 (27.7) 69 (24.2) AKI stage (%) < 0.001 Stage 2 298 (26.2) 42 (14.8) 69 (24.4) 77 (27) 110 (38.6) Stage 3 839 (73.8) 242 (85.2) 214 (75.6) 208 (73) 175 (61.4) AKIcause, (%) 0.001 Sepsis 793 (69.7) 168 (59.2) 197 (69.6) 211 (74) 217 (76.1) Nephrotoxin 37 ( 3.3) 18 (6.3) 7 (2.5) 5 (1.8) 7 (2.5) Ischemia 97 ( 8.5) 28 (9.9) 28 (9.9) 21 (7.4) 20 (7) Surgery 93 ( 8.2) 36 (12.7) 21 (7.4) 21 (7.4) 15 (5.3) Others 117 (10.3) 34 (12) 30 (10.6) 27 (9.5) 26 (9.1) Death_90D (%) 817 (71.9) 179 (63) 178 (62.9) 224 (78.6) 236 (82.8) < 0.001 BUN/Cr 19.8 (14.2, 28.8) 11.1 (9.4, 12.6) 16.8 (15.5, 18.2) 23.8 ± 2.6 45.0 ± 18.0 < 0.001 COPD Chronic Obstructive Pulmonary Disease, CCI Charlson Comorbidity Index, BMI Body Mass Index, AKIN Acute Kidney Injury Criteria, ICU Intensive Care Unit, CRRT Continuous Renal Replacement Therapy, eGFR Estimated Glomerular Filtration Rate, SOFA Sequential Organ Failure Assessment Score, APACHE II Acute Physiology and Chronic Health Evaluation II, SBP Systolic Blood Pressure, DBP Diastolic Blood Pressure, MAP Mean Arterial Pressure, BUN/Cr Blood Urea Nitrogen to Creatinine Ratio Table 2 demonstrates baseline characteristics stratified by 90-day survival status (survivors vs. non-survivors). Statistically significant intergroup differentials (p < 0.05) encompassed four domains: 1) Demographic & physiological support:Mechanical ventilation dependence, body mass index (BMI), and pre-CRRT mean arterial pressure (MAP); 2) Metabolic & haematologic indices:White blood cell count, haemoglobin, serum albumin, blood urea nitrogen (BUN), serum creatinine, estimated glomerular filtration rate (eGFR), and BUN-to-creatinine ratio (BUN/Cr); 3) Disease severity metrics:Charlson Comorbidity Index (CCI), Acute Physiology and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA); 4) CRRT initiation criteria:Primary clinical indications. Hypertension prevalence differed significantly between cohorts . Table 2 Baseline Characteristics of the AKI Cohort Stratified by Outcome Variables Total (n = 1137) Survivors (n = 320) Non-survivors (n = 817) P-value Age(years) 63.3 ± 14.4 62.7 ± 15.1 63.5 ± 14.1 0.392 Male Sex (%) 701 (61.7) 195 (60.9) 506 (61.9) 0.756 Myocardial infarction (%) 112 ( 9.9) 36 (11.2) 76 (9.3) 0.322 CHF (%) 185 (16.3) 58 (18.1) 127 (15.5) 0.289 Cerevascular_disease (%) 114 (10.1) 37 (11.6) 77 (9.5) 0.282 PVD(%) 45 ( 4.0) 14 (4.4) 31 (3.8) 0.652 dementia(%) 42 ( 3.7) 17 (5.3) 25 (3.1) 0.07 DM (%) 397 (34.9) 131 (40.9) 266 (32.6) 0.008 HTN (%) 596 (52.4) 201 (62.8) 395 (48.3) < 0.001 COPD(%) 80 ( 7.0) 29 (9.1) 51 (6.2) 0.095 Potassium (mEq/L) 4.7 ± 1.1 4.7 ± 1.0 4.7 ± 1.1 0.55 CCI 3.0 (2.0, 5.0) 2.0 (1.0, 4.0) 3.0 (2.0, 5.0) < 0.001 BMI(kg/m2) 23.8 ± 4.6 24.3 ± 4.3 23.6 ± 4.7 0.01 MAP(mmHg) 77.3 ± 14.6 81.1 ± 15.1 75.8 ± 14.1 < 0.001 MV(%) 893 (78.6) 215 (67.2) 678 (83.1) < 0.001 White blood cell (µL) 11700.0 (6510.0, 18640.0) 13320.0 (9060.0, 20195.0) 11160.0 (5305.0, 17950.0) < 0.001 Hemoglobin (g/dL) 9.6 ± 2.2 10.0 ± 2.3 9.5 ± 2.2 < 0.001 BUN (mg/dL) 49.0 (33.0, 73.0) 46.0 (32.0, 64.0) 52.0 (34.0, 76.0) 0.003 Cr (mg/dL) 2.4 (1.6, 3.4) 2.7 (1.8, 3.7) 2.2 (1.6, 3.2) < 0.001 Albumin (g/dL) 2.6 ± 0.6 2.8 ± 0.6 2.5 ± 0.5 < 0.001 GFR(ml/min) 26.4 (17.1, 39.1) 22.1 (15.1, 36.4) 27.9 (18.4, 39.7) < 0.001 APACHE II score 27.3 ± 8.0 25.0 ± 7.9 28.2 ± 7.8 < 0.001 SOFA score 12.1 ± 3.5 10.2 ± 3.4 12.9 ± 3.3 < 0.001 CRRTcause(%) 0.03 Volume overload 160 (14.1) 55 (17.2) 105 (12.9) Metablic acidosis 241 (21.2) 55 (17.2) 186 (22.8) Hyperkalemia 57 ( 5.0) 11 (3.4) 46 (5.6) Oliguria 114 (10.0) 37 (11.6) 77 (9.4) Uremia 291 (25.6) 92 (28.7) 199 (24.4) Others 274 (24.1) 70 (21.9) 204 (25) AKI stage (%) 0.896 Stage 2 298 (26.2) 83 (25.9) 215 (26.3) Stage 3 839 (73.8) 237 (74.1) 602 (73.7) AKIcause,(%) 0.183 Sepsis 793 (69.7) 211 (65.9) 582 (71.2) Nephrotoxin 37 ( 3.3) 13 (4.1) 24 (2.9) Ischemia 97 ( 8.5) 26 (8.1) 71 (8.7) Surgery 93 ( 8.2) 35 (10.9) 58 (7.1) Others 117 (10.3) 35 (10.9) 82 (10) BUN/Cr 19.8 (14.2, 28.8) 17.0 (12.4, 23.4) 21.4 (15.1, 30.9) < 0.001 COPD Chronic Obstructive Pulmonary Disease, CCI Charlson Comorbidity Index, BMI Body Mass Index, AKIN Acute Kidney Injury Criteria, ICU Intensive Care Unit, CRRT Continuous Renal Replacement Therapy, eGFR Estimated Glomerular Filtration Rate, SOFA Sequential Organ Failure Assessment Score, APACHE II Acute Physiology and Chronic Health Evaluation II, SBP Systolic,Blood Pressure, DBP Diastolic Blood Pressure, MAP Mean Arterial Pressure, BUN/Cr Blood Urea Nitrogen to Creatinine Ratio The R elationship Between BUN/Cr and Mortality s Figure 2 presents the Kaplan-Meier survival curves illustrating the association between the serum urea nitrogen-to-creatinine ratio (BUN/Cr) and survival probability among patients with acute kidney injury (AKI). The log-rank test revealed a statistically significant difference in survival across the BUN/Cr quartiles (p < 0.0001), indicating that patients in the highest BUN/Cr quartile had the lowest survival probability compared to those in the lower quartiles. Kaplan-Meier curves depicting cumulative all-cause mortality incidence stratified by BUN/Cr quartiles in AKI patients BUN/Cr: serum urea nitrogen-to-creatinine ratio. Association of BUN/Cr levels with 90-days mortality Table 3 . Multivariable Cox regression analyses of BUN/Cr association with 90-day mortality using Q1 as reference.When analyzed as a continuous variable, elevated BUN/Cr demonstrated a significant positive association with increased 90-day mortality risk in AKI patients. After covariate adjustment, each standard deviation increment in BUN/Cr conferred a 1% higher risk of in-hospital mortality (adjusted HR 1.01, 95% CI 1.01–1.02; p = 0.001).Categorical analysis revealed significantly higher mortality risks in Q3 (19.81–28.80) and Q4 (> 28.80) groups compared to Q1 (< 14.20). No significant association was observed for Q2 (14.20–19.80) versus Q1 (p = 0.821).In the fully adjusted model (Model 4), the highest quartile (Q4) of BUN/Cr ratio demonstrated a 77% increased risk of mortality (HR: 1.77, 95% CI: 1.18–1.77; P < 0.001), while Q3 still carried a 44% elevated risk (HR: 1.44, 95% CI: 1.43–2.17; P = 0.001). Table 3 Association between BUN/Cr and mortality in AKI patients. Variable Model 1 HR_95CI Model 2 HR_95CI Model 3 HR_95CI Model 4 HR_95CI HR P-value HR P-value HR P-value HR P-value BUN/Cr 1.01 (1.01 ~ 1.02) < 0.001 1.01 (1.01 ~ 1.02) < 0.001 1.01 (1.01 ~ 1.02) < 0.001 1.01 (1.01 ~ 1.02) < 0.001 BUN/Cr Q1(< 14.20) (Reference) 1 (Reference) 1 (Reference) 1 (Reference) 1 Q2(14.20–19.80) 0.99 (0.81 ~ 1.22) 0.961 0.98 (0.8 ~ 1.21) 0.876 0.95 (0.77 ~ 1.17) 0.605 0.98 (0.79 ~ 1.21) 0.821 Q3(19.81–28.80) 1.58 (1.29 ~ 1.92) < 0.001 1.57 (1.29 ~ 1.91) < 0.001 1.56 (1.27 ~ 1.91) < 0.001 1.44 (1.18 ~ 1.77) 28.80) 1.76 (1.45 ~ 2.13) < 0.001 1.75 (1.44 ~ 2.13) < 0.001 1.77 (1.45 ~ 2.16) < 0.001 1.77 (1.43 ~ 2.17) < 0.001 P for trend P < 0.001 P < 0.001 P < 0.001 P < 0.001 Regression results were presented as hazard ratios (HRs) estimates with 95% CI, and the reference group was tertile 1. Four levels of hierarchical multivariate adjustments were examined. Model 1: Rough model: no adjustment; Model 2: Adjusted based on age and sex; Model 3: model 2 adjustments, plus comorbidity history (myocardial infarction, heart failure, cerebrovascular disease, peripheral vascular disease, diabetes mellitus, hypertension, COPD, and dementia); Model 4: model 3 adjustments, plus SOFA score, APACHE II score, AKI stages, AKI causes, mean arterial pressure levels, and laboratory parameters hemoglobin. Our analysis revealed a nonlinear association between BUN/Cr and 90-day mortality in AKI patients. Following multivariable adjustment for age, sex, comorbidities (myocardial infarction, heart failure, cerebrovascular disease, peripheral vascular disease, diabetes mellitus, hypertension, chronic obstructive pulmonary disease, dementia), disease severity (SOFA and APACHE II scores), AKI stage, etiology, laboratory parameters (hemoglobin), and mean arterial pressure, restricted cubic spline analysis demonstrated a U-shaped relationship between BUN/Cr and in-hospital mortality (as illustrated in Fig. 3 ). Employing two-stage logistic regression analysis, we identified an inflection point for BUN/Cr at 11.3 mg/dL (Table 4 ). Among AKI patients: Left of inflection: Each 1 mg/dL BUN/Cr increment corresponded to a 10.9% decrease in 90-day mortality incidence (HR 0.891, 95% CI 0.795–0.998; p = 0.0461);Right of inflection: Each 1 mg/dL increase was associated with a 2.5% elevated mortality risk (HR 1.025, 95% CI 1.013–1.037; p < 0.001). Table 4 The nonlinear relationship between BUN/Cr and 90-day mortality BUN/Cr HR (95%CI) P value <11.3 0.891 (0.795,0.998) 0.0461 ≥ 11.3 1.025 (1.013,1.037) < 0.001 Likelihood Ratio test - 0.038 The results were adjusted based on age and gender, comorbidity history (myocardial infarction, heart failure, Cerevascular, peripheral vascular disease, diabetes mellitus, hypertension, chronic obstructive pulmonary disease and dementia), disease severity (SOFA score and APACHE II score), AKI staging, AKI cause, laboratory parameters (hemoglobin) and MAP level. Subgroup analysis As shown in Table 5 , we conducted subgroup analyses to assess the relationship between BUN/Cr and in-hospital mortality. After adjusting for confounding factors including age (< 65 years and ≥ 65 years), sex, BMI, myocardial infarction, heart failure, cerebrovascular disease, peripheral vascular disease, diabetes, hypertension, COPD, and dementia, no significant interactions were observed (all interaction p-values > 0.05). Table 5 Subgroup analysis Variables Variable n n% Adj HR_95CI Adj P_value P.for.interaction Age BUN/Cr 0.261 Age<65 533 383 (71.9) 1.01 (1.01 ~ 1.02) < 0.001 Age ≥ 65 604 434 (71.9) 1.02 (1.01 ~ 1.02) < 0.001 BMI BUN/Cr 0.99 BMI<23 716 528 (73.7) 1.01 (1.01 ~ 1.02) < 0.001 BMI 23–30 324 219 (67.6) 1.02 (1.01 ~ 1.03) 30 77 51 (66.2) 1.01 (0.98 ~ 1.04) 0.5 Gender BUN/Cr 0.663 Male 701 506 (72.2) 1.01 (1.01 ~ 1.02) < 0.001 Female 436 311 (71.3) 1.01 (1.01 ~ 1.02) < 0.001 MI BUN/Cr 0.521 No 1025 741 (72.3) 1.01 (1.01 ~ 1.02) < 0.001 Yes 112 76 (67.9) 1.02 (1 ~ 1.04) 0.052 CHF BUN/Cr 0.829 NO 952 690 (72.5) 1.01 (1.01 ~ 1.02) < 0.001 Yes 185 127 (68.6) 1.01 (1 ~ 1.03) 0.027 Cerevascular BUN/Cr 0.372 No 1019 737 (72.3) 1.01 (1.01 ~ 1.02) < 0.001 Yes 114 77 (67.5) 1.02 (1 ~ 1.03) 0.01 PVD BUN/Cr 0.266 No 1092 786 (72) 1.01 (1.01 ~ 1.02) < 0.001 Yes 45 31 (68.9) 1.07 (1.01 ~ 1.13) 0.014 dementia BUN/Cr 0.452 No 1095 792 (72.3) 1.01 (1.01 ~ 1.02) < 0.001 Yes 42 25 (59.5) 1.03 (0.99 ~ 1.07) 0.144 DM BUN/Cr 0.767 No 739 550 (74.4) 1.01 (1.01 ~ 1.02) < 0.001 Yes 397 266 (67) 1.02 (1.01 ~ 1.02) < 0.001 HTN BUN/Cr 0.011 No 541 422 (78) 1.01 (1 ~ 1.02) 0.001 Yes 596 395 (66.3) 1.02 (1.01 ~ 1.02) < 0.001 COPD BUN/Cr 0.345 No 1057 766 (72.5) 1.01 (1.01 ~ 1.02) < 0.001 Yes 80 51 (63.7) 1.02 (1 ~ 1.04) 0.109 Discussion AKI is a critical disease posing a serious threat to public health and life safety, and early identification of AKI risk stratification remains a highly challenging issue [ 20 ]. This study first reveals that elevated BUN/Cr levels constitute an independent risk factor for 90-day all-cause mortality in AKI patients undergoing CRRT. This association persists even after adjusting for confounding factors. BUN/Cr can predict mortality in AKI patients. Furthermore, Kaplan–Meier survival analysis demonstrated that AKI patients with BUN/Cr > 19.81 exhibited significantly higher 90-day mortality compared to those with BUN/Cr ≤ 19.81. Subgroup analysis further supported this finding. Consequently, this study provides a novel, simple, and efficient biomarker for mortality risk stratification in AKI patients. Blood urea nitrogen (BUN) is the primary end product of human protein metabolism. After glomerular filtration, BUN is reabsorbed in the renal tubules. When renal perfusion is insufficient and renal function is severely impaired, BUN is released in large quantities, providing a better reflection of the severity of renal injury. Furthermore, BUN can trigger immune dysregulation by promoting excessive catabolism and activating neurohumoral mechanisms, thereby increasing the risk of mortality in critically ill AKI patients [ 21 ].Research indicates that BUN levels constitute a risk factor for AKI patients requiring renal replacement therapy [ 22 ]. Furthermore, elevated BUN correlates with mortality outcomes in AKI patients [ 23 ]. However, blood urea nitrogen exhibits lower sensitivity compared to glomerular filtration rate (GFR) and serum creatinine (Scr). Additionally, BUN is influenced by multiple factors including age, high-protein diets, gastrointestinal bleeding, dehydration, and catabolic states. In recent years, BUN/Cr has been demonstrated to be a more reliable tool for predicting outcomes in critically ill patients across various conditions[ 11 – 13 ], as it simultaneously accounts for both BUN and Scr levels, enabling a more comprehensive assessment of renal function and fluid status. Given the evidence supporting BUN and BUN/Cr, this study aimed to explore the prognostic significance of BUN/Cr in AKI patients, particularly its relationship with mortality risk.Interestingly, we observed a U-shaped association between BUN/Cr and mortality. Specifically, on the left side of the U-shaped curve, the risk of death gradually decreased as BUN/Cr increased. However, on the right side of the curve, higher BUN/Cr corresponded to a sharp increase in mortality risk. This nonlinear relationship can be explained by relevant pathophysiological mechanisms. This study investigated the association between BUN/Cr and mortality risk in patients with AKI. Our findings revealed a U-shaped relationship between BUN/Cr and mortality risk: initially, a moderate increase in BUN/Cr was associated with a reduced risk of death, but mortality risk rose sharply once a certain threshold was exceeded.This nonlinear relationship remained significant after adjusting for potential confounders, highlighting an important and under-explored finding in this field. These results suggest that BUN/Cr may serve as a valuable prognostic indicator in the ICU setting, aiding clinicians in early identification of high-risk AKI patients and guiding timely interventions. In fact, our comprehensive study has a relatively large sample size. However, certain limitations must also be considered. Firstly, our study is retrospective and relies on data from a single database, which may limit the generalizability of our findings. Although we have adjusted for many potential confounding factors and conducted multiple subgroup analyses, residual confounding factors cannot be completely eliminated, given that this study is of an observational nature. Conclusion A study revealed a U-shaped association between BUN/Cr and 90-day mortality in AKI patients, with both extremely low and elevated BUN/Cr levels linked to increased mortality risk. This research demonstrates the clinical utility of BUN/Cr as an easily accessible, cost-effective, and practical prognostic indicator for predicting long-term outcomes in AKI. Abbreviations AKI Acute kidney injury CCI Charlson Comorbidity Index CKD chronic kidney disease AKIN Acute Kidney Injury Network BMI body mass index SBP comorbidities, systolic blood pressure DBP diastolic blood pressure MAP mean arterial pressure MV mechanical ventilation HGB hemoglobin WBC white blood cell count CRP C-reactive protein CREA creatinine BUN blood urea nitrogen GFR glomerular filtration rate ALB albumin HCO3- hydrogen carbonate K blood potassium P blood phosphorus AKIcause cause of acute kidney injury CHF congestive heart failure PVD peripheral vascular disease DM diabetes mellitus HTN hypertension Declarations Conflict of Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest . Author Contributions CK.Z. and ZF.J. drafted the main manuscript text. X.L. and XF.M. conducted the data analysis. YM.Z. handled the project administration. CK.Z. created the figures and tables. All authors reviewed the manuscript Funding This study was supported by the Traditional Chinese Medicine Science and Technology Project of Shandong Province (M-2023283)；Key Research and Development Program of Jining City(2024YXNS027) Acknowledgments We thank Liu Jie (People’s Liberation Army of China General Hospital, Beijing, China) for helping with the revision. Institutional Review Board Statement This study was approved by the Institutional Review Board of Severance Hospital, Yonsei University Health System, and conducted in accordance with the Declaration of Helsinki (Approval No.: 4-2016-1073). Informed Consent Statement Given the retrospective nature of this study, the Ethics Committee of Severance Hospital, Yonsei University Health System, determined that written informed consent was not required. Data Availability Statement Data are available from the Dryad repository (https://datadryad.org/stash) via DOI identifier 10.5061/dryad.6v0j9. References Hoste, E. A. et al. Epidemiology of acute kidney injury in critically ill patients: the multinational AKI-EPI study. INTENS CARE MED. 41 , 1411–1423 (2015). Hoste, E. et al. Global epidemiology and outcomes of acute kidney injury. NAT. REV. NEPHROL. 14 , 607–625 (2018). Lee, C. C. et al. Characteristics of and Outcomes After Dialysis-Treated Acute Kidney Injury, 2009–2018: A Taiwanese Multicenter Study. AM. J. KIDNEY DIS. 81 , 665–674 (2023). Teixeira, J. P., Neyra, J. A. & Tolwani, A. Continuous KRT: A Contemporary Review. CLIN. J. AM. SOC. NEPHRO . 18 , 256–269 (2023). Hwang, S. et al. Impact of Renal Replacement Therapy on Mortality and Renal Outcomes in Critically Ill Patients with Acute Kidney Injury: A Population-Based Cohort Study in Korea between 2008 and 2015. J. CLIN. MED. 11 , (2022). Pérez-Fernández, X. et al. Clinical variables associated with poor outcome from sepsis-associated acute kidney injury and the relationship with timing of initiation of renal replacement therapy. J. CRIT. CARE . 40 , 154–160 (2017). Armstrong, L. E., Kavouras, S. A., Walsh, N. P. & Roberts, W. O. Diagnosing dehydration? Blend evidence with clinical observations. CURR. OPIN. CLIN. NUTR. 19 , 434–438 (2016). Becker, J. & Friedman, E. Renal function status. AM. J. ROENTGENOL. 200 , 827–829 (2013). Kashani, K., Rosner, M. H. & Ostermann, M. Creatinine: From physiology to clinical application. EUR. J. INTERN. MED. 72 , 9–14 (2020). Palinrungi, M. A., Faruk, M. & Christeven, R. Traumatic Kidney Injury: A 6-Year Retrospective Study in Childhood and Adolescence. RES. REP. UROL. 15 , 415–424 (2023). Li, B. et al. The association of blood urea nitrogen-to-creatinine ratio and in-hospital mortality in acute ischemic stroke patients with atrial fibrillation: data from the MIMIC-IV database. FRONT. NEUROL. 15 , 1331626 (2024). Chen, P. et al. Prediction of prognosis in patients with nontraumatic intracranial hemorrhage using blood urea nitrogen-to-creatinine ratio on admission: a retrospective cohort study based on data from the medical information Mart for intensive care-IV database. FRONT. NEUROL. 14 , 1267815 (2023). Puri, A., Giri, M., Huang, H. & Zhao, Q. Blood urea nitrogen to creatinine ratio is associated with in-hospital mortality in critically ill patients with venous thromboembolism: a retrospective cohort study. FRONT. CARDIOVASC. MED. 11 , 1400915 (2024). Wen, J. et al. Association of hydration status and in-hospital mortality in critically ill patients with ischemic stroke: Data from the MIMIC-IV database. CLIN. NEUROL. NEUROSUR . 244 , 108451 (2024). Chen, T. et al. The Association of Blood Urea Nitrogen to Creatinine Ratio and the Prognosis of Critically Ill Patients with Cerebral Infarction: A Cohort Study. MEDIAT INFLAMM. : : 2151840, 2022 (2022). Wan, Y. et al. J-shaped association between blood urea nitrogen-to-creatinine ratio and mortality in critically ill patients with acute pancreatitis: a retrospective cohort study using the MIMIC-IV database. EUR. J. MED. RES. 30 , 185 (2025). Jung, S. Y. et al. Phosphate is a potential biomarker of disease severity and predicts adverse outcomes in acute kidney injury patients undergoing continuous renal replacement therapy. PLOS ONE . 13 , e191290 (2018). Mehta, R. L. et al. Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury. CRIT. CARE . 11 , R31 (2007). Quan, H. et al. Updating and validating the Charlson comorbidity index and score for risk adjustment in hospital discharge abstracts using data from 6 countries. AM. J. EPIDEMIOL. 173 , 676–682 (2011). Selby, N. M., Fluck, R. J., Kolhe, N. V. & Taal, M. W. International Criteria for Acute Kidney Injury: Advantages and Remaining Challenges. PLOS MED. 13 , e1002122 (2016). Kazory, A. Emergence of blood urea nitrogen as a biomarker of neurohormonal activation in heart failure. AM. J. CARDIOL. 106 , 694–700 (2010). Chen, C. Y. et al. Clinical factors in predicting acute renal failure caused by rhabdomyolysis in the ED. AM. J. EMERG. MED. 31 , 1062–1066 (2013). Perianayagam, M. C., Seabra, V. F., Tighiouart, H., Liangos, O. & Jaber, B. L. Serum cystatin C for prediction of dialysis requirement or death in acute kidney injury: a comparative study. AM. J. KIDNEY DIS. 54 , 1025–1033 (2009). Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9450994","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":639202353,"identity":"62c4d43e-4a86-44b0-8abb-72ab95270a8b","order_by":0,"name":"Chuankang Zhou","email":"","orcid":"","institution":"Jining Medical University","correspondingAuthor":false,"prefix":"","firstName":"Chuankang","middleName":"","lastName":"Zhou","suffix":""},{"id":639202354,"identity":"5c915066-4cf8-44be-970f-1a9b33cace14","order_by":1,"name":"Xiang Li","email":"","orcid":"","institution":"Affiliated Hospital of Jining Medical 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Jiao","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAwElEQVRIiWNgGAWjYBACxgbGBwwSDHJybOzNB4jVwmwA1GJszMdzLIFYe4BaGBiME+dJ5CgQqWFGMpuExR+D9DaGHAaGHxXbiHAYSIsEj0FuG8PZA4w9Z24ToyX/mISExJ/cNsa+BGbGNqK0gGwxMEhnY+YxIEVLgkECGxvRWnoeM1tIHDAwbONhSzhIlF8M25MZb0v8MZCXn//44IMfFcRomZDAIi0B5RwgrB4I5PkPMH/8QJTSUTAKRsEoGLEAAGYNNg+KZBOGAAAAAElFTkSuQmCC","orcid":"","institution":"Affiliated Hospital of Jining Medical University","correspondingAuthor":true,"prefix":"","firstName":"Zhanfeng","middleName":"","lastName":"Jiao","suffix":""}],"badges":[],"createdAt":"2026-04-17 15:53:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9450994/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9450994/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":109173333,"identity":"55d60a4d-c63c-43a0-852c-9a715609ca92","added_by":"auto","created_at":"2026-05-13 09:12:32","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":166264,"visible":true,"origin":"","legend":"\u003cp\u003ePatient Screening Flowchart.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9450994/v1/e0bab58f91c9446d74994882.png"},{"id":109173360,"identity":"a126df78-2ac6-44ee-a684-a0b77fd82bb8","added_by":"auto","created_at":"2026-05-13 09:12:48","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":220633,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eKaplan-Meier curves\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9450994/v1/c3928f7d50598144c21a9e37.png"},{"id":109173856,"identity":"4b14198d-bd28-4e4c-acdb-96b68a5c1185","added_by":"auto","created_at":"2026-05-13 09:13:51","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":154323,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eRCS plot for all-cause mortality (90- day mortality)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-9450994/v1/11d11c38c6aa91d8f7bf7d24.png"},{"id":109174336,"identity":"1087028a-b584-4c0e-a469-b4f5bc64ec64","added_by":"auto","created_at":"2026-05-13 09:16:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1256560,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9450994/v1/032e182d-09fc-4f12-a6a9-eb71d73f7252.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Association Between Blood Urea Nitrogen to Creatinine Ratio and 90-Day Mortality in Patients with Acute Kidney Injury: a Retrospective Cohort Study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAcute kidney injury (AKI) affects approximately half of all critically ill patients admitted to intensive care units (ICUs), and is associated with substantially poorer clinical outcomes and heightened healthcare expenditures [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Continuous renal replacement therapy (CRRT) has been established as the preferred and indispensable modality for managing AKI in critically ill patients, particularly those with hemodynamic instability[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Despite technological advancements in CRRT techniques, mortality rates among AKI patients receiving CRRT remain alarmingly high, ranging from 40% to 60% [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Consequently, the early identification of high-risk AKI patients undergoing CRRT is clinically imperative to facilitate timely therapeutic interventions aimed at mitigating mortality risk.\u003c/p\u003e \u003cp\u003eBlood urea nitrogen (BUN), a metabolic byproduct derived from protein catabolism, is primarily excreted via the kidneys. It serves as a conventional biomarker for evaluating renal function, hydration status, and metabolic conditions. For instance, elevated BUN levels typically indicate impaired renal function or dehydration[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. However, BUN elevation may also arise from congestive heart failure, gastrointestinal hemorrhage, or excessive protein intake[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Similarly, creatinine (Cr), a breakdown product of skeletal muscle metabolism, represents a reliable indicator of renal function due to its relatively constant production rate and exclusive renal excretion. Patients with chronic kidney disease (CKD) or acute kidney injury (AKI) consistently demonstrate significantly elevated Cr levels [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eGiven that isolated BUN or Cr measurements are confounded by extraneous physiological variables, the BUN-to-creatinine ratio (BUN/Cr) has gained clinical traction as a more robust diagnostic parameter. This ratio mitigates the impact of individual fluctuations in BUN or Cr levels, thereby providing a more consistent clinical assessment[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Previous investigations have established BUN/Cr as an independent predictor of adverse outcomes in critically ill populations, including those with stroke, non-traumatic intracranial hemorrhage, venous thromboembolism, cerebral infarction, and atrial fibrillation[\u003cspan additionalcitationids=\"CR12 CR13 CR14\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Furthermore, emerging evidence suggests an association between BUN/Cr levels and all-cause mortality in acute pancreatitis patients[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Nevertheless, the prognostic significance of BUN/Cr specifically in AKI patients remains incompletely characterized.\u003c/p\u003e"},{"header":"Method","content":"\u003cp\u003eStudy \u003cb\u003ePopulation\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThis secondary analysis utilized data from a retrospective cohort study[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], accessed via the DATADRYAD repository (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://datadryad.org/stash\u003c/span\u003e\u003cspan address=\"https://datadryad.org/stash\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e; DOI: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.5061/dryad.6v0j9\u003c/span\u003e\u003cspan address=\"10.5061/dryad.6v0j9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e). The dataset comprised 1,144 critically ill patients who underwent continuous renal replacement therapy (CRRT) in intensive care units (ICUs) at Severance Hospital, Yonsei University Health System, and Ilsan Hospital, National Health Insurance Service, Korea, between January 2009 and September 2016.\u003c/p\u003e \u003cp\u003eAmong 2,391patients initially screened for eligibility, inclusion required stage 2 or higher acute kidney injury (AKI) per the Acute Kidney Injury Network (AKIN) criteria[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], defined as either serum creatinine elevation\u0026thinsp;\u0026ge;\u0026thinsp;200% from baseline or urine output\u0026thinsp;\u0026lt;\u0026thinsp;0.5 mL/kg/h for \u0026ge;\u0026thinsp;12 hours. Exclusion criteria encompassed: age\u0026thinsp;\u0026lt;\u0026thinsp;18 years, pregnancy/lactation, pre-existing chronic kidney disease (CKD) or dialysis history, prior renal transplantation, postrenal obstruction, and missing serum urea nitrogen or creatinine measurements. Consequently 1137 patients were included in the final analysis (Figue. 1).\u003c/p\u003e \u003cp\u003eThe original study protocol received ethical approval from the Institutional Review Board of Severance Hospital, Yonsei University Health System (Approval No. 4-2016-1073), adhering to the principles of the Declaration of Helsinki. As the dataset was fully anonymized, waiver of informed consent was granted for this secondary analysis.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThis figure illustrates the patient inclusion criteria. This secondary analysis evaluated 1,144 patients meeting the inclusion criteria from the original study. Seven patients were excluded due to missing baseline blood urea nitrogen (BUN) or creatinine (Cr) values. The final analysis included 1,137 subjects enrolled in this study.\u003c/p\u003e \u003cp\u003eStudy \u003cb\u003eParameters and Endpoints\u003c/b\u003e\u003c/p\u003e \u003cp\u003eEpidemiological and clinical data, including age, gender body mass index, and comorbidities, were prospectively recorded prior to continuous renal replacement therapy (CRRT) initiation. Biochemical laboratory parameters were collected at CRRT initiation (0-hour), supplemented by age-adjusted Charlson Comorbidity Index (CCI)[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], Sequential Organ Failure Assessment (SOFA) score[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], and Acute Physiology and Chronic Health Evaluation II (APACHE II) score. The decision and timing for CRRT implementation were determined by nephrology specialists in the primary study[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eClinical Measurements\u003c/h2\u003e \u003cp\u003eDemographic characteristics and comorbidity data were extracted from hospital information systems upon intensive care unit (ICU) admission, encompassing age, gender, height, weight, mean arterial pressure (MAP), and documented histories of cerebrovascular disease, heart failure (HF), peripheral vascular disease (PVD), myocardial infarction (MI), diabetes mellitus (DM), hypertension, chronic obstructive pulmonary disease (COPD), and dementia. Dementia was clinically defined as physician-diagnosed Alzheimer's disease or related dementias. Body mass index (BMI) was calculated as weight in kilograms divided by height in meters squared (kg/m\u0026sup2;).\u003c/p\u003e \u003cp\u003eBaseline laboratory parameters measured at CRRT initiation included serum albumin (ALB), hemoglobin (HGB), blood urea nitrogen (BUN), serum creatinine (SCr), potassium (K⁺), and estimated glomerular filtration rate (eGFR). All assays were performed using standardized automated analyzers according to manufacturer-specified protocols.\u003c/p\u003e \u003cp\u003eCRRT \u003cb\u003eProtocol\u003c/b\u003e\u003c/p\u003e \u003cp\u003ePatients with acute kidney injury (AKI) in the intensive care unit (ICU) underwent nephrologist assessment for continuous renal replacement therapy (CRRT) initiation. Indications for CRRT included oliguria/anuria, life-threatening volume overload, refractory hyperkalemia (serum potassium\u0026thinsp;\u0026gt;\u0026thinsp;6.5 mmol/L), or profound metabolic acidosis.\u003c/p\u003e \u003cp\u003eVascular access was established via temporary catheterization of the internal jugular, subclavian, or femoral veins. For critically ill AKI patients, regional citrate anticoagulation was preferentially employed using hemofilters with smaller membrane surface areas (1.0\u0026ndash;1.4 m\u0026sup2;). The prescribed CRRT dose was maintained at 35 mL/kg/h, with the median treatment duration exceeding 24 hours for the initial session. This approach optimizes hemodynamic stability and mitigates circuit-related complications in critically ill populations.\u003c/p\u003e \u003cp\u003eExposure and Outcome Ascertainment\u003c/p\u003e \u003cp\u003eThe primary variable examined in this study was the serum urea nitrogen-to-creatinine ratio (BUN/Cr). The BUN/Cr ratio was calculated by dividing the serum BUN level (mg/dL) by the serum Cr level (mg/dL).To evaluate its association with adverse outcomes, participants were stratified into quartiles: Q1 (\u0026lt;\u0026thinsp;14.20), Q2 (14.20\u0026ndash;19.80), Q3 (19.81\u0026ndash;28.80), and Q4 (\u0026gt;\u0026thinsp;28.80). Additionally, BUN/Cr was analyzed as a continuous variable to assess dose-response relationships.\u003c/p\u003e \u003cp\u003eThe primary outcome was all-cause mortality within 90 days post-CRRT initiation. Mortality events, including both status and dates, were systematically documented through electronic medical records and national death registries, irrespective of follow-up schedules.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eCategorical variables were presented as frequencies and percentages. Continuous variables conforming to normal distribution were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD), while non-normally distributed variables were reported as median with interquartile range (IQR). For comparisons of normally distributed continuous variables, one-way analysis of variance (ANOVA) or Student's t-test was used; for non-normally distributed continuous variables, the Kruskal-Wallis test or Mann-Whitney U test was employed. Categorical variables were compared using Pearson's χ\u0026sup2; test or Fisher's exact test. The association between blood urea nitrogen/creatinine ratio (BUN/Cr) and mortality was assessed using Kaplan-Meier curves and multivariate Cox proportional hazards regression models. Variables with P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 in univariate analysis and clinically significant variables were included in the model. Results were expressed as hazard ratios (HR) with 95% confidence intervals (CI). Restricted cubic spline (RCS) analysis explored the nonlinear relationship between BUN/Cr ratio and mortality. Subgroup analyses were performed to evaluate differential effects of BUN/Cr ratio across subgroups. All tests were two-sided with a significance level of 0.05.All analyses were performed using the Free Statistics software version 2.3(\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.clinicalscientists.cn/freestatistics\u003c/span\u003e\u003cspan address=\"http://www.clinicalscientists.cn/freestatistics\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e). A descriptive study was conducted on all participants.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eBaseline Characteristics\u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e delineates the baseline clinical profiles and laboratory parameters of the study cohort. The cohort comprised 1,137 patients with a mean age of 63.2\u0026thinsp;\u0026plusmn;\u0026thinsp;14.4 years, of whom 701 (61.7%) were male. Comorbid conditions included diabetes mellitus in 397 patients (34.0%) and heart failure in 185 patients (16.3%). At continuous renal replacement therapy (CRRT) initiation, the mean serum creatinine level was 2.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6 mg/dL. The median Charlson Comorbidity Index (CCI) was 3.0 (interquartile range [IQR] 2.0\u0026ndash;5). Mean Sequential Organ Failure Assessment (SOFA) and Acute Physiology Chronic Health Evaluation II (APACHE II) scores were 12.1\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5 and 27.3\u0026thinsp;\u0026plusmn;\u0026thinsp;8.0, respectively. Mean arterial pressure (MAP) measured at CRRT commencement (0-hour) was 77.3\u0026thinsp;\u0026plusmn;\u0026thinsp;14.6 mmHg. Mechanical ventilation was required in 893 patients (78.6%). The median white blood cell count was 11,700.0/\u0026micro;L (IQR 6,510.0\u0026ndash;18,640.0). The cumulative 90-day all-cause mortality rate following CRRT initiation was 71.9%.as illustrated in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe basic characteristics of the AKI population stratified by quartiles of the BUN/Cr ratio.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal (n\u0026thinsp;=\u0026thinsp;1137)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eQ1 (n\u0026thinsp;=\u0026thinsp;284)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eQ2 (n\u0026thinsp;=\u0026thinsp;283)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eQ3 (n\u0026thinsp;=\u0026thinsp;285)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eQ4 (n\u0026thinsp;=\u0026thinsp;285)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge(years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e63.3\u0026thinsp;\u0026plusmn;\u0026thinsp;14.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e59.4\u0026thinsp;\u0026plusmn;\u0026thinsp;15.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e65.7\u0026thinsp;\u0026plusmn;\u0026thinsp;13.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e64.2\u0026thinsp;\u0026plusmn;\u0026thinsp;13.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e63.8\u0026thinsp;\u0026plusmn;\u0026thinsp;13.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale Sex (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e701 (61.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e194 (68.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e176 (62.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e171 (60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e160 (56.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.025\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMyocardial infarction (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e112 ( 9.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e34 (12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e31 (11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e25 (8.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e22 (7.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.301\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCHF (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e185 (16.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36 (12.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e46 (16.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e56 (19.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e47 (16.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.165\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCerevascular_disease (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e114 (10.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28 (9.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32 (11.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30 (10.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e24 (8.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePVD(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e45 ( 4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (3.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11 (3.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e16 (5.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8 (2.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.362\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDementia(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42 ( 3.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (3.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10 (3.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9 (3.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13 (4.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.831\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDM (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e397 (34.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e103 (36.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e97 (34.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e91 (32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e106 (37.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.581\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHTN (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e596 (52.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e137 (48.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e152 (53.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e150 (52.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e157 (55.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.392\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOPD(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e80 ( 7.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15 (5.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19 (6.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e17 (6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e29 (10.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.103\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePotassium (mEq/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.304\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCCI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.0 (2.0, 5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.0 (2.0, 5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.0 (1.0, 4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.0 (2.0, 5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.0 (2.0, 5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.043\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI(kg/m2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e23.9\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e22.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMAP(mmHg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e77.3\u0026thinsp;\u0026plusmn;\u0026thinsp;14.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e76.5\u0026thinsp;\u0026plusmn;\u0026thinsp;15.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e78.7\u0026thinsp;\u0026plusmn;\u0026thinsp;13.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e77.0\u0026thinsp;\u0026plusmn;\u0026thinsp;14.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e77.1\u0026thinsp;\u0026plusmn;\u0026thinsp;14.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.307\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMV(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e893 (78.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e211 (74.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e226 (79.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e225 (78.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e231 (81.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.197\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWhite blood cell (\u0026micro;L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11700.0 (6510.0, 18640.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12290.0 (6760.0, 19305.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12070.0 (7730.0, 18720.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12280.0 (6755.0, 20570.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10520.0 (5085.0, 16150.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHemoglobin (g/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.7\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.7\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBUN (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e49.0 (33.0, 73.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33.0 (23.0, 47.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44.0 (32.0, 60.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e56.0 (40.0, 77.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e74.0 (54.0, 95.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCreatinine (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.4 (1.6, 3.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.2 (2.1, 4.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.6 (1.9, 3.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.4 (1.6, 3.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.7 (1.2, 2.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlbumin (g/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.016\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGFR(ml/min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26.4 (17.1, 39.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.8 (12.7, 30.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23.2 (15.0, 34.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e25.9 (17.4, 37.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e37.7 (27.2, 54.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAPACHE II score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27.3\u0026thinsp;\u0026plusmn;\u0026thinsp;8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27.3\u0026thinsp;\u0026plusmn;\u0026thinsp;8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.0\u0026thinsp;\u0026plusmn;\u0026thinsp;8.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e27.8\u0026thinsp;\u0026plusmn;\u0026thinsp;7.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e27.2\u0026thinsp;\u0026plusmn;\u0026thinsp;7.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.705\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSOFA score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.1\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.2\u0026thinsp;\u0026plusmn;\u0026thinsp;3.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12.0\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.045\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCRRTcause (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.527\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVolume overload\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e160 (14.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36 (12.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e36 (12.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e39 (13.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e49 (17.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMetablic Acidosis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e241 (21.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68 (23.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e65 (23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e56 (19.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e52 (18.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHyperkalemia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57 ( 5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16 (5.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13 (4.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12 (4.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e16 (5.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUremia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e114 (10.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32 (11.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23 (8.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e25 (8.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e34 (11.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOliguria\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e291 (25.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e74 (26.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e78 (27.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e74 (26)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e65 (22.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOthers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e274 (24.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e58 (20.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e68 (24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e79 (27.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e69 (24.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAKI stage (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage 2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e298 (26.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42 (14.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e69 (24.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e77 (27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e110 (38.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e839 (73.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e242 (85.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e214 (75.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e208 (73)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e175 (61.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAKIcause, (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSepsis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e793 (69.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e168 (59.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e197 (69.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e211 (74)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e217 (76.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNephrotoxin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37 ( 3.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18 (6.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7 (2.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5 (1.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7 (2.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIschemia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e97 ( 8.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28 (9.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e28 (9.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e21 (7.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e20 (7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurgery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e93 ( 8.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36 (12.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e21 (7.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e21 (7.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15 (5.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOthers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e117 (10.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e34 (12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30 (10.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e27 (9.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e26 (9.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDeath_90D (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e817 (71.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e179 (63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e178 (62.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e224 (78.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e236 (82.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19.8 (14.2, 28.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.1 (9.4, 12.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16.8 (15.5, 18.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e23.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e45.0\u0026thinsp;\u0026plusmn;\u0026thinsp;18.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eCOPD Chronic Obstructive Pulmonary Disease, CCI Charlson Comorbidity Index, BMI Body Mass Index, AKIN Acute Kidney Injury Criteria, ICU Intensive Care Unit, CRRT Continuous Renal Replacement Therapy, eGFR Estimated Glomerular Filtration Rate, SOFA Sequential Organ Failure Assessment Score, APACHE II Acute Physiology and Chronic Health Evaluation II, SBP Systolic Blood Pressure, DBP Diastolic Blood Pressure, MAP Mean Arterial Pressure, BUN/Cr Blood Urea Nitrogen to Creatinine Ratio\u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e demonstrates baseline characteristics stratified by 90-day survival status (survivors vs. non-survivors). Statistically significant intergroup differentials (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05) encompassed four domains: 1) Demographic \u0026amp; physiological support:Mechanical ventilation dependence, body mass index (BMI), and pre-CRRT mean arterial pressure (MAP); 2) Metabolic \u0026amp; haematologic indices:White blood cell count, haemoglobin, serum albumin, blood urea nitrogen (BUN), serum creatinine, estimated glomerular filtration rate (eGFR), and BUN-to-creatinine ratio (BUN/Cr); 3) Disease severity metrics:Charlson Comorbidity Index (CCI), Acute Physiology and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA); 4) CRRT initiation criteria:Primary clinical indications. Hypertension prevalence differed significantly between cohorts .\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBaseline Characteristics of the AKI Cohort Stratified by Outcome\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal (n\u0026thinsp;=\u0026thinsp;1137)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSurvivors (n\u0026thinsp;=\u0026thinsp;320)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNon-survivors (n\u0026thinsp;=\u0026thinsp;817)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge(years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e63.3\u0026thinsp;\u0026plusmn;\u0026thinsp;14.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e62.7\u0026thinsp;\u0026plusmn;\u0026thinsp;15.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e63.5\u0026thinsp;\u0026plusmn;\u0026thinsp;14.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.392\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale Sex (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e701 (61.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e195 (60.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e506 (61.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.756\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMyocardial infarction (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e112 ( 9.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36 (11.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e76 (9.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.322\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCHF (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e185 (16.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e58 (18.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e127 (15.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.289\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCerevascular_disease (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e114 (10.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37 (11.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e77 (9.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.282\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePVD(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e45 ( 4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14 (4.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e31 (3.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.652\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003edementia(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42 ( 3.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17 (5.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e25 (3.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDM (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e397 (34.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e131 (40.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e266 (32.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHTN (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e596 (52.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e201 (62.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e395 (48.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOPD(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e80 ( 7.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29 (9.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e51 (6.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.095\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePotassium (mEq/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.55\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCCI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.0 (2.0, 5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.0 (1.0, 4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.0 (2.0, 5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI(kg/m2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMAP(mmHg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e77.3\u0026thinsp;\u0026plusmn;\u0026thinsp;14.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e81.1\u0026thinsp;\u0026plusmn;\u0026thinsp;15.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e75.8\u0026thinsp;\u0026plusmn;\u0026thinsp;14.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMV(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e893 (78.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e215 (67.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e678 (83.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWhite blood cell (\u0026micro;L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11700.0 (6510.0, 18640.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13320.0 (9060.0, 20195.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11160.0 (5305.0, 17950.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHemoglobin (g/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBUN (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e49.0 (33.0, 73.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e46.0 (32.0, 64.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e52.0 (34.0, 76.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCr (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.4 (1.6, 3.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.7 (1.8, 3.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.2 (1.6, 3.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlbumin (g/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGFR(ml/min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26.4 (17.1, 39.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.1 (15.1, 36.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.9 (18.4, 39.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAPACHE II score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27.3\u0026thinsp;\u0026plusmn;\u0026thinsp;8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.0\u0026thinsp;\u0026plusmn;\u0026thinsp;7.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e28.2\u0026thinsp;\u0026plusmn;\u0026thinsp;7.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSOFA score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.1\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10.2\u0026thinsp;\u0026plusmn;\u0026thinsp;3.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCRRTcause(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVolume overload\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e160 (14.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e55 (17.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e105 (12.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMetablic acidosis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e241 (21.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e55 (17.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e186 (22.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHyperkalemia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57 ( 5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11 (3.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e46 (5.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOliguria\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e114 (10.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37 (11.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e77 (9.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUremia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e291 (25.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e92 (28.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e199 (24.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOthers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e274 (24.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e70 (21.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e204 (25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAKI stage (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.896\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage 2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e298 (26.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e83 (25.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e215 (26.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e839 (73.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e237 (74.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e602 (73.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAKIcause,(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.183\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSepsis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e793 (69.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e211 (65.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e582 (71.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNephrotoxin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37 ( 3.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13 (4.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24 (2.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIschemia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e97 ( 8.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26 (8.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e71 (8.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurgery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e93 ( 8.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35 (10.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e58 (7.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOthers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e117 (10.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35 (10.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e82 (10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19.8 (14.2, 28.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17.0 (12.4, 23.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e21.4 (15.1, 30.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eCOPD Chronic Obstructive Pulmonary Disease, CCI Charlson Comorbidity Index, BMI Body Mass Index, AKIN Acute Kidney Injury Criteria, ICU Intensive Care Unit, CRRT Continuous Renal Replacement Therapy, eGFR Estimated Glomerular Filtration Rate, SOFA Sequential Organ Failure Assessment Score, APACHE II Acute Physiology and Chronic Health Evaluation II, SBP Systolic,Blood Pressure, DBP Diastolic Blood Pressure, MAP Mean Arterial Pressure, BUN/Cr Blood Urea Nitrogen to Creatinine Ratio\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe R\u003cb\u003eelationship Between BUN/Cr and Mortality\u003c/b\u003es\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e presents the Kaplan-Meier survival curves illustrating the association between the serum urea nitrogen-to-creatinine ratio (BUN/Cr) and survival probability among patients with acute kidney injury (AKI). The log-rank test revealed a statistically significant difference in survival across the BUN/Cr quartiles (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), indicating that patients in the highest BUN/Cr quartile had the lowest survival probability compared to those in the lower quartiles.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eKaplan-Meier curves depicting cumulative all-cause mortality incidence stratified by BUN/Cr quartiles in AKI patients BUN/Cr: serum urea nitrogen-to-creatinine ratio.\u003c/p\u003e\n\u003ch3\u003eAssociation of BUN/Cr levels with 90-days mortality\u003c/h3\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Multivariable Cox regression analyses of BUN/Cr association with 90-day mortality using Q1 as reference.When analyzed as a continuous variable, elevated BUN/Cr demonstrated a significant positive association with increased 90-day mortality risk in AKI patients. After covariate adjustment, each standard deviation increment in BUN/Cr conferred a 1% higher risk of in-hospital mortality (adjusted HR 1.01, 95% CI 1.01\u0026ndash;1.02; p\u0026thinsp;=\u0026thinsp;0.001).Categorical analysis revealed significantly higher mortality risks in Q3 (19.81\u0026ndash;28.80) and Q4 (\u0026gt;\u0026thinsp;28.80) groups compared to Q1 (\u0026lt;\u0026thinsp;14.20). No significant association was observed for Q2 (14.20\u0026ndash;19.80) versus Q1 (p\u0026thinsp;=\u0026thinsp;0.821).In the fully adjusted model (Model 4), the highest quartile (Q4) of BUN/Cr ratio demonstrated a 77% increased risk of mortality (HR: 1.77, 95% CI: 1.18\u0026ndash;1.77; P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), while Q3 still carried a 44% elevated risk (HR: 1.44, 95% CI: 1.43\u0026ndash;2.17; P\u0026thinsp;=\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAssociation between BUN/Cr and mortality in AKI patients.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eModel 1\u003c/p\u003e \u003cp\u003eHR_95CI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eModel 2\u003c/p\u003e \u003cp\u003eHR_95CI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003eModel 3\u003c/p\u003e \u003cp\u003eHR_95CI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003eModel 4\u003c/p\u003e \u003cp\u003eHR_95CI\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eHR\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eHR\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003eHR\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003eHR\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQ1(\u0026lt;\u0026thinsp;14.20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e(Reference)\u0026nbsp;\u0026nbsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e(Reference)\u0026nbsp;\u0026nbsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e(Reference)\u0026nbsp;\u0026nbsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e(Reference)\u0026nbsp;\u0026nbsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQ2(14.20\u0026ndash;19.80)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.99 (0.81\u0026thinsp;~\u0026thinsp;1.22)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.961\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.98 (0.8\u0026thinsp;~\u0026thinsp;1.21)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.876\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.95 (0.77\u0026thinsp;~\u0026thinsp;1.17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.605\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.98 (0.79\u0026thinsp;~\u0026thinsp;1.21)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.821\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQ3(19.81\u0026ndash;28.80)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.58 (1.29\u0026thinsp;~\u0026thinsp;1.92)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.57 (1.29\u0026thinsp;~\u0026thinsp;1.91)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.56 (1.27\u0026thinsp;~\u0026thinsp;1.91)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.44 (1.18\u0026thinsp;~\u0026thinsp;1.77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQ4(\u0026gt;\u0026thinsp;28.80)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.76 (1.45\u0026thinsp;~\u0026thinsp;2.13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.75 (1.44\u0026thinsp;~\u0026thinsp;2.13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.77 (1.45\u0026thinsp;~\u0026thinsp;2.16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.77 (1.43\u0026thinsp;~\u0026thinsp;2.17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP for trend\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eRegression results were presented as hazard ratios (HRs) estimates with 95% CI, and the reference group was tertile 1. Four levels of hierarchical multivariate adjustments were examined.\u003c/p\u003e \u003cp\u003eModel 1: Rough model: no adjustment;\u003c/p\u003e \u003cp\u003eModel 2: Adjusted based on age and sex;\u003c/p\u003e \u003cp\u003eModel 3: model 2 adjustments, plus comorbidity history (myocardial infarction, heart failure, cerebrovascular disease, peripheral vascular disease, diabetes mellitus, hypertension, COPD, and dementia);\u003c/p\u003e \u003cp\u003eModel 4: model 3 adjustments, plus SOFA score, APACHE II score, AKI stages, AKI causes, mean arterial pressure levels, and laboratory parameters hemoglobin.\u003c/p\u003e \u003cp\u003eOur analysis revealed a nonlinear association between BUN/Cr and 90-day mortality in AKI patients. Following multivariable adjustment for age, sex, comorbidities (myocardial infarction, heart failure, cerebrovascular disease, peripheral vascular disease, diabetes mellitus, hypertension, chronic obstructive pulmonary disease, dementia), disease severity (SOFA and APACHE II scores), AKI stage, etiology, laboratory parameters (hemoglobin), and mean arterial pressure, restricted cubic spline analysis demonstrated a U-shaped relationship between BUN/Cr and in-hospital mortality (as illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eEmploying two-stage logistic regression analysis, we identified an inflection point for BUN/Cr at 11.3 mg/dL (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Among AKI patients: Left of inflection: Each 1 mg/dL BUN/Cr increment corresponded to a 10.9% decrease in 90-day mortality incidence (HR 0.891, 95% CI 0.795\u0026ndash;0.998; p\u0026thinsp;=\u0026thinsp;0.0461);Right of inflection: Each 1 mg/dL increase was associated with a 2.5% elevated mortality risk (HR 1.025, 95% CI 1.013\u0026ndash;1.037; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe nonlinear relationship between BUN/Cr and 90-day mortality\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHR (95%CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026lt;11.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.891 (0.795,0.998)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0461\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;11.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.025 (1.013,1.037)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLikelihood Ratio test\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.038\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eThe results were adjusted based on age and gender, comorbidity history (myocardial infarction, heart failure, Cerevascular, peripheral vascular disease, diabetes mellitus, hypertension, chronic obstructive pulmonary disease and dementia), disease severity (SOFA score and APACHE II score), AKI staging, AKI cause, laboratory parameters (hemoglobin) and MAP level.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eSubgroup analysis\u003c/h3\u003e\n\u003cp\u003eAs shown in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, we conducted subgroup analyses to assess the relationship between BUN/Cr and in-hospital mortality. After adjusting for confounding factors including age (\u0026lt;\u0026thinsp;65 years and \u0026ge;\u0026thinsp;65 years), sex, BMI, myocardial infarction, heart failure, cerebrovascular disease, peripheral vascular disease, diabetes, hypertension, COPD, and dementia, no significant interactions were observed (all interaction p-values\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSubgroup analysis\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003en%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eAdj HR_95CI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eAdj P_value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eP.for.interaction\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.261\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u0026lt;65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e533\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e383 (71.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u0026thinsp;\u0026ge;\u0026thinsp;65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e604\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e434 (71.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.02 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBMI\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI\u0026lt;23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e716\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e528 (73.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI 23\u0026ndash;30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e324\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e219 (67.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.02 (1.01\u0026thinsp;~\u0026thinsp;1.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI\u0026gt;30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e51 (66.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (0.98\u0026thinsp;~\u0026thinsp;1.04)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eGender\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.663\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e701\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e506 (72.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e436\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e311 (71.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMI\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.521\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1025\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e741 (72.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e112\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e76 (67.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.02 (1\u0026thinsp;~\u0026thinsp;1.04)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.052\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCHF\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.829\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e952\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e690 (72.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e185\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e127 (68.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1\u0026thinsp;~\u0026thinsp;1.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.027\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCerevascular\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.372\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1019\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e737 (72.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e114\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e77 (67.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.02 (1\u0026thinsp;~\u0026thinsp;1.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePVD\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.266\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1092\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e786 (72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e31 (68.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.07 (1.01\u0026thinsp;~\u0026thinsp;1.13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.014\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003edementia\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.452\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1095\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e792 (72.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e25 (59.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.03 (0.99\u0026thinsp;~\u0026thinsp;1.07)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.144\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDM\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.767\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e739\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e550 (74.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e397\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e266 (67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.02 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eHTN\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.011\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e541\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e422 (78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e596\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e395 (66.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.02 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCOPD\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBUN/Cr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.345\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1057\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e766 (72.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.01 (1.01\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e51 (63.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.02 (1\u0026thinsp;~\u0026thinsp;1.04)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.109\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eAKI is a critical disease posing a serious threat to public health and life safety, and early identification of AKI risk stratification remains a highly challenging issue [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. This study first reveals that elevated BUN/Cr levels constitute an independent risk factor for 90-day all-cause mortality in AKI patients undergoing CRRT. This association persists even after adjusting for confounding factors. BUN/Cr can predict mortality in AKI patients. Furthermore, Kaplan\u0026ndash;Meier survival analysis demonstrated that AKI patients with BUN/Cr\u0026thinsp;\u0026gt;\u0026thinsp;19.81 exhibited significantly higher 90-day mortality compared to those with BUN/Cr\u0026thinsp;\u0026le;\u0026thinsp;19.81. Subgroup analysis further supported this finding. Consequently, this study provides a novel, simple, and efficient biomarker for mortality risk stratification in AKI patients.\u003c/p\u003e \u003cp\u003eBlood urea nitrogen (BUN) is the primary end product of human protein metabolism. After glomerular filtration, BUN is reabsorbed in the renal tubules. When renal perfusion is insufficient and renal function is severely impaired, BUN is released in large quantities, providing a better reflection of the severity of renal injury. Furthermore, BUN can trigger immune dysregulation by promoting excessive catabolism and activating neurohumoral mechanisms, thereby increasing the risk of mortality in critically ill AKI patients [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].Research indicates that BUN levels constitute a risk factor for AKI patients requiring renal replacement therapy [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Furthermore, elevated BUN correlates with mortality outcomes in AKI patients [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. However, blood urea nitrogen exhibits lower sensitivity compared to glomerular filtration rate (GFR) and serum creatinine (Scr). Additionally, BUN is influenced by multiple factors including age, high-protein diets, gastrointestinal bleeding, dehydration, and catabolic states.\u003c/p\u003e \u003cp\u003eIn recent years, BUN/Cr has been demonstrated to be a more reliable tool for predicting outcomes in critically ill patients across various conditions[\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], as it simultaneously accounts for both BUN and Scr levels, enabling a more comprehensive assessment of renal function and fluid status. Given the evidence supporting BUN and BUN/Cr, this study aimed to explore the prognostic significance of BUN/Cr in AKI patients, particularly its relationship with mortality risk.Interestingly, we observed a U-shaped association between BUN/Cr and mortality. Specifically, on the left side of the U-shaped curve, the risk of death gradually decreased as BUN/Cr increased. However, on the right side of the curve, higher BUN/Cr corresponded to a sharp increase in mortality risk. This nonlinear relationship can be explained by relevant pathophysiological mechanisms.\u003c/p\u003e \u003cp\u003eThis study investigated the association between BUN/Cr and mortality risk in patients with AKI. Our findings revealed a U-shaped relationship between BUN/Cr and mortality risk: initially, a moderate increase in BUN/Cr was associated with a reduced risk of death, but mortality risk rose sharply once a certain threshold was exceeded.This nonlinear relationship remained significant after adjusting for potential confounders, highlighting an important and under-explored finding in this field. These results suggest that BUN/Cr may serve as a valuable prognostic indicator in the ICU setting, aiding clinicians in early identification of high-risk AKI patients and guiding timely interventions.\u003c/p\u003e \u003cp\u003eIn fact, our comprehensive study has a relatively large sample size. However, certain limitations must also be considered. Firstly, our study is retrospective and relies on data from a single database, which may limit the generalizability of our findings. Although we have adjusted for many potential confounding factors and conducted multiple subgroup analyses, residual confounding factors cannot be completely eliminated, given that this study is of an observational nature.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eA study revealed a U-shaped association between BUN/Cr and 90-day mortality in AKI patients, with both extremely low and elevated BUN/Cr levels linked to increased mortality risk. This research demonstrates the clinical utility of BUN/Cr as an easily accessible, cost-effective, and practical prognostic indicator for predicting long-term outcomes in AKI.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAKI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAcute kidney injury\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCCI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCharlson Comorbidity Index\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCKD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003echronic kidney disease\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAKIN\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAcute Kidney Injury Network\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eBMI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ebody mass index\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSBP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ecomorbidities, systolic blood pressure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDBP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ediastolic blood pressure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMAP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003emean arterial pressure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003emechanical ventilation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHGB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ehemoglobin\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eWBC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ewhite blood cell count\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCRP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eC-reactive protein\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCREA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ecreatinine\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eBUN\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eblood urea nitrogen\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGFR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eglomerular filtration rate\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eALB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ealbumin\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHCO3-\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ehydrogen carbonate\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eK\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eblood potassium\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eblood phosphorus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAKIcause\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ecause of acute kidney injury\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCHF\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003econgestive heart failure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePVD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eperipheral vascular disease\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ediabetes mellitus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHTN\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ehypertension\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003eConflict of Interest\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003eAuthor Contributions\u003c/p\u003e\n\u003cp\u003eCK.Z. and ZF.J. drafted the main manuscript text. X.L. and XF.M. conducted the data analysis. YM.Z. handled the project administration. CK.Z. created the figures and tables. All authors reviewed the manuscript\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThis study was supported by the Traditional Chinese Medicine Science and Technology Project of Shandong Province (M-2023283)；Key Research and Development Program of Jining City(2024YXNS027)\u003c/p\u003e\n\u003cp\u003eAcknowledgments\u003c/p\u003e\n\u003cp\u003eWe thank Liu Jie (People\u0026rsquo;s Liberation Army of China General Hospital, Beijing, China) for helping with the revision.\u003c/p\u003e\n\u003cp\u003eInstitutional Review Board Statement\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Institutional Review Board of Severance Hospital, Yonsei University Health System, and conducted in accordance with the Declaration of Helsinki (Approval No.: 4-2016-1073).\u003c/p\u003e\n\u003cp\u003eInformed Consent Statement\u003c/p\u003e\n\u003cp\u003eGiven the retrospective nature of this study, the Ethics Committee of Severance Hospital, Yonsei University Health System, determined that written informed consent was not required.\u003c/p\u003e\n\u003cp\u003eData\u0026nbsp;Availability Statement\u003c/p\u003e\n\u003cp\u003eData are available from the Dryad repository (https://datadryad.org/stash) via DOI identifier 10.5061/dryad.6v0j9.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHoste, E. A. et al. Epidemiology of acute kidney injury in critically ill patients: the multinational AKI-EPI study. \u003cem\u003eINTENS CARE MED.\u003c/em\u003e \u003cb\u003e41\u003c/b\u003e, 1411\u0026ndash;1423 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHoste, E. et al. Global epidemiology and outcomes of acute kidney injury. \u003cem\u003eNAT. REV. NEPHROL.\u003c/em\u003e \u003cb\u003e14\u003c/b\u003e, 607\u0026ndash;625 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee, C. C. et al. Characteristics of and Outcomes After Dialysis-Treated Acute Kidney Injury, 2009\u0026ndash;2018: A Taiwanese Multicenter Study. \u003cem\u003eAM. J. KIDNEY DIS.\u003c/em\u003e \u003cb\u003e81\u003c/b\u003e, 665\u0026ndash;674 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeixeira, J. P., Neyra, J. A. \u0026amp; Tolwani, A. Continuous KRT: A Contemporary Review. \u003cem\u003eCLIN. J. AM. SOC. 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KIDNEY DIS.\u003c/em\u003e \u003cb\u003e54\u003c/b\u003e, 1025\u0026ndash;1033 (2009).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Blood Urea Nitrogen-to-Creatinine Ratio, Continuous Renal Replacement Therapy, Acute Kidney Injury, Prognosis, All-Cause Mortality","lastPublishedDoi":"10.21203/rs.3.rs-9450994/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9450994/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAlthough blood urea nitrogen (BUN) and serum creatinine (Scr) levels are routinely monitored in clinical practice, the prognostic significance of the blood urea nitrogen to creatinine ratio (BUN/Cr) in patients with acute kidney injury (AKI) remains incompletely elucidated. This study aims to evaluate the association between blood urea nitrogen-to-creatinine ratio (BUN/Cr) and 90-day mortality in critically ill patients with acute kidney injury (AKI) undergoing continuous renal replacement therapy (CRRT). This will assist clinicians in risk stratification, identifying high-risk patients, and implementing individualized clinical interventions.This retrospective observational study included 1,137 critically ill patients with acute kidney injury (AKI) who initiated continuous renal replacement therapy (CRRT). Patients were divided into four groups based on BUN/Cr quartiles: Q1 (\u0026lt;\u0026thinsp;14.20), Q2 (14.20\u0026ndash;19.80), Q3 (19.81\u0026ndash;28.80), and Q4 (\u0026gt;\u0026thinsp;28.80), with Q1 serving as the reference group. The primary outcome measure was 90-day all-cause mortality. Multivariate Cox regression analysis and Kaplan-Meier curves were employed to evaluate the association between BUN/Cr and in-hospital mortality.In addition, subgroup analyses were performed to assess consistency between groups.Multivariable analysis demonstrated that each standard deviation increase in BUN/Cr was associated with a 1% elevated risk of in-hospital mortality (adjusted HR 1.01, 95% CI 1.01\u0026ndash;1.02; p\u0026thinsp;=\u0026thinsp;0.01). When analyzed categorically, Q3 and Q4 groups exhibited significantly higher mortality risks compared to Q1 (reference group), whereas Q2 showed no significant association with 90-day mortality (p\u0026thinsp;=\u0026thinsp;0.821).RCS analysis revealed a U-shaped relationship between the BUN/Cr ratio and 28-day mortality (p for non-linearity: 0.023), with an inflection point at 11.3 mg/dL. Mortality risk decreased to the left of the inflection point and increased to the right of it. Subgroup analyses revealed no significant interaction effects (all p-interaction\u0026thinsp;\u0026gt;\u0026thinsp;0.5). Kaplan-Meier survival curves demonstrated the poorest survival probability in the Q4 cohort.The serum urea nitrogen-to-creatinine ratio (BUN/Cr) serves as a potential biomarker for predicting 90-day in-hospital mortality risk in acute kidney injury (AKI) patients, with elevated BUN/Cr levels demonstrating a dose-dependent association with increased mortality risk.\u003c/p\u003e","manuscriptTitle":"Association Between Blood Urea Nitrogen to Creatinine Ratio and 90-Day Mortality in Patients with Acute Kidney Injury: a Retrospective Cohort Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-13 09:08:21","doi":"10.21203/rs.3.rs-9450994/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"165601106130103767770407479578769517678","date":"2026-05-18T14:58:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"69180959093699513277910832547211763830","date":"2026-05-14T19:28:16+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-09T21:44:48+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"28079197343372409074266858911696117650","date":"2026-05-05T14:03:13+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-05-05T10:18:08+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-04-23T12:44:41+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-18T05:33:58+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-18T05:33:05+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2026-04-17T15:35:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"424bae1c-8de2-49fb-9658-7cdb8cadaa13","owner":[],"postedDate":"May 13th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"165601106130103767770407479578769517678","date":"2026-05-18T14:58:11+00:00","index":56,"fulltext":""},{"type":"reviewerAgreed","content":"69180959093699513277910832547211763830","date":"2026-05-14T19:28:16+00:00","index":55,"fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-09T21:44:48+00:00","index":49,"fulltext":""},{"type":"reviewerAgreed","content":"28079197343372409074266858911696117650","date":"2026-05-05T14:03:13+00:00","index":43,"fulltext":""},{"type":"reviewersInvited","content":"12","date":"2026-05-05T10:18:08+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":68034210,"name":"Health sciences/Biomarkers"},{"id":68034211,"name":"Health sciences/Diseases"},{"id":68034212,"name":"Health sciences/Medical research"},{"id":68034213,"name":"Health sciences/Nephrology"},{"id":68034214,"name":"Health sciences/Risk factors"}],"tags":[],"updatedAt":"2026-05-13T09:08:21+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-13 09:08:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9450994","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9450994","identity":"rs-9450994","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}