Risk factors for prolonged mechanical ventilation in critically pregnant women: a retrospective observational study

Risk factors for prolonged mechanical ventilation in critically pregnant women: a retrospective observational 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 Research Article Risk factors for prolonged mechanical ventilation in critically pregnant women: a retrospective observational study Jialin Yang, Zhanqi Zhao, Mingwang Jia, Yinling Wang, Fang Peng, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7935843/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 10 You are reading this latest preprint version Abstract Background Prolonged mechanical ventilation (MV) is associated with increased morbidity and mortality in critically ill pregnant women.This study aimed to identify risk factors associated with the duration of MV in critically ill pregnant women using clinical and laboratory parameters. Methods We conducted a retrospective analysis of pregnant and postpartum women admitted to the intensive care unit(ICU) between January 1, 2019 and April 30, 2025. Patients were stratified into two groups based on MV duration (≤ 24 hours vs. >24 hours). Risk factors were analyzed using multifactorial logistic regression. Results Among 621 enrolled patients, 354(57%) required MV for ≤ 24 hours,and 267(43%) for > 24 hours. Significant intergroup differences were observed in body mass index(BMI), mortality, APACHE II score, patients referred by the external hospitals, estimated blood loss(ml), volume of red blood cell transfusion (RBC), volume of plasma transfusion(l), acute kidney injury(AKI) grading ( P < 0.001 ), and myocardial injury(all P < 0.005 ). Multivariable analysis identified RBC transfusion volume (OR = 2.66, 95% CI: 1.77–3.56; P < 0.001 ), plasma transfusion volume (OR = 7.823, 95% CI: 4.19–11.46; P < 0.001 ), and AKI grading (OR = 13.17, 95% CI: 3.64–22.69; P = 0.007) as independent risk factors for prolonged MV. Conclusions Greater transfusion requirements for RBCs and plasma, along with more severe AKI,are independent risk factors for prolonged MV in critically pregnant women.Close monitoring and early intervention targeting these factors may improve patient outcomes. mechanical ventilation pregnancy critical illness risk factors acute kidney injury transfusion Figures Figure 1 Figure 2 Background Maternal mortality and morbidity remain challenging issues in developing countries. In recent years, the incidence of scarred uterus and complications in late pregnancy has increased significantly with the implementation of two-child and three-child policy in China [ 1 , 2 , 3 ] . Profound physiologic changes affecting the cardiovascular, endocrine, urinary and respiratory systems during pregnancy can predispose women to serious obstetric complications, Furthermore,the need to fetal well-being adds a layer of complexity, making the managemen of critically pregnant women is a significant challenge for ICU clinicians [ 4 , 5 ] .Maternal admission to ICU during pregnancy or postpartum is a marker of severe acute maternal morbidity (SAMM) [ 6 , 7 , 8 ] . Critically pregnant women admitted to the ICU often require invasive hemodynamic monitoring, Mechanical ventilation (MV) and blood purification [ 9 , 10 ] . The implementation of these measures is associated with prolonged hospital stay, increased cost and poor prognosis. MV is an important measure of advanced life support, not only provide respiratory support in surgical patients, but also afford active life support in patients with inadequate ventilation. Studies had shown that prolonged mechanical ventilation (PMV) is associated with complications and increased medical cost [ 11 ] , PMV in critically ill pregnant women has also received increasing attention in recent years. Similar studies have been conducted globally, but the data on MV is relatively less. We conducted a retrospective study, The primary outcome was the risk factors for PMV in critically pregnant women. Secondary outcomes was the the predictive ability of the multivariate regression model. Material Methods This retrospective observational study was conducted in the Third Affiliated Hospital of Guangzhou Medical University (GAMU),a major obstetric critical care center in South China (Guangzhou,Guangdong), We screened the medical records of all pregnant and postpartum women admitted to the ICU between January 1, 2019 and April 30, 2025. The inclusion criteria were: 1. Pregnant or postpartum women. 2. those who requiried invasive mechanical ventilation during their ICU stay. Patients were excluded if they were: 1. under 18 years of age; 2. discharged from the hospital while still requiring mechanical ventilation. All patients signed a clinical research informed consent form before treatment, and the study was approved by the Ethics Committee of the Third Affiliated Hospital of Guangzhou Medical University: [2024]No. 167. Measures A total of 621 critically ill pregnant women who met the inclusion criteria were enrolled, The primary outcome measure was the duration of mechanical ventilation. The clinical parameters (Table 1 ) included age, gestational weeks, body mass index(BMI), times of pregnancy, APACHE II score, predicted blood loss, red blood cell transfusion volume, plasma transfusion volume, myocardial injury, acute kidney injury(AKI), hepatic function, and oxygenation index (PaO 2 /FiO 2 ), the basal value of creatinine.Since there is no universally recognized diagnostic criteria for AKI specific to pregnant women, we applied the Kidney Disease: Improving Global Outcomes (KDIGO) criteria: 1) An increase in serum creatinine by ≥ 0.3 mg/dl (≥ 26.5 µmol/l) within 48 h; 2) An increase in serum creatinine to ≥ 1.5 times baseline, which is known or presumed to have occurred within the prior 7 days; 3) Urine volume ≤ 0.5 ml/kg/h for 6 h. Kidney injury was graded according to the KDIGO classification (Table 1 ), and myocardial injury was based on troponin/CK-MB exceeding normal reference values. Table 1 KDIGO classification for AKI Stage Serum creatinine Urine output 1 1.5–1.9 times baseline OR ≥0.3 mg/dl (≥ 26.5 u mol/l) increase ≤ 0.5 ml/kg/h for 6–12 hours 2 2.0–2.9 times baseline < 0.5ml/kg/h for ≥ 12 hours 3 3.0 times baseline OR Increase in serum creatinine to ≥ 4.0 mg/dl (≥ 353.6 u mol/l) OR Initiation of renal replacement therapy OR, In patients < 18 years, decrease in eGFR to < 35 ml/min per 1.73 m 2 24 h vs. ≤24 h) and its independent risk factors. Secondary endpoints included mortality, acute kidney injury (incidence and stage), APACHE II score, oxygenation index, myocardial injury, transfusion requirements, surgical interventions, fluid balance, and referral status(Secondary endpoints was to establish a predictive model for the duration of mechanical ventilation in patients.). Statistical Analysis Statistical analyses were performed using SPSS Version 26.0. By analyzing the normality of continuous variables, we found that none of the data fit the normal distribution, so they were expressed as the median and interquartile range (IQR), independent sample nonparametric test were used between two groups. Count data were expressed as cases or percentages (%), and comparisons between groups were made using the Chi-Square test. Variables with statistically significant differences in univariate analysis were included in the multivariable logistic regression analysis model for risk factors, and P < 0.05 was considered statistically different. ROC curves were used to predict the accuracy of the model. Results A total of 621 patients were included in the final analysis. During the six-year study period (2019-2025), 1182 critically ill pregnant women were admitted to the ICU, accounting for approximately 2%(1182/66746)of all obstetric admissions to our hospital. Of these ICU admissions, 621 patients required mechanically ventilation and met the study criteria (Figure 1). The primary etiologies leading to MV are detailed in Table 2 , The five most frequent causes were hypertensive disorders of pregnancy (18%, 110/621), postpartum hemorrhage (18%, 109/621), hepatic (13%, 78/621), cardiac disease (12%, 74/621), and respiratory failure (10%, 63/621), Collectively, these conditions accounted for 70% (434/621). Based on whether the duration of MV was >24 hours, we divided the patients into two groups: 354 (57%) cases in the ≤24 hours group and 267 (43%) cases in the >24 hours group. BMI, mortality, APACHE II score, volume of red blood cell transfusion, volume of plasma transfusion, staging of renal injury, myocardial injury, and oxygenation index were significantly different between the two groups ( p < 0.05). More patients were referred from external hospitals (76%). The referred proportion from external hospitals in the group with ≤24 hours of MV was 71%, which was significantly lower than in the group with >24 hours (84%)(p24 hours, and 15 in the ≤24 hours group (Table 3). More than half (52%,326/621) of the patients developed AKI. The proportion of AKI was significantly higher in the group with ≥24 hours of MV (67% vs 42%, p<0.05). Univariate analysis showed that volume of red blood cell transfusion, volume of plasma transfusion, multiple (≥2) surgeries, APACHE II score, AKI grading, myocardial injury, B-type Natriuretic Peptide(BNP), Procalcitonin (PCT), and volume of fluids discharged were the risk factors for the duration of MV ( p24 hours):volume of RBC transfusion (OR=2.66, 95% CI: 1.77-3.56; P<0.001 ), volume of plasma transfusion (OR=7.83, 95% CI: 4.19-11.46; P<0.001 ) and AKI grading (OR=13.17, 95% CI: 3.64-22.69; P =0.007) were (Table 4). The area under the ROC curve of the prediction model based on independent risk factors was 0.708(95% CI: 0.665-0.750) (Figure 2). Discussion In this retrospective study of critically ill pregnant women, we identified several factors associated with a prolonged duration of mechanical ventilation, Univariate analysis revealed associations with transfusion volumes, multiple (≥ 2) surgeries, APACHE II score, number of hours of hemofiltration, AKI grading, myocardial injury, elevated BNP and PCT levels, and fluids balance. However, multivariable analysis demonstrated that the volumes of RBC and plasma transfusion, along with the AKI grading, were independent risk factors for prolonged MV. Maternal critical illness is often acute and severe, with high risk of multiple organ dysfunction syndromes (MODS) [ 12 ] . ICU care can improve survival [ 9 , 13 ] , yet prolonged mechanical ventilation (PMV) prolongs hospitalization and resource use. Definitions of PMV range widely [ 14 – 18 ] ; we adopted the Society of Thoracic Surgeons (MV > 24 hours), as it reflects clinically meaningful deterioration and is widely applied for risk stratification. In our study, transfusion volume, multiple surgeries, APACHE II score, hemofiltration, AKI grade, myocardial injury, BNP, PCT, and fluid balance were significant predictors (p < 0.05). In our study, the incidence of critically ill pregnant women admitted to the ICU and requiring MV was 53%(621/1182), 267 (43%) of whom were ventilated for more than 24 hours, which is similar to the results of a Chinese multicenter report [ 13 ] . However, it has also been reported [ 9 ] that among 360 critically ill pregnant women admitted to an ICU, only 25 were mechanically ventilated for ≥ 24 h (6.94%). The reason for the obviously difference in the analysis was the different severity of the patients admitted, the median APACHE II score for critically ill pregnant women in that study was 7, which is far from the median APACHE II score of 19 in our study. This study identified red blood cell transfusion, plasma volume, and AKI as independent predictors of PMV. Fluid resuscitation with excessive input and reduced renal output may precipitate fluid overload, pulmonary edema, and impaired lung function, thereby extending ventilatory dependence [ 19 ] . Although the oxygenation index (OI) is widely recognized as a marker of lung injury and an important risk factor for PMV [ 9 , 20 , 21 ] , our findings did not confirm this association. A likely explanation is that 76% of patients were referred from other hospitals, many of whom had received oxygen therapy or mechanical ventilation prior to transfer, leading to improved OI values upon admission. Nonetheless, OI still differed significantly between patients ventilated ≤ 24 h and those ventilated > 24 h. Pregnancy-related hypertensive disorders and postpartum hemorrhage were the leading causes of ICU admission in our cohort, each accounting for 18% of mechanically ventilated cases (110/621 and 109/621, respectively), in line with previous reports [ 9 , 22 – 23 ] . Both conditions are well-recognized contributors to AKI in obstetric populations [ 24 ] , and patients with pregnancy-related AKI often require mechanical ventilation and renal replacement therapy, with generally poor outcomes [ 25 ] . Consistent with our findings, renal dysfunction may exacerbate fluid overload, aggravate pulmonary injury, and thereby prolong ventilatory dependence. National data further indicate that hypertensive disorders of pregnancy account for 27.3–46.1% of obstetric ICU admissions in China, higher than the 22.3–29.9% reported internationally [ 9 ] . The rising incidence of postpartum hemorrhage in China may be partially attributable to the two- and three-child policies, which have increased the prevalence of cesarean scar uterus and late-pregnancy complications [ 1 , 2 ] . Pathophysiologically, severe hypertensive disorders may lead to microangiopathic hemolysis, hepatic dysfunction, cardiac insufficiency, and renal impairment [ 26 ] , while postpartum hemorrhage is commonly associated with uterine atony, birth canal trauma, placental abnormalities, and coagulation disorders [ 27 ] . Our findings indicate that myocardial injury and elevated BNP are important predictors of PMV in critically ill obstetric patients. Cardiovascular impairment in this population is often driven by hypertensive disorders of pregnancy and postpartum hemorrhage, which exacerbate hypoperfusion, hypoxia, and fluid overload. Prior studies have reported similar associations, including myocardial injury in over half of patients with severe postpartum hemorrhage [ 28 ] and frequent troponin elevation in women with hypertensive disorders of pregnancy [ 29 ] . Together, these results emphasize the central role of cardiac dysfunction in prolonging ventilatory support. We also observed a strong association between elevated PCT and PMV, underscoring the impact of infection and systemic inflammation. Maternal sepsis is a leading cause of ICU admission and is often complicated by multiorgan failure and high mortality [ 30 – 32 ] , yet nearly half of sepsis-related deaths are considered preventable with early recognition and intervention [ 33 ] . Monitoring PCT may therefore provide clinical value in identifying infection-related deterioration, predicting PMV, and guiding timely management in this high-risk population. Limitation There are some limitations to this study. First, this study was a single-center study, the admission criteria may differ from other studies; Second, the data were analyzed retrospectively, and some data from patients' external hospitals were missed, which may led to data bias. Third, we derived three independent risk factors for prolonged MV and created a mapping diagram for visualizing and promoting clinical practice. However, we did not validate the nomogram with a new database. a prospective study is needed to address these issues and validate our findings. Conclusions Therefore, we propose the following recommendations: 1)early identification and assessment of critical pregnancies; 2) attention to and timely control of obstetric hemorrhage; 3) during fluid resuscitation, in addition to actively maintaining hemodynamic stability and tissue perfusion, it is necessary to prevent excessive fluid intake; 4) close monitoring of the function of the kidneys, lungs, heart, and other organs of the critically ill mother; 5) focus on infections, critical pregnant women who develop infections or are at risk of infection need to be assessed early and managed appropriately, e.g., timely specimen retention and antibiotic use. In conclusion, the early assessment and management of critically ill pregnant women admitted to the ICU is very important and even requires the participation of multiple specialists such as obstetricians, respiratory and cardiovascular physicians in addition to ICU physicians in the management of critically ill obstetrics patients in order to shorten the duration of mechanical ventilation. Abbreviations ICU intensive care unit BMI body mass index RBC red blood cell transfusion AKI acute kidney injury MV Mechanical ventilation PMV prolonged mechanical ventilation GAMU Guangzhou Medical University KDIGO Improving Global Outcomes IQR interquartile range BNP B-type Natriuretic Peptide PCT Procalcitonin MODS multiple organ dysfunction syndromes PMV prolonged mechanical ventilation OI oxygenation index Declarations Authors’ Contributions Jialin Yang, Zhanqi Zhao drafted the article. Mingwang Jia, Yingling Wang, and Fang Peng collected clinical cases. Yichun Wang provided guidance and expertise. Guangyuan Liao, as the corresponding author, led the statistical analysis and revised the article for intellectual content. All authors contributed to the study design and interpretation of data, as well as providing critical revision of the article. All authors read and approved the final manuscript. Funding Information JY is funded by the Wu Jieping Medical Foundation Clinical Research Special Grant (Project No. 320.6750.2024-23-02). Data availability The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request. Ethics approval and consent to participate All procedures involving human participants were conducted in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments. The study protocol was reviewed and approved by the Ethics Committee of the Third Affiliated Hospital of Guangzhou Medical University (Approval No. [2024]167). All participants provided written informed consent before enrollment in the study. Consent to publish All participants provided consent for publication of anonymized data. No identifiable personal information is included in this manuscript. Competing interests The authors declare that they have no competing interests. References Zhang HX, Zhao YY, Wang YQ. Analysis of the Characteristics of Pregnancy and Delivery before and after Implementation of the Two-child Policy. Chin Med J (Engl). 2018 Jan 5;131(1):37-42. Li HT, Luo S, Trasande L, Hellerstein S, et al. Geographic Variations and Temporal Trends in Cesarean Delivery Rates in China, 2008-2014. JAMA. 2017 Jan 3;317(1):69-76. Lin L, Chen YH, Sun W,et al. Risk factors of obstetric admissions to the intensive care unit: An 8-year retrospective study. 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Tables Table 2: Main etiology composition of the patients classification disease n/disease n/classification Hypertensive disorders of pregnancy Pre-eclampsia 68 110 eclampsia 22 HELLP syndrome 20 Obstetric Hemorrhage Postpartum Hemorrhage 109 109 Respiratory system Pneumonia 30 63 Pulmonary Hypertension 18 Pulmonary Embolism 10 Tuberculosis 4 Bronchial Asthma 1 Lung cancer 1 Circulatory system Rheumatic heart disease 14 74 Congenital Heart Disease 10 Cardiac arrest 11 Heart Failure 19 Infectious endocarditis 6 Peripartum cardiomyopathy 5 Aortic coarctation 2 Ascending Aortic Aneurys 1 Congenital myocardial insufficiency 1 Myocardial infarction 2 Cardiac Shock 1 Aortic valve insufficiency 1 Mitral valve vegetation 1 digestive system Acute fatty liver 34 78 Acute Pancreatitis 29 Acute Liver Failure 9 Hepatitis B 5 Hepatitis A 1 nervous system Eepilepsia 12 42 Intracranial venous sinus thrombosis 9 Cerebral hemorrhage 12 Meningeal arteriovenous fistula 1 Meningioma 2 Arachnoid cysts 1 Subarachnoid hemorrhage 3 Viral encephalitis 2 Reproductive system/other diseases related to pregnancy amniotic fluid embolism 16 50 Intrauterine infection 5 Acute Chorioamnionitis 6 Ectopic pregnancy 11 Placental abruption 3 Reproductive Tract Infection 2 Uterine rupture 6 Malignant tumor of the ovary 1 urinary system Urinary tract infections 16 25 Chronic Renal Failure 2 Nephrotic syndrome 2 Kidney Rupture 1 Adrenal Cortical Adenoma 2 renal artery aneurysm 1 Autoimmune diseases Systemic Lupus Erythematosu 24 27 desmosis 1 Autoimmune encephalitis 2 Hematological diseases leukemia 4 11 Severe anemia 3 Aplastic anemia 3 Hemophagocytic syndrome 1 Endocrine system diseases Hyperthyroidism 4 10 Diabetic ketoacidosis 3 Myasthenia gravis 3 else Ruptured spleen 1 3 Multiple fractures 1 Scrub typhus 1 Table 3: Comparison of parameters between the two groups with different duration of MV Variables Overall MV≤24 hours MV> 24 hours P value Number 621 354 267 - Gestational weeks(IQR) 30(27-36) 32(27 -36) 32(27 -36) 0.927 Time of pregnancies(IQR) 2(1 -4) 2(1-4) 2(1-3) 0.501 Age(y) (IQR) 32(28-36) 32(28-36) 31(27-35) 0.081 Advanced maternal age (> 35 years) n (%) 167(27) 101(28) 66(25) 0.824 BMI(Kg/cm 2 ) (IQR) 22(20-25) 22(20-25) 23(20-26) 0.026 Days in ICU(IQR) 4(2-8) 3(2-4) 8(4-15) <0.001 Days of hospitalization(IQR) 13(9-20) 11(8-16) 16(11-26) <0.001 Number of deaths: (%) 29(5) 5(0.1) 24(9) 0.025 APACHE II Score (after ICU admission / within 24h after MV) (IQR) 17(14-22) 15(13-20) 19(15-25) Transfer from external hospitals n (%) 475(76) 250(71) 225(84) 0.012 Estimated blood loss (ml) (IQR) 500(300-1364) 506(352-1297) 449(300-1677) 0.035 Multiple (≧2) operations n (%) 167(27) 83(23) 84(31) 0.030 Rehydration volume (ml) (after admission to ICU/within 24h after MV) (IQR) 3124(2425-4195) 3315(2347-5000) 3695(2798-5025) <0.001 Urine output (ml) (minimum 24h during hospitalization) (IQR) 2670(1515-4080) 2810(1800-4050) 2540(960-4205) 0.034 Volume of fluid discharged (ml) (after admission to ICU/within 24 h of MV) (IQR) 3610(2535-5260) 3693(2640-5272) 3850(2700-5472) 0.007 Infusion of red blood cells (u) (IQR) 2(0-8) 0(0-6) 4(0-13) <0.001 Volume of plasma transfused(l) (IQR) 0(0-1.4) 0(0-1) 0(0-3) <0.001 MV (h) (IQR) 20(7-57) 9(3-16) 70(39-129) <0.001 Creatinine (umol/L) (admission base / lowest value) (IQR) 63(47-107) 56(45-84) 76(52-132) 0.268 Creatinine (umol/L) (highest value) (IQR) 79(57-137) 70(54-104) 103(65-191) <0.001 AKI grading (after ICU admission / within 24h after MV) No damage(%) 295(48) 206(58) 89(33) <0.001 Level 1(%) 128(21) 84(24) 44(16) Level 2(%) 77(12) 33(9) 44(16) Level 3(%) 121(19) 31(9) 90(34) myocardial injury (%) 339(55) 174(49) 165(62) <0.001 TBIL, u mol/L (within 24h of MV) (IQR) 12(6-25) 11(6-23) 13(6-33) 0.046 Albumin, g / L (within 24h of MV) (IQR) 28(25-32) 28(25-32) 28(24-32) 0.392 BNP, pg/ml (after ICU admission / within 24h after MV) (IQR) 416(118-1861) 299(70-1111) 852(201-3638) <0.001 PCT, ng/mL (after ICU admission / within 24h after MV) (IQR) 0.6(0.2-2.9) 0(0-2.) 1(0-8) <0.001 WBC, 109L (after ICU entry / within 24h after MV) (IQR) 14(10-19) 13(10-18) 15(10-20) 0.131 HB, g / L (after ICU admission / within 24h after MV) (IQR) 96(82-112) 96(83-112) 95(79-111) 0.392 PLT, 1012L (after ICU entry / within 24h after MV) (IQR) 146(72-215) 153(85-214) 125(58-220) 0.021 Lactate, mmol/L (after ICU entry / within 24h after MV) (IQR) 2.8(2-4) 3(2-4) 3(2-5) <0.001 PH (after ICU admission / within 24h after MV) (IQR) 7.39(7.34-7.44) 7.38(7.34-7.43) 7.40(7.33-7.45) 0.223 PaO 2 (after ICU admission / within 24h after MV) (IQR) 124(88-167) 135(99-174) 107(79-154) <0.001 PaCO 2 , mmHg (after ICU admission / within 24h after MV) (IQR) 34(30-39) 35(31-39) 33(29-39) 0.053 Bicarbonate, mmol/L (after ICU entry / within 24h after MV) (IQR) 21(18-23) 21(19-23) 20(18-24) 0.206 OI(IQR) 273(184-383) 307(219-407) 218(150-345) <0.001 Abbreviations: BMI body mass index, ICU intensive care unit ,APACHE acute physiology and chronic health evaluation, MV mechanical ventilation, AKI acute kidney injury, TBIL total bilirubin, BNP brain natriuretic peptide, PCT procalcitonin, WBC white blood cell, HB hemoglobin,PLT platelet, PaO 2 arterial partial pressure of oxygen, PaCO 2 arterial partial pressure of carbon dioxide,OI the ratio of the arterial partial pressure of oxygen and the fraction of inspired oxygen Table 4. Risk factors for the duration of MV Variables Univariate analysis Multivariate analysis OR P 95% CI OR P 95% CI Creatinine (admission base/ lowest value) 0.223 0.001 0.087-0.358 - - - APACHE score 3.300 <0.001 1.538-5.061 - - - Volume of fluid discharged 0.006 0.033 0.001-0.012 - - - Infusion of red blood cells 3.900 <0.001 3.144-4.656 2.662 <0.001 1.770-3.555 Volume of plasma transfused 14.985 <0.001 11.647-18.323 7.827 <0.001 4.191-11.463 Creatinine (highest value) 0.168 <0.001 0.084-0.251 - - - AKI grading 33.219 <0.001 23.494-42.945 13.168 0.007 3.643-22.694 myocardial injury 39.040 0.001 16.409-61.670 - - - BNP 0.005 <0.001 0.003-0.007 - - - PCT 1.148 0.001 0.500-1.795 - - - Abbreviations: MV mechanical ventilation,APACHE acute physiology and chronic health evaluation, AKI acute kidney injury, BNP brain natriuretic peptide, PCT procalcitonin Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 23 Feb, 2026 Reviews received at journal 14 Feb, 2026 Reviewers agreed at journal 13 Feb, 2026 Reviews received at journal 10 Nov, 2025 Reviewers agreed at journal 10 Nov, 2025 Reviewers invited by journal 06 Nov, 2025 Editor invited by journal 30 Oct, 2025 Editor assigned by journal 28 Oct, 2025 Submission checks completed at journal 28 Oct, 2025 First submitted to journal 23 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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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-7935843","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":546547639,"identity":"0d908b21-50ee-446f-9414-ff3735c83af1","order_by":0,"name":"Jialin Yang","email":"","orcid":"","institution":"Guangzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Jialin","middleName":"","lastName":"Yang","suffix":""},{"id":546547641,"identity":"9ce4e7ca-0368-44c1-a7cb-675b5bdb9556","order_by":1,"name":"Zhanqi Zhao","email":"","orcid":"","institution":"Guangzhou Medical 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1","display":"","copyAsset":false,"role":"figure","size":126639,"visible":true,"origin":"","legend":"\u003cp\u003eLegend not included with this version\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7935843/v1/b267c10861d74f50ecd22afd.png"},{"id":96249159,"identity":"0357b04d-8e2f-4494-b30c-d563ee4bcfe0","added_by":"auto","created_at":"2025-11-19 07:30:28","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":57061,"visible":true,"origin":"","legend":"\u003cp\u003eReceiver operator characteristic(ROC) curve of the prediction model based on independent risk factors for duration of mechanical ventilation, Area under the ROC curve was 0.708(95% CI: 0.665-0.750)\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7935843/v1/0138a64d39a61643554d2129.png"},{"id":96363134,"identity":"16657af6-c6b6-4e50-9555-70b9f694b875","added_by":"auto","created_at":"2025-11-20 10:04:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":996740,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7935843/v1/466fdd3a-7cd4-488f-9270-894e2e9e3693.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Risk factors for prolonged mechanical ventilation in critically pregnant women: a retrospective observational study","fulltext":[{"header":"Background","content":"\u003cp\u003eMaternal mortality and morbidity remain challenging issues in developing countries. In recent years, the incidence of scarred uterus and complications in late pregnancy has increased significantly with the implementation of two-child and three-child policy in China\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. Profound physiologic changes affecting the cardiovascular, endocrine, urinary and respiratory systems during pregnancy can predispose women to serious obstetric complications, Furthermore,the need to fetal well-being adds a layer of complexity, making the managemen of critically pregnant women is a significant challenge for ICU clinicians \u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e.Maternal admission to ICU during pregnancy or postpartum is a marker of severe acute maternal morbidity (SAMM)\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Critically pregnant women admitted to the ICU often require invasive hemodynamic monitoring, Mechanical ventilation (MV) and blood purification\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e. The implementation of these measures is associated with prolonged hospital stay, increased cost and poor prognosis.\u003c/p\u003e\u003cp\u003eMV is an important measure of advanced life support, not only provide respiratory support in surgical patients, but also afford active life support in patients with inadequate ventilation. Studies had shown that prolonged mechanical ventilation (PMV) is associated with complications and increased medical cost\u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e, PMV in critically ill pregnant women has also received increasing attention in recent years. Similar studies have been conducted globally, but the data on MV is relatively less. We conducted a retrospective study, The primary outcome was the risk factors for PMV in critically pregnant women. Secondary outcomes was the the predictive ability of the multivariate regression model.\u003c/p\u003e"},{"header":"Material Methods","content":"\u003cp\u003e This retrospective observational study was conducted in the Third Affiliated Hospital of Guangzhou Medical University (GAMU),a major obstetric critical care center in South China (Guangzhou,Guangdong), We screened the medical records of all pregnant and postpartum women admitted to the ICU between January 1, 2019 and April 30, 2025. The inclusion criteria were: 1. Pregnant or postpartum women. 2. those who requiried invasive mechanical ventilation during their ICU stay. Patients were excluded if they were: 1. under 18 years of age; 2. discharged from the hospital while still requiring mechanical ventilation. All patients signed a clinical research informed consent form before treatment, and the study was approved by the Ethics Committee of the Third Affiliated Hospital of Guangzhou Medical University: [2024]No. 167.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eMeasures\u003c/h2\u003e\u003cp\u003eA total of 621 critically ill pregnant women who met the inclusion criteria were enrolled, The primary outcome measure was the duration of mechanical ventilation. The clinical parameters (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) included age, gestational weeks, body mass index(BMI), times of pregnancy, APACHE II score, predicted blood loss, red blood cell transfusion volume, plasma transfusion volume, myocardial injury, acute kidney injury(AKI), hepatic function, and oxygenation index (PaO\u003csub\u003e2\u003c/sub\u003e/FiO\u003csub\u003e2\u003c/sub\u003e), the basal value of creatinine.Since there is no universally recognized diagnostic criteria for AKI specific to pregnant women, we applied the Kidney Disease: Improving Global Outcomes (KDIGO) criteria: 1) An increase in serum creatinine by \u0026ge;\u0026thinsp;0.3 mg/dl (\u0026ge;\u0026thinsp;26.5 \u0026micro;mol/l) within 48 h; 2) An increase in serum creatinine to \u0026ge;\u0026thinsp;1.5 times baseline, which is known or presumed to have occurred within the prior 7 days; 3) Urine volume\u0026thinsp;\u0026le;\u0026thinsp;0.5 ml/kg/h for 6 h. Kidney injury was graded according to the KDIGO classification (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), and myocardial injury was based on troponin/CK-MB exceeding normal reference values.\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\u003eKDIGO classification for AKI\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\u003eStage\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSerum creatinine\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eUrine output\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.5\u0026ndash;1.9 times baseline OR \u0026ge;0.3 mg/dl (\u0026ge;\u0026thinsp;26.5 u mol/l) increase\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026le;\u0026thinsp;0.5 ml/kg/h for 6\u0026ndash;12 hours\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.0\u0026ndash;2.9 times baseline\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.5ml/kg/h for \u0026ge;\u0026thinsp;12 hours\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.0 times baseline OR Increase in serum creatinine to \u0026ge;\u0026thinsp;4.0 mg/dl (\u0026ge;\u0026thinsp;353.6 u mol/l)\u003c/p\u003e\u003cp\u003eOR\u003c/p\u003e\u003cp\u003eInitiation of renal replacement therapy\u003c/p\u003e\u003cp\u003eOR, In patients\u0026thinsp;\u0026lt;\u0026thinsp;18 years, decrease in eGFR to \u0026lt;\u0026thinsp;35 ml/min per 1.73 m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.3ml/kg/h for \u0026ge;\u0026thinsp;24 hours\u003c/p\u003e\u003cp\u003eOR\u003c/p\u003e\u003cp\u003eAnuria for \u0026ge;\u0026thinsp;12 hours\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 primary endpoint was the duration of mechanical ventilation (\u0026gt;\u0026thinsp;24 h vs. \u0026le;24 h) and its independent risk factors. Secondary endpoints included mortality, acute kidney injury (incidence and stage), APACHE II score, oxygenation index, myocardial injury, transfusion requirements, surgical interventions, fluid balance, and referral status(Secondary endpoints was to establish a predictive model for the duration of mechanical ventilation in patients.).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eStatistical analyses were performed using SPSS Version 26.0. By analyzing the normality of continuous variables, we found that none of the data fit the normal distribution, so they were expressed as the median and interquartile range (IQR), independent sample nonparametric test were used between two groups. Count data were expressed as cases or percentages (%), and comparisons between groups were made using the Chi-Square test. Variables with statistically significant differences in univariate analysis were included in the multivariable logistic regression analysis model for risk factors, and P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically different. ROC curves were used to predict the accuracy of the model.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 621 patients were included in the final analysis. During the six-year study period (2019-2025), 1182 critically ill pregnant women were admitted to the ICU, accounting for approximately 2%(1182/66746)of all obstetric admissions to our hospital. Of these ICU admissions, 621 patients required mechanically ventilation and met the study criteria (Figure 1).\u003c/p\u003e\n\u003cp\u003eThe primary etiologies leading to\u0026nbsp;MV are detailed in Table 2 ,\u0026nbsp;The five most frequent causes were hypertensive disorders of pregnancy (18%, 110/621), postpartum hemorrhage (18%, 109/621), hepatic (13%, 78/621), cardiac disease (12%, 74/621), and respiratory failure (10%, 63/621), Collectively, these conditions accounted for \u0026nbsp;70% (434/621). Based on whether the duration of MV was \u0026gt;24 hours, we divided the patients into two groups: 354 (57%) cases in the\u0026nbsp;\u0026le;24 hours group and 267 (43%) cases in the \u0026gt;24 hours group. BMI, mortality, APACHE II score, volume of red blood cell transfusion, volume of plasma transfusion, staging of renal injury, myocardial injury, and oxygenation index were significantly different between the two groups ( p \u0026lt; 0.05). More patients were referred from external hospitals (76%). The referred proportion from external hospitals in the group with\u0026nbsp;\u0026le;24 hours of MV was 71%, which was significantly lower than in the group with \u0026gt;24 hours (84%)(p\u0026lt;0.05), indicating that patients transferred from external hospitals were significantly more serious. The overall APACHE II score median was 17, which was 19 in the group with a duration of MV \u0026gt;24 hours, and 15 in the\u0026nbsp;\u0026le;24 hours group (Table 3).\u003c/p\u003e\n\u003cp\u003eMore than half (52%,326/621) of the patients developed AKI. The proportion of AKI was significantly higher in the group with\u0026nbsp;\u0026ge;24 hours of MV (67% vs 42%, p\u0026lt;0.05). Univariate analysis showed that volume of red blood cell transfusion, volume of plasma transfusion, multiple (\u0026ge;2) surgeries, APACHE II score, AKI grading, myocardial injury, B-type Natriuretic Peptide(BNP), Procalcitonin (PCT), and volume of fluids discharged were the risk factors for the duration of MV ( p\u0026lt;0.05) (Table 4).\u003c/p\u003e\n\u003cp\u003eMultivariable logistic regression analysis identified three independent risk factors for prolonged MV\u0026nbsp;(\u0026gt;24 hours):volume of RBC transfusion (OR=2.66, 95% CI:\u0026nbsp;1.77-3.56; \u003cem\u003eP\u0026lt;0.001\u003c/em\u003e), volume of plasma transfusion (OR=7.83, 95% CI:\u0026nbsp;4.19-11.46; \u003cem\u003eP\u0026lt;0.001\u003c/em\u003e) and AKI grading (OR=13.17, 95% CI:\u0026nbsp;3.64-22.69; \u003cem\u003eP\u003c/em\u003e=0.007) were (Table 4). The area under the ROC curve of the prediction model based on independent risk factors was 0.708(95% CI: 0.665-0.750) (Figure 2).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this retrospective study of critically ill pregnant women, we identified several factors associated with a prolonged duration of mechanical ventilation, Univariate analysis revealed associations with transfusion volumes, multiple (\u0026ge;\u0026thinsp;2) surgeries, APACHE II score, number of hours of hemofiltration, AKI grading, myocardial injury, elevated BNP and PCT levels, and fluids balance. However, multivariable analysis demonstrated that the volumes of RBC and plasma transfusion, along with the AKI grading, were independent risk factors for prolonged MV.\u003c/p\u003e\u003cp\u003eMaternal critical illness is often acute and severe, with high risk of multiple organ dysfunction syndromes (MODS)\u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. ICU care can improve survival\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e, yet prolonged mechanical ventilation (PMV) prolongs hospitalization and resource use. Definitions of PMV range widely\u003csup\u003e[\u003cspan additionalcitationids=\"CR15 CR16 CR17\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e; we adopted the Society of Thoracic Surgeons (MV\u0026thinsp;\u0026gt;\u0026thinsp;24 hours), as it reflects clinically meaningful deterioration and is widely applied for risk stratification. In our study, transfusion volume, multiple surgeries, APACHE II score, hemofiltration, AKI grade, myocardial injury, BNP, PCT, and fluid balance were significant predictors (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e\u003cp\u003eIn our study, the incidence of critically ill pregnant women admitted to the ICU and requiring MV was 53%(621/1182), 267 (43%) of whom were ventilated for more than 24 hours, which is similar to the results of a Chinese multicenter report\u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. However, it has also been reported\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e that among 360 critically ill pregnant women admitted to an ICU, only 25 were mechanically ventilated for \u0026ge;\u0026thinsp;24 h (6.94%). The reason for the obviously difference in the analysis was the different severity of the patients admitted, the median APACHE II score for critically ill pregnant women in that study was 7, which is far from the median APACHE II score of 19 in our study.\u003c/p\u003e\u003cp\u003eThis study identified red blood cell transfusion, plasma volume, and AKI as independent predictors of PMV. Fluid resuscitation with excessive input and reduced renal output may precipitate fluid overload, pulmonary edema, and impaired lung function, thereby extending ventilatory dependence\u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e. Although the oxygenation index (OI) is widely recognized as a marker of lung injury and an important risk factor for PMV\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e, our findings did not confirm this association. A likely explanation is that 76% of patients were referred from other hospitals, many of whom had received oxygen therapy or mechanical ventilation prior to transfer, leading to improved OI values upon admission. Nonetheless, OI still differed significantly between patients ventilated\u0026thinsp;\u0026le;\u0026thinsp;24 h and those ventilated\u0026thinsp;\u0026gt;\u0026thinsp;24 h.\u003c/p\u003e\u003cp\u003ePregnancy-related hypertensive disorders and postpartum hemorrhage were the leading causes of ICU admission in our cohort, each accounting for 18% of mechanically ventilated cases (110/621 and 109/621, respectively), in line with previous reports\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e. Both conditions are well-recognized contributors to AKI in obstetric populations\u003csup\u003e[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e, and patients with pregnancy-related AKI often require mechanical ventilation and renal replacement therapy, with generally poor outcomes\u003csup\u003e[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]\u003c/sup\u003e. Consistent with our findings, renal dysfunction may exacerbate fluid overload, aggravate pulmonary injury, and thereby prolong ventilatory dependence. National data further indicate that hypertensive disorders of pregnancy account for 27.3\u0026ndash;46.1% of obstetric ICU admissions in China, higher than the 22.3\u0026ndash;29.9% reported internationally \u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. The rising incidence of postpartum hemorrhage in China may be partially attributable to the two- and three-child policies, which have increased the prevalence of cesarean scar uterus and late-pregnancy complications\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e. Pathophysiologically, severe hypertensive disorders may lead to microangiopathic hemolysis, hepatic dysfunction, cardiac insufficiency, and renal impairment\u003csup\u003e[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e, while postpartum hemorrhage is commonly associated with uterine atony, birth canal trauma, placental abnormalities, and coagulation disorders\u003csup\u003e[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eOur findings indicate that myocardial injury and elevated BNP are important predictors of PMV in critically ill obstetric patients. Cardiovascular impairment in this population is often driven by hypertensive disorders of pregnancy and postpartum hemorrhage, which exacerbate hypoperfusion, hypoxia, and fluid overload. Prior studies have reported similar associations, including myocardial injury in over half of patients with severe postpartum hemorrhage\u003csup\u003e[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/sup\u003e and frequent troponin elevation in women with hypertensive disorders of pregnancy\u003csup\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/sup\u003e. Together, these results emphasize the central role of cardiac dysfunction in prolonging ventilatory support.\u003c/p\u003e\u003cp\u003eWe also observed a strong association between elevated PCT and PMV, underscoring the impact of infection and systemic inflammation. Maternal sepsis is a leading cause of ICU admission and is often complicated by multiorgan failure and high mortality\u003csup\u003e[\u003cspan additionalcitationids=\"CR31\" citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]\u003c/sup\u003e, yet nearly half of sepsis-related deaths are considered preventable with early recognition and intervention\u003csup\u003e[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/sup\u003e. Monitoring PCT may therefore provide clinical value in identifying infection-related deterioration, predicting PMV, and guiding timely management in this high-risk population.\u003c/p\u003e"},{"header":"Limitation","content":"\u003cp\u003eThere are some limitations to this study. First, this study was a single-center study, the admission criteria may differ from other studies; Second, the data were analyzed retrospectively, and some data from patients' external hospitals were missed, which may led to data bias. Third, we derived three independent risk factors for prolonged MV and created a mapping diagram for visualizing and promoting clinical practice. However, we did not validate the nomogram with a new database. a prospective study is needed to address these issues and validate our findings.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eTherefore, we propose the following recommendations: 1)early identification and assessment of critical pregnancies; 2) attention to and timely control of obstetric hemorrhage; 3) during fluid resuscitation, in addition to actively maintaining hemodynamic stability and tissue perfusion, it is necessary to prevent excessive fluid intake; 4) close monitoring of the function of the kidneys, lungs, heart, and other organs of the critically ill mother; 5) focus on infections, critical pregnant women who develop infections or are at risk of infection need to be assessed early and managed appropriately, e.g., timely specimen retention and antibiotic use. In conclusion, the early assessment and management of critically ill pregnant women admitted to the ICU is very important and even requires the participation of multiple specialists such as obstetricians, respiratory and cardiovascular physicians in addition to ICU physicians in the management of critically ill obstetrics patients in order to shorten the duration of mechanical ventilation.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003e\u003cstrong\u003eICU\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eintensive care unit\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBMI\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ebody mass index\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRBC\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ered blood cell transfusion\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAKI\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eacute kidney injury\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMV\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMechanical ventilation\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePMV\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eprolonged mechanical ventilation\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGAMU\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGuangzhou Medical University\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eKDIGO\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eImproving Global Outcomes\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIQR\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003einterquartile range\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBNP\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eB-type Natriuretic Peptide \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePCT\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eProcalcitonin\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMODS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003emultiple organ dysfunction syndromes\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePMV\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eprolonged mechanical ventilation\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOI\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eoxygenation index\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJialin Yang, Zhanqi Zhao drafted the article. Mingwang Jia, Yingling Wang, and Fang Peng collected clinical cases. Yichun Wang provided guidance and expertise. Guangyuan Liao, as the corresponding author, led the statistical analysis and revised the article for intellectual content. All authors contributed to the study design and interpretation of data, as well as providing critical revision of the article. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding Information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJY is funded by the Wu Jieping Medical Foundation Clinical Research Special Grant (Project No. 320.6750.2024-23-02).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll procedures involving human participants were conducted in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments. The study protocol was reviewed and approved by the Ethics Committee of the Third Affiliated Hospital of Guangzhou Medical University (Approval No. [2024]167). All participants provided written informed consent before enrollment in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to publish\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll participants provided consent for publication of anonymized data. No identifiable personal information is included in this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eZhang HX, Zhao YY, Wang YQ. Analysis of the Characteristics of Pregnancy and Delivery before and after Implementation of the Two-child Policy. 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J Clin Med. 2023 Aug 19;12(16):5386. \u003c/li\u003e\n\u003cli\u003ePollock W, Rose L, Dennis CL. Pregnant and postpartum admissions to the intensive care unit: a systematic review. Intensive Care Med. 2010 Sep;36(9):1465-74.\u003c/li\u003e\n\u003cli\u003eRomano DN, Hyman J, Katz D, et al. Retrospective Analysis of Obstetric Intensive Care Unit Admissions Reveals Differences in Etiology for Admission Based on Mode of Conception. Anesth Analg. 2020 Feb;130(2):436-444. \u003c/li\u003e\n\u003cli\u003eVargas M, Marra A, Buonanno P, et al. Obstetric Admissions in ICU in a Tertiary Care Center: A 5-Years Retrospective Study. Indian J Crit Care Med. 2019 May;23(5):213-219. \u003c/li\u003e\n\u003cli\u003eYue J, Huang Q, Ren Z, et al. [Analysis of treatment for 360 critically ill pregnant and parturient women in intensive care unit]. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2022 Aug;34(8):853-857. Chinese.\u003c/li\u003e\n\u003cli\u003eLin Y, Zhu X, Liu F, et al. Analysis of risk factors of prolonged intensive care unit stay of critically ill obstetric patients: a 5-year retrospective review in 3 hospitals in Beijing. Zhongguo Wei Zhong Bing Ji Jiu Yi Xue. 2011 Aug;23(8):449-53.\u003c/li\u003e\n\u003cli\u003eGhauri SK, Javaeed A, Mustafa KJ, et al. Predictors of prolonged mechanical ventilation in patients admitted to intensive care units: A systematic review. Int J Health Sci (Qassim). 2019 Nov-Dec;13(6):31-38.\u003c/li\u003e\n\u003cli\u003eLiu Y, Wang D, Wang Y, et al. [Analysis of treatment with 167 critically ill pregnant women in intensive care unit]. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2018 Oct;30(10):964-967. Chinese.\u003c/li\u003e\n\u003cli\u003eZhao Z, Han S, Yao G, et al. Pregnancy-Related ICU Admissions From 2008 to 2016 in China: A First Multicenter Report. Crit Care Med. 2018 Oct;46(10):e1002-e1009.\u003c/li\u003e\n\u003cli\u003eGillespie DJ, Marsh HM, Divertie MB, Meadows JA 3rd. Clinical outcome of respiratory failure in patients requiring prolonged (greater than 24 hours) mechanical ventilation. Chest. 1986 Sep;90(3):364-9.\u003c/li\u003e\n\u003cli\u003eChelluri L, Im KA, Belle SH, et al. Mendelsohn AB, Pinsky MR. Long-term mortality and quality of life after prolonged mechanical ventilation. Crit Care Med. 2004 Jan;32(1):61-9.\u003c/li\u003e\n\u003cli\u003eMacIntyre NR, Epstein SK, Carson S, et al. National Association for Medical Direction of Respiratory Care. Management of patients requiring prolonged mechanical ventilation: report of a NAMDRC consensus conference. Chest. 2005 Dec;128(6):3937-54.\u003c/li\u003e\n\u003cli\u003eWang Guangjie, Zhao Huiying, Liu Fang, et al. Analysis of risk factors for prolonged mechanical ventilation in critically ill pregnant women. Chinese Clinical Journal of Obstetrics and Gynecology, 2020,21 (4): 392-395.\u003c/li\u003e\n\u003cli\u003eD\u0026apos;Agostino RS, Jacobs JP, Badhwar V, et al. The Society of Thoracic Surgeons Adult Cardiac Surgery Database: 2019 Update on Outcomes and Quality. Ann Thorac Surg. 2019 Jan;107(1):24-32.\u003c/li\u003e\n\u003cli\u003eSentilhes L, Merlot B, Madar H, et al. Postpartum haemorrhage: prevention and treatment. Expert Rev Hematol. 2016 Nov;9(11):1043-1061.\u003c/li\u003e\n\u003cli\u003eARDS Definition Task Force; Ranieri VM, Rubenfeld GD, Thompson BT, et al. Acute respiratory distress syndrome: the Berlin Definition. JAMA. 2012 Jun 20;307(23):2526-33. \u003c/li\u003e\n\u003cli\u003eZhao H, Wang G, Lyu J, et al. Prediction of mechanical ventilation greater than 24 hours in critically ill obstetric patients: ten years of data from a tertiary teaching hospital in mainland China. BMC Pregnancy Childbirth. 2021 Jan 9;21(1):40.\u003c/li\u003e\n\u003cli\u003eAsaba H, Aoki Y, Akinaga C, et al. Obstetric admission to intensive care units in Japan: a cohort study using the Japanese Intensive care PAtient Database. J Anesth. 2023 Aug;37(4):539-545.\u003c/li\u003e\n\u003cli\u003eZhao Z, Han S, Yao G, et al. Pregnancy-Related ICU Admissions From 2008 to 2016 in China: A First Multicenter Report. Crit Care Med. 2018 Oct;46(10):e1002-e1009. \u003c/li\u003e\n\u003cli\u003eColes H, Steer P, Hughes P, et al. Factors associated with acute kidney injury during delivery or the postpartum period: A case control study. Eur J Obstet Gynecol Reprod Biol. 2021 Jun;261:200-204. \u003c/li\u003e\n\u003cli\u003eYadav S, Chauhan M, Jain D, et al. Renal Outcomes of Pregnancy-Related Acute Kidney Injury: a Single Centre Experience in India. Maedica (Bucur). 2022 Mar;17(1):80-87. \u003c/li\u003e\n\u003cli\u003eHypertensive Disorders in Pregnancy Subgroup, Chinese Society of Obstetrics and Gynecology, Chinese Medical Association. Diagnosis and treatment of hypertension and pre-eclampsia in pregnancy: a clinical practice guideline in China(2020). Zhonghua Fu Chan Ke Za Zhi. 2020 Apr 25;55(4):227-238.\u003c/li\u003e\n\u003cli\u003eObstetrics Subgroup, Chinese Society of Obstetrics and Gynecology, Chinese Medical Association; Chinese Society of Perinatal Medicine, Chinese Medical Association. [Guidelines for prevention and treatment of postpartum hemorrhage (2023)]. Zhonghua Fu Chan Ke Za Zhi. 2023 Jun 25;58(6):401-409.\u003c/li\u003e\n\u003cli\u003eKarpati PC, Rossignol M, Pirot M, et al.High incidence of myocardial ischemia during postpartum hemorrhage .Anesthesiology.2004 Jan;100(1):30-6; discussion 5A.\u003c/li\u003e\n\u003cli\u003ePergialiotis V, Prodromidou A, Frountzas M, et al. Maternal cardiac troponin levels in pre-eclampsia: a systematic review. J Matern Fetal Neonatal Med. 2016 Oct;29(20):3386-90. \u003c/li\u003e\n\u003cli\u003eSociety for Maternal-Fetal Medicine (SMFM); Shields AD, Plante LA, Pacheco LD, et al; SMFM Publications Committee.Electronic address: [email protected] for Maternal-Fetal Medicine Consult Series #67: Maternal sepsis .Am J Obstet Gynecol.2023 Sep;229(3):B2-B19.\u003c/li\u003e\n\u003cli\u003eCresswell JA, Alexander M, Chong MYC, et al. Global and regional causes of maternal deaths 2009-20: a WHO systematic analysis. Lancet Glob Health. 2025 Apr;13(4):e626-e634.\u003c/li\u003e\n\u003cli\u003eShields A, de Assis V, Halscott T. Top 10 Pearls for the Recognition, Evaluation, and Management of Maternal Sepsis. Obstet Gynecol. 2021 Aug 1;138(2):289-304.\u003c/li\u003e\n\u003cli\u003eBonet M, Souza JP, Abalos E, et al. The global maternal sepsis study and awareness campaign (GLOSS): study protocol. Reprod Health. 2018 Jan 30;15(1):16. \u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 2: Main etiology composition of the patients\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eclassification\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003edisease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003en/disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 107px;\"\u003e\n \u003cp\u003en/classification\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eHypertensive disorders of pregnancy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003ePre-eclampsia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e110\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eeclampsia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eHELLP syndrome\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eObstetric Hemorrhage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003ePostpartum Hemorrhage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e109\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e109\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"6\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eRespiratory system\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003ePneumonia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"5\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e63\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003ePulmonary Hypertension\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003ePulmonary Embolism\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eTuberculosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eBronchial Asthma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eLung cancer\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"13\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eCirculatory system\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eRheumatic heart disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"12\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e74\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eCongenital Heart Disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eCardiac arrest\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eHeart Failure\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eInfectious endocarditis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003ePeripartum cardiomyopathy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAortic coarctation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAscending Aortic Aneurys\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eCongenital myocardial insufficiency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eMyocardial infarction\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eCardiac Shock\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAortic valve insufficiency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eMitral valve vegetation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"5\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003edigestive system\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAcute fatty liver\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"5\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e78\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAcute Pancreatitis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAcute Liver Failure\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eHepatitis B\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eHepatitis A\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"8\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003enervous system\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eEepilepsia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"7\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e42\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eIntracranial venous sinus thrombosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eCerebral hemorrhage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eMeningeal arteriovenous fistula\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eMeningioma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eArachnoid cysts\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eSubarachnoid hemorrhage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eViral encephalitis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"8\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eReproductive system/other diseases related to pregnancy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eamniotic fluid embolism\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"8\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eIntrauterine infection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAcute Chorioamnionitis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eEctopic pregnancy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003ePlacental abruption\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eReproductive Tract Infection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eUterine rupture\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eMalignant tumor of the \u0026nbsp;ovary\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"6\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eurinary system\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eUrinary tract infections\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"5\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eChronic Renal Failure\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eNephrotic syndrome\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eKidney Rupture\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAdrenal Cortical Adenoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003erenal artery aneurysm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eAutoimmune diseases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eSystemic Lupus Erythematosu\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e27\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003edesmosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAutoimmune encephalitis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eHematological diseases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eleukemia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"4\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eSevere anemia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAplastic anemia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eHemophagocytic syndrome\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eEndocrine system diseases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eHyperthyroidism\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eDiabetic ketoacidosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eMyasthenia gravis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 177px;\"\u003e\n \u003cp\u003eelse\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eRuptured spleen\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 107px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eMultiple fractures\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 189px;\"\u003e\n \u003cp\u003eScrub typhus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 94px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3: Comparison of parameters between the two groups with different duration of MV\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOverall\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMV\u0026le;24 hours\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMV\u0026gt; 24 hours\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eNumber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e621\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e354\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e267\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eGestational weeks(IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e30(27-36)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e32(27 -36)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e32(27 -36)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.927\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eTime of pregnancies(IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2(1 -4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2(1-4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2(1-3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.501\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eAge(y) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e32(28-36)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e32(28-36)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e31(27-35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.081\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eAdvanced maternal age (\u0026gt; 35 years) n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e167(27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e101(28)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e66(25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.824\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eBMI(Kg/cm\u003csup\u003e2\u003c/sup\u003e) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e22(20-25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e22(20-25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e23(20-26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.026\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eDays in ICU(IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4(2-8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3(2-4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8(4-15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eDays of hospitalization(IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e13(9-20)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e11(8-16)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e16(11-26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eNumber of deaths: (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e29(5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5(0.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e24(9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eAPACHE\u0026nbsp;II Score (after ICU admission / within 24h after\u0026nbsp;\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eMV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e17(14-22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e15(13-20)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e19(15-25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eTransfer from external hospitals n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e475(76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e250(71)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e225(84)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.012\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eEstimated blood loss (ml) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e500(300-1364)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e506(352-1297)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e449(300-1677)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.035\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eMultiple (≧2) operations n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e167(27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e83(23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e84(31)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.030\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eRehydration volume (ml) (after admission to ICU/within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3124(2425-4195)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3315(2347-5000)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3695(2798-5025)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eUrine output (ml) (minimum 24h during hospitalization) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2670(1515-4080)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2810(1800-4050)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2540(960-4205)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.034\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eVolume of fluid discharged (ml) (after admission to ICU/within 24 h of MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3610(2535-5260)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3693(2640-5272)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3850(2700-5472)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.007\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eInfusion of red blood cells (u) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2(0-8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0(0-6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4(0-13)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eVolume of plasma transfused(l) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0(0-1.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0(0-1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0(0-3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eMV\u0026nbsp;(h) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e20(7-57)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9(3-16)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e70(39-129)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eCreatinine (umol/L) (admission base / lowest value) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e63(47-107)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e56(45-84)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e76(52-132)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.268\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eCreatinine (umol/L) (highest value)\u0026nbsp;(IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e79(57-137)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e70(54-104)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e103(65-191)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\"\u003e\n \u003cp\u003eAKI grading\u0026nbsp;(after ICU admission / within 24h after MV)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNo damage(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e295(48)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e206(58)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e89(33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"4\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eLevel 1(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e128(21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e84(24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e44(16)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eLevel 2(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e77(12)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e33(9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e44(16)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eLevel 3(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e121(19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e31(9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e90(34)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003emyocardial injury (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e339(55)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e174(49)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e165(62)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eTBIL, u mol/L (within 24h of MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12(6-25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e11(6-23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e13(6-33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.046\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eAlbumin, g / L (within 24h of MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e28(25-32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e28(25-32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e28(24-32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.392\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eBNP, pg/ml (after ICU admission / within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e416(118-1861)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e299(70-1111)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e852(201-3638)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003ePCT, ng/mL (after ICU admission / within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.6(0.2-2.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0(0-2.)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1(0-8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eWBC, 109L (after ICU entry / within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e14(10-19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e13(10-18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e15(10-20)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.131\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eHB, g / L (after ICU admission / within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e96(82-112)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e96(83-112)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e95(79-111)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.392\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003ePLT, 1012L (after ICU entry / within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e146(72-215)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e153(85-214)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e125(58-220)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.021\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eLactate, mmol/L (after ICU entry / within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.8(2-4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3(2-4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3(2-5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003ePH (after ICU admission / within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7.39(7.34-7.44)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7.38(7.34-7.43)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7.40(7.33-7.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.223\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003ePaO\u003csub\u003e2\u003c/sub\u003e (after ICU admission / within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e124(88-167)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e135(99-174)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e107(79-154)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003ePaCO\u003csub\u003e2\u003c/sub\u003e, mmHg (after ICU admission / within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e34(30-39)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e35(31-39)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e33(29-39)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.053\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eBicarbonate, mmol/L (after ICU entry / within 24h after MV) (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e21(18-23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e21(19-23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e20(18-24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.206\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eOI(IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e273(184-383)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e307(219-407)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e218(150-345)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations:\u0026nbsp;BMI body mass index, ICU intensive care unit ,APACHE acute physiology and chronic health evaluation, MV mechanical ventilation, AKI acute kidney injury, TBIL total bilirubin, BNP brain natriuretic peptide, PCT procalcitonin, WBC white blood cell, HB hemoglobin,PLT platelet, PaO\u003csub\u003e2\u0026nbsp;\u003c/sub\u003earterial partial pressure of oxygen, PaCO\u003csub\u003e2\u0026nbsp;\u003c/sub\u003earterial partial pressure of carbon dioxide,OI the ratio of the arterial partial pressure of oxygen and the fraction of inspired oxygen\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4. Risk factors for the duration of MV\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 238px;\"\u003e\n \u003cp\u003eUnivariate analysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eMultivariate analysis\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003eOR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e95% CI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003eOR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e95% CI\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eCreatinine \u0026nbsp;(admission base/ lowest value)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.223\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e0.087-0.358\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eAPACHE\u0026nbsp;score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e3.300\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e1.538-5.061\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eVolume of fluid discharged\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.006\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e0.033\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e0.001-0.012\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eInfusion of red blood cells\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e3.900\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e3.144-4.656\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e2.662\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e1.770-3.555\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eVolume of plasma transfused\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e14.985\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e11.647-18.323\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e7.827\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e4.191-11.463\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eCreatinine \u0026nbsp;(highest value)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.168\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e0.084-0.251\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eAKI grading\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e33.219\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e23.494-42.945\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e13.168\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e0.007\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e3.643-22.694\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003emyocardial injury\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e39.040\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e16.409-61.670\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eBNP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e0.003-0.007\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003ePCT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e1.148\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 118px;\"\u003e\n \u003cp\u003e0.500-1.795\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations: MV mechanical ventilation,APACHE acute physiology and chronic health evaluation, AKI acute kidney injury, BNP brain natriuretic peptide, PCT procalcitonin\u003c/p\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":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"mechanical ventilation, pregnancy, critical illness, risk factors, acute kidney injury, transfusion","lastPublishedDoi":"10.21203/rs.3.rs-7935843/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7935843/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eProlonged mechanical ventilation (MV) is associated with increased morbidity and mortality in critically ill pregnant women.This study aimed to identify risk factors associated with the duration of MV in critically ill pregnant women using clinical and laboratory parameters.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eWe conducted a retrospective analysis of pregnant and postpartum women admitted to the intensive care unit(ICU) between January 1, 2019 and April 30, 2025. Patients were stratified into two groups based on MV duration (\u0026le;\u0026thinsp;24 hours vs. \u0026gt;24 hours). Risk factors were analyzed using multifactorial logistic regression.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eAmong 621 enrolled patients, 354(57%) required MV for \u0026le;\u0026thinsp;24 hours,and 267(43%) for \u0026gt;\u0026thinsp;24 hours. Significant intergroup differences were observed in body mass index(BMI), mortality, APACHE II score, patients referred by the external hospitals, estimated blood loss(ml), volume of red blood cell transfusion (RBC), volume of plasma transfusion(l), acute kidney injury(AKI) grading (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/em\u003e), and myocardial injury(all \u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.005\u003c/em\u003e). Multivariable analysis identified RBC transfusion volume (OR\u0026thinsp;=\u0026thinsp;2.66, 95% CI: 1.77\u0026ndash;3.56; \u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/em\u003e), plasma transfusion volume (OR\u0026thinsp;=\u0026thinsp;7.823, 95% CI: 4.19\u0026ndash;11.46; \u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/em\u003e), and AKI grading (OR\u0026thinsp;=\u0026thinsp;13.17, 95% CI: 3.64\u0026ndash;22.69; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.007) as independent risk factors for prolonged MV.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eGreater transfusion requirements for RBCs and plasma, along with more severe AKI,are independent risk factors for prolonged MV in critically pregnant women.Close monitoring and early intervention targeting these factors may improve patient outcomes.\u003c/p\u003e","manuscriptTitle":"Risk factors for prolonged mechanical ventilation in critically pregnant women: a retrospective observational study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-18 08:48:15","doi":"10.21203/rs.3.rs-7935843/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-02-23T10:36:15+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-14T13:31:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"217584353638251609173018992638797891114","date":"2026-02-13T13:08:21+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-11T03:41:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"166588228882193201062333089548186154601","date":"2025-11-11T01:48:07+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-11-06T18:59:46+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-10-30T07:38:44+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-29T00:48:43+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-29T00:47:15+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pregnancy and Childbirth","date":"2025-10-24T01:42:33+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6fb824bb-2c46-48cf-90b4-f8de81744dd3","owner":[],"postedDate":"November 18th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-22T12:40:04+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-18 08:48:15","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7935843","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7935843","identity":"rs-7935843","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}