A nomogram for predicting sedation-related adverse events in elderly patients undergoing painless gastrointestinal endoscopy

A nomogram for predicting sedation-related adverse events in elderly patients undergoing painless gastrointestinal endoscopy | 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 A nomogram for predicting sedation-related adverse events in elderly patients undergoing painless gastrointestinal endoscopy Liu Xu, Qiyuan Yin, Hui Liu, Qian Liu, Hongyan Zhang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7472714/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Elderly patients undergoing painless gastrointestinal endoscopy are at increased risk for sedation-related adverse events (SRAEs) because of their greater physiological vulnerability and higher likelihood of comorbidities. Risk stratification before endoscopy may improve perioperative safety and individualize sedation and management. Objective This study aimed to develop and validate a model based on machine learning to predict risk of SRAEs in elderly undergoing painless gastrointestinal endoscopy. Methods Prospective data from 520 patients at least 60 years old who underwent painless gastrointestinal endoscopy between April 2023 and June 2024 at our medical center were randomly divided into a training set (n = 364) and validation set (n = 156). SRAEs were defined as intraoperative hypotension or hypoxemia, and independent predictors of SRAEs in the training set were identified through multivariate logistic regression. A nomogram to predict risk of SRAEs was developed using R software and tested against the validation set. Its performance was assessed in terms of receiver operating characteristic curves, calibration plots, and decision curve analysis. Results In the training set, hypotension occurred in 39.0% patients and hypoxemia in 33.5%, and independent predictors were older age, history of snoring, frailty, preexisting hypertension, chronic obstructive pulmonary disease, prolonged fasting before the procedure, and higher initial dose of etomidate-propofol. Conversely, regular physical activity was a protective factor. The nomogram built from the training set discriminated between people in the validation set who experienced SRAEs or not with an area under the curve of 0.95 (95%CI 0.92–0.99), it showed good calibration in the Hosmer–Lemeshow test ( P = 0.405), and decision curve analysis demonstrated clinical utility across a wide range of threshold probabilities. Conclusion A predictive model based on readily available clinical variables can accurately estimate SRAE risk in elderly patients undergoing painless gastrointestinal endoscopy. The model may be useful for individualizing sedation and patient management. Trial registration Chinese Clinical Trial Registry ChiCTR2300069816. Registered on 23 March 2023. Sedation Gastrointestinal endoscopy Elderly patients Hypotension Hypoxemia Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 1. Introduction Endoscopy has become a widely used clinical tool for the early detection of gastrointestinal malignancies, and a growing number of patients opt for sedation during the procedure to increase diagnostic accuracy and comfort [ 1 ] . However, sedation increases the risk of hypotension and hypoxemia, and it can lead in rare cases to life-threatening cardiocerebrovascular events [ 2 , 3 ] . For example, the most frequently used sedative for painless gastrointestinal endoscopy is propofol, which causes hypotension in up to 36% of patients and hypoxemia in up to 21% of patients. The risk of these sedation-related adverse events (SRAEs) is likely to be higher among elderly than younger patients [ 4 ] , because elderly are more likely to be experiencing respiratory depression, upper airway obstruction, decreased chest wall compliance [ 2 , 3 , 5 ] , reduced cardiopulmonary reserve, impaired hepatic and renal function, and multiple chronic comorbidities. Therefore, early identification of elderly patients at high risk of SRAEs during painless gastrointestinal endoscopy is critical for individualizing peri-sedation management and improving patient safety. Although studies have described models to predict risk of intra-procedural hypotension and other SRAEs [ 6 , 7 ] , the literature on SRAEs has not focused on elderly or taken into account variables from throughout the sedation process. We reasoned that machine learning may generate more reliable models because of its ability to handle large datasets and capture complex, multidimensional relationships among variables [ 8 ] . Therefore we took comprehensive account of peri-procedural variables to develop a nomogram to predict SRAEs in elderly patients undergoing painless gastrointestinal endoscopy, which we validated internally. The model may inform clinical decision-making to improve anesthetic care in this vulnerable population. 2. Materials and Methods 2.1 Patients This was a prospective, single-center, observational study conducted at Wenjiang District People's Hospital of Chengdu. The study protocol was approved by the institutional ethics committee (approval EC-Research-2023-003), and the trial was prospectively registered in the Chinese Clinical Trial Registry (registration ChiCTR2300069816, registration date: March 27, 2023). Informed consent was obtained from all participants prior to enrollment. Data were collected from a consecutive series of patients at least 60 years old who underwent painless gastrointestinal endoscopy between April 2023 and June 2024 at our hospital and who had a American Society of Anesthesiologists (ASA) physical status I–III at baseline. The case report form (CRF) used in this study was specifically developed for this project to collect demographic, clinical, anesthetic, and hemodynamic data of elderly patients undergoing painless gastrointestinal endoscopy. The CRF has not been previously published elsewhere. An English version of the CRF is provided as Supplementary File 1.Patients were excluded if they (1) were known to be allergic or hypersensitive to sedative or anesthetic agents; (2) were suffering from gastric retention or acute upper gastrointestinal bleeding involving excessive gastric content; (3) had a history of epilepsy, psychiatric disorders, hearing impairment, dementia, or other conditions affecting their compliance in the study; (4) experienced hemodynamic shock or instability before endoscopy; (5) had severe hepatic or renal insufficiency before endoscopy; (6) had systolic blood pressure > 160 mmHg or 100 mmHg or < 60 mmHg before endoscopy; (7) had peripheral oxygen saturation (SpO₂) < 90% with room air before endoscopy; or (8) received medications other than sedatives, such as norepinephrine spray, during endoscopy. 2.2 Minimal sample size Given the rule of thumb of at least 20 subjects per potential predictor variable, we reasoned that we needed to recruit at least 360 patients in the training set because of the 18 anesthesia-related risk factors listed in Table 1 . We reasoned further that we needed at least 156 patients in the validation set because the number needed to be a multiple of 3 and we planned to split the data 7:3 between training and validation sets [ 9 ][ 10 ] . To account for an anticipated 10% dropout rate, we recruited a total of 578 patients. 2.3 Sedation and management Before endoscopy, all patients were evaluated at our anesthesia outpatient clinic, during which they provided written informed consent to undergo the procedure and to participate in our study. Patients fasted for at least 8 h and abstained from liquids for at least 4 h before the procedure. Patients scheduled for colonoscopy also received oral sodium phosphate solution and simethicone emulsion for bowel cleansing. In the procedure room, patients were positioned in the left lateral decubitus position, intravenous access was established via the right dorsal hand vein, and lactated Ringer’s solution was infused. Heart rate, SpO₂ and non-invasive blood pressure on the left upper arm were monitored continuously. Oxygen was administered via nasal cannula at 2–3 L/min. Endoscopic procedures were performed by qualified endoscopists under the supervision of board-certified anesthesiologists, in accordance with standard diagnostic and therapeutic protocols. Anesthesia was induced using intravenous fentanyl citrate at 0.5 µg/kg, followed by administration of 1% lidocaine at 0.3 mg/kg after 1.5-2 min, then slow injection of 0.2 mL/kg of an etomidate-propofol mixture that had been prepared by combining 10 mL propofol with 10 mL etomidate. Anesthesia was maintained by administering an additional 0.07 mL/kg of the etomidate-propofol mixture every 5 min. If the patient exhibited body movement or cough reflex during the procedure, additional etomidate-propofol mixture was given as needed at a dose of 0.07 mL/kg. Intraoperative hypotension was treated with intravenous ephedrine 3–6 mg, while sinus bradycardia, defined as a heart rate below 50 bpm, was treated with intravenous atropine 0.3–0.5 mg. Hypoxemia, defined as SpO₂ < 90%, was initially managed through manual chin lifting; if this proved ineffective, endoscopy was paused and oxygen was delivered under positive pressure via facemask until SpO₂ ≥ 90%. After the procedure, patients were transferred to the post-anesthesia care unit, from which they were discharged in the company of a family member once they met the criteria routinely used at our hospital. 2.4 Definition of SRAEs SRAEs in this study were defined as either hypotension or hypoxemia occurring between the initiation of anesthesia induction and patient discharge from the procedure room. Hypotension was defined as a decrease in systolic blood pressure by at least 20% from the level before anesthesia induction [ 11 ] . Hypoxemia was defined asSpO 2 between 75% and 90% that lasted 5 to 60 sec [ 12 ] . 2.5 Definition of potential risk factors of SRAEs Potential risk factors of intraoperative SRAEs were extracted from the literature and our clinical experience and integrated into a standardized data collection form. When patients arrived in the waiting area before sedation and endoscopy, trained investigators conducted face-to-face interviews to obtain baseline information about these potential risk factors as well as demographic and clinical characteristics. The collected data included the following: sex, age, body mass index, physical status on the American Society of Anesthesiologists scale, smoking and alcohol history, physical activity level, history of snoring, frailty status, comorbidities, fasting time before the procedure, and type of endoscopic procedure. Smoking meant daily consumption of ≥ 10 cigarettes within 2 weeks before the procedure. Alcohol consumption meant drinking any type of alcohol at least twice per week during the 2 weeks prior to the procedure. Regular physical activity was defined as exercising for at least 30 min at least 3 times per week at moderate intensity (e.g., brisk walking) during the previous month [ 13 ] . Snoring severity was graded on the following 4-point scale [ 14 ] : grade 0, no snoring; grade 1, snoring without apnea or related symptoms; grade 2, loud snoring with symptoms (e.g., daytime fatigue) but no apnea; grade 3, snoring with apnea and evidence of end-organ damage. Frailty was assessed using the Fried Frailty Phenotype, and the scores were categorized as follows [ 15 ] : 0 points, robust; 1–2 points, pre-frail; ≥ 3 points, frail. The following perioperative vital signs were recorded before anesthesia and immediately before endoscope insertion: systolic and diastolic blood pressure, mean arterial pressure, heart rate, and SpO₂. Intraoperative adverse events included hypotension, hypoxemia, patient movement, sinus bradycardia, and repeated coughing, which was defined as ≥ 3 cough episodes during intubation. Patient discomfort immediately after the procedure was also documented. 2.6 Development and validation of a nomogram to predict SRAEs The dataset was randomly divided into a training set (70%) and a validation set (30%) using a computer-generated allocation sequence, and patients were assigned to a group who experienced at least one SRAE or not. Data were compared between the two groups using SPSS 25.0 (IBM, Armonk, NY, USA). Continuous variables with a normal distribution were reported as mean ± standard deviation, and intergroup differences were assessed for significance using the independent-samples t test. Continuous variables with a skewed distribution were reported as median and interquartile range (IQR), and intergroup differences were assessed using the Mann–Whitney U test. Categorical variables were reported as n (%), and differences were assessed using the χ² test. Differences that were associated with two-sided P < 0.05 were considered statistically significant. Variables differing significantly between groups in the training set at the significance level P < 0.05 were entered into multivariate logistic regression to identify independent risk factors of SRAEs, which were incorporated into a predictive nomogram constructed in R 4.2.0, The model was internally validated in the validation cohort using bootstrap resampling (1,000 iterations). The model's performance in both training and validation sets was evaluated in terms of the area under the receiver operating characteristic curve (AUC), calibration plots, the Hosmer–Lemeshow goodness-of-fit test, and clinical utility based on decision curve analysis. Where appropriate, results were reported together with their associated 95% confidence interval (CI). 3. Results Of the 578 elderly patients who underwent sedation-assisted gastrointestinal endoscopy at our hospital during the enrollment period, 58 (10.0%) were excluded because their medical data were incomplete or because they were lost to follow-up. The remaining 520, who were 68 ± 6.5 years old (range, 60–93 years) and 266 of whom were men, were included in the final analysis (Fig. 1 ). Just over half the sample underwent both gastroscopy and colonoscopy (286, 55.0%), while a smaller proportion underwent only gastroscopy (174, 33.5%) and even fewer underwent only colonoscopy (60, 11.5%). Intraoperative hypotension occurred in 201 patients (38.7%), while intraoperative hypoxemia occurred in 166 (31.9%). Endotracheal intubation was not required during the study. 3.1 Identification of risk factors for SRAEs Patients were randomly assigned in a 7:3 ratio to either the training set (n = 364) or the validation set (n = 156), and the two sets did not differ significantly in any of the baseline clinicodemographic characteristics that we examined (Table 1 ). In contrast, several baseline variables differed significantly between patients who experienced at least one SRAE or not within the training and validation sets (Table 2 ). The variables that differed significantly in the training set were coded (Table 3 ) and entered into multivariate logistic regression, which identified the following independent risk factors for SRAEs (Table 4 ): advanced age, history of snoring, frailty, preoperative hypertension, chronic obstructive pulmonary disease, prolonged fasting before the procedure, and increased initial dose of etomidate-propofol. Conversely, regular physical activity was found to be a protective factor. Table 1 Comparison of baseline characteristics and perioperative variables between the training and validation sets Characteristic Training set (n = 364) Validation set (n = 156) t / χ 2 / z P Sex 0.529 0.467 Men 190 (52.2) 76 (48.7) Women 174 (47.8) 80 (51.3) Age, yr 68 ± 7 68 ± 6 0.734 0.511 Body mass index, kg/m 2 23.2 ± 2.8 23.7 ± 3.5 1.572 0.117 Status on the American Society of Anesthesiologists scale 1.467 0.690 Ⅰ 25 (6.9) 9 (5.8) Ⅱ 250 (68.7) 102 (65.4) Ⅲ 89 (24.5) 45 (28.9) Smoking 54 (14.8) 16 (10.3) 1.965 0.161 Alcohol consumption 94 (25.8) 41 (26.3) 0.012 0.913 Regular physical activity 262 (72.0) 106 (68.0) 0.857 0.355 History of snoring 6.449 0.092 None 204 (56.0) 95 (60.9) Mild (grade 1) 104 (28.6) 29 (18.6) Moderate (grade 2) 38 (10.4) 21 (13.5) Severe (grade 3) 18 (5.0) 11 (7.1) Frailty 2.361 0.307 Robust 131 (36.0) 48 (30.8) Pre-frail 182 (50.0) 79 (50.6) Frail 51 (14.0) 29 (18.6) Comorbidities Hypertension 119 (32.7) 58 (37.2) 0.979 0.322 Coronary artery disease 57 (15.7) 24 (15.4) 0.006 0.937 COPD 152 (41.8) 59 (37.8) 0.702 0.402 Renal insufficiency 34 (9.3) 15 (9.6) 0.010 0.922 Diabetes mellitus 55 (15.1) 20 (12.8) 0.464 0.496 Fasting time before precedure, h 17(14.0, 18.0) 17(16.0, 18.0) 1.430 0.153 Endoscopy type 1.671 0.434 Gastroscopy 121 (33.2) 53 (34.0) Colonoscopy 38 (10.4) 22 (14.1) Both 205 (56.3) 81 (51.9) Sufentanil, µg 2.7 ± 0.7 2.7 ± 0.6 0.482 0.630 Initial EP mixture, mL 12 ± 1.9 11.9 ± 2.1 0.476 0.634 Change from baseline (%) in Systolic blood pressure 17.0 (11.0, 23.0) 18.0 (12.0, 22.0) -1.274 0.203 Diastolic blood pressure 18.0 (10.0, 25.0) 18(11.0, 24.0) -0.860 0.390 Heart rate 0.0 (13.0) 0.0 (9.2) -0.317 0.752 Hypotension 142 (39.0) 59 (37.8) 0.065 0.798 Hypoxemia 122 (33.5) 44 (28.2) 1.418 0.234 Body movement 21 (5.8) 11 (7.1) 0.311 0.577 Coughing 11 (3.0) 4 (2.6) 0.082 0.775 Values are n (%), mean ± SD, or median (interquartile range), unless otherwise noted. COPD, chronic obstructive pulmonary disease; EP, etomidate-propofol. Table 2 Comparison of baseline characteristics and perioperative variables between patients who exerienced at least one SRAE or not in the training and validation sets Characteristic Training set Validation set No SRAE (n = 198) SRAE (n = 166) P No SRAE n = 95 SRAE n = 61 P Sex, 0.548 0.701 Men 100(50.5) 90(54.2) 44(46.3) 31(50.8) Women 98(49.5) 76(45.8) 51(53.7) 30(49.2) Age, yr 67.9 ± 5.6 69.3 ± 7.2 0.033 65.8 ± 5.9 68.7 ± 6.6 0.006 Body mass index, kg/m 2 22.8 ± 2.8 23.5 ± 2.6 0.014 22.8 ± 3.8 23.8 ± 3.3 0.084 Status on the American Society of Anesthesiologists scale < 0.001 < 0.001 Ⅰ 163(82.3) 13(80.7) 72(75.8) 52(85.3) Ⅱ 0(0.00) 13(7.8) 22(23.2) 3(4.9) Ⅲ 35(17.7) 19(11.5) 1(1.1) 6(9.8) Smoking 2(1.0) 51(30.7) < 0.001 2(2.1) 14(23.0) < 0.001 Alcohol consumption 40(20.2) 58(34.9) 0.002 38(40.0) 5(8.2) < 0.001 Regular physical activity 191(98.0) 75(45.2) < 0.001 92(96.8) 24(39.3) < 0.001 History of snoring < 0.001 < 0.001 None 133(67.2) 64(38.6) 71(74.7) 28(45.9) Mild (grade 1) 63(31.8) 49(29.5) 24(25.3) 15(24.6) Moderate (grade 2) 2(1.0) 35(21.1) 0(0.0) 11(18.0) Severe (grade 3) 0(0.00) 18(10.9) 0(0.0%) 7(11.5) Frailty < 0.001 < 0.001 Robust(0 points) 81(41.0) 51(30.7) 40(42.1) 19(31.2) Pre-frail 117(59.1) 64(38.6) 52(54.7) 16(26.2) Frail 0(0.00%) 51(30.7) 3(3.2) 26(42.6) Comorbidities Hypertension, 54(27.3) 64(38.6) 0.029 36(37.9) 18(29.5) 0.367 Coronary artery disease 18(9.1) 39(23.5) < 0.001 20(21.1) 10(16.4) 0.608 COPD 0(0.0) 122(73.5) < 0.001 0(0.0) 44(72.1) < 0.001 Renal insufficiency 24(12.1) 13(7.8) 0.241 11(11.6) 7(11.5) 1.001 Diabetes mellitus 30(15.2) 25(15.7) 1.001 10(10.5) 10(16.4) 0.409 Fasting time before precedure, h 17(16.0,18.0) 17(15.0,19.0) 0.02 17(16.0, 19.0) 17(13.0,18.0) 0.01 Endoscopy type 0.514 0.92 Gastroscopy 66(38.4) 53(25.9) 34(35.8) 20(32.8) Colonoscopy 20(10.1) 17(10.2) 13(13.7) 9(14.8) Both 112(51.5) 96(63.8) 48(50.5) 32(52.5) Sufentanil dosage, µg 2.2 ± 0.5 2.4 ± 0.7 0.001 2.1 ± 0.5 2.3 ± 0.7 0.125 Initial EP mixture, mL 12.0 ± 1.5 12.3 ± 1.9 0.037 11.9 ± 1.3 12.4 ± 1.8 0.081 Change from baseline in (%) Systolic blood pressure 17 (10.5, 23.5) 17 (11.0, 23.0) 0.534 18 (14.0,23.0) 17 (13.0,22.0) 0.513 Diastolic blood pressure 17 (10.0,24.0) 19 (11.0, 26.0) 0.185 18 (12.0, 24.0) 18 (12.0,26.0) 0.893 Heart rate 1 (-9.0,5.0) -1.0 (-9.0, 5.0) 0.093 0 (-5.0,3.0) 0(-5.0,7.0) 0.437 ASA, American Society of Anesthesiologists; COPD, chronic obstructive pulmonary disease; EP, etomidate-propofol; SRAE, sedation-related adverse event Table 3 Definitions of variables in logistic regression Variable Name Description Sex X1 Male = 1, Female = 2 Age, yr X2 60–69 = 1, 70–79 = 2, 80 + = 3 Body mass index, kg/m 2 X3 28 = 3 ASA classification X4 Ⅰ-Ⅱ = 1, Ⅲ = 2, Ⅳ = 3 Smoking X5 No = 0, Yes = 1 Alcohol consumption X6 No = 0, Yes = 1 Regular physical activity X7 Regular exercise = 0, No exercise = 1 History of snoring X8 None = 0, Mild = 1, Moderate = 2, Severe = 3 Frailty status X9 Robust = 0, Pre-frail = 1, Frail = 2 Hypertension X10 None = 0, Stage 1 = 1, Stage 2 = 2 Coronary artery disease X11 No = 0, Yes = 1 COPD X12 No = 0, Yes = 1 Renal insufficiency X13 No = 0, Yes = 1 Diabetes mellitus X14 No = 0, Yes = 1 Fasting time before procedure X15 ≤ 20 h = 0, >20 h = 1 Endoscopy type X16 Gastroscopy = 0, Colonoscopy = 1, Both = 2 Sufentanil dosage, µg X17 1–3 µg = 0, 4–5 µg = 1 Initial EP dose, mL X18 ≤ 8 mL = 0, 9–15 mL = 1, >15 mL = 2 ASA, American Society of Anesthesiologists; COPD, chronic obstructive pulmonary disease; EP, etomidate-propofol. Table 4 Multivariate logistic regression to identify risk factors of sedation-related adverse events in the training set Variable B Wald P Exp (B) 95% confidence interval Age 1.469 18.970 < 0.001 4.346 2.244–8.418 Regular physical activity -2.564 24.022 < 0.001 0.077 0.028–0.215 History of snoring 2.037 27.599 < 0.001 7.665 3.585–16.388 Frailty 3.930 32.056 < 0.001 147.899 0.000-0.112 Hypertension 1.346 14.537 < 0.001 3.841 1.923–7.671 Chronic obstructive pulmonary disease 0.884 5.377 0.020 2.420 1.147–5.106 Fasting time before procedure 5.621 50.601 < 0.001 276.094 58.678-1299.088 Initial etomidate-propofol dose 4.756 13.773 < 0.001 116.287 9.433-1433.473 Constant -6.834 20.990 < 0.001 0.001 Not applicable 3.2 Development and internal validation of a nomogram to predict SRAEs A nomogram was constructed based on the eight independent risk factors of SRAEs identified through multivariate logistic regression (Fig. 2 ). The nomogram accurately predicted SRAEs in the training set, giving an AUC of 0.96 (95%CI 0.94–0.98; Fig. 3 ). A bias-corrected calibration curve, generated through bootstrap resampling (1,000 iterations), indicated excellent agreement between predicted and observed probabilities of SRAEs (Fig. 4 ). Consistently, the Hosmer–Lemeshow test showed no significant deviation between predicted and actual outcomes ( P = 0.392). Next the nomogram was internally validated against the validation set using bootstrap resampling (1,000 iterations). The AUC was 0.95 (95%CI 0.92–0.99), and the optimal cut off value of 0.622, which was based on the Youden index, yielded sensitivity of 97.5% and specificity of 81.9%. The calibration curve showed excellent agreement between predicted and observed probabilities of SRAEs, which was confirmed in the Hosmer–Lemeshow test ( P = 0.405). The nomogram predicted that SRAEs would occur in 86.5% of patients in the validation set and 88.4% in the training set, underscoring the vulnerability of elderly patients undergoing painless gastrointestinal endoscopy. 3.3 Clinical utility of the nomogram Decision curves indicated that the nomogram showed good clinical utility across a broad range of threshold probabilities, whether in the training set (13–95%) or validation set (8–97%) (Fig. 5 ). 4. Discussion In this study, perioperative data from 520 elderly patients undergoing painless gastrointestinal endoscopy was used to develop a nomogram to predict SRAEs based on eight independent risk factors, which performed well in internal validation and showed clinical utility across a broad range of threshold probabilities. This model may help identify individuals at high risk of SRAEs and personalize perioperative procedures. Anesthesia was induced and maintained in our sample using a 1:1 mixture of etomidate and propofol, which have complementary pharmacodynamic profiles: propofol allows rapid onset and recovery, while etomidate has more stable hemodynamic properties [ 16 ] . Each of the drugs is associated with different types of adverse events that do not overlap: propofol increases risk of hypotension and respiratory depression [ 17 , 18 ] , while etomidate increases risk of adrenal suppression and myoclonus [ 19 ] . Therefore, combining the two drugs should not increase risk beyond monotherapy. Our results support the idea that their combination can ensure adequate sedation while keeping cardiovascular and respiratory risk low in elderly patients, at least for short-duration procedures such as painless endoscopy. At the same time, we detected a significant positive association between higher initial etomidate-propofol dose and incidence of hypotension, consistent with the known vasodilatory effect of propofol [ 20 – 22 ] . This highlights the need for individualized anesthetic dosing, especially in older populations. Future work should explore how to optimize anesthesia protocols for elderly, such as by replacing propofol with remimazolam [ 23 ] , and how to adjust the nomogram to predict SRAE risk accordingly. The independent predictors of SRAEs in our sample are consistent with age-related decline. As individuals grow older, arteriosclerosis reduces vascular elasticity and the autonomic regulatory system becomes weaker, increasing risk of intraoperative hypotension. Fraily is associated with lower physiological reserves across multiple systems, rendering patients more vulnerable to the hemodynamic stress of anesthesia induction [ 24 , 25 ] . For example, frailty may reduce oxygenation [ 26 ] , increasing the risk of intraoperative hypoxemia. Indeed, hypotension and hypoxemia were more frequent among our frail patients than among younger ones, raising the possibility that conventional anesthesia protocols may fail to meet the perfusion and oxygenation demands of this population. Future research should explore this in detail. Longer fasting time before endoscopy was associated with higher risk of SRAEs in our sample. Elderly may be more sensitive to fluid imbalance than younger individuals [ 27 ] , and the hypovolemia arising from extended fasting may exacerbate the already strong variations in blood pressure and heart rate that older patients experience during gastroscopy [ 28 ] . It may be necessary to tailor fluid management strategies for elderly undergoing gastroscopy, which should be explored in future work. History of snoring predicted intraoperative hypoxemia in our sample, consistent with the known association between such a history and risk of airway obstruction during anesthesia due to mandibular relaxation, posterior tongue displacement or upper airway collapse [ 29 , 30 ] . Chronic obstructive pulmonary disease also predicted intraoperative hypoxemia in our sample, probably reflecting that the compromised alveolar function, ventilation–perfusion mismatch, chronic inflammation, and airway hyperresponsiveness of the disease can compromise oxygenation during anesthesia [ 31 ] . Regular physical activity protected against SRAEs in our sample. Moderate exercise is known to enhance cardiopulmonary function, improve oxygen uptake and use, delay age-related organ decline, and promote metabolic efficiency. Exercise-based interventions can improve postoperative outcomes and reduce risk of complications in elderly with gastrointestinal malignancies [ 32 ] . Our study extends these findings to the context of sedation for painless endoscopy. Exercise and potentially other lifestyle factors may be important to consider when stratifying patients by SRAE risk and when planning their sedation before the procedure and their management afterwards. Our study substantially extends the literature on SRAEs by focusing on elderly and defining a composite endpoint of either hypotension or hypoxemia, rather than only one SRAE [ 33 ] . It considered factors related to lifestyle (e.g., physical activity, snoring), physiological status (frailty), and the perioperative experience (preoperative fasting time, initial dose of etomidate-propofol) when predicting SRAE risk. Our finding that fasting time before the procedure appeared in the final nomogram underscores the importance of proper preparation of elderly patients before the procedure. Our consideration of a broader range of potential predictors may help explain why the predictive ability of our nomogram (AUC 0.95–0.96) was superior to that of other machine learning models such as XGBoost and random forest AUC 0.85–0.89 [ 34 ] . At the same time, our findings should be interpreted with caution in light of the relatively small sample from a single center. This may limit the generalizability of our results, and it prevented us from analyzing subgroups of patients stratified by clinically relevant variables. Our nomogram remains to be validated and extended through external validation studies, preferably with large, multicenter patient populations. Future work should also explore whether the nomogram can beintegrated into intelligent anesthesia management systems to enhance perioperative safety and personalize the care of elderly patients. Declarations Human Ethics and Consent to Participate This study was approved by the Institutional Ethics Committee of Wenjiang District People's Hospital of Chengdu (approval number: EC-Research-2023-003). The study was conducted in accordance with the Declaration of Helsinki.Written informed consent was obtained from all participants prior to enrollment. Consent to Publish Not applicable. Clinical Trial Registration This trial was prospectively registered in the Chinese Clinical Trial Registry (ChiCTR; registration number:ChiCTR2300069816; registration date: March 27, 2023; http://www.chictr.org.cn/) Author contributions Liu Xu contributed to the study design, protocol development, and manuscript writing. Qiyuan Yin and Hui Liu were responsible for patient recruitment, clinical data collection, and preliminary analysis. Qian Liu provided statistical support and guidance on data interpretation. Hongyan Zhang oversaw overall project coordination and timeline management and supervised the study’s overall direction, ensured research quality, and reviewed the final manuscript. Funding This study was supported by the Health Commission of Sichuan Province Medical Science and Technology Program (24QNMP067), the Medical Research Subject of Chengdu Health Commission (2024083), and the Medical Research Project of Sichuan Medical Association (S2024086). Adherence to CONSORT guidelines This study adhered to the CONSORT (Consolidated Standards of Reporting Trials) guidelines for reporting clinical trials. A completed CONSORT checklist is provided as an additional file. Conflicts of interest The authors confirm that there are no conflicts of interest. Availability of Data and Materials The datasets generated and analyzed during the current study are not publicly available due to patient privacy and hospital policy but are available from the corresponding author on reasonable request. 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Hypoxemia during moderate sedation for gastrointestinal endoscopy: causes and associations [J]. Digestion, 2011, 84(1): 37-45. GENG W, JIA D, WANG Y, et al. A prediction model for hypoxemia during routine sedation for gastrointestinal endoscopy [J]. Clinics (Sao Paulo, Brazil), 2018, 73: e513. WANG Z, MA J, LIU X, et al. Development and validation of a predictive model for PACU hypotension in elderly patients undergoing sedated gastrointestinal endoscopy [J]. Aging clinical and experimental research, 2024, 36(1): 149. SHELLEY B, SHAW M. Machine learning and preoperative risk prediction: the machines are coming [J]. British journal of anaesthesia, 2024, 133(5): 925-30. WU J, ZHANG H, LI L, et al. A nomogram for predicting overall survival in patients with low-grade endometrial stromal sarcoma: A population-based analysis [J]. Cancer communications (London, England), 2020, 40(7): 301-12. LEI M, FENG T, CHEN M, et al. Establishment and validation of an artificial intelligence web application for predicting postoperative in-hospital mortality in patients with hip fracture: a national cohort study of 52 707 cases [J]. International journal of surgery (London, England), 2024, 110(8): 4876-92. LIU X, GAO Z, JIANG Y, et al. Comparison of Low-Frequency or High-Frequency Electrical Acupoint Stimulation on Hypotension After Spinal Anesthesia in Parturients: A Prospective Randomized Controlled Clinical Trial [J]. Journal of integrative and complementary medicine, 2024, 30(8): 770-5. WANG S, SHENG T, YUAN G, et al. Bilevel positive airway pressure ventilation in patients susceptible to hypoxemia during procedural sedation for colonoscopy: a prospective randomized controlled study [J]. Gastrointestinal endoscopy, 2024, 99(6): 989-97. DUAN Y, LU G. A Randomized Controlled Trial to Determine the Impact of Resistance Training versus Aerobic Training on the Management of FGF-21 and Related Physiological Variables in Obese Men with Type 2 Diabetes Mellitus [J]. Journal of sports science & medicine, 2024, 23(1): 495-503. [Expert consensus on perioperative management of adult patients combined with obstructive sleep apnea (2025 edition)] [J]. Zhonghua yi xue za zhi, 2025, 105(14): 1045-54. GELADARI E, ALEXOPOULOS T, VASILIEVA L, et al. Evaluation of Five Screening Tools in Detecting Physical Frailty in Cirrhosis and Their Prognostic Role [J]. J Clin Med, 2024, 13(17). ZHENG Z, SU Y, FAN X, et al. BIS feedback closed-loop target-controlled infusion of propofol or etomidate in elderly patients with spinal surgery [J]. American journal of translational research, 2023, 15(2): 1231-8. GAN T J, BERTOCH T, HABIB A S, et al. Comparison of the Efficacy of HSK3486 and Propofol for Induction of General Anesthesia in Adults: A Multicenter, Randomized, Double-blind, Controlled, Phase 3 Noninferiority Trial [J]. Anesthesiology, 2024, 140(4): 690-700. BARBOSA E C, ESPíRITO SANTO P A, BARALDO S, et al. Remimazolam versus propofol for sedation in gastrointestinal endoscopic procedures: a systematic review and meta-analysis [J]. British journal of anaesthesia, 2024, 132(6): 1219-29. LU Z, ZHENG H, CHEN Z, et al. Effect of Etomidate vs Propofol for Total Intravenous Anesthesia on Major Postoperative Complications in Older Patients: A Randomized Clinical Trial [J]. JAMA surgery, 2022, 157(10): 888-95. QIAO L, WANG Z, SHEN J, et al. Impact of Dexmedetomidine on Hemodynamics, Plasma Catecholamine Levels, and Delirium Incidence Among Intubated Patients in the ICU--A Randomized Controlled Trial [J]. Therapeutics and clinical risk management, 2024, 20: 689-700. YAMAMOTO K. Current issues in frailty and hypertension management [J]. Hypertension research : official journal of the Japanese Society of Hypertension, 2023, 46(8): 1917-22. MARTíNEZ-GONZáLEZ Ó, ALONSO-FERNáNDEZ M, GARCíA-ALONSO M, et al. Deep sedation for gastrointestinal endoscopy in elderly patients. Subgroup analysis [J]. Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver, 2025, 57(6): 1266-72. LEE J H, LEE J, PARK S H, et al. Comparison between remimazolam and propofol anaesthesia for interventional neuroradiology: a randomised controlled trial [J]. Anaesthesia, critical care & pain medicine, 2024, 43(2): 101337. DAUM N, HOFF L, SPIES C, et al. Influence of frailty status on the incidence of intraoperative hypotensive events in elective surgery: Hypo-Frail, a single-centre retrospective cohort study [J]. British journal of anaesthesia, 2025. SCHNETZ M, ZAKARIA L, AHUJA S, et al. Frailty and intraoperative hypotension: is the risk significant and modifiable? [J]. British journal of anaesthesia, 2025. VERDURI A, CLINI E, CARTER B, et al. Influence of frailty on cardiovascular events and mortality in patients with Chronic Obstructive Pulmonary Disease (COPD): Study protocol for a multicentre European observational study [J]. PloS one, 2024, 19(6): e0300945. MLADINOV D, ISAZA E, GOSLING A F, et al. Perioperative Fluid Management [J]. Clinics in geriatric medicine, 2025, 41(1): 83-99. DENG R, WU J, XU K, et al. The impact of early gastroscopy examination on cardiovascular event-related indices in elderly patients with acute upper gastrointestinal bleeding [J]. Medicine, 2024, 103(13): e37378. SEET E, WASEEM R, CHAN M T V, et al. Characteristics of Patients with Unrecognized Sleep Apnea Requiring Postoperative Oxygen Therapy [J]. Journal of personalized medicine, 2022, 12(10). KANDASAMY G, ALMELEEBIA T. A Prospective Study on Obstructive Sleep Apnea, Clinical Profile and Polysomnographic Variables [J]. Journal of personalized medicine, 2023, 13(6). OWENS R L, DEROM E, AMBROSINO N. Supplemental oxygen and noninvasive ventilation [J]. European respiratory review : an official journal of the European Respiratory Society, 2023, 32(167). HAMAD A, ZHANG H, ZHANG Y, et al. Understanding the mechanism behind preoperative exercise therapy in patients with gastrointestinal cancers: a prospective randomized clinical trial [J]. BMC sports science, medicine & rehabilitation, 2025, 17(1): 50. ZHENG L, WU X, GU W, et al. Development and validation of a hypoxemia prediction model in middle-aged and elderly outpatients undergoing painless gastroscopy [J]. Scientific reports, 2025, 15(1): 17965. CHEN M, ZHANG D. Machine learning-based prediction of post-induction hypotension: identifying risk factors and enhancing anesthesia management [J]. BMC medical informatics and decision making, 2025, 25(1): 96. 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12:22:21","extension":"html","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":142940,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7472714/v1/7855dd88c8faaa017433aaf5.html"},{"id":93773076,"identity":"45a37673-4062-4535-a680-82932a06ec42","added_by":"auto","created_at":"2025-10-17 12:22:21","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":92007,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart of patient enrollment, allocation and analysis. SRAE, sedation-related adverse event.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7472714/v1/b2d85446cc2c9948c09fe409.png"},{"id":93773074,"identity":"93e529a8-1cf4-4d8b-9d8b-152768004ce7","added_by":"auto","created_at":"2025-10-17 12:22:21","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":206517,"visible":true,"origin":"","legend":"\u003cp\u003eNomogram to predict sedation-related adverse events in elderly patients undergoing painless gastrointestinal endoscopy. The nomogram incorporates eight independent risk factors identified through multivariate logistic regression of data in the training set. COPD, chronic obstructive pulmonary disease.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7472714/v1/1ee7a93856882dd3cd3de713.png"},{"id":93773071,"identity":"0fcf3296-4ff7-4abc-a39b-e1b59989e434","added_by":"auto","created_at":"2025-10-17 12:22:21","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":63330,"visible":true,"origin":"","legend":"\u003cp\u003eReceiver operating characteristic curves to asess the ability of the nomogram to predict sedation-related adverse events in the training set (blue) or validation set (orange). The areas under the curves and corresponding 95% confidence intervals are shown at the lower right. The diagonal dotted line represents perfect prediction.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7472714/v1/14eb9e31c4abdd04db7edba5.png"},{"id":93776545,"identity":"6e9013f9-13df-4370-8e89-8bf4fddce76b","added_by":"auto","created_at":"2025-10-17 12:38:21","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":166085,"visible":true,"origin":"","legend":"\u003cp\u003eCalibration curves of the nomogram when applied to the \u003cstrong\u003e(A)\u003c/strong\u003e training set or \u003cstrong\u003e(B)\u003c/strong\u003evalidation set. The diagonal dotted line represents perfect prediction.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7472714/v1/3cad5bf85ba10eeddf7cb497.png"},{"id":93776547,"identity":"a04fa26b-4d65-485c-a948-c4f009e822ca","added_by":"auto","created_at":"2025-10-17 12:38:21","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":253958,"visible":true,"origin":"","legend":"\u003cp\u003eDecision curves of the nomogram when applied to the \u003cstrong\u003e(A)\u003c/strong\u003e training set or \u003cstrong\u003e(B)\u003c/strong\u003e validation set.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7472714/v1/4a43c435da71667e75bc1d89.png"},{"id":94066031,"identity":"95123185-d362-486c-b6cf-44181b1695b1","added_by":"auto","created_at":"2025-10-22 08:01:48","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1930337,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7472714/v1/b916d433-30dd-4726-ae7b-db58f052b767.pdf"},{"id":93773072,"identity":"da319d71-1b69-4cb9-af3e-e1e289596dd3","added_by":"auto","created_at":"2025-10-17 12:22:21","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":73090,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryFile1CaseReportForm.docx","url":"https://assets-eu.researchsquare.com/files/rs-7472714/v1/0aa4cd35d4a8515351b7df44.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"A nomogram for predicting sedation-related adverse events in elderly patients undergoing painless gastrointestinal endoscopy","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eEndoscopy has become a widely used clinical tool for the early detection of gastrointestinal malignancies, and a growing number of patients opt for sedation during the procedure to increase diagnostic accuracy and comfort\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. However, sedation increases the risk of hypotension and hypoxemia, and it can lead in rare cases to life-threatening cardiocerebrovascular events\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. For example, the most frequently used sedative for painless gastrointestinal endoscopy is propofol, which causes hypotension in up to 36% of patients and hypoxemia in up to 21% of patients. The risk of these sedation-related adverse events (SRAEs) is likely to be higher among elderly than younger patients\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e, because elderly are more likely to be experiencing respiratory depression, upper airway obstruction, decreased chest wall compliance\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e, reduced cardiopulmonary reserve, impaired hepatic and renal function, and multiple chronic comorbidities. Therefore, early identification of elderly patients at high risk of SRAEs during painless gastrointestinal endoscopy is critical for individualizing peri-sedation management and improving patient safety.\u003c/p\u003e\u003cp\u003eAlthough studies have described models to predict risk of intra-procedural hypotension and other SRAEs\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e, the literature on SRAEs has not focused on elderly or taken into account variables from throughout the sedation process. We reasoned that machine learning may generate more reliable models because of its ability to handle large datasets and capture complex, multidimensional relationships among variables\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Therefore we took comprehensive account of peri-procedural variables to develop a nomogram to predict SRAEs in elderly patients undergoing painless gastrointestinal endoscopy, which we validated internally. The model may inform clinical decision-making to improve anesthetic care in this vulnerable population.\u003c/p\u003e"},{"header":"2. Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Patients\u003c/h2\u003e\u003cp\u003eThis was a prospective, single-center, observational study conducted at Wenjiang District People's Hospital of Chengdu. The study protocol was approved by the institutional ethics committee (approval EC-Research-2023-003), and the trial was prospectively registered in the Chinese Clinical Trial Registry (registration ChiCTR2300069816, registration date: March 27, 2023). Informed consent was obtained from all participants prior to enrollment.\u003c/p\u003e\u003cp\u003eData were collected from a consecutive series of patients at least 60 years old who underwent painless gastrointestinal endoscopy between April 2023 and June 2024 at our hospital and who had a American Society of Anesthesiologists (ASA) physical status I\u0026ndash;III at baseline. The case report form (CRF) used in this study was specifically developed for this project to collect demographic, clinical, anesthetic, and hemodynamic data of elderly patients undergoing painless gastrointestinal endoscopy. The CRF has not been previously published elsewhere. An English version of the CRF is provided as Supplementary File 1.Patients were excluded if they (1) were known to be allergic or hypersensitive to sedative or anesthetic agents; (2) were suffering from gastric retention or acute upper gastrointestinal bleeding involving excessive gastric content; (3) had a history of epilepsy, psychiatric disorders, hearing impairment, dementia, or other conditions affecting their compliance in the study; (4) experienced hemodynamic shock or instability before endoscopy; (5) had severe hepatic or renal insufficiency before endoscopy; (6) had systolic blood pressure\u0026thinsp;\u0026gt;\u0026thinsp;160 mmHg or \u0026lt;\u0026thinsp;90 mmHg or diastolic blood pressure\u0026thinsp;\u0026gt;\u0026thinsp;100 mmHg or \u0026lt;\u0026thinsp;60 mmHg before endoscopy; (7) had peripheral oxygen saturation (SpO₂)\u0026thinsp;\u0026lt;\u0026thinsp;90% with room air before endoscopy; or (8) received medications other than sedatives, such as norepinephrine spray, during endoscopy.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Minimal sample size\u003c/h2\u003e\u003cp\u003eGiven the rule of thumb of at least 20 subjects per potential predictor variable, we reasoned that we needed to recruit at least 360 patients in the training set because of the 18 anesthesia-related risk factors listed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. We reasoned further that we needed at least 156 patients in the validation set because the number needed to be a multiple of 3 and we planned to split the data 7:3 between training and validation sets\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e][\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e. To account for an anticipated 10% dropout rate, we recruited a total of 578 patients.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Sedation and management\u003c/h2\u003e\u003cp\u003e Before endoscopy, all patients were evaluated at our anesthesia outpatient clinic, during which they provided written informed consent to undergo the procedure and to participate in our study. Patients fasted for at least 8 h and abstained from liquids for at least 4 h before the procedure. Patients scheduled for colonoscopy also received oral sodium phosphate solution and simethicone emulsion for bowel cleansing. In the procedure room, patients were positioned in the left lateral decubitus position, intravenous access was established via the right dorsal hand vein, and lactated Ringer\u0026rsquo;s solution was infused. Heart rate, SpO₂ and non-invasive blood pressure on the left upper arm were monitored continuously. Oxygen was administered via nasal cannula at 2\u0026ndash;3 L/min. Endoscopic procedures were performed by qualified endoscopists under the supervision of board-certified anesthesiologists, in accordance with standard diagnostic and therapeutic protocols.\u003c/p\u003e\u003cp\u003eAnesthesia was induced using intravenous fentanyl citrate at 0.5 \u0026micro;g/kg, followed by administration of 1% lidocaine at 0.3 mg/kg after 1.5-2 min, then slow injection of 0.2 mL/kg of an etomidate-propofol mixture that had been prepared by combining 10 mL propofol with 10 mL etomidate. Anesthesia was maintained by administering an additional 0.07 mL/kg of the etomidate-propofol mixture every 5 min. If the patient exhibited body movement or cough reflex during the procedure, additional etomidate-propofol mixture was given as needed at a dose of 0.07 mL/kg.\u003c/p\u003e\u003cp\u003eIntraoperative hypotension was treated with intravenous ephedrine 3\u0026ndash;6 mg, while sinus bradycardia, defined as a heart rate below 50 bpm, was treated with intravenous atropine 0.3\u0026ndash;0.5 mg. Hypoxemia, defined as SpO₂ \u0026lt; 90%, was initially managed through manual chin lifting; if this proved ineffective, endoscopy was paused and oxygen was delivered under positive pressure via facemask until SpO₂ \u0026ge; 90%. After the procedure, patients were transferred to the post-anesthesia care unit, from which they were discharged in the company of a family member once they met the criteria routinely used at our hospital.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e2.4 Definition of SRAEs\u003c/h2\u003e\u003cp\u003eSRAEs in this study were defined as either hypotension or hypoxemia occurring between the initiation of anesthesia induction and patient discharge from the procedure room. Hypotension was defined as a decrease in systolic blood pressure by at least 20% from the level before anesthesia induction\u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. Hypoxemia was defined asSpO\u003csub\u003e2\u003c/sub\u003e between 75% and 90% that lasted 5 to 60 sec\u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e2.5 Definition of potential risk factors of SRAEs\u003c/h2\u003e\u003cp\u003ePotential risk factors of intraoperative SRAEs were extracted from the literature and our clinical experience and integrated into a standardized data collection form. When patients arrived in the waiting area before sedation and endoscopy, trained investigators conducted face-to-face interviews to obtain baseline information about these potential risk factors as well as demographic and clinical characteristics. The collected data included the following: sex, age, body mass index, physical status on the American Society of Anesthesiologists scale, smoking and alcohol history, physical activity level, history of snoring, frailty status, comorbidities, fasting time before the procedure, and type of endoscopic procedure. Smoking meant daily consumption of \u0026ge; 10 cigarettes within 2 weeks before the procedure. Alcohol consumption meant drinking any type of alcohol at least twice per week during the 2 weeks prior to the procedure. Regular physical activity was defined as exercising for at least 30 min at least 3 times per week at moderate intensity (e.g., brisk walking) during the previous month\u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. Snoring severity was graded on the following 4-point scale\u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/sup\u003e: grade 0, no snoring; grade 1, snoring without apnea or related symptoms; grade 2, loud snoring with symptoms (e.g., daytime fatigue) but no apnea; grade 3, snoring with apnea and evidence of end-organ damage. Frailty was assessed using the Fried Frailty Phenotype, and the scores were categorized as follows\u003csup\u003e[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e: 0 points, robust; 1\u0026ndash;2 points, pre-frail; \u0026ge; 3 points, frail. The following perioperative vital signs were recorded before anesthesia and immediately before endoscope insertion: systolic and diastolic blood pressure, mean arterial pressure, heart rate, and SpO₂. Intraoperative adverse events included hypotension, hypoxemia, patient movement, sinus bradycardia, and repeated coughing, which was defined as \u0026ge; 3 cough episodes during intubation. Patient discomfort immediately after the procedure was also documented.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e2.6 Development and validation of a nomogram to predict SRAEs\u003c/h2\u003e\u003cp\u003eThe dataset was randomly divided into a training set (70%) and a validation set (30%) using a computer-generated allocation sequence, and patients were assigned to a group who experienced at least one SRAE or not. Data were compared between the two groups using SPSS 25.0 (IBM, Armonk, NY, USA). Continuous variables with a normal distribution were reported as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation, and intergroup differences were assessed for significance using the independent-samples \u003cem\u003et\u003c/em\u003e test. Continuous variables with a skewed distribution were reported as median and interquartile range (IQR), and intergroup differences were assessed using the Mann\u0026ndash;Whitney U test. Categorical variables were reported as n (%), and differences were assessed using the χ\u0026sup2; test. Differences that were associated with two-sided \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 were considered statistically significant.\u003c/p\u003e\u003cp\u003eVariables differing significantly between groups in the training set at the significance level \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 were entered into multivariate logistic regression to identify independent risk factors of SRAEs, which were incorporated into a predictive nomogram constructed in R 4.2.0, The model was internally validated in the validation cohort using bootstrap resampling (1,000 iterations). The model's performance in both training and validation sets was evaluated in terms of the area under the receiver operating characteristic curve (AUC), calibration plots, the Hosmer\u0026ndash;Lemeshow goodness-of-fit test, and clinical utility based on decision curve analysis. Where appropriate, results were reported together with their associated 95% confidence interval (CI).\u003c/p\u003e\u003c/div\u003e"},{"header":"3. Results","content":"\u003cp\u003eOf the 578 elderly patients who underwent sedation-assisted gastrointestinal endoscopy at our hospital during the enrollment period, 58 (10.0%) were excluded because their medical data were incomplete or because they were lost to follow-up. The remaining 520, who were 68\u0026thinsp;\u0026plusmn;\u0026thinsp;6.5 years old (range, 60\u0026ndash;93 years) and 266 of whom were men, were included in the final analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Just over half the sample underwent both gastroscopy and colonoscopy (286, 55.0%), while a smaller proportion underwent only gastroscopy (174, 33.5%) and even fewer underwent only colonoscopy (60, 11.5%). Intraoperative hypotension occurred in 201 patients (38.7%), while intraoperative hypoxemia occurred in 166 (31.9%). Endotracheal intubation was not required during the study.\u003c/p\u003e\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003ch2\u003e3.1 Identification of risk factors for SRAEs\u003c/h2\u003e\u003cp\u003ePatients were randomly assigned in a 7:3 ratio to either the training set (n\u0026thinsp;=\u0026thinsp;364) or the validation set (n\u0026thinsp;=\u0026thinsp;156), and the two sets did not differ significantly in any of the baseline clinicodemographic characteristics that we examined (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). In contrast, several baseline variables differed significantly between patients who experienced at least one SRAE or not within the training and validation sets (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The variables that differed significantly in the training set were coded (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) and entered into multivariate logistic regression, which identified the following independent risk factors for SRAEs (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e): advanced age, history of snoring, frailty, preoperative hypertension, chronic obstructive pulmonary disease, prolonged fasting before the procedure, and increased initial dose of etomidate-propofol. Conversely, regular physical activity was found to be a protective factor.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of baseline characteristics and perioperative variables between the training and validation sets\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eCharacteristic\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTraining set\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;364)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eValidation set\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;156)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003et\u003c/em\u003e / \u003cem\u003eχ\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e / \u003cem\u003ez\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eSex\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.529\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.467\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMen\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e190 (52.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e76 (48.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWomen\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e174 (47.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e80 (51.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eAge, yr\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e68\u0026thinsp;\u0026plusmn;\u0026thinsp;7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e68\u0026thinsp;\u0026plusmn;\u0026thinsp;6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.734\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.511\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eBody mass index, kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e23.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e23.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.572\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.117\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e\u003cp\u003eStatus on the American Society of Anesthesiologists scale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.467\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.690\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eⅠ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e25 (6.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e9 (5.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eⅡ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e250 (68.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e102 (65.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eⅢ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e89 (24.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e45 (28.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eSmoking\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e54 (14.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e16 (10.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.965\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.161\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eAlcohol consumption\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e94 (25.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e41 (26.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.012\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.913\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eRegular physical activity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e262 (72.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e106 (68.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.857\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.355\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eHistory of snoring\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e6.449\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.092\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e204 (56.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e95 (60.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMild (grade 1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e104 (28.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e29 (18.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eModerate (grade 2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e38 (10.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e21 (13.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSevere (grade 3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18 (5.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e11 (7.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eFrailty\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.361\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.307\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eRobust\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e131 (36.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e48 (30.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePre-frail\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e182 (50.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e79 (50.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFrail\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e51 (14.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e29 (18.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eComorbidities\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHypertension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e119 (32.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e58 (37.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.979\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.322\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCoronary artery disease\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e57 (15.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e24 (15.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.006\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.937\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCOPD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e152 (41.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e59 (37.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.702\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.402\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eRenal insufficiency\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e34 (9.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15 (9.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.010\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.922\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDiabetes mellitus\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e55 (15.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e20 (12.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.464\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.496\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eFasting time before precedure, h\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17(14.0, 18.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e17(16.0, 18.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.430\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.153\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eEndoscopy type\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.671\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.434\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGastroscopy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e121 (33.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e53 (34.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eColonoscopy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e38 (10.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e22 (14.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eBoth\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e205 (56.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e81 (51.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eSufentanil, \u0026micro;g\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.482\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.630\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eInitial EP mixture, mL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e11.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.476\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.634\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eChange from baseline (%) in\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eSystolic blood pressure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17.0 (11.0, 23.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e18.0 (12.0, 22.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-1.274\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.203\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eDiastolic blood pressure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18.0 (10.0, 25.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e18(11.0, 24.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-0.860\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.390\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eHeart rate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.0 (13.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.0 (9.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-0.317\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.752\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eHypotension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e142 (39.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e59 (37.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.065\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.798\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eHypoxemia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e122 (33.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e44 (28.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.418\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.234\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eBody movement\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e21 (5.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e11 (7.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.311\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.577\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eCoughing\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11 (3.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4 (2.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.082\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.775\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\u003eValues are n (%), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD, or median (interquartile range), unless otherwise noted. COPD, chronic obstructive pulmonary disease; EP, etomidate-propofol.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of baseline characteristics and perioperative variables between patients who exerienced at least one SRAE or not in the training and validation sets\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"10\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e\u003cp\u003eCharacteristic\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e\u003cp\u003eTraining set\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c10\" namest=\"c7\"\u003e\u003cp\u003eValidation set\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo SRAE\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;198)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSRAE\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;166)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003eNo SRAE\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;95\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eSRAE\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;61\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eSex,\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.548\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.701\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMen\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e100(50.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e90(54.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e44(46.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e31(50.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWomen\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e98(49.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e76(45.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e51(53.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e30(49.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eAge, yr\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e67.9\u0026thinsp;\u0026plusmn;\u0026thinsp;5.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e69.3\u0026thinsp;\u0026plusmn;\u0026thinsp;7.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.033\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e65.8\u0026thinsp;\u0026plusmn;\u0026thinsp;5.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e68.7\u0026thinsp;\u0026plusmn;\u0026thinsp;6.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.006\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eBody mass index, kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e22.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e23.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.014\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e22.8\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e23.8\u0026thinsp;\u0026plusmn;\u0026thinsp;3.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.084\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eStatus on the American Society of Anesthesiologists scale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eⅠ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e163(82.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e13(80.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e72(75.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e52(85.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eⅡ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0(0.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e13(7.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e22(23.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e3(4.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eⅢ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e35(17.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e19(11.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1(1.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e6(9.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eSmoking\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2(1.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e51(30.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e2(2.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e14(23.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eAlcohol consumption\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e40(20.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e58(34.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.002\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e38(40.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e5(8.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eRegular physical activity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e191(98.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e75(45.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e92(96.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e24(39.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eHistory of snoring\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c9\" namest=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e133(67.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e64(38.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e71(74.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e28(45.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMild (grade 1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e63(31.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e49(29.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e24(25.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e15(24.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eModerate (grade 2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2(1.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e35(21.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0(0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e11(18.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSevere (grade 3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0(0.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e18(10.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0(0.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e7(11.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eFrailty\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eRobust(0 points)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e81(41.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e51(30.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e40(42.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e19(31.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePre-frail\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e117(59.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e64(38.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e52(54.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e16(26.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFrail\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0(0.00%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e51(30.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e3(3.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e26(42.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"10\" nameend=\"c10\" namest=\"c1\"\u003e\u003cp\u003eComorbidities\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHypertension,\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e54(27.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e64(38.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.029\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e36(37.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e18(29.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.367\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCoronary artery disease\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18(9.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e39(23.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e20(21.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e10(16.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.608\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCOPD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0(0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e122(73.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0(0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e44(72.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eRenal insufficiency\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24(12.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e13(7.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.241\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e11(11.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e7(11.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e1.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDiabetes mellitus\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30(15.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e25(15.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e10(10.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e10(16.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.409\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eFasting time before precedure, h\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17(16.0,18.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e17(15.0,19.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e17(16.0, 19.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e17(13.0,18.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eEndoscopy type\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.514\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.92\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGastroscopy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e66(38.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e53(25.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e34(35.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e20(32.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eColonoscopy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e20(10.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e17(10.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e13(13.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e9(14.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eBoth\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e112(51.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e96(63.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e48(50.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003e32(52.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eSufentanil dosage, \u0026micro;g\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e2.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e2.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.125\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eInitial EP mixture, mL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e12.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.037\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e11.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e12.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.081\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eChange from baseline in (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"8\" nameend=\"c10\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eSystolic blood pressure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17 (10.5, 23.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e17 (11.0, 23.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.534\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e18 (14.0,23.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e17 (13.0,22.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.513\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eDiastolic blood pressure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17 (10.0,24.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e19 (11.0, 26.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.185\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e18 (12.0, 24.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e18 (12.0,26.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.893\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eHeart rate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (-9.0,5.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-1.0 (-9.0, 5.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.093\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u003cp\u003e0 (-5.0,3.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e0(-5.0,7.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u003cp\u003e0.437\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\u003eASA, American Society of Anesthesiologists; COPD, chronic obstructive pulmonary disease; EP, etomidate-propofol; SRAE, sedation-related adverse event\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDefinitions of variables in logistic regression\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\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eName\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e\u003ccolgroup cols=\"1\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003eDescription\u003c/tr\u003e\u003c/thead\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMale\u0026thinsp;=\u0026thinsp;1, Female\u0026thinsp;=\u0026thinsp;2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge, yr\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e60\u0026ndash;69\u0026thinsp;=\u0026thinsp;1, 70\u0026ndash;79\u0026thinsp;=\u0026thinsp;2, 80\u0026thinsp;+\u0026thinsp;=\u0026thinsp;3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBody mass index, kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;24\u0026thinsp;=\u0026thinsp;1, 24\u0026ndash;28\u0026thinsp;=\u0026thinsp;2, \u0026gt;28\u0026thinsp;=\u0026thinsp;3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eASA classification\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eⅠ-Ⅱ = 1, Ⅲ = 2, Ⅳ = 3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSmoking\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo\u0026thinsp;=\u0026thinsp;0, Yes\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAlcohol consumption\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo\u0026thinsp;=\u0026thinsp;0, Yes\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRegular physical activity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRegular exercise\u0026thinsp;=\u0026thinsp;0, No exercise\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHistory of snoring\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNone\u0026thinsp;=\u0026thinsp;0, Mild\u0026thinsp;=\u0026thinsp;1, Moderate\u0026thinsp;=\u0026thinsp;2, Severe\u0026thinsp;=\u0026thinsp;3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFrailty status\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRobust\u0026thinsp;=\u0026thinsp;0, Pre-frail\u0026thinsp;=\u0026thinsp;1, Frail\u0026thinsp;=\u0026thinsp;2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypertension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNone\u0026thinsp;=\u0026thinsp;0, Stage 1\u0026thinsp;=\u0026thinsp;1, Stage 2\u0026thinsp;=\u0026thinsp;2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCoronary artery disease\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo\u0026thinsp;=\u0026thinsp;0, Yes\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCOPD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo\u0026thinsp;=\u0026thinsp;0, Yes\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRenal insufficiency\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo\u0026thinsp;=\u0026thinsp;0, Yes\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDiabetes mellitus\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNo\u0026thinsp;=\u0026thinsp;0, Yes\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFasting time before procedure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026le;\u0026thinsp;20 h\u0026thinsp;=\u0026thinsp;0, \u0026gt;20 h\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEndoscopy type\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGastroscopy\u0026thinsp;=\u0026thinsp;0, Colonoscopy\u0026thinsp;=\u0026thinsp;1, Both =\u0026thinsp;2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSufentanil dosage, \u0026micro;g\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u0026ndash;3 \u0026micro;g\u0026thinsp;=\u0026thinsp;0, 4\u0026ndash;5 \u0026micro;g\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInitial EP dose, mL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eX18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026le;\u0026thinsp;8 mL\u0026thinsp;=\u0026thinsp;0, 9\u0026ndash;15 mL\u0026thinsp;=\u0026thinsp;1, \u0026gt;15 mL\u0026thinsp;=\u0026thinsp;2\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\u003eASA, American Society of Anesthesiologists; COPD, chronic obstructive pulmonary disease; EP, etomidate-propofol.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMultivariate logistic regression to identify risk factors of sedation-related adverse events in the training set\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eB\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eWald\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eExp (B)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003e95% confidence interval\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.469\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18.970\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4.346\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.244\u0026ndash;8.418\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRegular physical activity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-2.564\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24.022\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.077\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.028\u0026ndash;0.215\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHistory of snoring\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.037\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e27.599\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e7.665\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e3.585\u0026ndash;16.388\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFrailty\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.930\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e32.056\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e147.899\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.000-0.112\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypertension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.346\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14.537\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.841\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.923\u0026ndash;7.671\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eChronic obstructive pulmonary disease\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.884\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.377\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.020\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.420\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.147\u0026ndash;5.106\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFasting time before procedure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.621\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e50.601\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e276.094\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e58.678-1299.088\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInitial etomidate-propofol dose\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.756\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13.773\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e116.287\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e9.433-1433.473\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eConstant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-6.834\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e20.990\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eNot applicable\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003e3.2 Development and internal validation of a nomogram to predict SRAEs\u003c/h2\u003e\u003cp\u003eA nomogram was constructed based on the eight independent risk factors of SRAEs identified through multivariate logistic regression (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The nomogram accurately predicted SRAEs in the training set, giving an AUC of 0.96 (95%CI 0.94\u0026ndash;0.98; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). A bias-corrected calibration curve, generated through bootstrap resampling (1,000 iterations), indicated excellent agreement between predicted and observed probabilities of SRAEs (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Consistently, the Hosmer\u0026ndash;Lemeshow test showed no significant deviation between predicted and actual outcomes (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.392).\u003c/p\u003e\u003cp\u003eNext the nomogram was internally validated against the validation set using bootstrap resampling (1,000 iterations). The AUC was 0.95 (95%CI 0.92\u0026ndash;0.99), and the optimal cut off value of 0.622, which was based on the Youden index, yielded sensitivity of 97.5% and specificity of 81.9%. The calibration curve showed excellent agreement between predicted and observed probabilities of SRAEs, which was confirmed in the Hosmer\u0026ndash;Lemeshow test (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.405). The nomogram predicted that SRAEs would occur in 86.5% of patients in the validation set and 88.4% in the training set, underscoring the vulnerability of elderly patients undergoing painless gastrointestinal endoscopy.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003e3.3 Clinical utility of the nomogram\u003c/h2\u003e\u003cp\u003eDecision curves indicated that the nomogram showed good clinical utility across a broad range of threshold probabilities, whether in the training set (13\u0026ndash;95%) or validation set (8\u0026ndash;97%) (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eIn this study, perioperative data from 520 elderly patients undergoing painless gastrointestinal endoscopy was used to develop a nomogram to predict SRAEs based on eight independent risk factors, which performed well in internal validation and showed clinical utility across a broad range of threshold probabilities. This model may help identify individuals at high risk of SRAEs and personalize perioperative procedures.\u003c/p\u003e\u003cp\u003eAnesthesia was induced and maintained in our sample using a 1:1 mixture of etomidate and propofol, which have complementary pharmacodynamic profiles: propofol allows rapid onset and recovery, while etomidate has more stable hemodynamic properties\u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e. Each of the drugs is associated with different types of adverse events that do not overlap: propofol increases risk of hypotension and respiratory depression\u003csup\u003e[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e, while etomidate increases risk of adrenal suppression and myoclonus\u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e. Therefore, combining the two drugs should not increase risk beyond monotherapy. Our results support the idea that their combination can ensure adequate sedation while keeping cardiovascular and respiratory risk low in elderly patients, at least for short-duration procedures such as painless endoscopy.\u003c/p\u003e\u003cp\u003eAt the same time, we detected a significant positive association between higher initial etomidate-propofol dose and incidence of hypotension, consistent with the known vasodilatory effect of propofol\u003csup\u003e[\u003cspan additionalcitationids=\"CR21\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e. This highlights the need for individualized anesthetic dosing, especially in older populations. Future work should explore how to optimize anesthesia protocols for elderly, such as by replacing propofol with remimazolam\u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e, and how to adjust the nomogram to predict SRAE risk accordingly.\u003c/p\u003e\u003cp\u003eThe independent predictors of SRAEs in our sample are consistent with age-related decline. As individuals grow older, arteriosclerosis reduces vascular elasticity and the autonomic regulatory system becomes weaker, increasing risk of intraoperative hypotension. Fraily is associated with lower physiological reserves across multiple systems, rendering patients more vulnerable to the hemodynamic stress of anesthesia induction\u003csup\u003e[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]\u003c/sup\u003e. For example, frailty may reduce oxygenation\u003csup\u003e[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e, increasing the risk of intraoperative hypoxemia. Indeed, hypotension and hypoxemia were more frequent among our frail patients than among younger ones, raising the possibility that conventional anesthesia protocols may fail to meet the perfusion and oxygenation demands of this population. Future research should explore this in detail.\u003c/p\u003e\u003cp\u003eLonger fasting time before endoscopy was associated with higher risk of SRAEs in our sample. Elderly may be more sensitive to fluid imbalance than younger individuals\u003csup\u003e[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]\u003c/sup\u003e, and the hypovolemia arising from extended fasting may exacerbate the already strong variations in blood pressure and heart rate that older patients experience during gastroscopy\u003csup\u003e[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/sup\u003e. It may be necessary to tailor fluid management strategies for elderly undergoing gastroscopy, which should be explored in future work.\u003c/p\u003e\u003cp\u003eHistory of snoring predicted intraoperative hypoxemia in our sample, consistent with the known association between such a history and risk of airway obstruction during anesthesia due to mandibular relaxation, posterior tongue displacement or upper airway collapse\u003csup\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]\u003c/sup\u003e. Chronic obstructive pulmonary disease also predicted intraoperative hypoxemia in our sample, probably reflecting that the compromised alveolar function, ventilation\u0026ndash;perfusion mismatch, chronic inflammation, and airway hyperresponsiveness of the disease can compromise oxygenation during anesthesia\u003csup\u003e[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eRegular physical activity protected against SRAEs in our sample. Moderate exercise is known to enhance cardiopulmonary function, improve oxygen uptake and use, delay age-related organ decline, and promote metabolic efficiency. Exercise-based interventions can improve postoperative outcomes and reduce risk of complications in elderly with gastrointestinal malignancies\u003csup\u003e[\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]\u003c/sup\u003e. Our study extends these findings to the context of sedation for painless endoscopy. Exercise and potentially other lifestyle factors may be important to consider when stratifying patients by SRAE risk and when planning their sedation before the procedure and their management afterwards.\u003c/p\u003e\u003cp\u003eOur study substantially extends the literature on SRAEs by focusing on elderly and defining a composite endpoint of either hypotension or hypoxemia, rather than only one SRAE\u003csup\u003e[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/sup\u003e. It considered factors related to lifestyle (e.g., physical activity, snoring), physiological status (frailty), and the perioperative experience (preoperative fasting time, initial dose of etomidate-propofol) when predicting SRAE risk. Our finding that fasting time before the procedure appeared in the final nomogram underscores the importance of proper preparation of elderly patients before the procedure. Our consideration of a broader range of potential predictors may help explain why the predictive ability of our nomogram (AUC 0.95\u0026ndash;0.96) was superior to that of other machine learning models such as XGBoost and random forest AUC 0.85\u0026ndash;0.89\u003csup\u003e[\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eAt the same time, our findings should be interpreted with caution in light of the relatively small sample from a single center. This may limit the generalizability of our results, and it prevented us from analyzing subgroups of patients stratified by clinically relevant variables. Our nomogram remains to be validated and extended through external validation studies, preferably with large, multicenter patient populations. Future work should also explore whether the nomogram can beintegrated into intelligent anesthesia management systems to enhance perioperative safety and personalize the care of elderly patients.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eHuman Ethics and Consent to Participate\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Institutional Ethics Committee of Wenjiang District People\u0026apos;s Hospital of Chengdu (approval number: EC-Research-2023-003). The study was conducted in accordance with the Declaration of Helsinki.Written informed consent was obtained from all participants prior to enrollment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eConsent to Publish\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eClinical Trial Registration\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis trial was prospectively registered in the Chinese Clinical Trial Registry (ChiCTR; registration number:ChiCTR2300069816; registration date: March 27, 2023; http://www.chictr.org.cn/)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAuthor contributions\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e Liu Xu contributed to the study design, protocol development, and manuscript writing. Qiyuan Yin and Hui Liu were responsible for patient recruitment, clinical data collection, and preliminary analysis. Qian Liu provided statistical support and guidance on data interpretation. Hongyan Zhang oversaw overall project coordination and timeline management and supervised the study\u0026rsquo;s overall direction, ensured research quality, and reviewed the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFunding\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was supported by the Health Commission of Sichuan Province Medical Science and Technology Program (24QNMP067), the Medical Research Subject of Chengdu Health Commission (2024083), and the Medical Research Project of Sichuan Medical Association (S2024086).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAdherence to CONSORT guidelines\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study adhered to the CONSORT (Consolidated Standards of Reporting Trials) guidelines for reporting clinical trials. A completed CONSORT checklist is provided as an additional file.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eConflicts of interest\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors confirm that there are no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAvailability of Data and Materials\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and analyzed during the current study are not publicly available due to patient privacy and hospital policy but are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eZHOU S, ZHU Z, DAI W, et al. National survey on sedation for gastrointestinal endoscopy in 2758 Chinese hospitals [J]. British journal of anaesthesia, 2021, 127(1): 56-64.\u003c/li\u003e\n\u003cli\u003eSNEYD J R, ABSALOM A R, BARENDS C R M, et al. Hypotension during propofol sedation for colonoscopy: a retrospective exploratory analysis and meta-analysis [J]. British journal of anaesthesia, 2022, 128(4): 610-22.\u003c/li\u003e\n\u003cli\u003eWANG L, ZHANG Y, HAN D, et al. Effect of high flow nasal cannula oxygenation on incidence of hypoxia during sedated gastrointestinal endoscopy in patients with obesity: multicentre randomised controlled trial [J]. BMJ (Clinical research ed), 2025, 388: e080795.\u003c/li\u003e\n\u003cli\u003eSHIMIZU H, HOMMA Y, NORII T. Incidence of adverse events among elderly vs non-elderly patients during procedural sedation and analgesia with propofol [J]. The American journal of emergency medicine, 2021, 44: 411-4.\u003c/li\u003e\n\u003cli\u003eQADEER M A, LOPEZ A R, DUMOT J A, et al. Hypoxemia during moderate sedation for gastrointestinal endoscopy: causes and associations [J]. Digestion, 2011, 84(1): 37-45.\u003c/li\u003e\n\u003cli\u003eGENG W, JIA D, WANG Y, et al. A prediction model for hypoxemia during routine sedation for gastrointestinal endoscopy [J]. Clinics (Sao Paulo, Brazil), 2018, 73: e513.\u003c/li\u003e\n\u003cli\u003eWANG Z, MA J, LIU X, et al. Development and validation of a predictive model for PACU hypotension in elderly patients undergoing sedated gastrointestinal endoscopy [J]. Aging clinical and experimental research, 2024, 36(1): 149.\u003c/li\u003e\n\u003cli\u003eSHELLEY B, SHAW M. Machine learning and preoperative risk prediction: the machines are coming [J]. British journal of anaesthesia, 2024, 133(5): 925-30.\u003c/li\u003e\n\u003cli\u003eWU J, ZHANG H, LI L, et al. A nomogram for predicting overall survival in patients with low-grade endometrial stromal sarcoma: A population-based analysis [J]. Cancer communications (London, England), 2020, 40(7): 301-12.\u003c/li\u003e\n\u003cli\u003eLEI M, FENG T, CHEN M, et al. Establishment and validation of an artificial intelligence web application for predicting postoperative in-hospital mortality in patients with hip fracture: a national cohort study of 52 707 cases [J]. International journal of surgery (London, England), 2024, 110(8): 4876-92.\u003c/li\u003e\n\u003cli\u003eLIU X, GAO Z, JIANG Y, et al. Comparison of Low-Frequency or High-Frequency Electrical Acupoint Stimulation on Hypotension After Spinal Anesthesia in Parturients: A Prospective Randomized Controlled Clinical Trial [J]. Journal of integrative and complementary medicine, 2024, 30(8): 770-5.\u003c/li\u003e\n\u003cli\u003eWANG S, SHENG T, YUAN G, et al. Bilevel positive airway pressure ventilation in patients susceptible to hypoxemia during procedural sedation for colonoscopy: a prospective randomized controlled study [J]. Gastrointestinal endoscopy, 2024, 99(6): 989-97.\u003c/li\u003e\n\u003cli\u003eDUAN Y, LU G. A Randomized Controlled Trial to Determine the Impact of Resistance Training versus Aerobic Training on the Management of FGF-21 and Related Physiological Variables in Obese Men with Type 2 Diabetes Mellitus [J]. Journal of sports science \u0026amp; medicine, 2024, 23(1): 495-503.\u003c/li\u003e\n\u003cli\u003e[Expert consensus on perioperative management of adult patients combined with obstructive sleep apnea (2025 edition)] [J]. Zhonghua yi xue za zhi, 2025, 105(14): 1045-54.\u003c/li\u003e\n\u003cli\u003eGELADARI E, ALEXOPOULOS T, VASILIEVA L, et al. Evaluation of Five Screening Tools in Detecting Physical Frailty in Cirrhosis and Their Prognostic Role [J]. J Clin Med, 2024, 13(17).\u003c/li\u003e\n\u003cli\u003eZHENG Z, SU Y, FAN X, et al. BIS feedback closed-loop target-controlled infusion of propofol or etomidate in elderly patients with spinal surgery [J]. American journal of translational research, 2023, 15(2): 1231-8.\u003c/li\u003e\n\u003cli\u003eGAN T J, BERTOCH T, HABIB A S, et al. Comparison of the Efficacy of HSK3486 and Propofol for Induction of General Anesthesia in Adults: A Multicenter, Randomized, Double-blind, Controlled, Phase 3 Noninferiority Trial [J]. Anesthesiology, 2024, 140(4): 690-700.\u003c/li\u003e\n\u003cli\u003eBARBOSA E C, ESP\u0026iacute;RITO SANTO P A, BARALDO S, et al. Remimazolam versus propofol for sedation in gastrointestinal endoscopic procedures: a systematic review and meta-analysis [J]. British journal of anaesthesia, 2024, 132(6): 1219-29.\u003c/li\u003e\n\u003cli\u003eLU Z, ZHENG H, CHEN Z, et al. Effect of Etomidate vs Propofol for Total Intravenous Anesthesia on Major Postoperative Complications in Older Patients: A Randomized Clinical Trial [J]. JAMA surgery, 2022, 157(10): 888-95.\u003c/li\u003e\n\u003cli\u003eQIAO L, WANG Z, SHEN J, et al. Impact of Dexmedetomidine on Hemodynamics, Plasma Catecholamine Levels, and Delirium Incidence Among Intubated Patients in the ICU--A Randomized Controlled Trial [J]. Therapeutics and clinical risk management, 2024, 20: 689-700.\u003c/li\u003e\n\u003cli\u003eYAMAMOTO K. Current issues in frailty and hypertension management [J]. Hypertension research : official journal of the Japanese Society of Hypertension, 2023, 46(8): 1917-22.\u003c/li\u003e\n\u003cli\u003eMART\u0026iacute;NEZ-GONZ\u0026aacute;LEZ \u0026Oacute;, ALONSO-FERN\u0026aacute;NDEZ M, GARC\u0026iacute;A-ALONSO M, et al. Deep sedation for gastrointestinal endoscopy in elderly patients. Subgroup analysis [J]. Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver, 2025, 57(6): 1266-72.\u003c/li\u003e\n\u003cli\u003eLEE J H, LEE J, PARK S H, et al. Comparison between remimazolam and propofol anaesthesia for interventional neuroradiology: a randomised controlled trial [J]. Anaesthesia, critical care \u0026amp; pain medicine, 2024, 43(2): 101337.\u003c/li\u003e\n\u003cli\u003eDAUM N, HOFF L, SPIES C, et al. Influence of frailty status on the incidence of intraoperative hypotensive events in elective surgery: Hypo-Frail, a single-centre retrospective cohort study [J]. British journal of anaesthesia, 2025.\u003c/li\u003e\n\u003cli\u003eSCHNETZ M, ZAKARIA L, AHUJA S, et al. Frailty and intraoperative hypotension: is the risk significant and modifiable? [J]. British journal of anaesthesia, 2025.\u003c/li\u003e\n\u003cli\u003eVERDURI A, CLINI E, CARTER B, et al. Influence of frailty on cardiovascular events and mortality in patients with Chronic Obstructive Pulmonary Disease (COPD): Study protocol for a multicentre European observational study [J]. PloS one, 2024, 19(6): e0300945.\u003c/li\u003e\n\u003cli\u003eMLADINOV D, ISAZA E, GOSLING A F, et al. Perioperative Fluid Management [J]. Clinics in geriatric medicine, 2025, 41(1): 83-99.\u003c/li\u003e\n\u003cli\u003eDENG R, WU J, XU K, et al. The impact of early gastroscopy examination on cardiovascular event-related indices in elderly patients with acute upper gastrointestinal bleeding [J]. Medicine, 2024, 103(13): e37378.\u003c/li\u003e\n\u003cli\u003eSEET E, WASEEM R, CHAN M T V, et al. Characteristics of Patients with Unrecognized Sleep Apnea Requiring Postoperative Oxygen Therapy [J]. Journal of personalized medicine, 2022, 12(10).\u003c/li\u003e\n\u003cli\u003eKANDASAMY G, ALMELEEBIA T. A Prospective Study on Obstructive Sleep Apnea, Clinical Profile and Polysomnographic Variables [J]. Journal of personalized medicine, 2023, 13(6).\u003c/li\u003e\n\u003cli\u003eOWENS R L, DEROM E, AMBROSINO N. Supplemental oxygen and noninvasive ventilation [J]. European respiratory review : an official journal of the European Respiratory Society, 2023, 32(167).\u003c/li\u003e\n\u003cli\u003eHAMAD A, ZHANG H, ZHANG Y, et al. Understanding the mechanism behind preoperative exercise therapy in patients with gastrointestinal cancers: a prospective randomized clinical trial [J]. BMC sports science, medicine \u0026amp; rehabilitation, 2025, 17(1): 50.\u003c/li\u003e\n\u003cli\u003eZHENG L, WU X, GU W, et al. Development and validation of a hypoxemia prediction model in middle-aged and elderly outpatients undergoing painless gastroscopy [J]. Scientific reports, 2025, 15(1): 17965.\u003c/li\u003e\n\u003cli\u003eCHEN M, ZHANG D. Machine learning-based prediction of post-induction hypotension: identifying risk factors and enhancing anesthesia management [J]. BMC medical informatics and decision making, 2025, 25(1): 96.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Sedation, Gastrointestinal endoscopy, Elderly patients, Hypotension, Hypoxemia","lastPublishedDoi":"10.21203/rs.3.rs-7472714/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7472714/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eElderly patients undergoing painless gastrointestinal endoscopy are at increased risk for sedation-related adverse events (SRAEs) because of their greater physiological vulnerability and higher likelihood of comorbidities. Risk stratification before endoscopy may improve perioperative safety and individualize sedation and management.\u003c/p\u003e\u003ch2\u003eObjective\u003c/h2\u003e\u003cp\u003eThis study aimed to develop and validate a model based on machine learning to predict risk of SRAEs in elderly undergoing painless gastrointestinal endoscopy.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eProspective data from 520 patients at least 60 years old who underwent painless gastrointestinal endoscopy between April 2023 and June 2024 at our medical center were randomly divided into a training set (n\u0026thinsp;=\u0026thinsp;364) and validation set (n\u0026thinsp;=\u0026thinsp;156). SRAEs were defined as intraoperative hypotension or hypoxemia, and independent predictors of SRAEs in the training set were identified through multivariate logistic regression. A nomogram to predict risk of SRAEs was developed using R software and tested against the validation set. Its performance was assessed in terms of receiver operating characteristic curves, calibration plots, and decision curve analysis.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eIn the training set, hypotension occurred in 39.0% patients and hypoxemia in 33.5%, and independent predictors were older age, history of snoring, frailty, preexisting hypertension, chronic obstructive pulmonary disease, prolonged fasting before the procedure, and higher initial dose of etomidate-propofol. Conversely, regular physical activity was a protective factor. The nomogram built from the training set discriminated between people in the validation set who experienced SRAEs or not with an area under the curve of 0.95 (95%CI 0.92\u0026ndash;0.99), it showed good calibration in the Hosmer\u0026ndash;Lemeshow test (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.405), and decision curve analysis demonstrated clinical utility across a wide range of threshold probabilities.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eA predictive model based on readily available clinical variables can accurately estimate SRAE risk in elderly patients undergoing painless gastrointestinal endoscopy. The model may be useful for individualizing sedation and patient management.\u003c/p\u003e\u003ch2\u003eTrial registration\u003c/h2\u003e\u003cp\u003eChinese Clinical Trial Registry ChiCTR2300069816. Registered on 23 March 2023.\u003c/p\u003e","manuscriptTitle":"A nomogram for predicting sedation-related adverse events in elderly patients undergoing painless gastrointestinal endoscopy","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-17 12:22:16","doi":"10.21203/rs.3.rs-7472714/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"2c7b77c6-6381-4c75-a185-b6a061084690","owner":[],"postedDate":"October 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-10-22T07:53:38+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-17 12:22:16","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7472714","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7472714","identity":"rs-7472714","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}