Risk Factors For Prolonged Ventilation Research Articles

Factors associated with mechanical ventilation longer than 24 h after liver transplantation in patients at risk for bleeding

BackgroundThis risk analysis aimed to explore all modifiable factors associated with prolonged mechanical ventilation (lasting > 24 h) after liver transplantation, based on prospectively collected data from a clinical trial.MethodsWe evaluated 306 candidates. Ninety-three patients were excluded for low risk for transfusion (preoperative haemoglobin > 130 g.l−1), and 31 patients were excluded for anticoagulation therapy, bleeding disorders, familial polyneuropathy, or emergency status. Risk factors were initially identified with a log-binomial regression model. Relative risk was then calculated and adjusted for age, sex, and disease severity (Model for End-Stage Liver Disease [MELD] score).ResultsEarly tracheal extubation was performed in 149 patients (84.7%), and 27 patients (15.3%) required prolonged mechanical ventilation. Reoperations were required for 6.04% of the early extubated patients and 44% of patients who underwent prolonged ventilation (p = 0.001). A MELD score > 23 was the main risk factor for prolonged ventilation. Once modifiable risk factors were adjusted for MELD score, sex, and age, three factors were significantly associated with prolonged ventilation: tranexamic acid (p = 0.007) and red blood cell (p = 0.001) infusion and the occurrence of postreperfusion syndrome (p = 0.004). The median (IQR) ICU stay was 3 (2–4) days in the early extubation group vs. 5 (3–10) days in the prolonged ventilation group (p = 0.001). The median hospital stay was also significantly shorter after early extubation, at 14 (10–24) days, vs. 25 (14–55) days in the prolonged ventilation group (p = 0.001). Eight patients in the early-extubation group (5.52%) were readmitted to the ICU, nearly all for reoperations, with no between-group differences in ICU readmissions (prolonged ventilation group, 3.7%). Conclusion.We conclude that bleeding and postreperfusion syndrome are the main modifiable factors associated with prolonged mechanical ventilation and length of ICU stay, suggesting that trials should explore vasopressor support strategies and other interventions prior to graft reperfusion that might prevent potential fibrinolysis.Trial Registration.European Clinical Trials Database (EudraCT 2018–002510-13,) and on ClinicalTrials.gov (NCT01539057).

Predictors of major adverse events and complications after ventricular septal defects surgical closure in children less than 10 kg

BackgroundVentricular septal defect (VSD) is the most common congenital cardiac defect for which outcomes are not uniform. There is a lack of consensus on the risk factors for the unfavorable outcomes following surgical VSD closure.AimThe aim of this study was to determine the risk factors and the predictors of major adverse events (MAEs) and complications following surgical closure of VSD in children weighing less than 10 kg.MethodsThis retrospective cohort study included children less than 10 kg who underwent surgical closure of congenital VSD of any type with or without associated congenital heart diseases. Patients with associated major cardiac anomalies were excluded. Preoperative, operative and postoperative data were collected from medical records.ResultsThis study included 127 patients 52.8% were males, the median age was 8.0 months (IQR = 6.0–11.0 months), and their median weight was 5.7 kg (IQR = 4.8–7.0). Mortality was in one patient (0.8%) Multivariable logistic regression analysis revealed that male sex group (observational data), previous pulmonary artery banding (PAB), and significant intraoperative residual VSD were significant risk factors for the development of MAEs (odds ratios were 3.398, 14.282, and 8.634, respectively). Trisomy 21 syndrome (odds ratio: 5.678) contributed significantly to prolonged ventilation. Pulmonary artery banding (odds ratio: 14.415), significant intraoperative (3 mm) residual VSD (odds ratio: 11.262), and long cross-clamp time (odds ratio: 1.064) were significant predictors of prolonged ICU stay, whereas prolonged hospital stay was observed significantly in male sex group (odds ratio: 12.8281), PAB (odds ratio: 2.669), and significant intraoperative (3 mm) residual VSD (odds ratio: 19.551).ConclusionsSurgical VSD repair is considered a safe procedure with very low mortality. Trisomy 21 was a significant risk factor for prolonged ventilation. Further, PAB, significant intraoperative residual of 3 mm or more that required a second pulmonary bypass, and a greater cross-clamp time were significant predictors of MAE and associated complications with prolonged ICU and hospital stay.

Risk factors of prolonged ventilation after thymectomy in thymoma myasthenia gravis patients

BackgroundTo explore the risk factors for prolonged ventilation after thymectomy in patients with thymoma associated with myasthenia gravis (TAMG).MethodsWe reviewed the records of 112 patients with TAMG after thymectomy between January 2010 and December 2019 in Peking University People’s Hospital. Demographic, pathological, preoperative data and the Anesthesia, surgery details were assessed with multivariable logistic regression analysis to predict the risk of prolonged ventilation after thymectomy. A nomogram to predict the probability of post-thymectomy ventilation was constructed with R software. Discrimination and calibration were employed to evaluate the performance of the nomogram.ResultsBy multivariate analysis, male, low vital capacity (VC), Osserman classification (IIb, III, IV), total intravenous anesthesia, and long operation time were identified as the risk factors and entered into the nomogram. The nomogram showed a robust discrimination, with an area under the receiver operating characteristic curve (AUC) of 0. 835 (95% confidence interval [CI], 0.757–0.913). The calibration plot indicated that the nomogram-predicted probabilities compared very well with the actual probabilities (Hosmer–Lemeshow test: P = 0.921).ConclusionThe nomogram is a valuable predictive tool for prolonged ventilation after thymectomy in patients with TAMG.

Risk factors for prolonged ventilation after the modified Fontan procedure.

To investigate the risk factors associated with prolonged ventilation after Fontan surgery. Retrospective case series. Tertiary childrens hospital. We included 123 children who underwent Fontan surgery without delayed sternal closure or extracorporeal membrane oxygenation between 2011 and 2017. Fontan surgery. Prolonged ventilation was defined as intubation for more than 24 hours after surgery. Preoperative, intraoperative, and perioperative data were collected retrospectively from medical records. Multivariate logistic regression analysis was used to identify risk factors for prolonged ventilation. The median age and weight of patients were 2.2 years and 10.0 kg, respectively. Seventeen per cent of the patients (n = 21) received prolonged mechanical ventilation, and the median intubation period was 2.9 days. There were no 90-day or in-hospital deaths. The independent predictors of prolonged ventilation identified were fenestration (p < 0.01), low pulmonary artery index (p = 0.02), and advanced atrioventricular regurgitation (p < 0.01). The duration of ICU stay was significantly longer in the prolonged ventilation group than in the early extubation group (10 days versus 6 days, p < 0.01). Fenestration, low pulmonary artery index, and significant atrioventricular regurgitation are risk factors for prolonged ventilation after Fontan surgery. Careful preoperative and perioperative management that considers the risk factors for prolonged ventilation in each individual is important.

Impact of body mass index on early and mid-term outcomes after surgery for acute Stanford type A aortic dissection

BackgroundObesity is dramatically increasing worldwide, and more obese patients may develop aortic dissection and present for surgical repair. The study aims to analyse the impact of body mass index (BMI) on surgical outcomes in patients with acute Stanford type A aortic dissection (ATAAD).MethodsFrom January 2017 to June 2019, the clinical data of 268 ATAAD patients in a single centre were retrospectively reviewed. They were divided into three groups based on the BMI: normal weight (BMI 18.5 to < 25 kg/m2, n = 110), overweight (BMI 25 to < 30 kg/m2, n = 114) and obese (BMI ≥30 kg/m2, n = 44).ResultsThere was no statistical difference among the three groups in terms of the composite adverse events including 30-day mortality, stroke, paraplegia, renal failure, hepatic failure, reintubation or tracheotomy and low cardiac output syndrome (20.9% vs 21.9% vs 18.2% for normal, overweight and obese, respectively; P = 0.882). No significant difference was found in the mid-term survival among the three groups. The proportion of prolonged ventilation was highest in the obese group followed by the overweight and normal groups (59.1% vs 45.6% vs 34.5%, respectively; P = 0.017). Multivariable logistic regression analysis suggested that BMI was not associated with the composite adverse events, while BMI ≥30 kg/m2 was an independent risk factor for prolonged ventilation (OR 2.261; 95% CI 1.056–4.838; P = 0.036).ConclusionsBMI had no effect on the early major adverse outcomes and mid-term survival after surgery for ATAAD. Satisfactory surgical outcomes can be obtained in patients with ATAAD at all weights.

Impact of a Higher Body Mass Index on Prolonged Intubation in Patients Undergoing Surgery for Acute Thoracic Aortic Dissection

In recent years, obese patients presenting with acute thoracic aortic dissection have not been uncommon and there are often pulmonary complications among them. Whether a higher body mass index (BMI) is associated with more pulmonary complications or even a higher mortality rate has yet to be determined. This study aimed to evaluate the effects of higher BMI on pulmonary complications and other surgical outcomes. A total of 404 patients who underwent acute thoracic aortic dissection surgery were retrospectively studied. They were divided into three groups based on their BMI: normal weight (BMI 18.5 to <25 kg/m2, n=173), overweight (BMI 25 to <30 kg/m2, n=145) and obese (BMI ≥30 kg/m2, n=86). Clinical data were collected and analysed among groups. No statistical significance was detected among the groups for postoperative complications, in-hospital mortality and hospital or ICU stay, except for prolonged intubation, the proportion of which was highest in the obese group followed by the overweight and normal groups (40.7% vs 29% vs 11%, respectively; p<0.001). Furthermore, logistic regression analysis showed that postoperative renal failure (OR=16.984) and cardiopulmonary bypass time (OR=1.013) were independent risk factors for in-hospital mortality, while higher BMI (OR=7.148 for BMI ≥25 and 18.967 for BMI ≥30), transfused red blood cells (OR=1.004), and postoperative renal failure (OR=7.386) were independent risk factors for prolonged ventilation (p<0.05). Body mass index had no effect on in-hospital mortality but may be closely correlated with prolonged intubation for patients undergoing aortic dissection surgery. This finding suggests that these patients should receive more aggressive pulmonary management.

Nakata index above 1500 mm2/m2 predicts death in absent pulmonary valve syndrome.

Absent pulmonary valve syndrome is a rare congenital heart disease with severe airway compression due to dilatation of the pulmonary arteries (PAs). We investigated risk factors for death and prolonged mechanical ventilation (>7 days) and a threshold PA size for these outcomes. This retrospective 2-centre cohort study included 68 patients with complete repair between January 1996 and December 2015. Median age at repair was 3.9 months (1.3-8.7 months), and median weight was 5 kg (4-7 kg). The mortality rate before hospital discharge was 12%, and the mortality rate at last follow-up was 19%. In multivariable analysis, risk factors for death were higher Nakata index [hazard ratio (HR) 1.001, 95% confidence interval (CI) 1.001-1.002; P < 0.001] and lower SpO2 (HR 1.06, 95% CI 1.02-1.09; P = 0.002). The accuracy of the Nakata index to predict death was excellent (area under the curve at 6 months: 0.92; P = 0.010). A Nakata index above 1500 mm2/m2 predicted mortality at 6 months with a sensitivity of 98% and a specificity of 82%. Twenty-five patients (37%) had prolonged mechanical ventilation. The only multivariable risk factor for prolonged ventilation was lower weight at repair (odds ratio 2.9, 95% CI 1.3-6.7; P = 0.008). Neither PA plasty nor the LeCompte manoeuvre had a protective effect on mortality or prolonged ventilation. A Nakata index above 1500 mm2/m2 remained a risk factor for mortality (P = 0.022) in patients who had a PA plasty or the LeCompte manoeuvre. In patients with absent pulmonary valve syndrome, the Nakata index predicts mortality with a cut-off of 1500 mm2/m2. Lower weight at repair is the only multivariable risk factor for prolonged ventilation. Neither PA plasty nor the LeCompte manoeuvre had a protective effect on these outcomes.

Factors associated with prolonged ventilation and reintubation in adult spinal deformity surgery

Prolonged ventilation or reintubation are severe complications after scoliosis surgery, but there is limited data regarding their incidence and risk factors. The purpose of this study is to investigate the incidence and risk factors for prolonged ventilation and reintubation in adult spinal deformity (ASD) surgery. The American College of Surgeons National Surgical Quality Improvement Program database (2007–2013) was reviewed. Inclusion criteria were adult patients over 21years of age who underwent spinal fusion for ASD. The association between patient/operative characteristics and prolonged ventilation/reintubation was investigated via multivariate analysis. Results are presented as odds ratios (OR) with 95% confidence intervals (CI). There were 1250 patients who underwent ASD surgery and met our inclusion criteria. Among these, there were 34 patients who required prolonged ventilation (2.7%) and 22 patients who underwent reintubation (1.8%). Factors associated with prolonged ventilation after multivariate analysis were history of bleeding disorder (OR 5.67; 95% CI, 1.01–31.83) and operative time over 6h (OR 3.72; 95% CI, 1.17–11.80). For reintubation, these included older age (OR 1.06; 95% CI, 1.01–1.12), history of bleeding disorder (OR 12.21; 95% CI, 2.03–73.42), and fusion of 13 or more spinal levels (OR 9.14; 95% CI, 1.53–54.63). In conclusion, prolonged ventilation and reintubation in ASD surgery are uncommon events. Older patients, patients with bleeding disorders, and those undergoing long operations and fusion of 13 more spinal segments may be at an increased risk for these occurrences.

A protocol-driven approach to early extubation after heart surgery

We assessed the effectiveness of standardized protocols in decreasing postoperative mechanical ventilation time to <6 hours. In 2061 patients undergoing coronary bypass, the proportion extubated in <6 hours was calculated for 3 sequential time periods. During period 1 patients were weaned per baseline practices; during period 2, per a protocol developed by a multidisciplinary committee; and during period 3, as in period 2 but with paralytic reversal and extubation performed at lower body temperatures and an extubation reminder sheet prominently displayed. We used a χ(2) test to examine differences in ventilation times among the 3 time periods and logistic regression modeling to control for independent risk factors for prolonged ventilation. As measures of patient safety, we examined rates of reintubation and rates of patient shivering following paralytic reversal. Twelve percent of patients were extubated in <6 hours during period 1, 24% during period 2 (P<.01), and 38% during period 3 (P<.01 compared with both periods 1 and 2). After controlling for 12 risk factors, patients were more likely to be extubated in <6 hours during period 2 (odds ratio, 2.39; 95% confidence interval, 1.84-3.10) and period 3 (odds ratio, 5.05; 95% confidence interval, 3.65-6.99) than during period 1. There was no difference in reintubation rates across periods, and the rate of patient shivering did not increase with paralytic reversal at lower body temperature. The standardized protocols outlined in this article dramatically improved early extubation performance.

A local risk prediction model for prolonged ventilation after adult heart valve surgery in a Chinese single center

Background and Aim of the StudyThe aim of this study was to develop a logistic risk prediction model for prolonged ventilation after adult heart valve surgery. Materials and MethodsThis is a retrospective observational study of collected data on 3965 consecutive patients older than 18 years, who had undergone heart valve surgery between January 2000 and December 2010. Data were randomly split into a development dataset (n = 2400) and a validation dataset (n = 1565). A multivariate logistic regression analysis was undertaken using the development dataset to identify independent risk factors for prolonged ventilation (defined as ventilation greater than 72 h). Performance of the model was then assessed by observed and expected rates of prolonged ventilation on the development and validation dataset. Model calibration and discriminatory ability were analyzed by the Hosmer–Lemeshow goodness-of-fit statistic and the area under the receiver operating characteristic (ROC) curve, respectively. ResultsThere were 303 patients that required prolonged ventilation (7.6%). Preoperative independent predictors of prolonged ventilation are shown with odds ratio and P value as follows: (1) age, 1.9, P < .0001; (2) hypercholesterolemia, 5.3, P = .001; (3) renal failure, 18.2, P = .004; (4) previous cardiac surgery, 2.4, P = .0002; (5) left bundle branch block, 4.2, P = .011; (6) ejection fraction, 1.4, P = .003; (7) left ventricle weight, 1.5, P = .007; (8) New York Heart Association class III-IV, 1.8, P = .021; (9) critical preoperative state, 4.5, P < .0001; (10) tricuspid insufficiency, 1.2, P = .031; (11) concurrent CABG, 2.2, P = .019; and (12) concurrent other cardiac surgery, 2.1, P = .001. The Hosmer–Lemeshow goodness-of-fit statistic was not statistically significant in both development and validation dataset (P = .202 vs P = .291). The ROC curve for the prediction of prolonged ventilation in development and validation dataset was .789 and .710, respectively. ConclusionsWe developed and validated a local risk prediction model for prolonged ventilation after adult heart valve surgery. This model can be used to calculate patient-specific risk by the logistic equation with an equivalent predicted risk at our center in future clinical practice.

Risk factors of prolonged mechanical ventilation following open heart surgery: what has changed over the last decade?

To identify the risk factors for prolonged invasive mechanical ventilation after open heart surgery in Pakistan. This study is based on retrospective analysis of database. We conducted study of all patients who underwent open heart surgery at CPE Institute of Cardiology, Multan from March 2009 to May 2011. The data was retrieved from the database in the form of electronic spreadsheet which was then analyzed using SPSS software. The patients with incomplete data entries were removed from the analysis resulting in a set of 1,617 patients. The data of each patient consisted of 65 preoperative, operative and postoperative variables. The data was summarized as means, medians and standard deviations for numeric variables and frequencies and percentages or categoric variables. These risk factors were compared using Chi-sqaure test. Their ODDs ratios and 95% confidence intervals of ODD's Ratios and P values were calculated. Out of a total of 1,617 patients, 77 patients (4.76%) had prolonged ventilation for a cumulated duration of more than over 24 hours. Preoperative renal failure, emphysema, low EF (<30%), urgent operation, preoperative critical state, prolonged bypass time, prolonged cross clamp time, complex surgical procedures and peri-operative myocardial infarction were found to be risk factors for PIMV. Old age, female gender, advanced ASA class, advanced NYHA class, diabetes mellitus, smoking, history of COPD, redo surgery, left main stenosis, obesity and use of intra-aortic balloon pump were not found to have significant ODDs ratios for PIMV. The patients with prolonged ventilation had significantly high mortality i.e. 32.47% while the normal ventilation group had 0.32% overall mortality. Many of the previously considered risk factors for prolonged ventilation after open heart study are no more significant risk factors. However, prolonged ventilation continues to be associated with very high mortality.

Logistic Risk Model for Prolonged Ventilation After Adult Cardiac Surgery

The aim of this study was to develop a multivariate risk prediction model for prolonged ventilation after adult cardiac surgery. This is a retrospective analysis of prospectively collected data on 12,662 consecutive patients undergoing adult cardiac surgery between April 1997 and March 2005. Data were randomly split into a development dataset (n = 6,000) and a validation dataset (n = 6,662). A multivariate logistic regression analysis was undertaken using a forward stepwise technique to identify independent risk factors for prolonged ventilation (defined as ventilation greater than 48 hours). The area under the receiver operating characteristic (ROC) curve and the Hosmer-Lemeshow goodness-of-fit statistic were calculated to assess the performance and calibration of the model, respectively. Patients were split into low-, medium-, and high-risk groups based on their predicted probability of prolonged ventilation. Three hundred thirty-three patients had prolonged ventilation (5.5%). Independent variables, identified with prolonged ventilation, are shown with relevant coefficient values and p values as follows: (1) age 65 to 75 years, 0.7831, p < 0.001; (2) age 75 to 80 years, 1.5605, p < 0.001; (3) age greater than 80 years, 1.7115, p < 0.001; (4) forced expiratory volume less than 70% predicted, 0.3707, p = 0.013; (5) current smoker, 0.5315, p = 0.001; (6) serum creatinine 125 to 175 micromol/L, 0.6371, p < 0.001; (7) serum creatinine greater than 175 micromol/L, 1.3817, p < 0.001; (8) peripheral vascular disease, 0.6212, p < 0.001; (9) ejection fraction less than 0.30, 0.7839, p < 0.001; (10) myocardial infraction less than 90 days, 0.7415, p < 0.001; (11) preoperative ventilation, 1.3540, p = 0.004; (12) prior cardiac surgery, 0.8946, p < 0.001; (13) urgent surgery, 0.4414, p = 0.004; (14) emergency surgery, 0.7421, p = 0.005; (15) mitral valve surgery, 0.7715, p < 0.001; (16) aortic surgery, 1.7043, p < 0.001; and (17) use of cardiopulmonary bypass, 0.4052, p = 0.025; intercept, -4.7666. The ROC curve for the predicted probability of prolonged ventilation was 0.79, indicating a good discrimination power. The prediction equation was well-calibrated, predicting well at all levels of risk. A simplified additive scoring system was also developed. In the validation dataset, 5.1% of patients had prolonged ventilation compared with 5.4% expected. The ROC curve for the validation dataset was 0.75. We developed a contemporaneous multivariate prediction model for prolonged ventilation after cardiac surgery. This tool can be used in day-to-day practice to calculate patient-specific risk by the logistic equation or a simple scoring system with an equivalent predicted risk.

Risk factors prolonging ventilation in young children after cardiac surgery: Impact of noninfectious pulmonary complications.

OBJECTIVE: To determine risk factors for prolonged ventilation after cardiac surgery in young children and assess the impact of noninfectious pulmonary complications on ventilatory duration. DESIGN: Retrospective case series analysis. SETTING: A tertiary pediatric cardiac center. PATIENTS: Clinical records of 222 consecutive children aged </=3 yrs undergoing cardiac surgery for congenital heart disease were reviewed. Fifteen patients, consisting of six premature babies and nine who died within 72 hrs of surgery, were excluded. MEASUREMENTS AND MAIN RESULTS: The demographic data, preoperative risk factors, surgical procedures performed, intraoperative variables, and postoperative complications of the remaining 207 children were reviewed. Univariate analysis was performed to compare patients who required prolonged ventilation (>72 hrs) to those who could be extubated at </=72 hrs, and multivariate analyses were performed to identify significant determinants on ventilatory duration and impact of noninfectious complications. Of the 182 patients undergoing open heart surgery, 45 (25%) required prolonged ventilation for a median of 8 days. The latter were significantly younger in age and lighter in weight and were more likely to have Down syndrome, preoperative pulmonary hypertension and ventilatory support, undergone more complex surgery requiring longer bypass and circulatory arrest time, postoperative cardiovascular and pulmonary complications, and extubation failure (all p values <.01). Of the 25 patients who had closed heart surgery, five (20%) required prolonged ventilation for a median of 14 days. The latter were more likely to require preoperative ventilation, have undergone more complex surgery, had postoperative cardiovascular and pulmonary complications, and had extubation failure (all p values <.05). Cox proportional hazard regression identified body weight (p <.001), Down syndrome (p =.02), need for preoperative ventilation (p <.001), complexity of surgery (p <.001), cardiovascular complications (p <.001), and infective (p <.001) and noninfective (p <.001) pulmonary complications to be significant factors that determined the ventilatory duration. Noninfectious pulmonary complications occurred in 31.9% (58/182) and 20% (5/25) of patients after open and closed heart surgery, respectively. In the absence of other risk factors, the median time to extubation was similar between patients with and without noninfectious complications (1 vs. 0.8 day). However, in the presence of other risk factors, noninfectious pulmonary complications prolonged the median time to extubation from 8 to 18 days. Logistic regression identified Down syndrome (p =.005), preoperative ventilation (p =.001), complexity of surgery (p =.006), and bypass time (p =.005) as risk factors for development of noninfectious pulmonary complications. CONCLUSIONS: Noninfectious pulmonary complications that occurred commonly after cardiac surgery in young children prolong ventilatory duration only in the presence of other risk factors, with which it acts in a synergistic fashion.