Perioperative Factors Associated with Prolonged Mechanical Ventilation after Major Thoracic and Abdominal Oncosurgeries: A Retrospective Cohort Study

Background and Aims: Major thoracic and abdominal oncologic surgeries are associated with substantial physiological stress and a high risk of postoperative complications. Patients undergoing these procedures frequently require postoperative intensive care and mechanical ventilation. Prolonged postoperative mechanical ventilation (PMV) is associated with increased morbidity, longer intensive care unit (ICU) stay and greater healthcare resource utilisation. This study aimed to determine the incidence of PMV and evaluate perioperative factors associated with delayed extubation following major oncologic surgery. Methods: This retrospective cohort study was conducted at a tertiary cancer centre in North India. Adult patients undergoing major thoracic or abdominal oncologic surgery under general anaesthesia who were transferred postoperatively to the ICU while mechanically ventilated were included. PMV was defined as mechanical ventilation for more than 24 h after ICU admission. Perioperative variables were extracted from anaesthesia and ICU records. Bivariate analyses were performed to identify factors associated with PMV, and clinically relevant variables were entered into a multivariable logistic regression model. Model discrimination was assessed using receiver operating characteristic analysis. Results: Eighty-five patients were included, of whom 12 (14.1%) required PMV. Higher American Society of Anesthesiologists physical status, longer duration of surgery, intraoperative vasopressor use, higher driving pressure and elevated arterial lactate levels were associated with prolonged ventilation on bivariate analysis. In multivariable analysis, intraoperative vasopressor use demonstrated the strongest association with PMV (adjusted odds ratios 12.7; 95% confidence interval 1.25–128.6; P = 0.031). The model showed moderate discrimination (area under the curve 0.692). Patients with PMV had longer ICU stays (median: 4.5 vs. 2.0 days; P = 0.002) and hospital stays (median: 15 vs. 9 days; P = 0.021), and higher rates of pulmonary complications (75.0% vs. 13.7%; P = 0.041) and major postoperative complications (Clavien–Dindo ≥ IIIa: 50.0% vs. 8.2%; P = 0.039). Conclusions: PMV occurred in approximately one in seven patients undergoing major thoracic and abdominal oncologic surgery requiring postoperative ICU admission. Intraoperative vasopressor use was independently associated with prolonged ventilation and may reflect perioperative physiological stress. Recognition of patients at risk may assist in perioperative risk stratification and postoperative monitoring.