Postoperative Pulmonary Complications Following Craniotomy: A 5-Year ACS-NSQIP Analysis of Risk Factors for Pneumonia, Unplanned Intubation, and Prolonged Ventilation

Background: Postoperative pulmonary complications remain a significant source of morbidity following craniotomy. We sought to identify independent predictors of postoperative pneumonia, unplanned intubation, and failure to wean from mechanical ventilation using fully adjusted multivariable regression models. Methods: Adult patients undergoing craniotomy between 2018 and 2022 were identified from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Multivariable logistic regression models were constructed for 3 outcomes: postoperative pneumonia, unplanned intubation, and prolonged mechanical ventilation (>48 h). All clinically relevant covariates were retained in final models regardless of univariate significance. Adjusted odds ratios (ORs) with 95% CIs were calculated. Model discrimination was assessed using the area under the receiver operating characteristic curves (AUC). Results: A total of 24,232 patients were included. Increasing age (OR: 1.025/y, P <0.001), smoking (OR: 1.42, P =0.002), chronic obstructive pulmonary disease (OR: 1.80, P <0.001), congestive heart failure (OR: 2.86, P <0.001), steroid use (OR: 1.50, P <0.001), prolonged operative time (OR: 1.002/min, P <0.001), and higher ASA classification were independently associated with postoperative pneumonia (AUC: 0.706). Unplanned intubation was independently associated with operative duration (OR: 1.002/min, P <0.001), ASA class, functional dependence, smoking (OR: 1.31, P =0.028), and congestive heart failure (OR: 2.02, P =0.023) (AUC 0.666). Failure to wean was strongly associated with higher ASA class (ASA IV versus II—OR: 4.13; ASA V versus II—OR: 31.01; P <0.001), functional dependence (OR: 2.61, P <0.001), congestive heart failure (OR: 2.92, P <0.001), operative time (OR: 1.004/min, P <0.001), and general anesthesia (OR: 2.31, P =0.005) (AUC 0.707). Conclusions: Postoperative pulmonary complications following craniotomy are strongly associated with systemic physiological reserve, comorbidity burden, and operative duration. ASA classification demonstrates a graded and clinically meaningful relationship with respiratory morbidity. Preoperative risk stratification and targeted perioperative optimization may reduce pulmonary complications in high-risk cranial surgery patients.