Impact of General Anesthesia on Post Operative Respiratory Complications in Obese Patients Undergoing Intra-Abdominal Surgeries

Abstract

Background: Obesity predisposes surgical patients to postoperative pulmonary complications (PPCs) through impaired respiratory mechanics, reduced functional residual capacity, and anesthesia-related atelectasis, with risk potentially amplified during intra-abdominal surgery under general anesthesia. Objective: To determine the incidence of early PPCs and identify associated risk factors in obese adults undergoing elective intra-abdominal surgery under general anesthesia. Methods: A cross-sectional observational study was conducted from January to June 2025 among adults (≥18 years) with BMI ≥30 kg/m² scheduled for elective intra-abdominal surgery under general anesthesia. Consecutively recruited participants were followed in the post-anesthesia care unit and for 48 hours postoperatively. PPCs (hypoxemia, atelectasis, bronchospasm, pneumonia, or reintubation) were recorded using standardized clinical documentation. Associations were evaluated using chi-square testing and multivariable logistic regression (SPSS v27). Results: Among 200 patients, 45 developed PPCs (22.5%). Hypoxemia was most frequent (12.5%), followed by atelectasis (7.5%), pneumonia (3.0%), bronchospasm (2.5%), and reintubation (2.0%). PPC incidence was higher with surgical duration >2 hours (35.0% vs 12.0%; p=0.007) and in patients with obstructive sleep apnea (31.0% vs 18.1%; p=0.012). In adjusted analysis, surgical duration >2 hours (aOR 3.92; 95% CI 1.78–8.63; p=0.001), obstructive sleep apnea (aOR 2.14; 95% CI 1.05–4.35; p=0.036), and residual neuromuscular blockade (aOR 2.67; 95% CI 1.21–5.89; p=0.015) independently predicted PPCs. Conclusion: Early PPCs are common after elective intra-abdominal surgery under general anesthesia in obese patients, with prolonged operative time, obstructive sleep apnea, and residual neuromuscular blockade conferring increased risk.