ObjectiveTo explore the effect of different ventilation modes on pulmonary complications (PCs) after laparoscopic weight loss surgery in obese patients. MethodsThe obese patients who underwent laparoscopic weight loss surgery in the Xiaolan People’s Hospital of Zhongshan from January 2019 to June 2023 were retrospectively collected, then were assigned into pressure-controlled ventilation-volume guaranteed (PCV-VG) group and volume controlled ventilation (VCV) group according to the different ventilation modes during anesthesia. The clinicopathologic data of the patients between the PCV-VG group and VCV group were compared. The occurrence of postoperative PCs was understood and the risk factors affecting the postoperative PCs for the obese patients underwent laparoscopic weight loss surgery were analyzed by multivariate logistic regression analysis. ResultsA total of 294 obese patients who underwent laparoscopic weight loss surgery were enrolled, with 138 males and 156 females; Body mass index (BMI) was 30–55 kg/m2, (42.40±4.87) kg/m2. The postoperative PCs occurred in 63 cases (21.4%). There were 160 cases in the PCV-VG group and 134 cases in the VCV group. The anesthesia time, tidal volume at 5 min after tracheal intubation, peak inspiratory pressure and driving pressure at 5 min after tracheal intubation, 60 min after establishing pneumoperitoneum, and the end of surgery, as well as incidence of postoperative PCs in the PCV-VG group were all less or lower than those in the VCV group (P<0.05). The indicators with statistical significance by univariate analysis in combination with significant clinical indicators were enrolled in the multivariate logistic regression model, such as the smoking history, American Society of Anesthesiologists classification, hypertension, BMI, operation time, forced expiratory volume in 1 second (FEV1), FEV1/forced vital capacity, and intraoperative ventilation mode. It was found that the factors had no collinearity (tolerance>0.1, and variance inflation factor<10). The results of the multivariate logistic regression analysis showed that the patients with higher BMI and intraoperative VCV mode increased the probability of postoperative PCs (P<0.05). ConclusionsFrom the preliminary results of this study, for the obese patients underwent laparoscopic weight loss surgery, the choice of ventilation mode is closely related to the risk of developing postoperative PCs. In clinical practice, it is particularly important to pay attention to the risk of postoperative PCs for the patients with higher degree obesity.