Abstract: Objective To investigate the influencing factors of pulmonary infection in elderly patients with gastric cancer (GC) after laparoscopic surgery.Methods A total of 228 elderly patients with GC who underwent laparoscopic radical resection in our hospital from September 2020 to September 2023 were selected.According to the pulmonary infection within 30 days after operation,they were divided into pulmonary infection group and control group.The clinical data of the two groups were compared,the independent risk factors of postoperative pulmonary infection were identified,the regression risk prediction model was established,and the goodness of fit and prediction efficiency of the model were judged.Results There were 31 cases (13.60 %) of postoperative pulmonary infection in 228 elderly patients with GC.Logistic regression analysis showed that operation time,intraoperative blood transfusion,postoperative wound pain,nutritional risk and frailty were independent risk factors for postoperative pulmonary infection (P<0.05).Hosmer-Lemeshow test showed that P=0.147,suggesting that the model was effective.The receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) of the model for predicting postoperative pulmonary infection was 0.775,the predictive sensitivity was 70.97 %,and the specificity was 81.22 %.Conclusion Operative time, intraoperative blood transfusion, postoperative wound pain, nutritional risk and frailty were all independent risk factors for postoperative pulmonary infection in elderly patients with GC (OR were 1.022, 2.607, 3.629, 2.938, 2.789, respectively)(P < 0.05). The risk model established based on these factors had good predictive value.

Key words: Gastric cancer, Laparoscopy, Pulmonary infection, Influencing factors