Objective To explore the effect of individualized positive end expiratory pressure guided by driving pressure on lung protection after laparoscopic radical gastrectomy for elderly patients.Methods A total of 64 patients underwent elective laparoscopic radical gastrectomy for gastric cancer in the Second Affiliated Hospital of Anhui Medical University were selected.According to the random number table method,patients were divided into the driving the pressure guided individualized positive end-expiratory pressure(PEEP)group(experimental group)and the fixed PEEP group(control group),32 cases in each group.In the control group,PEEP = 5 cmH2O.In the experimental group,PEEP titration was performed according to the increasing method,and the PEEP corresponding to the lowest driving pressure was selected until extubation.Peak airway pressure(Ppeak),plateau airway pressure(Pplat)and PEEP were recorded at 5 min after intubation(T1),immediately after PEEP titration(T2),1 h after operation(T3),2 h after operation(T4),and 10 min after pneumoperitoneum release(T5).Driving pressure(ΔP)and lung dynamic compliance(Cdyn)were calculated.Arterial blood was collected at T1-5 for blood gas analysis,arterial partial pressure of oxygen(PaO2)was recorded,and oxygenation index(OI)was calculated.The occurrence of pulmonary complications(PPCs)within 7 days after operation was recorded.Modified clinical pulmonary infection score(mCPIS)was recorded on the second day after operation.The pulmonary function was evaluated before operation,1 day,3 days and 5 days after operation.Results Compared with T1,Ppeak,Pplat and ΔP were increased and Cdyn was decreased at T2-5,while OI was decreased at T4 in control group(P＜0.05).Compared with the control group,Ppeak,Pplat and Cdyn in the experimental group were increased at T2-5,ΔP was decreased,and OI was increased at T3-5(P＜0.05).Compared with the preoperative results,FVC at 1,3 and 5 days after surgery was decreased,and FEV1 and maximum expiratory flow(PEF)were decreased 1 and 3 days after surgery in the experimental groups(P＜0.05).Compared with the control group,FVC,FEV1 and PEF were higher 1 day after operation in the experimental group(P＜0.05).Compared with the preoperative results,mCPIS scores of the two groups were higher on the second day after surgery(P＜0.05).Compared with the control group,the mCPIS score was lower on day 2 after surgery in the experimental group(P＜0.05).The incidence of PPCs within 7 days after surgery was lower in the experimental group than that in the control group(15.6%vs.40.6%).Conclusion Individualized PEEP guided by drive pressure can improve lung compliance,reduce drive pressure,improve oxygenation function and early postoperative lung function,reduce the incidence of postoperative lung complications,and has a certain lung protection effect.