Effect Of Driving Pressure-guided Positive End-expiratory Pressure Ventilation On Pulmonary Function In Elderly Patients Undergoing Laparoscopic Radical Prostatectomy

Objective To investigate the effect of driving pressure-guided individualized positive end-expiratory pressure（PEEP）ventilation on pulmonary function in elderly patients undergoing laparoscopic radical prostatectomy.Methods Elderly patients undergoing elective laparoscopic radical prostatectomy were enrolled,aged≥65 years,BMI 18.5 to 30,ASA Grade II orШ.The patients were randomly divided into two groups by random number table method:the driving pressure-guided group（group P）and the control group（group C）,30 cases in each group.Group C was given PEEP of 5 cm H₂O,and group P was given PEEP guided by driving pressure（Gradually increasing the PEEP value from low to high after mechanical ventilation,calculating the driving pressure,and selecting the PEEP value corresponding to the lowest driving pressure）,the intraoperative fluid infusion volume and the use of vasoactive drugs were recorded after the operation.MAP,HR and blood gas analysis were recorded and oxygenation index（OI）was calculated immediately after the establishment of pneumoperitoneum-Trendelenburg position（T₀）,30 minutes(T₁)and 1 hour（T₂）and 2 hours after the completion of PEEP titration（T₃）,and 30minutes after the operation（T₄）.The respiratory mechanics indexes such as Ppeak,Pplat,Cdyn,MAP and HR at T_0-3 were recorded;FEV₁,FVC,FEV₁/FVC and PEF were measured on the 1^st day before surgery（T₅）,1^st day after surgery（T₆）,3^rd day after surgery（T₇）,and 7^th day after surgery（T₈）;The Clinical Pulmonary Infection Score（CPIS）was performed and the incidence of postoperative pulmonary complications（PPCs）was recorded.Results There was no significant difference in age,BMI,operation time,anesthesia time and pneumoperitoneum pressure between the two groups（P>0.05）.Compared with group C,the amount of fluid infusion and the use of vasoactive drugs increased in group P（P<0.05）;Compared with group C,OI,Pa O₂,Pa CO₂,Ppeak,Pplat,and Cdyn increased at T_1-4 in group P（P<0.05）,whileΔP decreased at T_1-3（P<0.05）;At T_0-4,there was no significant difference in HR and MAP between the two groups;Compared with group C,the amount of intraoperative fluid replacement and the use of vasoactive drugs increased in group P（P<0.05）;At T_6-7,FEV₁,FVC,FEV₁/FVC,and PEF in group P were all higher than those in group C（P<0.05）.Compared with group C,postoperative CPIS score and the incidence of PPCs in group P decreased（P<0.05）.Conclusion Individualized PEEP ventilation guided by driving pressure can improve postoperative pulmonary function and reduce the incidence of postoperative pulmonary complications in elderly patients undergoing laparoscopic radical prostatectomy,but the PEEP titration process has a certain impact on hemodynamics.