Effect of positive end-expiratory pressure on pulmonary compliance and pulmonary complications in patients undergoing robot-assisted laparoscopic radical prostatectomy: a double-blind randomized control trial

Purpose: To observe the effects of different levels of positive end-expiratory pressure (PEEP) ventilation strategies on pulmonary compliance and complications in patients undergoing robotic-assisted laparoscopic prostate surgery. Methods: A total of 120 patients with American Society of Anesthesiologists Physical Status Class I or II who underwent elective robotic-assisted laparoscopic prostatectomy were enrolled. The patients were randomly divided into three groups of 40 patients each: control (PEEP=0 cmH 2 O), low-level (PEEP=5 cmH 2 O), and high-level (PEEP=10 cmH 2 O). Volume control ventilation with an intraoperative deep muscle relaxation strategy was used intraoperatively. Respiratory mechanics indexes were recorded at six time points: 10 min after anesthesia induction, immediately after pneumoperitoneum establishment, 30 min, 1 h, 1.5 h, and at the end of pneumoperitoneum (T1-T6). Arterial blood gas analysis and oxygenation index calculation were performed at T1, T4, and after tracheal extubation (T7). Postoperative pulmonary complications were also recorded. Results: After pneumoperitoneum, peak inspiratory pressure (Ppeak), plateau pressure (Pplat), mean pressure (Pmean), driving pressure (ΔP), and airway resistance (Raw) increased significantly and pulmonary compliance (Crs) decreased, persisting during pneumoperitoneum in all groups. Between T2–T5, Pulmonary compliance in Group high-level was higher compared with Groups low-level (53.7/39.2/37.2/35.8 vs. 46/33.6/33.7/32.5; P<0.05) and control (53.7/39.2/37.2/35.8 vs. 38.4/28.2/26.7/27.4; P<0.05) .The driving pressure (ΔP) at T2–T5 in Group high-level was lower compared with Groups low-level (9.7/13.2/13.8/14.3 vs. 12.3/16.0/16.2/17.3; P<0.05) and control (9.7/13.2/13.8/14.3 vs. 17.0/21/22.3/22.0; P<0.05).At T4 and T7, the PaCO2 and PaO2/FiO2 did not significantly differ among the three groups((P＞0.05). There was no significant difference in postoperative pulmonary complications among the three groups(P＞0.05). Conclusion: High levels of intraoperative PEEP increased lung compliance without significantly reducing postoperative pulmonary complications. Registered： The study was registered in the China Clinical Trials Registry 30/05/ 2020 (Registration No. ChiCTR2000033380).