Effects of individualized positive end-expiratory pressure on intraoperative oxygenation and postoperative pulmonary complications in patients requiring pneumoperitoneum with Trendelenburg position: a systematic review and meta-analysis

Background: Whether individualized positive end-expiratory pressure (PEEP) improves intraoperative oxygenation and reduces postoperative pulmonary complications (PPCs) remains unclear. This systematic review and meta-analysis examined whether individualized PEEP is associated with improved intraoperative oxygenation and reduced PPCs for patients needing pneumoperitoneum with the Trendelenburg position during surgery. Methods: Medline, Embase, the Cochrane Library, and www.clinicaltrials.gov were searched for randomized controlled trials evaluating the effects of individualized PEEP on intraoperative oxygenation and PPCs in patients who required Trendelenburg positioning with pneumoperitoneum. The primary outcome was the oxygenation (PaO2/FiO(2)) during the procedure. Secondary outcomes included PPCs, intraoperative respiratory mechanics (driving pressure, compliance), and vasopressor consumption. DerSimonian-Laird random effects models were used to calculate mean differences (MDs) and log risk ratios (log RRs) with 95% confidence intervals (CIs). The Cochrane Risk-of-Bias tool 2.0 was applied to assess the risk of bias in included studies. The protocol of this meta-analysis has been registered in PROSPERO. Results: We included 14 studies (1121 patients) that employed different individualized PEEP strategies. Compared with control groups, individualized PEEP groups exhibited a significantly improved intraoperative PaO2/FiO(2) (MD=56.52 mmHg, 95% CI: [33.98-79.06], P<0.001) and reduced incidence of PPCs (log RR=-0.50, 95% CI: [-0.84 to -0.16], P=0.004). Individualized PEEP reduced driving pressure while improving respiratory compliance. Intraoperative vasopressor consumption was similar between both groups. The weighted mean PEEP in the individual PEEP groups was 13.2 cmH(2)O [95% CI, 11.7-14.6]. No evidence indicated that one individualized PEEP strategy is superior to others. Conclusions: Individualized PEEP seems to work positively for lung protection in the Trendelenburg position and pneumoperitoneum in patients undergoing general anesthesia.