Individualised Positive End-Expiratory Pressure Settings Reduce the Incidence of Postoperative Pulmonary Complications: A Systematic Review and Meta-Analysis

Progressive atelectasis regularly occurs during general anaesthesia; hence, positive end-expiratory pressure (PEEP) is often applied. Individualised PEEP titration may reduce the incidence of postoperative pulmonary complications (PPCs) and improve oxygenation as compared to fixed PEEP settings; however, evidence is lacking. This systematic review and meta-analysis was registered on PROSPERO (CRD42021282228). A systematic search in four databases (MEDLINE Via PubMed, EMBASE, CENTRAL, and Web of Science) was performed on 14 October 2021 and updated on 26 April 2024. We searched for randomised controlled trials comparing the effects of individually titrated versus fixed PEEP strategies during abdominal surgeries. The primary endpoint was the incidence of PPCs. The secondary endpoints included the PaO /FiO at the end of surgery, individually set PEEP value, vasopressor requirements, and respiratory mechanics. We identified 30 trials (2602 patients). The incidence of PPCs was significantly lower among patients in the individualised group (RR = 0.70, CI: 0.58-0.84). A significantly higher PaO /FiO ratio was found in the individualised group as compared to controls at the end of the surgery (MD = 55.99 mmHg, 95% CI: 31.78-80.21). Individual PEEP was significantly higher as compared to conventional settings (MD = 6.27 cm H O, CI: 4.30-8.23). Fewer patients in the control group needed vasopressor support; however, this result was non-significant. Lung-function-related outcomes showed better respiratory mechanics in the individualised group (Cstat: MD = 11.92 cm H O 95% CI: 6.40-17.45). Our results show that individually titrated PEEP results in fewer PPCs and better oxygenation in patients undergoing abdominal surgery.