Recruitment maneuvers in patients undergoing thoracic surgery: a meta-analysis

Objective Pulmonary atelectasis is a common postoperative complication that may lead to intrapulmonary shunt, refractory hypoxemia, and respiratory distress. Recruitment maneuvers may relieve pulmonary atelectasis in patients undergoing thoracic surgery. This meta-analysis of randomized controlled trials (RCTs) is to evaluate the effectiveness and safety of recruitment maneuvers in patients undergoing thoracic surgery. Methods We performed a literature search on the PubMed, Embase, and Cochrane Library databases and the ClinicalTrials.gov registry for trials published before April 2021. We investigated postoperative pulmonary atelectasis incidence, intrapulmonary shunt fraction, static lung compliance, and mean arterial pressure. Results Six RCTs involving 526 patients were reviewed. Patients receiving a recruitment maneuver exhibited a significant decrease in intrapulmonary shunt fraction [weighted mean difference (WMD) - 0.02, 95% CI - 0.03 to - 0.01], improved static lung compliance (WMD 2.16; 95% CI 1.14-3.18), and PaO2/FIO2 ratio (WMD 31.31; 95% CI 12.11-50.52) without a significant difference in mean arterial pressure (WMD - 0.64; 95% CI - 4.92 to 3.64). The incidence pulmonary atelectasis favored recruitment maneuver group, but was not statistically significant (RR 0.55; 95% CI 0.27-1.12). Conclusions Recruitment maneuvers may be a viable treatment for reducing intra-pulmonary shunt and improving static lung compliance and PaO2/FIO2 ratio without the disturbance of hemodynamics in patients undergoing thoracic surgery.