Importance: The efficacy of a semirecumbent position (SRP) in reducing postoperative hypoxemia during anesthesia emergence is unclear despite its widespread use.
Objective: To determine the differences in postoperative hypoxemia between patients in an SRP and a supine position.
Design, setting, and participants: This randomized clinical trial was performed at a tertiary hospital in China between March 20, 2021, and May 10, 2022. Patients scheduled to undergo laparoscopic upper abdominal surgery under general anesthesia were enrolled. Study recruitment and follow-up are complete.
Interventions: Patients were randomized to 1 of the following positions at the end of the operation until leaving the postanesthesia care unit: supine (group S), 15° SRP (group F), or 30° SRP (group T).
Main outcomes and measures: The primary outcome was the incidence of postoperative hypoxemia in the postanesthesia care unit. Severe hypoxemia was also evaluated.
Results: Out of 700 patients (364 men [52.0%]; mean [SD] age, 47.8 [11.3] years), 233 were randomized to group S (126 men [54.1%]; mean [SD] age, 48.2 [10.9] years), 233 to group F (122 men [52.4%]; mean [SD] age, 48.1 [10.9] years), and 234 to group T (118 women [50.4%]; mean [SD] age, 47.2 [12.1] years). Postoperative hypoxemia differed significantly among the 3 groups (group S, 109 of 233 [46.8%]; group F, 105 of 233 [45.1%]; group T, 76 of 234 [32.5%]; P = .002). This difference was statistically significant for groups T vs S (risk ratio [RR], 0.69 [95% CI, 0.55-0.87]; P = .002) and groups T vs F (RR, 0.72 [95% CI, 0.57-0.91]; P = .007), but not for groups F vs S (RR, 0.96 [95% CI, 0.79-1.17]; P = .78). Severe hypoxemia also differed among the 3 groups (group S, 61 of 233 [26.2%]; group F, 53 of 233 [22.7%]; group T, 36 of 234 [15.4%]; P = .01). This difference was statistically significant for groups T vs S (RR, 0.59 [95% CI, 0.41-0.85]; P = .005).
Conclusions and relevance: In this randomized clinical trial of SRP during anesthesia recovery in patients undergoing laparoscopic upper abdominal surgery, postoperative hypoxemia was significantly reduced in group T compared with group F or group S.
Trial registration: Chinese Clinical Trial Registry Identifier: ChiCTR2100045087.