Standard digit-based versus 90 degrees rotation technique for supraglottic airway device insertion: a meta-analysis of randomized controlled trials

Background: Prompt insertion and placement of supraglottic airway (SGA) devices in the correct position are required to secure the airway. This meta-analysis was performed to validate the usefulness of the 90 degrees rotation technique as compared with the standard digit-based technique for the insertion of SGA devices in anesthetized patients in terms of insertion success rate, insertion time, and postoperative complications. Methods: A literature search of PubMed, EMBASE, CENTRAL, CINAHL, Scopus, and Web of Science was conducted. Randomized controlled trials, without limitations on publication period, language, journal, or region, until July 2021, that compared the 90 degrees rotation and the standard digit-based techniques for insertion of SGA devices in anesthetized patients were included. Results: The first-attempt (risk ratio [RR]: 1.16, 95% CI [1.09, 1.25], P < 0.001) and overall success rates (RR: 1.06, 95% CI [1.03, 1.09], P < 0.001) were significantly higher in the 90 degrees rotation group. The insertion time was shorter in the 90 degrees rotation group (mean difference: -4.42 s, 95% CI [-6.70, -2.15 s], P < 0.001). The incidences of postoperative sore throat (RR: 0.63, 95% CI [0.49, 0.83], P < 0.001) and blood staining (RR: 0.28, 95% CI [0.20, 0.39], P < 0.001) were lower in the 90 degrees rotation group. Conclusions: The use of the 90 degrees rotation technique increases the success rate of SGA device insertion and decreases postoperative complications as compared with that of the standard digit-based technique in anesthetized patients.