Comparison between the standard method and the 30° curved tongue depressor-aided technique for insertion of a laryngeal mask airway: a randomized controlled trial

Abstract

Background: Laryngeal mask airway (LMA) has been increasingly used for airway management; however, LMA insertion can be difficult and cause adverse effects. Therefore, the rapid, safe, and effective insertion of LMA is necessary. This study aimed to compare the efficacy of the standard method with that of the 30 degrees curved tongue depressor-aided technique for LMA insertion to determine the superior technique. Methods: This study included 154 patients aged 18-70 years (American Society of Anesthesiologists class I or II) scheduled for general anesthesia. The patients were randomly assigned to the standard LMA insertion group (Group C, n = 77) or the 30 degrees curved tongue depressor-aided LMA insertion group (Group T, n = 77). The primary outcome evaluated was the first-attempt success rate. The secondary outcomes were the second-attempt success rate, insertion time, fiberoptic position grade, oropharyngeal leak pressure (OPLP), and adverse events. Results: The first-attempt success rate was significantly higher in Group T than in Group C (97.40% vs. 88.31%, P = 0.029). The second-attempt success rate (P = 0.209), insertion time (P = 0.340), fiberoptic position grade (P = 0.872), and OPLP (P = 0.203) were slightly improved in Group T; however, there was no statistical significance. Bleeding events were reduced in Group T than in Group C (6.49% vs. 14.29%); however, there was no statistical significance. The incidence of sore throat symptoms was significantly reduced in Group T than in Group C (5.19% vs. 15.58%, P = 0.035). Conclusions: The curved tongue depressor-aided technique significantly improved the first-attempt success rate of LMA insertion and reduced the incidence of sore throat symptoms. Trial registration: KCT0004964; Registered at https://cris.nih.go.kr on April 27, 2020.