Hyoid Cricoid Distance-Based Method Versus Weight‑Based Method for Choosing the Appropriate Size for Classic Laryngeal Mask Airway Selection in Adults.

Background: Selecting the appropriate sizes for laryngeal mask airways (LMAs) has become a concern for anesthesiologists. Traditionally, size selection has relied on factors like patient weight and gender. Nevertheless, emerging research indicates that incorporating anthropometric data could benefit the identification of the optimal LMA size for individual patients. Objectives: This randomized controlled trial aims to compare the effectiveness of LMA size selection based on weight against that determined by measuring the hyoid-cricoid distance (HCD). Methods: A total of 64 patients scheduled for eye surgery under general anesthesia were randomly assigned to two groups, each consisting of 32 participants. In the "W group", the size of the LMA was chosen based on the manufacturer's guidelines, which relied exclusively on the patient's weight. Conversely, in the "HCD group", the selection of LMA size was based on measuring the HCD. We compared postoperative complications and the ease of LMA insertion in these groups. Results: Data from 28 patients in the W group and 30 in the HCD group were analyzed. The incidence of postoperative complications was comparable between groups, with 16 patients in the W group and 12 in the HCD group experiencing complications (P = 0.1). Additionally, metrics such as the number of attempts, time to insertion, ease of insertion, peak airway pressure, and abnormal curve shape showed no statistically significant differences (P > 0.05). Conclusions: Based on the findings in this study, the method for selecting LMA size based on HCD did not statistically reduce airway complications nor did it facilitate the insertion process. We recommend conducting larger studies to further investigate this topic.