A Simpler Method for Choosing Adult i-gel Size: An Evaluation of Real-World Prehospital Data

The i-gel supraglottic airway device (Intersurgical, Berkshire, UK) is commonly used in the United States and worldwide for prehospital airway management. Previous research has suggested that a sex-based method of size selection (4.0 for female patients and 5.0 for male patients) is superior to a weight-based method in patients undergoing elective anesthesia. Our objective was to compare a sex-based i-gel size selection strategy with a weight-based strategy using real-world prehospital data.

The ESO Data Collaborative 2018 to 2022 dataset was used. All initial i-gel insertion attempts in patients > 18 years of age were evaluated for inclusion. Insertion attempts were excluded if age, sex, weight, success, or device size was not documented. Logistic regression was used to compare the rate of insertion failure on the first attempt for the group placed in alignment with the weight-based but not sex-based method with the group placed in alignment with the sex-based but not weight-based method.

After the application of the exclusion criteria, 39,867 initial i-gel insertion attempts were included. The overall rate of failure was 6.5% (2,585/39,867). The rate of unsuccessful i-gel placement was similar when i-gel devices were placed in alignment with a sex-based size selection method in comparison to i-gel placement in alignment with a weight-based selection strategy (6.0% vs. 6.4%). Logistic regression analysis did not reveal a significant difference between groups (odds ratio: 1.08; 95% confidence interval: 0.95-1.23).

The use of a sex-based method of i-gel size selection may be equivalent with respect to the rate of unsuccessful i-gel placement on the first attempt in comparison to a weight-based method.