Choosing appropriate size of I-Gel for initial success insertion: a prospective comparative study.

Purpose: The optimal size of the I-Gel remains unclear since the manufacturer's weight-based formula (size 3 for weight < 50 kg, size 4 for weight 50-90 kg, and size 5 for weight > 90 kg) for the laryngeal mask airway I-Gel is not evidence-based. We hypothesised that sex may also guide the choice of I-Gel size.

Methods: Insertion success rates of the I-Gel chosen according to the weight-based formula were prospectively recorded and compared with those of a patients' cohort ventilated with an I-Gel chosen according to the sex-based formula recorded.