I-gel for positive pressure ventilation

I-gel is a relatively new supra-glotitc airway device which is claimed to be superior to laryngeal mask airway. It can be used ingeneral anesthesia with spontaneous ventilation as well as with positive pressure ventilation.This study was designed to assess whether I-gel creates adequate laryngeal seal during positive pressure ventilation in patients undergoing laparoscopic surgery.

A prospective randomized study was made among the 60 patients who underwent laparoscopic cholecystectomy under general anesthesia. Airway was managed with either I-gel insertion or endotracheal intubation and positive pressure ventilation in 30 patients each. Airway pressure, end-tidal CO2and oxygen saturation were monitored and compared between two groups. Inhaled and exhaled tidal volume, minute volume were recorded and leak volume and leak fraction was calculated and compared between two groups.

Oxygenation and ventilation (oxygen saturation and end-tidal carbon dioxide pressure) was within normal limit in both groups and comparable. Leak volume in tracheal tube group was 25.33±12.41 ml and in I-gel group it was 26.43±13.19 ml. Leak fraction was 0.0487±0.023 and 0.0417±0.022 in tracheal group and I-gel group respectively. The airway pressure during C02 pneumoperitoneumwas 20.55±3.25 cm H20 in tracheal tube group and 20.21± 3.97 cm H20 in I-gel group and there was no significant leak in either group. Statistically, there was no significant difference in leak volume, leak fraction and airway pressure between the two groups.

I- gel may be an alternate to tracheal tube during general anesthesia with positive pressure ventilation in patients with normal airway pressure with acceptable leak, adequate oxygenation and ventilation.