A randomized clinical comparison of the Intersurgical i-gel and LMA Unique in non-obese adults during general surgery

The i-gel is a cuffless, single-use supralaryngeal airway device designed to provide a more effective seal than the laryngeal mask airway (LMA). Although the superiority of the i-gel compared to the LMA Classic was determined in a previous study, no studies have been performed that compare it to the disposable LMA Unique. The aim of this study was to compare the Intersurgical i-gelTM against the LMA UniqueTM (uLMA) in terms of ease of placement, time of insertion, and adequacy of placement through a randomized, controlled clinical trial.

Following Institutional Review Board (IRB) approval and written informed consent, 50 adult patients were recruited for this study. All enrolled patients were ASA 1-2, Mallampati I-II, and scheduled to receive general anesthesia. Patients were randomized to have either the i-gel or the uLMA placed for airway management. After standardized induction techniques, the airway was secured with the assigned device. All patients were interviewed postoperatively for sore throat, hoarseness, and dysphagia. Standard vital signs, end-tidal CO2, tidal volumes, and peak pressures were recorded. Insertion time, leak pressures, and anatomic placement as assessed fiberoptically for the i-gel were recorded. Ease of placement and complications were also recorded.

The insertion time was significantly less with the i-gel (21.04±12.6 s vs. 30.04±14.1 s, P=0.02). An inadequate seal was noted in three patients with the i-gel, and it was exchanged for the uLMA in all three cases. There were no significant differences in the ease of insertion, leak pressures, or fiberoptic view. Most of the fiberoptic views, as assessed through the drain tube, demonstrated esophageal mucosa (22/25). Patients receiving the i-gel were significantly more likely to require a second attempt at insertion by the anesthesiologist (OR 8.11, CI 1.1-58.6, P=0.03). Finally, patients receiving the size 5 i-gel were significantly more likely to complain of immediate postoperative symptoms, such as sore throat and dysphagia (OR 29.32, CI 1.4-613.1, P=0.03).

Although the i-gel had a faster insertion time in comparison to the uLMA, there was a greater need for repeat insertions. The weight criteria established by the manufacturer may need to be readjusted to recommend a larger size device in some patients less than 90 kg because all of the repeat insertions were in patients weighing more than 80 kg. In all other aspects of its use, the i-gel performed similarly to the uLMA.