I-GEL(TM) VS. AURAONCE(TM) LARYNGEAL MASK FOR GENERAL ANAESTHESIA WITH CONTROLLED VENTILATION IN PARALYZED PATIENTS

William Donaldson,Pavel Michalek,Alexander Abraham,Mairead Deighan

doi:10.5507/bp.2011.023

Abstract

The i-gel™ and the AuraOnce™ laryngeal mask are supraglottic airway devices used for airway management during general anaesthesia. Both devices are cheap, disposable and widely used. They may be used with both spontaneous and controlled ventilation. This study compared differences in the seal and peak pressures, and postoperative complications in these devices when used in paralyzed patients under controlled ventilation. A prospective randomized trial was designed to compare the i-gel™ and the AuraOnce™ in paralyzed adult patients under conditions of controlled ventilation. Two hundred and four patients (ASA class 1-3, age 18-89, weight 46-115 kg) were enrolled in the study. Standardized anaesthesia (fentanyl, propofol and sevoflurane in air-oxygen) was administered including neuromuscular blockade. The primary outcome measure was the difference in seal airway pressures between the two devices. Secondary outcome measures included peak airway pressures, insertion data and postoperative profiles--the incidence of sore throat, swallowing difficulties, numb tongue, hearing difficulties, neck pain, nausea and vomiting. First time insertions were 85.6% (i-gel) and 82% (AuraOnce) with overall success rates 96.3% (i-gel) and 94.2% (AuraOnce) (p=0.54). Average insertion times were 11.0 s (i-gel) and 11.6 s (AuraOnce) (p=0.19). Seal pressures were 30.4 cmH(2)O (i-gel) and 27.8 cmH(2)O (AuraOnce) (p=0.007). Peak pressures were 15.3 cmH(2)O (i-gel) and 15.6 cmH(2)O (AuraOnce) (p=0.57). Traumatic insertion occurred in 5.8% of i-gel™ and 2% of AuraOnce™ insertions. The overall incidence of postoperative complications was low, with the i-gel™ causing less sore throat and difficulty swallowing at 24h. Conclusion. Both devices provided effective seals for ventilation under positive pressure. I-gel™ may be a better alternative for the procedures with controlled ventilation because of higher seal pressures and lower incidence of sore throat postoperatively.

Highlights

Disposable supraglottic airway devices (SADs) are used for airway maintenance in the majority of cases where tracheal intubation is not clearly indicated
We were quite explicit with the ethics committee about the use of muscle relaxants, and the committee stipulated that the patient information sheet should mention that such agents were not necessarily a part of the anaesthetic regimen they would have undergone if they were not enrolled in the study
The results of this study showed that both devices performed without any significant difference apart from higher seal pressures in the i-gelTM group and lower incidence of postoperative sore throat and difficulty swallowing at 24 h in the i-gelTM group

Summary

Introduction

Disposable supraglottic airway devices (SADs) are used for airway maintenance in the majority of cases where tracheal intubation is not clearly indicated. There have been various SADs developed and clinically investigated. The i-gelTM airway [Intersurgical Ltd., Wokingham, UK] is a disposable SAD which was introduced into clinical practice in the United Kingdom in January 2007. It is composed of a stem with an integral buccal stabilizer and a cuff which is made from styrene ethylene butadiene styrene. The device incorporates a channel for communication with the oesophagus (Fig. 1). The i-gelTM has been studied in patients undergoing elective surgery and under both spontaneous and controlled ventilation[1,2] and was found to perform well under these conditions

Methods

Results

Conclusion