Analysis of 1500 laryngeal mask uses by one anaesthetist in adults undergoing routine anaesthesia

Abstract

An analysis of 1500 laryngeal mask airway uses by one anaesthetist using the standard insertion technique was conducted to determine successful insertion rates, position by fibreoptic larynoscopy, complication rates and whether there is a long-term learning curve. The correlation between laryngeal mask airway placement and modified Mallampati grade was also determined. The first time insertion rate was 95.5% with an overall failure rate after three attempts of 0.4%. One hundred and fifteen patients were Mallampati III or IV. All failed placements were Mallampati I or II. Problems occurred in 94 patients (6.27%), but oxygen saturation decreased below 90% on only ten occasions and below 80% on one occasion. There were no episodes of regurgitation. The vocal cords were visible from the mask aperture bars in 97.1%. Comparison of insertion rates, fibreoptic position and complications for the first and second 750 insertions provides evidence for a 'long' term learning curve. These data could be used as a guide for 'optimal' or expected successful laryngeal mask airway insertion rates in adults undergoing routine anaesthesia.