LARYNGEAL MASK BITE BLOCKS - ROLLED GAUZE VERSUS GUEDEL AIRWAY

Background: Biting on the silicone tube and pilot balloon of the laryn geal mask airway (LMA) may obstruct or damage them with the teeth and a bite block is recommended. The recommended bite block is a wad of ga uze swabs rolled into a cylindrical shape and placed alongside the LMA . It is considered that this avoids irritating the posterior pharyngea l wall and damage to teeth whilst supporting the LMA tube when taped t o it. The Guedel airway is commonly used as a bite block with the trac heal tube and many anaesthetists also use it with the LMA. The aim of the following study was to compare rolled gauze swabs with a Guedel ai rway as a bite block for the LMA. Methods: We compared the Guedel airw ay with rolled gauze swabs as a bite block for the laryngeal mask airw ay (LMA) in 120 ventilated patients in whom cuff pressures were limite d to 5.87 kPa (60 cm H2O) and anaesthesia management was standardised. Results: In the Guedel airway group, there was a higher incidence of ventilatory problems (0 vs 4, P<0.05), bleeding (0 vs 8, P<0.01), hoar seness (0 vs 4, P<0.05) and sore throat (2 vs 12, P<0.01). Conclusion: 1. The Guedel airway is an unsuitable bite block for the LMA. 2. Cuff pressure Limitation is compatible with adequate ventilation. 3. The c ombination of LMA and Guedel airway probably prevents either from sitt ing in the correct anatomical position. (C) Acta Anaesthesiologica Sca ndinavica 41 (1997).