Damage to the laryngeal mask by residual fluid in the cuff

It has been suggested that, in some situations, the cuff of the laryngeal mask should be filled with fluid. We speculated that this practice might damage the device during sterilisation in an autoclave. We studied whether injection of a small volume of water into the cuff of the laryngeal mask and subsequent sterilisation affected the integrity of the cuff. First, a pressure-volume relationship for each of 20 new masks was obtained by inflating the cuff with increasing volumes of air (5-45 ml). The masks were then randomly allocated into four groups (W0, W0.25, W0.5 or W1.0), 0, 0.25, 0.5 or 1.0 ml of water was injected into the cuff and the mask was then sterilised in an autoclave. After sterilisation, the shape of the cuff was examined and pressure-volume relationships were obtained again. The baseline intracuff pressures were similar in the four groups. After sterilisation, the pressure was significantly lower in groups W0.25, W0.5 and W1.0 than in group W0 (p < 0.05). Two masks in group W1.0 lost their integrity, resulting in herniation of and rupture of the cuff. We conclude that the cuff of the laryngeal mask should not be inflated with fluid unless the device is discarded afterwards.