A new laryngeal mask prototype. Preliminary evaluation of seal pressures and glottic isolation.

A new prototype laryngeal mask airway is described which incorporates a second mask to isolate the upper oesophagus and a second dorsal cuff to increase the seal against the glottis. We have made a within-patient comparison of seal pressures between the prototype and standard laryngeal mask airway in 20 patients, and determined if the prototype facilitates functional isolation of the glottis and upper oesophagus. Leak pressure was found to be significantly higher for the prototype and equalled or exceeded 5.0 kPa in all patients (p < 0.001). The prototype laryngeal mask airway provided functional isolation in all patients as judged by leak and placement of a gastric tube via the oesophageal mask. Ease of insertion and incidence of pharyngeal morbidity appeared similar to the standard laryngeal mask, but were not formally tested. The prototype laryngeal mask airway exhibits potentially useful new features which justify further evaluation and development.