The laryngeal mask and VBM laryngeal tube compared during spontaneous ventilation. A pilot study.

BACKGROUND AND OBJECTIVE: The laryngeal tube is a variant of the oesophageal obturator airway. The manufacturer claims that it is an alternative to ventilation with a facemask, laryngeal mask or endotracheal tube. To date, published studies have only involved controlled ventilation. We wished to find out if its use in spontaneous ventilation was equivalent to using the laryngeal mask airway. METHODS: We have compared the laryngeal tube with the laryngeal mask in a randomized prospective study involving patients breathing spontaneously under general anaesthesia. Criteria and a scoring system were used for the comparison. A sequential analysis chart with P=0.01 was chosen for each of two anaesthetists. RESULTS: Only seven and 10 pairs of patients were required to indicate that the laryngeal tube was poorer at airway maintenance than the laryngeal mask. Of the 17 patients who had received the laryngeal tube, successful airway maintenance was only possible in seven. In the remaining 10 patients, the laryngeal tube was abandoned and the rescue airway was the laryngeal mask in all cases. All 17 patients randomized to the laryngeal mask were successfully managed. CONCLUSIONS: We conclude that the laryngeal tube is not a satisfactory device for management of the airway during spontaneous ventilation.