The intubating laryngeal mask. Clinical appraisal of ventilation and blind tracheal intubation in 110 patients

This study assesses the efficacy of the intubating laryngeal mask as a ventilation device and blind intubation guide. Following induction of anaesthesia with propofol, the device was successfully inserted at the first attempt in 110/110 (100%) patients. Placement took less than 10 s in all patients. Size selection was based on nose-chin distance. Adequate ventilation was achieved in 104/110 (95%) patients. Blind tracheal intubation using an 8-mm internal diameter straight silicone cuffed tracheal tube was attempted 3 min after the administration of vecuronium. Passage of a lighted stylet through the intubating laryngeal mask was used to determine the position of the intubating laryngeal mask cuff before blind intubation. If resistance was felt during intubation, a sequence of adjusting manoeuvres was used, based on the depth at which resistance occurred. Tracheal intubation was possible in 104/104 (100%) patients. In 42 (40%) patients, no resistance was encountered and the trachea was intubated at the first attempt. Sixty-two (60%) patients required one adjusting manoeuvre. The mean (range) time taken to successful intubation, i.e. the time from disconnection of the intubating laryngeal mask from the breathing system to successful tracheal intubation, was 79 (12-315) s. Six patients with potential or known intubation problems were included in the study. The tracheas of all six patients were successfully intubated. We conclude that the intubating laryngeal mask is an effective ventilation device and intubation guide with potential for use in patients who may present difficulty in tracheal intubation.