THE INTUBATING LARYNGEAL MASK .2. A PRELIMINARY CLINICAL REPORT OF A NEW MEANS OF INTUBATING THE TRACHEA

We have assessed the efficacy of a new laryngeal mask prototype, the i ntubating laryngeal mask airway (ILMA), as a ventilatory device and bl ind intubation guide. The ILMA consists of an anatomically curved, sho rt, wide bore, stainless steel tube sheathed in silicone which is bond ed to a laryngeal mask and a guiding handle. It has a single moveable aperture bar, a guiding ramp and can accommodate an 8 mm tracheal tube (TT). After induction of anaesthesia with propofol 2.5 mg kg(-1) and fentanyl 2.5 mu g kg(-1), the device was inserted successfully at the first attempt in ail 150 (100%) patients and adequate ventilation achi eved in all, with minor adjustments required in four patients. Placeme nt did not require movement of the head and neck or insertion of the f ingers in the patient's mouth. Blind tracheal intubation using a strai ght silicone cuffed TT was attempted after administration of atracuriu m 0.5 mg kg(-1). If resistance was felt during intubation, a sequence of adjusting manoeuvres was used based on the depth at which resistanc e occurred. Tracheal intubation was possible in 149 of 150 (99.3%) pat ients. In 75 (50%) patients no resistance was encountered and the trac hea was intubated at the first attempt, 28 (19%) patients required one adjusting manoeuvre and 46 (31%) patients required 2-4 adjusting mano euvres before intubation was successful. There were 13 patients with p otential or known airway problems. The lungs of all of these patients were ventilated easily and the trachea intubated using the ILMA. In 10 of 13 (77%) of these patients, no resistance was encountered and the trachea was intubated at the first attempt; three of 13 (23%) patients required one adjusting manoeuvre. Tracheal intubation required signif icantly fewer adjusting manoeuvres in patients with a predicted or kno wn difficult airway (P < 0.05). We conclude that the ILMA appeared on initial assessment to be an effective ventilatory device and intubatio n guide for routine and difficult airway patients not at risk of gastr ic aspiration.