Use of the laryngeal tube after failed insertion of a laryngeal mask airway

The Laryngeal Tube (VBM, Medizintechnik, Germany) has a potential role during anaesthesia and cardiopulmonary resuscitation [1, 2]. It consists of an airway tube with a small balloon cuff attached at the tip and a larger balloon cuff at the middle part of the tube. We report successful use of the laryngeal tube in three patients in whom insertion of the laryngeal mask airway had failed. An 18-year-old fit and healthy woman (165 cm, 52 kg) was scheduled for left oophorectomy. After epidural catheterisation, general anaesthesia was induced with propofol 100 mg and deepened with sevoflurane. After no motor response to thrusting the jaw forward had been confirmed [3], the mouth was opened to insert a laryngeal mask airway. Enlarged tonsils were found. Because there was a gap between the tonsils (approximately 1.5 cm), we felt that it might be possible to insert the laryngeal mask, but failed to advance the device beyond the tonsils despite using the insertion technique described in the manufacturer’s instruction manual. Insertion of a flexible laryngeal mask (which should be easier to insert in patients with enlarged tonsils) also failed. Before tracheal intubation, we tried a laryngeal tube, which was easily inserted. The lungs were ventilated through the laryngeal tube without complications during the 80 min operation. A 46-year-old woman (159 cm, 55 kg), with a history of Basedow’s disease at 20 years and tonsillectomy at 34 years, was scheduled for left oophorectomy. Preoperative examination indicated a goitre (with normal thyroid function) without deviation of the trachea or difficulty in breathing. After epidural catheterisation, general anaesthesia was induced with propofol 100 mg and maintained with a targetcontrolled infusion. After no motor response to jaw thrusting had been confirmed, insertion of a laryngeal mask airway was attempted, but it was impossible to advance it beyond the back of the throat. In contrast, insertion of a laryngeal tube was easy. The operation (40 min) proceeded without complications. A 72-year-old man (157 cm, 74 kg) was scheduled for right total hip arthroplasty. Preoperatively, difficult tracheal intubation was predicted, because the view of the oropharynx was limited (Mallampati score 3), the thyromental distance was 5 cm, there was a mild difficulty in thrusting the jaw forward and extending the neck, and snoring during sleep. After epidural catheterisation, anaesthesia was induced with propofol 150 mg. Insertion of a laryngeal mask failed twice. In contrast, a laryngeal tube was easily inserted and was used during anaesthesia of 140 min, without complications. The exact reason for successful insertion of the laryngeal tube after failed insertion of the laryngeal mask airway in these cases is not known, but the success and failure might have been related to a difference in the width of these two devices. The pharyngeal space was narrowed by swollen tonsils in case 1, by a goitre in case 2, and possibly by redundant tissues in the pharynx (which produced the snoring) in case 3. Insertion of the laryngeal mask airway might not have been possible because the distal part of the mask had wedged in the narrowed pharynx. The distal segment of the laryngeal tube is not tapered, and the width of the tube is narrower than that of the laryngeal mask airway (Fig. 3), and thus the laryngeal tube might have passed through the narrowed space. We suggest that, when insertion of the laryngeal mask airway is difficult or impossible due to a narrowed pharynx, insertion of the laryngeal tube may be attempted, before considering tracheal intubation.