To the Editor:—

We read the article of van Vlymen et al.  1about the use of neuromuscular blocking agents and the intubating laryngeal mask airway (ILMA) with considerable interest. We feel that this article highlights the failure of the ILMA to find its true role in airway management.

There is no advantage afforded by the use of an ILMA in low-risk patients: insertion of the ordinary laryngeal mask airway 2and positive-pressure ventilation are well-tolerated both in the paralyzed 3and in the nonparalyzed population. 4In patients considered to have a high risk of aspiration but who are straightforward to intubate, the airway is most quickly and safely secured by tracheal intubation with direct vision. The blind technique of ILMA insertion has less success. 1 

In cases of expected difficult intubation, it is also more difficult to insert a laryngeal mask airway. 5Awake fiberoptic intubation is well-proven to provide a safe and controlled means of intubating the airway with direct vision, with the added advantage of no loss of protection from regurgitation. When the airway is safe, then neuromuscular relaxation can be given. In contrast, a trial with the ILMA found failure to intubate the trachea in 3 of 31 patients. 6This is unacceptably high in anesthetized, paralysed patients.

The laryngeal mask airway has found a place in the management of the unexpected difficult airway 7: to complicate a difficult situation by then attempting blind intubation via  the ILMA has little to commend it. Although the question that the authors posed was well-answered by their study, a more pertinent question would be this: If muscle relaxants are necessary, should the ILMA be used?

van Vlymen JM, Coloma M, Tongier WK, White PF: Use of the Intubating Laryngeal Mask Airway: Are muscle relaxants necessary? A nesthesiology 2000; 93: 340–5
Nakazawa K, Hikawa Y, Maeda M, Tanaka N, Ishikawa S, Makita K, Amaha K: Laryngeal mask airway insertion using propofol without muscle relaxants: A comparative study of pretreatment with midazolam or fentanyl. Eur J Anaesthesiol 1999; 16: 550–5
Agro F, Brimacombe J, Verghese C, Carassiti M, Cataldo R: Laryngeal mask airway and incidence of gastro-oesophageal reflux in paralysed patients undergoing ventilation for elective orthopaedic surgery. Br J Anaesth 1998; 81: 537–9
Keller C, Sparr HJ, Luger TJ, Brimacombe J: Patient outcomes with positive pressure versus spontaneous ventilation in non-paralysed adults with the laryngeal mask. Can J Anaesth 1998; 45: 564–7
McCrory CR, Moriarty DC: Laryngeal mask airway positioning is related to Mallampati grading in adults. Anesth Analg 1995; 81: 1001–4
Nakazawa K, Tanaka N, Ishikawa S, Ohmi S, Ueki M, Saitoh Y, Makita K, Amaha K: Using the intubating laryngeal mask airway (LMA-Fastrach) for blind endotracheal intubation in patients undergoing cervical spine operation. Anesth Analg 1999; 89: 1319–21
Parmet JL, Colonna-Romano P, Horrow JC, Miller F, Gonzales J, Rosenberg H: The laryngeal mask airway reliably provides rescue ventilation in cases of unanticipated difficult tracheal intubation along with difficult mask ventilation. Anesth Analg 1998; 87: 661–5