Could ‘safe practice’ be compromising safe practice? Should anaesthetists have to demonstrate that face mask ventilation is possible before giving a neuromuscular blocker?

Abstract

I read with great interest the thought-provoking editorial by Calder and Yentis [1]. I wholeheartedly agree with the authors’ considerable reservations about the rationale and safety of the practice of having to demonstrate effective face mask ventilation before administering muscle relaxants. This practice is by no means restricted to the UK and is not entrenched only in the minds of trainees but as much in those of many senior anaesthetists. When hypoxaemia develops in the presence of impossible face mask ventilation and at a level of anaesthesia which precludes the timely return of adequate spontaneous respiration, the ‘point of no return’ has been reached and immediate access to the patient’s airway literally becomes a question of life or death. If, at such a point, optimal intubating conditions are not present, we may be acutely confronted with one of the most threatening situations in anaesthetic practice, namely the ‘can’t ventilate, can’t intubate’ situation. I would argue that the still wide-spread practice of ‘no muscle relaxant before effective face mask ventilation’ may per se contribute to, and at times even provoke, this serious situation which would have to be regarded as entirely iatrogenic in origin. To avoid such a life-threatening situation, even the sternest proponents of the ‘no muscle relaxant before effective face mask ventilation’ rule would generally not hesitate to administer a muscle relaxant when failed mask ventilation reaches a point at which the patient becomes hypoxic. The logical consequence of insisting on demonstration of effective mask ventilation before injecting the muscle relaxant would be abandonment of rapid sequence induction (RSI) altogether. Instead, awake fibreoptic endotracheal intubation would have to be performed in all patients fulfilling the indications for RSI. But again during RSI even the sternest proponents of the ‘no muscle relaxant before effective face mask ventilation’ rule do not hesitate to administer a normal to high dose of a hypnotic drug immediately followed by the administration of a muscle relaxant knowingly precluding the testing for effective face mask ventilation and the possibility of return of adequate spontaneous respiration in case of airway problems. If ensuring effective mask ventilation before injection of the muscle relaxant were that essential for patient safety, why then compromising on such safety during RSI? Why should we proceed differently during routine induction of anaesthesia? The findings by Kheterpal et al. [2, 3] clearly support the view that the earliest possible administration of the muscle relaxant may well be the most effective and safest tactic in routine clinical practice [1, 4, 5]. During the futile attempts at ‘forcing’ air into the lungs of non-paralysed patients, one can’t help getting the impression that we are continually demonstrating that ventilating lungs in the absence of muscle relaxation is most often more difficult than doing so during muscle relaxation. The term ritual refers to a pattern of behaviour repeated in a fixed form and order as though prescribed by custom or authority, or as a series of actions habitually and invariably followed by someone. The term dogma refers to a fixed belief that people are expected to accept without any doubts, and to concepts as being ‘established’ only according to a particular point of view, and thus one of doubtful foundation. Would it be all that inappropriate to apply the terms ritual and dogma to the practice of, and to the insistence on performing the practice of, no administration of muscle relaxants before demonstrating effective face mask ventilation, respectively?