Confirmation of the ability to ventilate by facemask before administration of neuromuscular blocker: a non-instrumental piece of information?

BACKGROUND: Our aim was to determine whether anaesthetists routinely confirm their ability to ventilate a patient's lungs by a facemask before the administration of a neuromuscular blocker and the rationale for this practice.
METHODS: An online survey of trainee and non-trainee anaesthetists working in hospitals forming part of the Central London School of Anaesthesia collected 136 complete data sets over a 3 month period.
RESULTS: Seventy-eight of 136 (57%) routinely checked they could ventilate by the facemask ('checkers'). The reasons given for this varied, though the most common was the ability to 'enable escape wake-up'. The practice was most commonly adopted by anaesthetists with less experience. In a hypothetical 'cannot ventilate' scenario, the use of succinylcholine was advocated by the majority of respondents, both 'checkers' and 'non-checkers'.
CONCLUSIONS: Despite the lack of firm evidence to support the practice of confirming the ability to ventilate the lungs before administering a neuromuscular blocking drug (NMB), we found strongly held views that supported the practice and equally strongly held views that opposed it. However, in a hypothetical emergency situation where ventilation by the facemask after induction of anaesthesia was impossible, the majority of respondents (including 'checkers') would administer a neuromuscular blocker. This apparent paradox can be explained by well-recognized psychological mechanisms. We suggest that in checking the ability to ventilate by the facemask, some anaesthetists are seeking information that may be relevant but not instrumental in deciding when to administer an NMB.