Extubation guidelines: management of laryngospasm

Authors


We congratulate the Difficult Airway Society for producing excellent, well thought out guidelines on tracheal extubation [1]. However, we would like to comment on the Appendix concerning the prevention and treatment of laryngospasm.

As they correctly point out, laryngospasm is a serious complication and must be promptly managed to avoid serious physiological disturbance. In the recent analysis of 189 reports of laryngospasm to the Australian Incident Monitoring Study, one in three patients suffered significant physiological disturbance. In one in five patients, laryngospasm was triggered by blood, secretions, regurgitation or vomiting, and yet the guidelines fail to mention the importance of visually inspecting the pharynx [2]. Furthermore, the diagnosis of laryngospasm was not immediately obvious in a quarter of the reports, presenting late with desaturation or regurgitation.

Regarding the treatment of laryngospasm, the overriding principles of oxygenation and prompt management could have been made clearer in Table A1. The principle of continuous positive airway pressure (CPAP) with 100% inspired oxygen is accepted, but we consider the inclusion of Larson’s Manoeuvre surprising, as this technique is published in letter form only [3] and its use could delay definitive management with either intravenous propofol or suxamethonium.

Clarification is needed about suxamethonium administration in the event of lost intravenous access, or when no access has been attempted during the gaseous induction of anaesthesia in a child. The dose range quoted in Table A1 might not be helpful in these stressful circumstances. The accepted dose for intramuscular suxamethonium is 4 mg.kg−1. Lower doses will provide variable levels of paralysis, often as low as 20–30% of maximal twitch depression after 3–4 minutes [4], although the laryngeal muscles may be affected within 30–45 seconds [5] suggesting that intramuscular suxamethonium may be effective within one minute after laryngospasm. The dose of intralingual suxamethonium is accepted as 2 mg.kg−1, causing complete paralysis within 75 seconds, but possibly a higher incidence of arrhythmias compared with the intramuscular or intravenous route [6], together with loss of CPAP and a potential for haemorrhage during administration. The submental route of intralingual suxamethonium administration at a dose of 3 mg.kg−1 might also be considered, although the onset of complete paralysis is more variable, in the region of two minutes [7].

The management of laryngospasm can be very challenging and we would like to reiterate the importance of early diagnosis and oxygenation, with neuromuscular blockade if simple measures fail to resolve the problem.

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