Sugammadex in anticipated difficult airways 5

I read the recent case report by Paton et al. 1 and accompanying editorial 2 with interest. Sugammadex provides the anaesthetist with the ability to achieve complete and predictable reversal from any level of neuromuscular block. Complete reversal requires the administration of sugammadex on a patient-weight basis, giving a recommended dose depending on the depth of neuromuscular blockade. The authors of the case report elected to use 40 mg rocuronium (0.6 mg.kg−1 for a 69-kg patient). Sugammadex 400 mg was given 2–3 min after induction, equating to 5.79 mg.kg−1. The authors state that there then followed a difficult few minutes with improving spontaneous respiratory effort. The recommended doses of sugammadex are: 2 mg.kg−1 to reverse moderate neuromuscular block (at least two of a train of four twitches; 4 mg.kg−1 to reverse deep block (1–2 post-tetanic counts (PTC)); and 16 mg.kg−1 for immediate reversal after a dose of 1.2 mg.kg−1 rocuronium. When administering sugammadex, it is essential that the correct dose is used to ensure complete reversal of neuromuscular blockade. In the emergency situation reported, there was an understandable lack of neuromuscular blockade monitoring, and it is possible that the level of blockade 2-3 min after 0.6 mg.kg−1 rocuronium was more extensive than 1–2 PTC. A larger dose of sugammadex, for example 8 mg.kg−1, would have been more likely to reverse blockade completely. A degree of residual neuromuscular blockade may well have contributed to the ‘difficult few minutes’ reported by the authors; the laryngeal muscles are the most sensitive to neuromuscular blockade and any amount of residual block, however small, is likely to be clinically deleterious in a critical airway. An immediate further dose of sugammadex might have led to clinical improvement. I have given a number of talks on sugammadex to UK anaesthetic departments and have observed that the majority of anaesthetists have no clinical experience of using it, although it is often available for emergency use in a ‘can't intubate, can't ventilate’ situation. This situation is rare but I suggest that clinicians familiarise themselves with sugammadex so that they are not faced with having to use it for the first time in a difficult, stressful and life-threatening airway scenario. Whether or not a difficult airway situation is predicted or unanticipated, if rocuronium has been administered the airway plan should include the correct dose of sugammadex to ensure complete reversal of residual neuromuscular block.