Atracurium or vecuronium for MHS patients?

CORRESPONDENCE ATRACURIUM OR VECURONIUM FOR MHS PATIENTS? Sir,—I am writing in regard to comments made by Hunter [1] in her review entitled "Adverse Effects of Neuromuscular Blocking Drugs ", on the use of vecuronium and atracurium in malignant hyperthermia-susceptible (MHS) patients. She states that "satisfactory use of both agents has been reported in patients susceptible to malignant hyperpyrexia " and refers to papers by Buzello and colleagues [2] and Michel and Fronfield [3]. Buzello's study was on MHS swine, not patients, and one of eight swine triggered in response to vecuronium. The explanations offered by the authors did not fit the facts as presented [4]. A literature search done for me by Organon Canada Ltd in December 1986 revealed no other studies in MHS swine or patients on the safety of vecuronium. Michel and Fronfield [3] reported an 8 yr-old girl with a history of a previous MH crisis who was given atracurium for eye surgery without incident. There is other, more definitive proof of the safety of atracurium in MHS swine and patients. Skarpa and colleagues [5] reported that atracurium did not trigger MHS swine. Morrcll and Harrison [6] have also shown that atracurium did not trigger MH in susceptible swine. Hunter goes on to state that "it is considered preferable to allow spontaneous recovery from any non-depolarizing neuro-musular blocking agent". 0rding and Nielsen [7] reported the safe use of atracurium in 40 MHS patients, in all of whom blockade was antagonized with neostigmine and glycopyrrolate without incident. It is our practice to antagonize neuro-muscular blockade in MH patients whenever reversal would otherwise be indicated. In conclusion, there is support in the literature for the safe use of atracurium in MHS patients. There is as yet no such support for vecuronium. Ottawa REFERENCES 1. Hunter JM. Adverse effects of neuromuscular blocking drugs. Atracurium and its antagonism by neostigmine (plus glycopyrrolate) in patients susceptible to malignant hyperthermia. Sir,—When my review article was written the interesting paper by Ording and Nielson [1] on the use of anti-cholinesterases in MHS patients given atracurium was not yet in print, so I was unable to refer to it. Their work is reassuring over the use of neostigmine in such patients, but the authors themselves state that the antagonism of neuromuscular block in such circumstances "is still controversial." I doubt that allowing spontaneous recovery from neuromuscular block in the MHS patient could be considered anything …