Mivacurium Neuromuscular Block at the Adductor Muscles of the Larynx and Adductor Pollicis in Humans

Comment: This article confirms that, similar to the findings after systemic administration of other muscle relaxants, after intravenous injection of mivacurium: 1) the onset of neuromuscular block occurs more rapidly at the adductor muscles of the larynx than at the adductor pollicis muscle; 2) the sensitivity to the relaxant is less at the laryngeal adductors than at the adductor pollicis; and 3) recovery from the relaxant is faster at the laryngeal muscles than at the adductor pollicis. Although the findings are consistent with what had been predicted, this study nonetheless is still important. Mivacurium has a different metabolism from other nondepolarizing muscle relaxants and a much shorter time course. It should be comforting to the clinician to know that mivacurium's relative effectiveness at sites with different fiber types and different blood flows is similar to that of other non-depolarizing relaxants.