title: Muscle relaxation in patients with Duchenne's muscular dystrophy. Use of vecuronium in two patients.
abstract: Cumulative 50% and 90% neuromuscular blocking doses of vecuronium were determined in two 4-yr-old boys with Duchenne's muscular dystrophy. Vecuronium 20 micrograms kg-1 was required for 50% twitch depression in both patients. The 90% blocking doses were 43 and 57 micrograms kg-1. Although these data do not indicate a greater than normal sensitivity to vecuronium, the recovery time (75-25% block) of twitch tension was three to almost six times as long as in normal children. The evoked compound EMG, additionally recorded in one patient, reflected almost the same dose-response relationship as twitch tension, yet the EMG recovered faster than the twitch. The present findings do not exclude an increased sensitivity to neuromuscular blocking drugs in a larger population of patients with muscular dystrophy. Thus, the titration of the individual neuromuscular blocking dose with the aid of a nerve stimulator is mandatory. During a previous anaesthetic, cardiac arrest and acute rhabdomyolysis had occurred in one patient. The substitution of suxamethonium by vecuronium, or probably any other non-depolarizing myoneural blocking drug of intermediate or short duration of action, may help to avoid this complication.
mesh_terms: D002675:Child, Preschool; D004576:Electromyography; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation; D009136:Muscular Dystrophies / Q000503:physiopathology*; D013997:Time Factors; D014673:Vecuronium Bromide / Q000494:pharmacology
chemical_list: D014673:Vecuronium Bromide