A COMPARISON BETWEEN VECURONIUM AND ATRACURIUM IN MYASTHENIA-GRAVIS

We evaluated the effect of vecuronium bromide and atracurium besylate on the train-of-four response in the management of muscle relaxation i n 20 patients with myasthenia gravis (MG) who were undergoing thymecto my. We confirmed the safe use of these two non-depolarizing muscle rel axants in MG patients. Vecuronium (0.04 mg . kg-1) demonstrated a less er clinical duration than did atracurium (0.2 mg . kg-1) (38 +/- 19 vs 50 +/- 21 min, mean +/- s.e.mean). The recovery time for vecuronium p atients was shorter than that for atracurium patients (22 +/- 18 vs 38 +/- 18 min), but the time until onset of neuromuscular blockade was l onger with vecuronium (246 +/- 105 vs 107 +/- 103 s). During spontaneo us recovery from neuromuscular relaxation, at Tl/C of 25% and 100%, th e train-of-four fade with vecuronium was significantly greater than th at with atracurium (0.04 +/- 0.02, 0.16 +/- 0.03 vs 0.17 +/- 0.01, 0.8 3 +/- 0.03), suggesting that vecuronium had a greater prejunctional ef fect than did atracurium.