[Muscle relaxants for kidney transplantation. A comparison between vecuronium and atracurium]

A total of 26 patients with end-stage renal failure were assigned randomly to receive either atracurium (A) or vecuronium (V) for intra-operative relaxation during kidney transplantation. Following the induction of balanced anesthesia an initial bolus dose of A 0,5 mg/kg body weight (BW) or V 0,1 mg/kg BW was administered. Relaxation was maintained by repeated doses of A 0,1 mg/kg BW or V 0,02 mg/kg BW whenever the twitch height (T1) recovered to 20% of the control value. Neuromuscular function was monitored throughout using the train-of-four twitch technique. There were no significant differences in time of onset (A: 219 +/- 87 s, V: 206 +/- 70 s), initial clinical duration (T1 = 0% to T1 = 20%; A: 39 +/- 12 min, V 39 +/- 8 min) or recovery index (A: 19 +/- 6 min, V: 22 +/- 7 min). The clinical duration (T1 = 20% to T1 = 20%) was significantly different for A, with 27 +/- 9 min than for V, with 32 +/- 7 min (P less than 0.05, Wilcoxon-Mann-Whitney U-Test; all values means +/- standard deviation). Reversal of relaxants was mandatory according to electromyographic and clinical criteria in only one patient in the A group but in 5 in the V group (P less than 0.05, Fisher's exact test). We conclude that A might be more suitable in patients with renal insufficiency and that monitoring of neuromuscular transmission is highly valuable in this risk group.