Vecuronium and atracurium in patients with end-stage renal failure. A comparative study

Twenty patients with end-stage renal failure, undergoing kidney transplantation, were assigned randomly to receive either vecuronium or atracurium under evoked twitch tension control. The cumulative-dose technique was used to obtain 95% twitch depression (vecuronium: initial bolus 15 micrograms kg-1, increments 6 micrograms kg-1; atracurium: initial bolus 100 micrograms kg-1, increments 40 micrograms kg-1). Using ED95 values derived from the log-probit dose-response curves, vecuronium was 4.6 times more potent than atracurium. The durations of action of the initial cumulative-doses (from end of injection of the last increment to 25% recovery) were 11.1 +/- 3.3 min for vecuronium and 16.2 +/- 3.9 min for atracurium (P less than 0.05). In terms of duration of action of the maintenance doses (vecuronium one-quarter of the total incremental dose; atracurium one-third) some cumulation was observed with vecuronium (interaction time X treatment; cumulation ratio 1.46 +/- 0.31 v. 0.98 +/- 0.10 for atracurium, P less than 0.001). After 2 h of surgery, the mean recovery times (25% to 75% twitch height) did not differ (18.5 +/- 2.8 min and 16.7 +/- 4.4 min). It is concluded that vecuronium might be less safe than atracurium in patients with end-stage renal failure undergoing prolonged operations.