Postoperative neuromuscular block following atracurium or alcuronium in children.

Postoperative neuromuscular block (NMB) was evaluated in 60 children who received randomly either atracurium or alcuronium to induce and maintain an 85-95 per cent NMB during balanced anaesthesia. The EMG-monitor was turned away from the anaesthetist 10-15 min before the end of surgery. The average NMB was comparable between the groups at the time of reversal with neostigmine 50 micrograms.kg-1 (84 +/- 9 per cent, mean +/- SD) as were the NMB and the train-of-four ratio when the tracheas were extubated on a clinical basis (32 +/- 20 per cent and 50 +/- 18 per cent, respectively). Patients who had been paralyzed with atracurium arrived at the recovery room earlier and on arrival had greater train-of-four ratios than the patients paralyzed with alcuronium (P less than 0.01). Time to a train-of-four ratio of greater than 90 per cent was significantly shorter in the atracurium group (10 +/- 5 min vs 26 +/- 15 min, P less than 0.001). Thus, an intermediate-acting muscle relaxant offers a safer recovery profile of the NMB than a long-acting muscle relaxant in paediatric patients.