Early and late reversal of rocuronium and vecuronium with neostigmine in adults and children

We investigated the influence of the timing of neostigmine administration o n recovery from rocuronium or vecuronium neuromuscular blockade. Eighty adu lts and 80 children were randomized to receive 0.45 mg/kg rocuronium or 0.0 75 mg/kg vecuronium during propofol/fentanyl/N2O anesthesia. Neuromuscular blockade was monitored by train-of-four (TOF) stimulation and adductor poll icis electromyography. Further randomization was made to control (no neosti gmine) or reversal with 0.07 mg/kg neostigmine/0.01 mg/kg glycopyrrolate gi ven 5 min after relaxant, or first twitch (T-1) recovery of 1%, 10%, or 25% . Another eight adults and eight children received 1.5 mg/kg succinylcholin e. At each age, spontaneous recovery of T-1 and TOF was similar after rocur onium and vecuronium administration but was more rapid in children (P < 0.0 5). Spontaneous recovery to TOF0.7 after rocuronium and vecuronium administ ration in adults was 45.7 +/- 11.5 min and 52.5 +/- 15.6 min; in children, it was 28.8 +/- 7.8 min and 34.6 +/- 9.0 min. Neostigmine accelerated recov ery in all reversal groups (P < 0.05) by approximately 40%, but the times f rom relaxant administration to TOF0.7 were similar and independent of the t iming of neostigmine administration. Recovery to T-1 90% after succinylchol ine was similar in adults (9.4 +/- 5.0 min) and children (8.4 +/- 1.1 min) and was shorter than recovery to TOF0.7 in any reversal group after rocuron ium or vecuronium administration. Recovery from rocuronium and vecuronium b lockade after neostigmine administration was more rapid in children than in adults. Return of neuromuscular function after reversal was not influenced by the timing of neostigmine administration. These results suggest that re versal of intense rocuronium or vecuronium neuromuscular blockade need not be delayed until return of appreciable neuromuscular function has been demo nstrated. Implications: These results suggest that reversal of intense rocu ronium or vecuronium neuromuscular blockade need not be delayed until retur n of appreciable neuromuscular function has been demonstrated. Although spo ntaneous and neostigmine-assisted recovery is more rapid in children than i n adults, in neither is return of function as rapid as after succinylcholin e administration.