IS RECOVERY OF NEUROMUSCULAR-TRANSMISSION COMPLETE AFTER THE USE OF NEOSTIGMINE TO ANTAGONIZE BLOCK PRODUCED BY ROCURONIUM, VECURONIUM, ATRACURIUM AND PANCURONIUM

To test if recovery of neuromuscular transmission is complete after th e use of neostigmine under standardized conditions, we have measured a dductor pollicis mechanical activity in response to 0.1 Hz (twitch hei ght), train-of-four (TOF) and 100 Hz (RF 100 Hz) ulnar nerve stimulati ons. We studied 56 adult anaesthetized (thiopentone, fentanyl, nitrous oxide in patients, allocated randomly to one groups (n=14) to receive rocuronium Roc), vecuronium (group Vec), atracurium (group Atr) or pa ncuronium (group Pan). Recovery of neuromuscular transmission was stud ied for 15 min after neostigmine 40 mu g kg(-1) was given at 25% recov ery of twitch height. Fifteen minutes after antagonism, the TOF ratio was 0.91 (SEM 0.01), 0.88 (0.02) and 0.92 (0.01) (ns), and RF 100 Hz w as 0.78 (0.01), 0.79 (0.02) and 0.78 (0.01) (ns) respectively, in pati ents in groups Roc, Vec and Atr, respectively. In patients in group Pa n, TOF ratio and RF 100 tit were only 0.76 (0.01) and 0.33 (0.04) resp ectively (P<0.01, one-way analysis of variance, Duncan's multiple clas sification range tests). In contrast with pancuronium, antagonism of r ocuronium-, vecuronium- and atracurium-induced neuromuscular blocks pr oduced a similar high degree of recovery of neuromuscular transmission .