NEUROMUSCULAR AND CARDIOVASCULAR EFFECTS OF NEOSTIGMINE AND METHYL-ATROPINE ADMINISTERED AT DIFFERENT DEGREES OF ROCURONIUM-INDUCED NEUROMUSCULAR BLOCK

The neuromuscular and cardiovascular effects of neostigmine, 40 mug kg -1, and methyl-atropine, 7 mug kg-1, administered at different degrees of rocuronium-induced (600 mug kg-1) neuromuscular block were evaluat ed. In one group of patients spontaneous recovery was awaited (Group A ; n = 20). Neostigmine and methyl-atropine were administered 2 minutes after rocuronium (Group B; n = 20) or at 25% twitch recovery (Group C ; n = 20). Neuromuscular transmission was monitored mechanomyographica lly. Data are presented as mean (SD) [95%-Cl]. The initial rate of rec overy (time until a TOF ratio of 0.2) in group B, i.e. 14.2 (4.5) [12. 1-16.3] min, was significantly faster than in group C, i.e. 28.7 (5.3) [26.3-31.1] min. However, the time until clinically sufficient recove ry (time until a TOF ratio of 0.7) was similar for groups B, i.e. 29.3 (9.5) [24.9-33.7] min and group C, i.e. 31.8 (5.6) [29.2-34.4] min, b oth significantly different from that of group A, i.e. 53.2 (14.5) [46 .5-59.9] min. The increase in heart rate following neostigmine/methyl- atropine was more pronounced in the group reversed at 2 min after rocu ronium (P<0.01).