The Effects of Succinylcholine on the Neuromuscular Block of Mivacurium

Kim, Hae Kyung; Lee, Dong Chul; Kim, Min Jung; Lim, Jung Ae; Woo, Nam Sick; Lee, Ye Chul

Abstract

BACKGROUND: We studied the interaction between Succinylcholine (SCh) and mivacurium when mivacurium was administered during early and late recovery from SCh block was investigated.
METHODS
Eighty patients undergoing elective surgery under general anesthesia were studied. General anesthesia was induced and maintained with propofol under TCI control. Neuromuscular function was measured in response to TOF stimulation of the ulnar nerve using an electromyographic method. The patients were allocated randomly to the following four groups; group 1 (n = 20): a bolus intravenous injection of 0.08 mg/kg mivacurium; group 2 (n = 20): intravenous injection of 0.08 mg/kg mivacurium after 2 minutes of 1 mg/kg SCh injection; group 3 (n = 20): intravenous injection of 0.08 mg/kg mivacurium after 25% recovery of initial twitch height from twitch height depression induced by 1 mg/kg SCh; group 4 (n = 20): intravenous injection of 0.08 mg/kg mivacurium after 75% recovery of initial twitch height from twitch height depression induced by 1 mg/kg SCh. The onset and duration of neuromuscular blockade, recovery rate and TOF ratio at T75% were measured.
RESULTS
The onset of block in groups 3 and 4 were slower than in group 1 (5.2 +/- 0.7 and 2.3 +/- 0.6 vs 2.5 +/- 0.4 min P < 0.05). The clinical duration in groups 2 and 3 were longer than in groups 1 and 4 (12.5 +/- 2.1 min and 11.3 +/- 1.7 min vs 17.0 +/- 3.0 min and 18.5 +/- 2.6 min, p < 0.05). There was no difference in recovery index all groups. The TOF ratio of groups 2, 3 and 4 were smaller than for group 1 (38.2 +/- 5.3, 32.3 +/- 5.6 and 31.5 +/- 4.2 vs 56.0 +/- 7.3, P < 0.05).
CONCLUSIONS
The Previous 1 mg/kg SCh injection was affected the time course of action of mivacurium 0.08 mg/kg-induced neuromuscular block.