A comparison of d-tubocurarine pretreatment and no pretreatment in obstetric patients.

The effect of pretreatment with d-tubocurarine on the incidences of succinylcholine-induced fasciculations and post-operative muscle pain, and the time to onset of and 50% recovery from neuromuscular blockade were studied in 75 obstetric patients. Thirty women with term pregnancies undergoing general anesthesia for elective cesarean section or cesarean section indicated by cephalopelvic disproportion were randomly assigned to two groups. Group C-1 patients received 0.05 mg/kg of d-tubocurarine followed by 1.5 mg/kg of succinylcholine, and group C-2 patients received 1.5 mg/kg of succinylcholine, and group C-2 patients received 1 ml of normal saline followed by 1 mg/kg of succinylcholine. An investigator, unaware of the relaxant regimen used, judged severity of fasciculations and postoperative muscle pain and measured times to onset of and 50% recovery from neuromuscular blockade. This same study design was followed in a group of 30 women undergoing tubal ligation 1 day after vaginal delivery (groups T-1 and T-2). The incidence of both fasciculations and postoperative muscle pain was low and was not significantly different between pretreated and nonpretreated groups. Time to 100% twitch depression was also not significantly different between pretreated and nonpretreated groups. Time to 50% recovery from neuromuscular blockade was significantly longer in both nonpretreated groups (C-2 and T-2). An additional group of 15 patients undergoing general anesthesia for cesarean section using 0.7 mg/kg of succinylcholine without d-tubocurarine pretreatment was studied (group C-3). This smaller dose of succinylcholine produced onset and 50% recovery times similar to the group pretreated with d-tubocurarine (group C-1).(ABSTRACT TRUNCATED AT 250 WORDS)