neuromuscular effects of atracurium pretreatment and its effect on the neuromuscular blocking action of succinylcholine

ABSTRACT

Pretreatment with atracurium was studied in one hundred and twenty patients divided into four groups [n = 30 in each]. The first group [control] received normal saline [2 ml] as placebo, the second, third and fourth groups received atracurium in a dose of 0.04 mg/kg, 0.05 mg/kg and 0.06 mg/kg, respectively. Saline or atracurium was given three minutes before succinylcholine. Atracurium pretreatment in a small dose [0.04 mg/kg] did not affect the control twitch response. With atracurium 0.05 mg/kg, the twitch response depression was small and insignificant [1.33% +/- 0.79]. A greater effect was observed on increasing the dose of atracurium [0.06 mg/kg] which produced a highly significant decrease in twitch response [12.63% +/- 1.93]. Pretreated groups showed a significant prolongation in onset time of Sch. Such effect being greater and more significant on increasing the pretreatment dose. The mean time to abolition of twitch was 27.5 + 0.58, 30.33 +/- 0.68, 43.5 +/- 1.36 and 49.67 +/- 1.76 seconds in the first, second, third and fourth groups, respectively. All pretreated patients showed a significant decrease in duration of action of Sch. There was a highly significant difference in the intubating conditions between the control group [best intubating conditions] and the pretreated group