Study on the Pharmacodynamics of Cisatracurium by Decreasing Continuous Infusion

Objective The study is designed to compare the pharmacodynamics of cisatracurium by decreasing continuous infusion and intermittent bolus injection so as to find the best way of administration. Methods 40 ASA I~II patients undergoing elective spinal surgery were randomly divided into 2 groups. Patients in group Ⅰ received cisatracurium by decreasing continuous infusion and in group II by intermittent bolus injection. The responses of adductor pollicis were monitored by train-of-four(TOF) stimulation.The level of neuromuscular blockade and the total dose of cisatracurium were recorded, the average infusion rate was calculated; the recovery time of T1 to 25% and 75%, and recovery index(RI) of the two groups were recorded. Intravenous anesthesia was used for both induction and maintained by sevoflurane inhalation. Neuromuscular blockade was monitored until TOF ratio(T4/T1)≥75%. The patients were extubated when spontaneous breath recovered. Results The average infusion rate was significantly slower in group I than that in group II(P0.05); the recovery time of T1 to 25% and 75% was significantly faster in group I than that in group II(P0.05); There were no significant differences in the recovery index in both groups(P0.05). Conclusion Decreasing continuous infusion of cisatracurium can reduce the dose of cisatracurium used in the surgery and obtain a more stable neuromuscular blockade, and the spontaneous recovery from neuromuscular block is faster than that by intermittent bolus injection.