Comparative study on the pharmacodynamics of cisatracurium: continuous infusion or intermittent bolus injection.

To explore a better administration way through comparison of the pharmacodynamics of cisatracurium administered by continuous infusion or intermittent bolus injection. Thirty patients (ASAI-II) who had no neuromuscular disease and underwent selective surgery under general anesthesia were randomly divided into group I and II (each group with 15 patients). In group I, patients received cisatracurium by continuous infusion and in group II, by intermittent bolus injection. The responses of adductor pollicis to train-of-four (TOF) stimulation were monitored. The duration of neuromuscular blockade, recovery index and total dose of cisatracurium consumption were recorded in the two groups. Intravenous anesthesia was used for anesthesia induction and sevoflurane inhalation for maintenance of anesthesia. The mean infusion rate was significantly lower in group I (0.78 ± 0.15 μg.kg(-1).min(-1)) than in group II (1.09 ± 0.33 μg.kg(-1).min(-1)) (P<0.05). There was no significant difference in duration of neuromuscular blockade between the two groups (P>0.05). The recovery index was 13.13 ± 3.36 min in group I and 14.38 ± 4.48 min in group II, which indicated that the recovery was faster in group I than in group II, but without statistical significance (P>0.05). During the duration of neuromuscular blockade, 8 patients had T(1)<3%, 4 T(1) of 3%-7% and 3 T(1) of 7%-10% in group I; T(1) was maintained between 0 and 20% in group II. Although cisatracurium consumption was significantly lower in continuous infusion than in intermittent bolus injection, continuous infusion can obtain more stable neuromuscular blockade than intermittent bolus injection.