Abstract: Objective The study was designed to compare the pharmacodynamics of rocuronium administered by target-controlled infusion(TCI) and continuous infusion and to investigate the feasibility of target-controlled infusion of rocuronium.Methods Thirty female adult patients,ASA Ⅰ^Ⅱ,without any neuromuscular disease,undergoing elective surgery under general anesthesia,were randomly divided into two groups with fifteen patients each.In group Ⅰ patients received rocuronium by TCI and in group Ⅱ by continuous infusion.The responses of adductor pollicis to train-of-four(TOF) stimulation of ulnar nerve were monitored.The onset time,the time of maximal neuromuscular blockade,the duration of neuromuscular blockade,the spontaneous recovery time,dosages of rocuronium and intubations condition were recorded.Total intravenous anesthesia(TIVA) was used for both induction and maintenance of anesthesia.Patients received no antagonists for reversal of neuromuscular blockade and recovered spontaneously.Neuromuscular blockade monitoring ended when TOF ratio(T₁/Tc)≥75%.The patients were extubated when ventilation was satisfactory.Results The two groups were well-matched with regard to age,weight,height and duration of operation.The mean onset times were(73.3±26.6)s in group Ⅰ versus(88.7±36.2)s in group Ⅱ(P>0.05).The mean dosages of induction were(0.86±0.09)mg/kg in group Ⅰ versus(0.60±0.00)mg/kg in group Ⅱ(P<0.01).The mean target concentration of maintenance was 4.47mg/mL in group Ⅰ.There was no significant difference in the recovery time between the two groups.The total dosages between the two groups.Conclusion Target-controlled infusion of rocuronium can be used safely in clinical practice.The suggested effect-site concentration of induction is 9 mg/mL,at which intubation is accomplished 70 s after induction.The suggested effect-site concentration of maintenance is 4.5 mg/mL.TCI can provide satisfactory muscle relaxation,but is not advantageous over continuous infusion.

Key words: neuromuscular blockade, nondepolarizing agents, rocuronium, target-controlled infusion, total intravenous anesthesia