To evaluate the
effects of
enflurane or isoflurane on the
pharmacokinetics of
pancuronium (PAN), eighteen adult patients, ASA grade I, undergoing elective plastic surgery, were randomly divided equally into groups Ⅰ (control group), Ⅱ (enflurane group) and Ⅲ (isofluranc group). Anesthesia was maintained with inhalation of 60% nitrous oxide in oxygen combined with
intravenous thiopental in group I, and with Inhaling 1 MAC of enflurane or isoflurane in groups Ⅰ or Ⅱ respectively. The blood samples were taked at various times following intravenous bolus of PAN 100pg. kg-1 in three groups. The plasma concentrations of PAN were determined with an improved fluorometry and the pharmacokinetic variables were calculated with the standard formulae from a 3P87 program. The disposition of PAN can be best described mathematically by a two--compartment open model. The results showed that as compared with the control values in group I,the levels of TI/29 and MRT increased significantly in groups and Ⅲ (P<0.01) and ones of K10 and CL decreased markedly in group Ⅱ (P<0.05). There were no significant differences in T1/2, V1. V2. Vdss, V. K12, K21 and AUC between group 1 and either group or group N (P>0. 05). It is conclued that enflurane and isoflurane may affect the pharmacokinetics of PAN to prolong its duration of neuromuscular depression to a certain extent.