The Effects of Cholestasis and Hepatic Failure on Vecuronium - induced Neuromuscular Blockade in the Cat

Lee, Kyoung Min; Kwak, Young Ran; Shin, Yang Sik; Choi, Ryung; Kim, Jong Rae

Abstract

To determine th effects of experimental extrahepatic cholestasis in the pharmacodynamics of vecumnium, the author administered vecuronium 500 ug/kg intravenously to six normal cats(control group), and into each of six cats with hepatic failure (hepatic failure group) and cholestasis (cholestasis group). The hepatic failure was induced with galactosamine hydrochloride and the cholestasis with the ligation of the common bile duct and cystic duct, 16 hours and 8 days prior to the neuromuscular study, respectively. The force of the anterior tibialis muscle in response to supramaximal common peroneal nerve stimulations were recorded. The time intervals from vecuronium administration to attain 100% twitch depression (onset time), from vecumnium administration to recovery of 25% twitch tension (duration) and from 25% to 75% twitch recovery (recovery index) were compared among the three groups. The results are as follows: 1) There were no significant differences between the groups with respect to rectal temperature, heart rate and mean arterial pressure immediately before vecuronium administration. 2) According to the differences of base excesses, the pH of arterial blood was significantly lower in the hepatic failure and cholestasis groups than in the control groups. 3) After induction of the hepatic failure and cholestasis group, SGOT, SGPT and prothrombin time were significantly increased when compared to the preinduction data in the two groups and data from the control group. Total bilirubin, BUN and creatinine concentration after cholestasis was significantly higher than those of the control group and the hepatic failure group. 4) The onset time in the hepatic failure and cholestasis group was slightly prolonged as compared with that in the control group. However, there was no statistical significance. The duration was significantly longer in hepatic failure and cholestasis than in the control group, and also the recovery index was significantly increased in the hepatic failure and cholestasis groups, as compared with the control group, There were no significant differences between the hepatic failure and cholestasis groups. These vesults indicate that experimental extrahepatic cholestasis induced by complete obstruction of biliary tract prolongs the duration and recovery index of vecuronium, and the effects may be caused by the impairment of direct biliary excretion, hepatic dysfunction and renal impairment.