[Lidocaine metabolism associated with epidural anesthesia in patients for hepatic surgery].
We measured plasma concentrations of lidocaine and its principal metabolite, monoethylglycinexylidide (MEGX) associated with thoracic epidural anesthesia using continuous infusion of lidocaine in 10 patients for hepatectomy and other 10 patients for elective abdominal surgery as a control. Plasma concentrations of lidocaine and MEGX were analysed by fluorescence polarization immunoassay and high performance liquid chromatography, respectively. Plasma lidocaine concentration increased gradually, and peaked to 5.1 +/- 2.3 micrograms.ml-1 (mean +/- SD) at the end of surgery in the hepatectomy group, but not in the control group. No significant differences were observed in plasma MEGX concentration between these two groups. Our findings suggest that MEGX formation by the hepatic cytochrome P-450 system might be impaired associated with hepatic surgery. Hypoperfusion of the liver induced by surgical manipulation may have contributed to this impaired metabolism.
Sato
T
T
Second Department of Anesthesiology, Medical Research Institute, Dokkyo University School of Medicine, Tochigi.
Ono
T
T
Ozaki
M
M
Sakio
H
H
Yasuda
S
S
D000368:Aged; D000767:Anesthesia, Epidural; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000493:pharmacokinetics*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008658:Inactivation, Metabolic; D007268:Injections, Epidural; D008012:Lidocaine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000493:pharmacokinetics*; D008099:Liver / Q000201:enzymology; D008297:Male; D008875:Middle Aged
D000779:Anesthetics, Local; D003577:Cytochrome P-450 Enzyme System; D008012:Lidocaine; C001173:monoethylglycinexylidide