Clinical characteristics and biotransformation of sevoflurane in paediatric patients during antiepileptic drug therapy.

Patients with epilepsy on long term antiepileptic drug (AED) therapy deserve special consideration not only concerning seizure control but also the effect on anaesthetic metabolism and hepatorenal functions. In the present study, we examined the effects of sevoflurane anaesthesia on plasma inorganic fluoride (F-) level and hepatorenal function in patients with and without AED therapy. Twenty-two patients (12 with AEDs = AED group, and ten without AEDs = control group = C group), ASA I, who were free of hepatorenal disease, received approximately 2-3 h sevoflurane anaesthesia. Plasma F- analysis was performed at the stages of: 1) induction of anaesthesia, 2) conclusion of anaesthesia, 3) 15 h after the conclusion of anaesthesia, using an ion-selective electrode calibrated with a standard solution of sodium fluoride. Pre- and postoperative hepatic (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin) and renal (blood urea nitrogen, creatinine) function was tested. There were no significant differences between the two groups in the average age (AED group = 9.4 and control group = 10.1 y.o.), body weight, duration of anesthesia, and MAC hours (2.6 and 2.4). The mean peak F- levels were 15.5 and 13.6 microM, in AED and C groups (not significant), respectively. No patient exhibited F- values greater than 50 microM, the hypothetical nephrotoxic threshold. The patients showed no abnormal values either in hepatic or renal function tests postoperatively. These results suggest approximately 2-3 h sevoflurane anaesthesia to be safe in patients taking AEDs.