Effects Of Patients With Liver Dysfunction On The Free Hexafluoroisopropanol(HFIP) Of Sevoflurane Metabolites

Objective: To comparethe change of free hexafluoroisopropanol concentration between adult patients with normal liver function and hepatocirrhosis patients with B grade liver function after sevoflurane anesthesia using a same concentration and a same time,for observing the effect of differentliver function on the metabolism of sevoflurane.Furtherly,to evaluate the effect of free hexafluoroisopropanol on the recovery quality after sevoflurane anesthesia.Methods: Thirty patients undergoing elective abdominal surgery were divided into group A with normal liver function and group B with Child-Pugh Class B grade liver function.Each group was 15 patients and the expected operation time was about 3 hours.Anesthesia was maintained by inhaled sevoflurane with 1.5 MAC concentration and target-controlled infusion of remifentanil(target concentration4-6ng/ml)and continuously intravenousinfusion of atracurium besylate(1-3ug/kg.min).The oxygen flow rate was 2L/min.The auditory evoked potentialindex(AEPi)was maintainedbetween 15 and 30.All drugs were discontinued at the end of operation.Venous blood samples(each for 7 ml)were collected at the time points of 0.5h,1h,2h,3h after inhaled sevoflurane and 0.5,1h,2h,4h after inhaled anesthesia was discontinuated.The free hexafluoroisopropanol concentration in blood samples were determined by Gas Chromatography.Patients' recovery condition was observed at the end of the operation,including spontaneous breathing recovery time(T1),anesthesia recoverytime(T2),orientation recovery time(T3),command response time(T4),extubation time(T5).VAS pain score and Ramsay sedation score were also performed 0 min,15 min,0.5h,1h,2h,3h,4h after extubation.Results: The concentration of free HFIP in the two groups increased gradually with the prolongation of anesthesia time and reached a peak value and then decreased gradually during the sevoflurane anesthesia phase.The time for free HFIP in the group B reaching its peak value was 1h later than that in the group A,but no significant difference was found between their peak values.Both in the two groups,the concentration of free HFIP was continue to decrease within 4 hours after discontinued sevoflurane.Although the concentration of free HFIP in the group B at each time point was a little lower than that in the group A,no significant difference was found between the two groups at corresponding time point.The spontaneous breathing recovery time,anesthesia recovery time,orientation recovery time,command response time and the extubation time in the group B were longer than those of group A(P <0.05).The VAS pain scores in 15 min and 0.5 h after extubation in the group B were lower than those in the group A.(P <0.05),but the Ramsay sedation scores in 0.5 h,1 h,2 h after extubation in the group B were higher than those in the group A(P <0.05).Conclusion:(1).Compared to normal liver function patients,grade B liver function patients had no significant effects on the generation of hexafluoroisopropanol from sevoflurane.(2).The anesthesia recovery quality in patients with grade B liver function received sevoflurane anesthesia with a commonly used concentration(1.5MAC)was not affected by its metabolite--hexafluoroisopropanol.