| Objective:Hexafluoro-isopropanol(HFIP),a metabolite of sevoflurane,has a high anesthetic potency and blood/gas partition coefficient(B/G),suggesting that the HFIP produced by sevoflurane anesthesia easily remains in the body,which may affect the potency of sevoflurane and the quality of postoperative recovery.This study aims to determine the free hexafluoro-isopropanol(HFIP)concentration in blood when SD rats had been anesthetized with different sevoflurane concentrations for different times,to observe the change of free HFIP concentration in rats’ blood,and analyze the relationship between inhaled sevoflurane concentration and free HFIP concentration in blood among the three groups.Methods:One hundred and fourteen healthy adult SD rats were selected(half male,half female),in which six rats were used to determine the blood/gas partition coefficient(B/G)of HFIP,and the rest 108 rats were randomly divided into three groups(groups A1,A2 and A3)with 36 rats in each group,and anesthetized by sevoflurane with concentrations of 1.16%(group A1,0.5 MAC),2.32%(Group A2,1.0 MAC)and 3.48%(group A3,1.5 MAC),respectively.Every six rats in each group were anesthetized by inhaled sevoflurane with a preset sevoflurane concentration for 0.5 1.0,1.5,2.0,3.0 and 4.0 h,respectively.Then we took five to ten mL of abdominal aortic blood was obtained immediately at the end of anesthesia.Next,the concentrations of free HFIP in blood were measured by combining the headspace one-stage equilibrium method and the headspace two-stage headspace equilibrium method.Both the curves of free HFIP concentration in blood and inhaled sevoflurane concentration vs.anesthesia time were made,and the relationship among them was analyzed.Results:Free HFIP concentration could be detected at all observation time points.Its concentration expansion first and then reduced with the extension of inhalation anesthesia time.Its peak value occurred at one hour after inhalation anesthesia of sevoflurane in each group.Compared with group A1,the concentration of free HFIP in group A2 was higher at each corresponding time point(P<0.05),but except for the time point of 4.0 h,no significant differences were found in group A3 at corresponding time points(P>0.05).Compared with group A2,the free HFIP concentration in group A3 was statistically previously declined in group A3 at all time points.Conclusion:The free HFIP concentration in rats’ blood showed a tendency from initially increasing in one hour to subsequent decreasing during the period of anesthesia with different sevoflurane concentrations.However,when the inhaled sevoflurane concentration increased to some extent(3.48%,1.5 MAC),free HFIP concentration in blood showed a decreasing trend at each time point,and the metabolism of sevoflurane was inhibited. |
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