Determination Of Free Hexafluoro-2 Propanol(HFIP) In Adult Rats’ Blood After Sevoflurane Anesthesia

Objective: To determine free hexafluoro-2 propanol(HFIP) in adult male Sprague Dawley(SD) rats’ blood after inhaled different concentrations of sevoflurane at different intervals, and analyze the relationship between the content of free HFIP and the given concentration of sevoflurane or the time of anesthesia.Methods: One hundred healthy adult male SD rats were randomly divided into four groups, with 25 rats in each group anaesthetized by 0.5MAC, 1MAC, 1.5MAC, 2MAC concentration of sevoflurane, respectively. All rats were settled in a self-made device for anesthesia with inhaled sevoflurane. The actual concentration of sevoflurane was calibrated by gas chromatograph(GC7890A). Arterial blood samples(7 ml for each) were obtained from each group after anesthesia for 0.5h, 1h, 2h, 4h or 6h, respectively. The concentration of free HFIP in the blood was determined by gas chromatograph using a double equilibration technique. The average value of free HFIP in each time point was calculated. The relation curves of free HFIP concentrations in blood vs inhaled sevoflurane concentrations or vs the time of anesthesia. The relationship between the content of free HFIP and the given concentration of sevoflurane or its action time was analyzed.Results: The free HFIP in blood in each group was able to be detected after inhaled different concentration of sevoflurane. In each group, the concentration of free HFIP in blood increased gradually from 0.5h and reached its peak value at 4h after inhaled sevoflurane, then began to decrease from 4h to 6h.. Comparison among the four groups: The concentration of free HFIP was the lowest at each time point in the 0.5MAC group. While both the concentrations of free HFIP in the 1.0 MAC group and 1.5 MAC group were higher than that in the 2.0 MAC group obviously. The change tendency of free HFIP was most stable in the 1.5 MAC group.Conclusion: With the extension of the time for inhaled sevoflurane, the concentration of free HFIP in blood increased firstly and then decreased. The content of free HFIP yield in the moderate concentration group was higher than that in the low concentration group. But with the further increasing of inhaled sevoflurane concentration the concent of free HFIP in blood didn’t increase, but decreased instead.