Comparison of free hexafluoro-isopropanol concentrations in whole blood of patients inhaling differ-ent concentrations of sevoflurane: the relationship with emergence agitation / 中华麻醉学杂志

ABSTRACT

Objective To compare the free hexafluoro-isopropanol (HFIP) concentrations in whole blood of patients inhaling different concentrations of sevoflurane and further evaluate the relationship with e-mergence agitation. Methods Forty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients of both sexes, aged 18-64 yr, scheduled for elective laparoscopic gastrointestinal surgery, were divided into 3 groups according to the inhaled conentration of sevoflurane using a random number table 0. 86％group (group S1 , n= 13), 1. 71％ group (group S2 , n= 14) and 2. 57％ group (group S3 , n = 13). In S1 , S2 and S3 groups, the corresponding concentrations of sevoflurane were inhaled, remifentanil (target concentration 4-6 ng∕ml) was given by target-controlled infusion, and propofol (4-12 mg·kg-1 ·h-1 ) and cisatracurium 0. 1 mg·kg-1 ·h-1 were infused intravenously at the same time, and sevoflurane was in-haled for 3 h, and then inhalation was stopped. At 30 min and 1, 2 and 3 h of sevoflurane inhalation and 1, 3 and 5 h after stopping inhalation, central venous blood samples were collected for determination of free HFIP concentrations in whole blood by the method of two-stage headspace equilibration. The recovery time for spontaneous breathing, time for eye opening on verbal command, extubation time and development of agitation and moderate pain within 4 h after extubation were recorded. Results Free HFIP concentrations in whole blood peaked at 1 of inhalation, then gradually decreased, and the concentrations decreased con-tinuously after stopping inhalation in the three groups (P<0. 05). Compared with S1 group, free HFIP con-centrations in whole blood were significantly increased at each time point in S2 group, and free HFIP con-centrations in whole blood were decreased during inhalation and at 1 h after stopping inhalation in S3 group (P<0. 05). Compared with S2 group, free HFIP concentrations in whole blood were significantly decreased at each time point in S3 group (P<0. 05). The recovery time of spontaneous breathing, time for eye open-ing on verbal commands and extubation time were significantly longer in S3 group than in the other two groups (P<0. 05). There was no significant difference in the incidence of agitation or moderate pain among the three groups (P>0. 05). Conclusion Free HFIP concentrations in whole blood increase with the in-crease in inhaled sevoflurane concentrations, however, production of free HFIP is markedly inhibited when the inhaled concentration reaches 2. 57％, and free HFIP concentrations in whole blood decrease; free HFIP had nothing to do with the emergence agitation in patients.