Effect of hyperlipidemia on pulmonary uptake in patients inhaling sevoflurane for anesthesia

Abstract

Objective To evaluate the effect of hyperlipidemia on pulmonary uptake in the patients inhaling sevoflurane for anesthesia. Methods A total of 103 patients of both sexes, aged 20-50 yr, with body mass index of 18-25 kg/m2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, undergoing elective operation under general anesthesia, were enrolled in the study.Anesthesia was induced with iv midazolam 0.1 mg/kg, vecuronium 0.1 mg/kg, fentanyl 0.1 mg/kg and etomidate 0.3 mg/kg.Patients were mechanically ventilated after endotracheal intubation.Patients inhaled 2% sevoflurane for 30 min at an oxygen flow rate of 2 L/min.The inspired concentrations(Fi)and expired concentrations(Fe, Fe≈alveolar concentration[Fa]) of sevoflurane were recorded at 1, 3, 5, 7, 10, 15, 20 and 30 min of inhalation(T0-7). Patients were divided into either control group(group C)or hyperlipidemia group(group H)according to the results of blood lipid levels after the end of observation.The ratio of Fa/Fi and time spent in reaching the titration value(Fa/Fi= 0.8)were calculated in each group. Results There were 67 cases in group C and 36 cases in group H. Compared with group C, the Fa/Fi ratio was significantly decreased at 5, 7 and 10 min of inhalation, and the time spent in reaching the titration value was prolonged in group H(P < 0.05). Conclusion The pulmonary uptake of sevoflurane is increased, which may be associated with increased blood/gas partition coefficient. Key words: Hyperlipemia; Anesthetic, inhalation; Pulmonary uptake; Pharmacokinetics