Bito H, Ikeda K
Department of Anesthesiology and Intensive Care, Hamamatsu University School of Medicine, Japan.
Anesth Analg. 1996 Jan;82(1):173-6. doi: 10.1097/00000539-199601000-00032.
The safety of low-flow sevoflurane anesthesia, which produces higher concentrations of toxic compounds, has been questioned. One hundred surgical patients received sevoflurane or isoflurane anesthesia at a total flow rate of 1 L/min. End-tidal CO2 concentrations and inspired and end-tidal anesthetic concentrations were monitored during anesthesia. Pre- and postanesthetic clinical laboratory studies were performed in both groups, and no significant differences were found between groups. In the sevoflurane group, the concentrations of degradation products in the circuit were measured by gas chromatography and the temperature of the CO2 absorbent was also measured. Two degradation products were detected: CF2 = C(CF3-O-CH2F (Compound A) and CH3OCF2CH(CF3)OCH2F (Compound B). The highest measured mean concentration of Compound A was 24.6 +/- 7.2 (13.6-41.3) ppm, and that of Compound B (detected in 12 patients) was 1.5 ppm. In both groups, total bilirubin, direct bilirubin, aspartate aminotransferase, and alanine aminotransferase were increased postoperatively. There was no difference between groups. Low concentrations of Compound A were present in low-flow sevoflurane anesthesia, but no significant differences in clinical laboratory values were observed between low-flow sevoflurane and isoflurane anesthesia.
低流量七氟烷麻醉会产生较高浓度的有毒化合物，其安全性受到了质疑。一百名外科手术患者接受了七氟烷或异氟烷麻醉，总流速为1升/分钟。麻醉期间监测呼气末二氧化碳浓度以及吸入和呼气末麻醉剂浓度。两组均进行了麻醉前和麻醉后的临床实验室研究，两组之间未发现显著差异。在七氟烷组中，通过气相色谱法测量回路中降解产物的浓度，并测量二氧化碳吸收剂的温度。检测到两种降解产物：CF2 = C(CF3 - O - CH2F（化合物A）和CH3OCF2CH(CF3)OCH2F（化合物B）。化合物A测得的最高平均浓度为24.6 +/- 7.2（13.6 - 41.3）ppm，化合物B（在12名患者中检测到）的最高平均浓度为1.5 ppm。两组术后总胆红素、直接胆红素、天冬氨酸转氨酶和丙氨酸转氨酶均升高。两组之间无差异。低流量七氟烷麻醉中存在低浓度的化合物A，但低流量七氟烷麻醉和异氟烷麻醉之间在临床实验室值方面未观察到显著差异。
