Bergadano A, Lauber R, Zbinden A, Schatzmann U, Moens Y
University of Berne, Department of Clinical Veterinary Medicine, Anaesthesiology Division, Länggassstrasse 124, Postfach 8466 CH-3001, Bern, Switzerland. alessandra.bergadano @ knp.unibe.ch
Br J Anaesth. 2003 Aug;91(2):276-8. doi: 10.1093/bja/aeg151.
Blood/gas partition coefficients (lambda(b/g)) for volatile agents in horse blood are reported for halothane but not for isoflurane and sevoflurane. We measured the lambda(b/g) of halothane, isoflurane and sevoflurane in the blood of fasted horses. The correlation with age, weight and some haematological and biochemical variables was studied. The temperature correction factor for isoflurane solubility was calculated.
Twenty-four horses were randomly allocated to halothane (n=8), isoflurane (n=8) or sevoflurane (n=8). Blood samples were taken after 10 h' fasting. Calculation of lambda(b/g) was based on the measurement of anaesthetic partial pressures in blood at 37 degrees C, which was achieved with tonometer equilibration and headspace gas chromatography.
Mean lambda(b/g) was 1.66 (SD 0.06) for halothane, 0.92 (0.04) for isoflurane, and 0.47 (0.03) for sevoflurane. The lambda(b/g) values were all significantly lower than in humans (P<0.001). No correlation was found between lambda(b/g) and weight, age, haematocrit, plasma triglycerides, cholesterol or total bilirubin. The change in isoflurane solubility per 1 degrees C temperature increase was -2.63 (0.13)%.
The lambda(b/g) values of halothane, isoflurane and sevoflurane in fasted horses are significantly lower than those reported in humans. The lambda(b/g) for halothane in this study agrees with values reported in the literature but a positive correlation with plasma triglycerides could not be confirmed. Knowledge of lambda(b/g) can refine models of anaesthetic uptake.
已有关于氟烷在马血中挥发性麻醉剂的血/气分配系数（λ(b/g)）的报道，但异氟烷和七氟烷的相关报道尚未见。我们测定了禁食马匹血液中氟烷、异氟烷和七氟烷的λ(b/g)。研究了其与年龄、体重以及一些血液学和生化变量之间的相关性。计算了异氟烷溶解度的温度校正因子。
将24匹马随机分为氟烷组（n = 8）、异氟烷组（n = 8）或七氟烷组（n = 8）。禁食10小时后采集血样。λ(b/g)的计算基于在37℃下血液中麻醉剂分压的测量，这通过张力计平衡和顶空气相色谱法实现。
氟烷的平均λ(b/g)为1.66（标准差0.06），异氟烷为0.92（0.04），七氟烷为0.47（0.03）。这些λ(b/g)值均显著低于人类（P < 0.001）。未发现λ(b/g)与体重、年龄、血细胞比容、血浆甘油三酯、胆固醇或总胆红素之间存在相关性。异氟烷溶解度每升高1℃的变化为-2.63（0.13）%。
禁食马匹中氟烷、异氟烷和七氟烷的λ(b/g)值显著低于人类报道的值。本研究中氟烷的λ(b/g)与文献报道的值一致，但未能证实其与血浆甘油三酯呈正相关。了解λ(b/g)有助于完善麻醉摄取模型。
