Yang N C, Wang H F, Hwang K L, Ho W M
Department of Anesthesiology, Taichung Veterans General Hospital, Taichung, Taiwan.
J Anal Toxicol. 2004 Mar;28(2):122-7. doi: 10.1093/jat/28.2.122.
The loss by blood/gas (lambda) partition of inhalation anesthetics can be estimated by an equation for the percentage of loss. However, because lambdas of inhalation anesthetics at different temperatures have not been fully determined so far, the percentage of loss at varying temperature in various headspace volumes cannot be estimated. Therefore, a novel method was developed for the determination of inhalation anesthetic lambda, in this study. The method was precise, with a relative standard deviation of less than 5%. The average of lambda from seven distinct blood samples at 4 degrees C, 25 degrees C, and 37 degrees C were determined as 6.68, 2.04, and 1.32 of isoflurane; 3.47, 1.10, and 0.65 of sevoflurane; and 2.31, 0.75, and 0.46 of desflurane, respectively. In addition, increasing temperature was found to decrease lambda profoundly by a secondary order mechanism. Using the obtained value of lambda, the percentage of loss of isoflurane, sevoflurane, and desflurane were then predicted using a 5-mL vacuum tube as a collecting container for an example. In conclusion, a novel method was developed here for lambda determination, and lambdas of isoflurane, sevoflurane, and desflurane at various temperatures were given for estimating the loss resulting from liquid/gas partitioning.
吸入麻醉药的血/气分配系数（λ）损失可通过损失百分比的公式来估算。然而，由于目前尚未完全确定不同温度下吸入麻醉药的λ值，因此无法估算不同顶空体积在不同温度下的损失百分比。因此，本研究开发了一种测定吸入麻醉药λ的新方法。该方法精确，相对标准偏差小于5%。在4℃、25℃和37℃下，七个不同血样的异氟烷λ平均值分别为6.68、2.04和1.32；七氟烷的分别为3.47、1.10和0.65；地氟烷的分别为2.31、0.75和0.46。此外，发现温度升高会通过二级机制显著降低λ。以5毫升真空管作为收集容器为例，利用获得的λ值预测了异氟烷、七氟烷和地氟烷的损失百分比。总之，本研究开发了一种测定λ的新方法，并给出了不同温度下异氟烷、七氟烷和地氟烷的λ值，以估算液/气分配导致的损失。
