甲烷对快速测定挥发性麻醉药气体浓度的影响

The influences of methane in the determination of volatile anesthetic gas

目的探讨反刍动物和人产出的甲烷气体对常用的麻醉气体浓度快速分析测定的影响。方法采用GC法测定异氟烷和七氟烷气体的准确浓度,再将其与不同浓度的甲烷标准气随机混合后,分别使用Datex-ohmeda AGM-103和PhilipsM1026B麻醉气体分析仪测定,以确定不同麻醉气体分析仪在测量中受甲烷影响的范围。采用GC法分别测定山羊和人的甲烷呼出度,判定该范围内甲烷是否影响麻醉气体分析仪对麻醉气体的准确测定。结果在甲烷高于500 ppm时Datex-ohme-da AGM-103对异氟烷的测定受到干扰,Philips M1026B则在甲烷高于1×103 ppm时受到干扰;测定七氟烷时,两种麻醉气体分析仪都在甲烷高于500 ppm时受到干扰。山羊产生的呼末气、消化道中的甲烷分别为280.8±53.8、2.70±0.7 ppm,主要经肺排泄;健康人类志愿者呼出气中的甲烷为1.06±0.05 ppm。结论两种麻醉气体分析仪均会受到高浓度甲烷的影响,影响随甲烷浓度的增加而增大。但山羊和人呼出气中甲烷含量较低,均不会干扰到麻醉气体浓度的测量。

OBJECTIVE To investigate the influence of methane comes from the ruminant animal and human in the determination of the commonly used volatile anesthetic concentrations.METHODS GC was used to determine the concentrations of a group of isoflurane gas and a group of sevoflurane gas,and then they were randomly mixed with different concentrations of methane gas.The mixed gas was measured by Datex-ohmeda AGM-103 and Philips M1026B anesthetic gas module,and then methane influences of the different anesthetic gas module could be found.Methane in the goats and humans end tidal breath gas were measured by GC to determine whether this concentration range of methane affected the determination of anesthetic gas.RESULTS When the methane was more than 500 ppm,methane could influence the measurement of isoflurane concentrations for Datex-ohmeda AGM-103,compared to 1×103 ppm for Philips M1026B;while the measurement of sevoflurane concentrations of both Datex-ohmeda AGM-103 and Philips M1026B could be influenced by methane when the concentration was more than 500 ppm.The average methane concentration was 280.8±53.8 ppm in the end tidal gas of the goats,and 2.70±0.7 ppm in the digestive tract;goats produced methane and primarily excreted through the lungs.The average methane concentration in the exhaled gas of healthy human volunteers was 1.06±0.05 ppm.CONCLUSION The two anesthetic gas analyzers could be influenced by high concentrations of methane,with dose dependent.However,the methane that comes from the goats and humans could not affect the anesthetic gas measurements.