地氟醚对红外分光测定法呼气末二氧化碳浓度测定的影响

目的 观测吸入不同浓度的地氟醚对普通红外分光测定法呼气末二氧化碳浓度（ＰＥＴＣＯ２）测定的影响。方法 １５例全麻气管内插管的病人,用一台可同时测定ＰＥＴＣＯ２和地氟醚的红外分光测定仪Ｃａｐｎｏｍａｃ－ｕｌｔｉｍａ和一台单纯测定ＰＥＴＣＯ２的普通红外分光测定仪Ｃａｐｎｏｍａｃ－Ⅱ同时监测ＰＥＴＣＯ２。结果 在使用地氟醚后,Ｃａｐｎｏｍａｃ－ｕｌｔｉｍａ测定得的ＰＥＴＣＯ２明显低于Ｃａｐｎｏｍａｃ－Ⅱ测定得的ＰＥＴＣＯ２,其差异随着呼气末地氟醚浓度的升高而加大（直线相关ｙ＝０．６２＋０．７３,ｒ＝０．８３,Ｐ〈０．０１）,而关闭Ｃａｐｎｏｍａｃ－ｕｌｔｉｍａ地氟醚浓度测定（忽略其存在）后测定得的ＰＥＴＣＯ２则和Ｃａｒｄｉｏｃａｐ－Ⅱ测定得的ＰＥＴＣＯ２完全相关（ｙ＝１．６１χ－４．１,ｒ＝０．９７,Ｐ〈０．０１）。

The effect of desflurane on the measurement of end tidal carbon dioxide by infrared spectrometry

Objective To observe the effe ct of desflurane on PETCO2measureme nt b y infrared spectrometry．Methods PETCO2 wa s measured with an infrared spectrometry （Capnomac-ultima） that may measure PETCO2and desflurane concentration and a ge neral infrared spectrometry （Cardiocap-Ⅱ ） that can only measure PETCO2 simut aneo usly in 15 trachea-intubated patients u n der general anesthesia．Results I t was fo und that PETCO2 measured by Cardioca p-Ⅱ was significantly higher than that measu red by the Capnomac-ultima and the diffe rence between them was correlated well with the end-tidal desflurane concentrat ion（y＝0.62＋0.73,r＝0.83,P＜0.01）．As the ex istance of desflurane was neglected arti ficially（setting on no agent）,PETCO2 mea sured by Capnomac-ultima was correlated almost perfectly with that by Cardiocap- Ⅱ （y＝1.16χ－4.1,r＝0.97,P＜0.01）．Conclusion Desflurane makes PETCO2 measurement b y ge neral infrared spectrometry higher than its true value in a concentration-depend ent manner．