低流量N_2O-O_2单肺麻醉对动脉血气的影响

Effects of low-flow nitrous-oxide-oxygen anesthesia on arterial bloodgas during onelung ventilation

目的 探讨低流量N2 O O2 单肺麻醉对开胸病人动脉血气的影响。方法 2 5例ASAⅠ～Ⅱ级开胸病人随机分为两组 :Ⅰ组 (n =10 )为对照组 ,采用硬膜外 +单肺通气麻醉 ;Ⅱ组 (n =15 )为观察组 ,采用低流量N2 O O2 单肺麻醉。观察两组开胸后单肺通气 1小时的吸入气氧分量(FIO2 )、PETCO2 、PaO2 、PaCO2 、动脉血氧饱和度 (SaO2 )、pH、肺泡与动脉血氧分压差 (PA aO2 )、动脉血与呼气末二氧化碳分压差 (Pa ETCO2 )变化。结果 Ⅰ组血气参数变化较小 ,无缺O2 和CO2 蓄积危险。Ⅱ组PaO2 和SaO2 明显下降 ,CO2 有蓄积 ,pH值降低 ,但PaO2 、SaO2 和pH仍在正常范围 ,CO2蓄积较轻 ,恢复双肺通气后即可恢复正常。结论 低流量N2 O O2 单肺麻醉发生缺O2 和CO2 蓄积的危险性有所增加 ,应加强监测。

Objective To investigate the effects of low flow nitrous oxide oxygen(N 2O O 2) anesthesia on arterial bloodgas during onelung ventilation(OLV).Methods Twentyfive ASAⅠ Ⅱ patients undergoing thoracic surgery were randomly divided into two groups:group A( n= 10),epidural blockade plus OLV and group B( n= 15),low flow N 2O O 2 anesthesia during OLV.The Changs of F IO 2,P ET CO 2,PaO 2,PaCO 2,SaO 2,pH,P A a O 2 and P a ET CO 2 during one hour OLV were monitored.Results The bloodgas parameters in group A had little changes with out any risk of hypoxia and CO 2 retaintion.In group B,however,PaO 2 and SaO 2 were decreased significantly and CO 2 retained,which were reterned to the normal after restoration of twolung ventilation.Conclusion Dangers of hypoxia and CO 2 retaintion during low flow N 2O O 2 anesthesia with OLV is increased and the patients should be monitored all the time.