硬膜外阻滞复合全麻对单肺通气期间气体交换的影响

目的 观察胸段硬膜外阻滞复合全麻对单肺通气期间气体交换的影响.方法 随机选择ASA Ⅰ～Ⅱ级择期开胸手术病人80例,将病人随机分为两组,全麻复合硬膜外麻醉组(A组)和全麻组(B组),每组40例.两组病人在开胸前双肺通气20 min(T1)时及开胸后单肺通气(OLV)30 min(T2)、60 min(T3)、120 min(T4)时,分别采动脉血及混合静脉血,观察病人动静脉血气情况并计算肺内分流率(Qs/Qt)值、肺泡-动脉血氧分压差(A-aDO2)和无效腔量/潮气量(Vd/Vt)值.结果 与T1相比,两组T2-4时Paw均升高(P<0.01),T2-4时Qs/Qt均增加(P<0.01),A-aDO2增加(P<0.01),PaO2降低(P<0.01),而Vd/Vt,血压、心率变化无统计学差异(P>0.05);与B组相比,A组T2-4时的Qs/Qt增加(P<0.01),A-aDO2增加(P<0.01),PaO2,降低(P<0.01),而Vd/Vt,血压、心率变化无统计学差异(P>0.05).结论 单肺通气期间硬膜外阻滞复合全麻对肺换气功能有影响,使Qs/Qt增加,PaO2下降,A-aDO2增大;对肺泡通气功能指标Vd/Vt影响甚微.

Influence of general anesthesia combined with epidural block on gas exchang during one-lung ventilation in patients undergoing thoracic surgery

Objective To evaluate the effects of general anesthesia combined with throacic epidural block on pulmonary gas ex-change during one-lung ventilation in patients undergoing thoracic surgery. Methods Eighty patients of ASA Ⅰ-Ⅱ undergoing electivethroacic surgery were randomly divided into two Groups (n = 40 ) receiving combined genera] anesthesia with throacic epidural block(group A ) or general anesthesia (group B ). MAP, HR, SpO2, PETCO2, VT, Paw were monitored at both bronps. Arterial andmixed vein blood gas were analyzed and Qs/Qt ,A-aDO2,Vd/Vt were calculated in both groups at 20 rain ( T1 ) before one-lung ventila-tion and 30 min( T2 ), 60 min( T3 ), as well as 120 min ( T4 ) after one-lung ventilation. Results In both groups, Paw and Qs/Qt in-creased while PaO2 decreased significantly at T2-4, ( P<0.05 ). At T2-4, Qs/Qt was significantly higher and PaO2 was significantly lowerin group A than that in group B. Conclusion During one-lung ventilation, general anesthesia combined with throacic epidural blockhas increased Qs/Qt ,A-aDO2 ,Vd/Vt and decreased PaO2. The patients should be monitored carefully during all the surgical procedure.