机器人心脏手术中呼气末二氧化碳分压与动脉二氧化碳分压的相关性研究

摘要

目的 探讨机器人心脏手术中体外循环前后及单肺通气条件下呼气末二氧化碳分压(PETCO2)与动脉二氧化碳分压(PaCO2)的相关性.方法 80例行机器人心脏手术的患者,按疾病种类分为三组:先天性心脏病组35例(A组),二尖瓣疾病组27例(B组),冠心病组18例(C组),分别在诱导后双肺通气(TLV)30 min(T1),单肺通气(OLV)30 min(T2),OLV+二氧化碳气胸30 min(T3),OLV+二氧化碳气胸60 min(T4),OLV+二氧化碳气胸90 min(T5),停体外循环后OLV 30 min(T6),恢复TLV 30 min(T7)等时刻抽取动脉血做血气分析,比较PaCO2与PETCO2.结果 三组患者的PETCO2与 PaCO2除了在T2时刻没有相关性外(P>0.05),其余时刻均有相关性(P<0.05);A组和B组的PETCO2、PaCO2和PETCO2与PaCO2的差值(Pa-ETCO2)在体外循环后均增加(P<0.05);C组PETCO2与PaCO2在T3、T4、T5时刻逐渐升高,Pa-ETCO2也逐渐增大(P<0.05).结论 在机器人心脏手术的各类心脏疾病中的PETCO2与PaCO2有良好的相关性,随着二氧化碳气胸时间的延长,两者的差值逐渐增大;在体外循环后两者的差异也比体外循环前明显增大,所以PETCO2监测不能完全替代机器人心脏手术中的PaCO2测定.%Objective This study was performed to estimate the relationship between end - tidal carbon dioxide ( PETCO2 ) and arterial PCO2( PaCO2 ) during robotic cardiac surgery. Methods Eighty patients were divided into three groups: congenital heart disease group ( Group A, n = 35 ), mitral valve disease group ( Group B, n = 27 ), and coronary heart disease group ( Group C, n = 18 ). The premedication were subcutaneous morphine 0. 1 mg/kg and intramuscular scopolamine 0. 15 - 0. 3 mg. Anesthesia was induced with midazolam 1 -5 mg, etomidate 0. 3 mg/kg, lidocaine 1.0 -1.5 mg/kg, pipecuronium 0. 15 mg/kg and sulfentanyl 1.0-1.5 μg/kg. Measurements of PETCO2 from capnography values and PaCO2 from arterial blood gases were registered at seven time points: 30 min after anesthesia induction ( T1 ), 30 min after one lung ventilation ( OLV ) lasted ( T2 ), 30 min ( T3 ), 60 min ( T4 ) and 90 min ( T5 ) after carbon dioxide pneumothorax initiation, 30 min after cardiopulmonaty bypass termination ( T6 ) and 30 min after resume two lung ventilation ( T7 ). The gradient between PaCO2 and PETCO2( Pa_ETCO2 ) was calculated. Results A good agreement with a moderate variation was observed between PET CO2 and PaCO2 in three groups ( P < 0. 05 ) except at T2 during robotic cardiac surgery. Compared with those before cardiopulmonary bypass, PETCO2 , PaCO2 and Pa_EtCO2 increased in group A and B ( P <0. 05 ) and they also increased gradually in group C from T3 to T5 ( P <0. 05 ). Conclusion Theres good correlation of PETCO2 and PaCO2 in robotic cardiac surgery. The gradient between PaCO2 and PETCO2 increased in prolonged OLV, especially after cardiopulmonary bypass. The PaCO2 cannot be substituted by the PETCO2 thoroughly during anesthesia of robotic cardiac surgery.