先心病患儿体外循环围手术期PetCO_2与PaCO_2的相关性

A Study on the Correlation Between PetCO_2 and PaCO_2 in Children Cardiopulmonary Bypass Perioperative Period

目的探讨不同类型先天性心脏病患儿体外循环围手术期呼气末二氧化碳分压(PetCO_2)与动脉血二氧化碳分压(PaCO_2)的相关性及临床意义.方法选择60例择期行先天性心脏病体外循环的手术患儿,年龄1~14岁,ASAII^III级.依据术前超声心动图结果将患儿分为2组:A组为左向右分流的患儿,其中房间隔缺损(ASD)15例,室间隔缺损(VSD)15例;B组为右向左分流的患儿,为法洛四联症(TOF)30例.60例患儿均行静脉全麻、快速诱导经口气管插管.术后所有患儿均于外科重症监护室(SICU)接受呼吸机辅助通气8 h.分别于手术开始前(T_1)、麻醉诱导后15 min(T_2)、体外循环(CPB)开始前(T_3)、CPB停止后15 min(T_4)、手术结束(T_5)、转入SICU(T_6)、SICU监护2 h(T_7)、4 h(T_8)、6 h(T_9)、8 h(T_(10))时取动脉血2 m L行血气分析测PaCO_2,并记录各时间点的PaCO_2、PetCO_2,计算每个时间点两者相关性.结果 A组患儿各时间点PetCO_2和PaCO_2呈正相关(r为0.55~0.87,P<0.001),在T_2-6期间PetCO_2与PaCO_2相关性逐渐减小,T_(7-10)期间相关性逐渐增强.B组患儿手术开始前至CPB停止后15 min,PetCO_2与PaCO_2无显著相关性(r为0.21~0.38,P>0.05),从手术结束至SICU监护8 h期间,PetCO_2与PaCO_2呈正相关(r为0.54~0.83,P<0.05),T_(5-10)期间,两者相关性逐渐增强.结论左向右分流的先天性心脏病患儿在体外循环围手术期,PetCO_2可作为临床监护的评价指标.右向左分流的先天性心脏病患儿在手术结束前PetCO_2与PaCO_2无显著相关性,PetCO_2不能替代PaCO_2,但心内畸形纠正后,动态观察PetCO_2的改变来指导对PaCO_2的判断是有意义的.

Objective To investigate the clinical significance and correlation of end-tidalcarbon dioxide partial pressure（PetCO2） and arterial blood carbon dioxide pressure（PaCO2） of children with different types of congenital heart disease in perioperative period of cardiopulmonary bypass.Methods 60 children undergoing selective cardiopulmonary bypass surgery for congenital heart disease were chosen（aged 1-14 years old, ASA class II or III）.According to echocardiographic results, the children were divided into two groups. Group A：Left-to-right shunt in children,involving 15 cases of atrial septal defect and 15 cases of ventricular septal defect;Group B： Right-to-left shunt in children, involving 30 cases of Fallot tetrad. All 60 children underwent intravenous general anesthesia and rapid induction of orotracheal intubation. All patients underwent ventilator-assisted ventilation in the surgical intensive care unit for 8 hours after surgery. The brachial artery blood was collected for arterial blood gas analysis to measure PaCO2 at the beginning of surgery（T1）, 15 min after anesthesia（T2）, before CPB（T3）, 15 min after CPB（T4）, end of surgery（T5）,time to transfer to SICU（T6）,2 h after monitored in ICU（T7）, 4 h after monitored in SICU（T8）, 6 h after monitored in SICU（T9）,8 h after monitored in SICU（T（10））.The PaCO2 and PetCO2 were recorded at each time point. According to the result of PetCO2 and PaCO2,we studied the correlation of the two indexes at each time point.Results In group A,there was a positive correlation between PetCO2 and PaCO2 at each time point（the correlation was 0.55 to 0.87,P〈0.001）. The correlation between PETCO2 and PaCO2 decreased gradually during T（2-6）, and the correlation gradually increased during T（7-10）. There was no significant correlation between PetCO2 and PaCO2（the correlation was0.21 to 0.38,P〈0.05） before operation in group B until 15 minutes after CPB. From the end of surgery to 8 hours after SICU monitoring,PetCO2 was positively correlated with PaCO2（the correlation was0.54 to 0.83, P〈0.05）.The correlation between the two indexes increased gradually during T（5-10）. Conclusions During the perioperative period of cardiopulmonary bypass, PetCO2 can be used as an evaluation indicator for clinical monitoring in the children with Left-to-right shunt of congenital heart disease.There was no significant correlation between PetCO2 and PaCO2 in the children with congenital heart disease of right-to-left shunting before the end of surgery. PetCO2 could not replace PaCO2.With the improvement of postoperative conditions,It is significant to dynamically observe changes in PetCO2 to guide the analysis of PaCO2.