保护性肺通气在婴儿先天性心脏病术中的应用

Lung protective ventilation in the congenital heart disease operation of infants

目的探讨体外循环下行先心病纠治术的婴儿进行保护性肺通气的临床可行性及效应。方法20例选择性体外循环下主动脉阻断行先天性心脏病根治术的婴儿（≤1岁），术中行小潮气量通气，体外循环停机后行肺复张，并监测压力一容量环和肺动态顺应性确定最佳PEEP值通气至术毕。监测保护性肺通气过程中基本生命体征及不良反应情况，并比较体外循环停机超滤后（T1）、肺复张后（T2）及出手术室前（T3）患儿氧合指数（PaO2／FiO2）、气道峰压（Ppeak）、肺动态顺应性（Cdyn）、肺泡动脉血氧分压差（A-aDO2）、呼气末二氧化碳分压差（Pa-ETCO2）和肺内分流率（Fshunt）。结果所有患儿基本生命体征指标均处于正常稳定范围，无严重不良反应。T2与T1时比较，PaO2／FiO2、Cdyn增加（P〈0．01），A-aDO2及Fshunt减小（P〈0．01），Ppeak降低，Pa-ETCO2减小（P〈0．05）。其中，PaO2／FiO2、Cdyn、A-aDO2及Fshunt的改变效应可维持至B。结论保护性肺通气策略可安全地应用于婴儿体外循环下先天性心脏病手术中，并可改善患儿体外循环后氧合、肺顺应性、弥散功能及通气血流比，降低气道阻力，减小肺内分流。

Objective To evaluate the feasibility and effect of the lung protective ventilation strategy during congenital heart disease operation of infants under cardiopulmonary bypass（CPB）. Methods 20 congenital heart disease infants（year≤1） that selected for corrective operation under CPB with aorta cross-clamping were ventilated with small tidal volume, alveolar recruitment maneuver after CPB, and ventilated with the optimal PEEP determined by pressure-volume circle and pulmonary dynamic compliance. The basic vital signs and complication were observed during the whole procedure, the PaO2/FiO2 ,Ppeak, Cdyn ,A-aDO2 and Fshunt were compared among after CPB（T1）,after alveolar recruitment（T2）,operation finished（T3）.Results All the basic vital signs of the infants were stable and within the normal range, there were no serious complications. PaO2/FiO2、Cdyn increased（P〈0.01）, A-aDO2 and Fshunt decreased（P〈0.01）, Ppeak and Pa-ETCO2 decreased（P〈0.05）at T2 compared with T1. The effect of PaO2/FiO2、C、A-aDO2 and Fshunt lasted to T3.Conclusion The lung protective ventilation strategy can be applied in congenital heart disease operation of infants under CPB safely. It may improve the oxygenation, pulmonary compliance, diffusion and vent-flow ratio, decrease the airway resistance and intrapulmonary shunt.