不同通气模式对先心病患儿呼吸力学的影响

目的：比较不同通气模式对先心病患儿心内直视手术中呼吸力学的影响。方法：选择择期在体外循环（CPB）下行心脏直视手术的非紫绀型先心病患儿40例，心功能Ⅰ级或Ⅱ级，按年龄分为2组：A组（年龄〈2岁）、B组（2岁〈年龄〈4岁）。分别于切皮前（T1）、胸骨劈开后10min（T2）、鱼精蛋白中和后10min（T3）及缝皮后（T4）记录在定容（VCV）和定压（PCV）通气模式下的呼吸力学指标，分别作为体外循环前（T1、T2）和体外循环后（T3、T4）的数据，记录时使不同通气模式下的潮气量都维持在10ml／kg。结果：两组患儿CPB后（T3、T4）各模式下的气道峰压（Ppeak）、气道平台压（Pplat）均高于CPB前（T1、T2），动态肺顺应性（Cdyn）有所降低（P〈0．05）。A组患儿在定压通气模式下的Ppeak在各时间点均明显低于定容通气模式，Cdyn高于定容通气（P〈0．05）。B组患儿在CPB前的呼吸力学指标在不同通气模式下无差别，CPB后定压通气模式下的Ppeak低于定容通气组，Cdyn高于定容通气（P〈0．05）。结论：不同年龄先心病患儿在定容和定压通气模式下测定的呼吸力学指标有一定程度的差别，对2岁以下及体外循环后的婴幼儿定压通气更为合适。

Effect of different modes of ventilation on respiratory mechanics in children of congenital heart disease

Objective： To investigate the effect of different modes of ventilation on respiratory mechanics in children undergoing open heart surgery for congenital heart disease. Methods： Forty NYHA class Ⅰ-Ⅱ children with acyanotic congenital heart disease undergoing open heart surgery under CPB were divided into 2 age groups：group A 〈 2 age （n=20）;group B〉2 age-〈4 age （n=20）.Respiratory mechanics were measured before skin incision （T1） ,after sternum splite （T2）,protamine administration （T3）and after skin suture （T4）. The VT was kept at 10 ml/kg under different modes of ventilation. Results： The Ppeak and Pplat of group A and B were higher after CPB, and the Cdyn was lower （P〈0.05）.The Ppeak of group A under the mode of PCV was lower than VCV both before and after CPB, and the Cdyn was higher than VCV （P〈0.05）. There was no significant difference in respiratory mechanics in group B before CPB, the peak under the mode of PCV was lower than VCV after CPB, the Cdyn was higher than VCV （P〈0.05）. Conclusion： There are significant differences in respiratory mechanics between the 2 ages groups of children with acyanotic congenital heart disease undergoing volume control ventilation and pressure control ventilation, and the pressure control ventilation is more suitable for the children blew 2 years old.