婴幼儿心脏手术中红细胞比容变化对血压的影响

Influence of increased hematocrit on the blood pressure during modified ultrafiltration for open heart surgery

目的探讨开胸心脏手术中通过改良超滤技术快速提高患儿HCT对血压的影响。方法将室间隔缺损行室缺修补患儿40例随机分为观察组和对照组各20例,观察组在术后采用改良超滤(MUF),对照组行常规超滤(CUF)。监测两组患儿术中HCT值、血压和心率等改变情况,并通过Pearson积差相关系数分析HCT与血压之间的关联性。结果两组间的HCT、血压在术前差异无统计学意义(P>0.05),在超滤结束后MUF组HCT值、血压均高于对照组(P<0.05)。但通过相关性分析体外循环结束后15min血压与HCT间以及超滤前后改变的血压与HCT间的关系,观察组和对照组的HCT值与血压的改变均不存在相关性。结论改良超滤可在体外循环结束后短时间内浓缩血液,提高患儿血压,降低心率,但HCT值与血压改变不存在相关性,提示患儿超滤后血压升高与HCT改变无关。

Objective To investigate the relationship between increased hematocrit and blood pressure during modified ultrafiltration for pediatric open heart surgery. Methods Forty congenital heart disease patients who underwent ventricular sep- tal defect closure were randomly divided into two groups： group M （modified ultrafiltration, n=20） and group C （conventional ultrafiltration, n=20）. Effects of ultrafiltration on hematocrit, blood pressure and heart rate were recorded. The correlations between blood pressure and hematocrit were analyzed during modified ultrafiltration. Results There were no significant differences in HCT and blood pressure before ultrafiltration between the two groups （P〉0.05） . After ultrafiltration, HCT and blood pressure in group M were higher than that in group C （P〈0. 05） . However, the blood pressure was not correlated with increased hematocrit at 15 rain after extracorporeal circulation, and there was also no correlation between the percent increases in blood pressure and hematocrit. Conclusion The use of MUF can effectively concentrate the blood, transiently improve blood pressure and decrease heart rate in children. However, no correlations are detected between the increases in blood pressure and hematocrit. These results indicate hemoconcentration is not the major cause of the increased blood pressure during modified ultrafiltration.