呼气末正压通气对小儿心内直视手术后血液动力学的影响

The Effect of Positive Expiratory End Pressure on Hemodynamics of Children After Open Heart Operation

目的：呼气末正压通气（ＰＥＥＰ）是治疗心内直视手术后呼吸功能不全的主要方法之一。但是，较高的ＰＥＥＰ对患者的血液动力学有显著影响。本文探讨了小儿心内直视手术后不同的ＰＥＥＰ对患儿血液动力学的影响及其机制。方法：本实验采用置入Ｓｗａｎ－Ｇａｎｚ导管，对１４例小儿（１．５～５岁）心内直视手术后不同的ＰＥＥＰ下血液动力学指标的变化进行监测，并将数据输入ｄＢａｓｅＩＩ数据库，做自身配对ｔ检验及直线相关与回归分析。结果：当ＰＥＥＰ为０～０．６ｋＰａ（０～６ｃｍＨ２Ｏ）时，对血液动力学无显著影响（Ｐ＞０．０５）；当ＰＥＥＰ≥０．９ｋＰａ（９ｃｍＨ２Ｏ）时，可以引起心脏指数和氧运送的显著下降（Ｐ＜０．０１）。结论：当ＰＥＥＰ≥０．９ｋＰａ（９ｃｍＨ２Ｏ）时，通过减少心脏前负荷，抑制心脏收缩功能，导致心脏指数和氧运送显著下降。因此，临床上需使用较高的ＰＥＥＰ时，应做血液动力学和血气分析监测，以选择最佳的ＰＥＥＰ。

Objective:Positive expiratory end pressure(PEEP) is one of the main procedures for treating patients with impaired pulmonary function after open heart operation,but,it has marked influence on the hemodynamics of the patients.The effect of different levels of PEEP on the hemodynamics of children with congenital heart disease after surgical procedure was studied. Methods:The changes of hemodynamics at different levels of PEEP were measured in 14 children (1 5 to 5 years)after open heart surgery and the data were processed by statistical analysis. Results:Cardic index (CI) and oxygen delivery (DO 2) at PEEP from 0 to 0.6 kPa (0 6 cmH 2O) showed no significant change ( p >0.05).However,CI and DO 2 decreased significantly when PEEP was more than 0.9 kPa(9 cmH 2O)( p <0 01). Conclusion:PEEP decreases CI and DO 2 by reducing preload of the heart and depressing cardiac systolic function when PEEP is more than 0.9 kPa(9 cmH 2O).If high level of PEEP is necessary,the hemodynamic parameters and blood gas should be monitored for the choice of optimal PEEP level.