VSD体外循环前后血液流变学变化及其对呼吸力学的影响

The Hemorheological Changes after Cardiopulmonary Bypass and Its Effect on Respiratory Mechanics in Children with Ventricular Septal Defect

目的和方法：对２０例室间隔缺损（ＶＳＤ）小儿体外循环前、中、后血液流变学及肺功能的变化进行了临床研究。结果：ＶＳＤ小儿体外循环转流后血液流变学发生了很大的变化，血粘度各指标明显低于转流前，而呼吸力学指标劣于转流前。说明随着血粘度的降低，Ｈｃｔ下降，加之体外循环对肺的影响，使肺水增加，造成呼吸功能恶化。结论：ＶＳＤ小儿体外循环中，如过度血液稀释，体内多余水分不能立即排除，可使肺水增加，将导致呼吸力学指标恶化。

Objective: Changes in hemorheology and respiratory mechanics after CPB were studied in 20 children with VSD. Results: Hemorheology changed greatly after CPB, as shown by a significant decrease in blood viscosity. Respiratory mechanic parameters after CPB were worser than those before. Decrease of blood viscosity and Hct as well as CPB's harmful effect on the lungs resulted in an increase in lung water, which makes respiratory function much worse. Conclusion: The children with VSD are overhemodiluted during CPB and water excess can not be eliminated from their body after CPB. This will lead to lung water increase.