左心转流降主动脉瘤手术中致萎陷肺损伤因素的临床研究

Clinical Research on Factors Affecting the Collapse Lung Injury during Operation of Descending Aortic Aneurysm under Left Heart Bypass

为探讨左心转流降主动脉瘤手术中致萎陷肺出血的因素，作者对１４例手术中萎陷肺有不同程度出血（Ａ组）和１４例手术中无肺出血（Ｂ组）的临床资料进行了回顾性分析。结果表明：Ａ、Ｂ两组在转流量、上肢血压及ＣＶＰ存在显著性差异，而在年龄、体重、左心转流时间及主动脉阻断时间、瘤体大小及肺粘连等方面无明显区别，但两组均未测左房压。鉴于上述发现，作者在Ｃ组（８例）进行了前瞻性临床研究，即维持每分钟转流量３５±３．１ｍｌ／ｋｇ，通过调节左房引流控制左房压在０．６７～２．００ｋＰａ（５～１５ｍｍＨｇ），结果Ｃ组即无肺出血发生，也无明显肺组织病理学改变。作者认为左心转流降主动脉瘤手术期间维持转流量大于每分钟３０ｍｌ／ｋｇ，控制左房压在上述范围，可保证合适的肺循环和体循环血流动力学，防止萎陷肺损伤。

This paper tries to identify the affecting factors of collapse lung injury during operation of descending aortic aneurysm under left heart bypass.As a first step,the clinical materials of 14 such patients complicated with pulmonary hemorrhage (Group A) and 14 without (Group B) were analyzed retrospectively.The results demonstrated significant differences existing between Group A and B in bypass flow rate,arterial pressure of the upper extremity and CVP,but not in the age,body weight,duration of left heart bypass,aortic occlusion time,size of aortic aneurysm or amount of pleural adhesions.However,the left atrial pressure was not monitored in either groups.Based on these findings,a prospective study was undertaken,as the second step of our clinical research in Group C (n=8).The bypass flow rate was controlled at the range of 35±3.1ml·kg -1 ·min -1 and the left atrial pressure was gauged at 0.67～2.00kPa by regulating the left atrial drainage.The results showed no hemorrhage or obvious pathological changes in the lung biopsy specimens.It is suggested that maintaining the left atrial pressure at the range of 0.67～2.00kPa(5～15mmHg) is the key to prevention of pulmonary injury during operation of descending aortic aneurysm under left heart bypass with a flow rate of >30ml·kg -1 ·min -1 ,a rate which adequately maintained both pulmonary and systemic hemodynamics.