Laver M B, Scheidegger D
Schweiz Med Wochenschr. 1981 Nov 21;111(47):1804-9.
Acute respiratory failure, particularly if associated with sepsis, results in diffuse changes in pulmonary vascular geometry and the afterload characteristics against which the right ventricle must perform. Therapy in these patients frequently requires replacement of intravascular volume which, if pulmonary vascular resistance is abnormally elevated, may cause a substantial enlargement in right ventricular (RV) end-diastolic volume. The low compliance characteristics of the RV invalidate the use of filling pressure (CVP) as a guide to RV size. We have examined RV volume in critically ill patients by means of the gated 99TAc scan and noted a substantial increase in RV volume despite filling pressure in the upper normal range. This enlargement appears to encroach upon LV function because the ejection fraction of the LV remained high despite elevation of pulmonary capillary wedge pressure (PCWP). Older patients with "silent" right coronary artery disease may become hemodynamically limited during therapy for acute respiratory failure and sepsis due to RV enlargement, increased wall tension and RV ischemia, a condition not readily diagnosed at the bedside with the usual monitoring techniques.
急性呼吸衰竭，尤其是伴有脓毒症时，会导致肺血管几何形状及右心室必须应对的后负荷特征发生弥漫性改变。这些患者的治疗常常需要补充血管内容量，如果肺血管阻力异常升高，可能会导致右心室舒张末期容积大幅增大。右心室低顺应性特征使得不能将充盈压（中心静脉压）作为判断右心室大小的指标。我们通过门控99T锝扫描检查了危重症患者的右心室容积，发现尽管充盈压处于正常上限范围，但右心室容积仍大幅增加。这种增大似乎会影响左心室功能，因为尽管肺毛细血管楔压（PCWP）升高，但左心室射血分数仍保持较高水平。患有“隐匿性”右冠状动脉疾病的老年患者在急性呼吸衰竭和脓毒症治疗期间，可能会因右心室增大、室壁张力增加和右心室缺血而出现血流动力学受限，这一情况用常规床边监测技术不易诊断。
