Weisse A B, Moschos C B, Frank M J, Levinson G E, Cannilla J E, Regan T J
Am J Med. 1975 Jan;58(1):92-8. doi: 10.1016/0002-9343(75)90538-0.
Patients with cor pulmonale and high hematocrit levels are often subjected to phlebotomy in the belief that the adverse effects of high viscosity may outweigh the benefit of increased oxygen carrying capacity. To evaluate this, 12 patients with stable cor pulmonale and hematocrit values greater than 55 per cent were studied before and after a series of venesections. Right heart and aortic pressures, cardiac output and blood gases were measured at three mean hematocrit levels, 61 per cent (stage I), 50 per cent (stage II) and 44 per cent (stage III), with blood volume unchanged. From stages I to II, there were significant decreases in both man pulmonary artery pressure and total pulmonary resistance. Oxygen transport fell but not oxygen consumption. Right ventricular end-diastolic pressure and cardiac output did not change. Right ventricular work either fell or was maintained by increased output. Frank-Starling performance (supine exercise) improved. No significant changes occurred with further reduction in hematocrit to normal levels (stage III). The findings of this study support the concept of overcompensating erythrocytosis in cor pulmonale, and the effects of moderate hematocrit reduction should not be overlooked in these severely ill patients.
患有肺心病且血细胞比容水平高的患者常接受静脉放血，原因是人们认为高血液粘度的不良影响可能超过增加携氧能力带来的益处。为了对此进行评估，对12例稳定期肺心病且血细胞比容值大于55%的患者在一系列静脉切开放血前后进行了研究。在血容量不变的情况下，于三个平均血细胞比容水平，即61%（I期）、50%（II期）和44%（III期）时测量了右心和主动脉压力、心输出量及血气。从I期到II期，平均肺动脉压和总肺阻力均显著降低。氧运输量下降，但氧耗量未变。右心室舒张末期压力和心输出量未改变。右心室做功要么下降，要么通过增加输出量得以维持。弗兰克-斯塔林功能（仰卧位运动）得到改善。血细胞比容进一步降至正常水平（III期）时未出现显著变化。本研究结果支持肺心病中红细胞增多症过度代偿的概念，在这些重症患者中，血细胞比容适度降低的影响不应被忽视。
