Hackett P H, Roach R C, Hartig G S, Greene E R, Levine B D
Denali Medical Research Project, University of Alaska Anchorage.
Int J Sports Med. 1992 Oct;13 Suppl 1:S68-71. doi: 10.1055/s-2007-1024599.
High altitude pulmonary edema is characterized hemodynamically by a markedly restricted pulmonary vascular bed. Pulmonary vascular resistance is six to eight times higher than control values at altitude, and mean pulmonary pressure is generally elevated two to four-fold over control values. We wished to compare the effect of various vasodilators on the hemodynamics of HAPE, both to gauge their potential effectiveness in treatment of HAPE, and also to gain clues as to the mechanism of the altered pulmonary circulation. In a series of field experiments using a total of 16 subjects with HAPE and 10 well controls, we measured pulmonary hemodynamics by non-invasive Doppler echocardiography. The per cent reduction in pulmonary vascular resistance and mean pulmonary artery pressure, respectively, were 46 and 33 for oxygen, 30 and 29 for nifedipine, 29 and 25 with hydralazine, 57 and 42 with phentolamine, and 72 and 52 when oxygen and phentolamine were combined. All the vasodilators improved gas exchange, suggesting a link between edema formation and pulmonary vasoconstriction. A number of vasodilators may be useful in the treatment of HAPE; the superiority of an alpha adrenergic blocker may implicate the sympathetic nervous system in the pathophysiology of high altitude pulmonary edema.
高原肺水肿在血流动力学上的特征是肺血管床明显受限。在高原地区，肺血管阻力比对照值高6至8倍，平均肺动脉压通常比对照值升高2至4倍。我们希望比较各种血管扩张剂对高原肺水肿血流动力学的影响，以评估它们在治疗高原肺水肿方面的潜在效果，并了解肺循环改变的机制。在一系列实地实验中，我们总共使用了16名高原肺水肿患者和10名健康对照者，通过无创多普勒超声心动图测量肺血流动力学。氧气使肺血管阻力和平均肺动脉压分别降低46%和33%，硝苯地平使两者分别降低30%和29%，肼屈嗪使两者分别降低29%和25%，酚妥拉明使两者分别降低57%和42%，氧气与酚妥拉明联合使用时使两者分别降低72%和52%。所有血管扩张剂均改善了气体交换，提示水肿形成与肺血管收缩之间存在联系。多种血管扩张剂可能对治疗高原肺水肿有用；α肾上腺素能阻滞剂的优势可能表明交感神经系统参与了高原肺水肿的病理生理学过程。
