Blood rheology in acute mountain sickness and high-altitude pulmonary edema

934-938,1991.-The role of blood rheology in the pathogenesis of acute mountain sickness and high-altitude pulmonary edema was investigated. Twenty-three volunteers, 12 with a history of high-altitude pulmonary edema, were studied at low altitude (490 m) and at 2 h and 18 h after arrival at 4,559 m. Eight subjects remained healthy, seven developed acute moun-tain sickness, and eight developed high-altitude pulmonary edema. Hematocrit, whole blood viscosity, plasma viscosity, erythrocyte aggregation, and erythrocyte deformability (filtra-tion) were measured. Plasma viscosity and erythrocyte defor-mability remained unaffected. The hematocrit level was lower 2 h after the arrival at high altitude and higher after 18 h com-pared with low altitude. The whole blood viscosity changed ac-cordingly. The erythrocyte aggregation was about doubled 18 h after the arrival compared with low-altitude values, which re