CLINICAL STUDIES OF THE BLOOD VOLUME. VIII. MACROCYTIC AND HYPOCHROMIC ANEMIAS DUE TO CHRONIC BLOOD LOSS, HEMOLYSIS AND MISCELLANEOUS CAUSES, AND POLYCYTHEMIA VERA 1

Abstract

The so-called secondary anemias due to chronic blood loss, nephritis, hemolysis or idiopathic hypochromic anemias, all exhibit essentially the same blood vol. picture. In the severe stages circulating red cell vol. may be from 60 to 70% below normal before signs of impending collapse occur. Although plasma vol. is above, total blood vol. is always below normal in severe anemia. During recovery the relationship between changes in red cell and plasma vol. is such that total blood volume remains sub-normal until recovery is complete. The % deviation from normal red cell vol. closely parallels the red blood cell count in all stages of anemia. Polycythemia Vera is characterized by a great increase in total blood vol. due entirely to the tremendous increase in red cell vol., plasma vol. remaining normal. The effect of repeated phlebotomies is to materially reduce red cell vol. without changing the plasma vol. and hence reduce total blood vol.