Blood Volume Studies in Patients with Splenomegaly

Estimations of erythrocyte mass, plasma, and total blood volume showed a significantly increased plasma volume in patients with splenomegaly from a variety of disorders. Venous hematocrit provided a poor indication of erythrocyte mass in these subjects. Plasma and total blood volumes showed positive correlation with clinical measurements of spleen size; a lesser correlation was found between spleen size and erythrocyte mass. Factors leading to expanded blood volume are reviewed, and significant components are suggested to be the intrasplenic blood volume and an increase in splanchnic blood volume consequent to obstructive or hyperkinetic portal hypertension.