BLOOD VOLUME IN NORMAL INFANTS AND CHILDREN

Abstract

Knowledge concerning blood volumes has been limited until recent years by the lack of any reliable method that could be applied to living patients. Information about the blood volume is desirable both for the study of anemia and of disturbances in the water metabolism. The work reported in this and the three subsequent papers was under-taken from the latter viewpoint. There are two reliable methods of determining blood volumes which may be applied to patients. They are (a) the carbon monoxide method, first adapted to man by Haldane and Smith (1) and (b) the dye method of Keith, Rowntree and Geraghty (2). The former method gives results that are probably a little lower than the actual blood volume whereas the latter gives results a little higher than the actual blood volumes. The high results by the dye method have been shown by Smith (3) to be due to transfusion of part of the dye into the lymph. However, the amount of dye disappearing in the lymph is small and fairly constant and the method is accurate for comparative results. Our knowledge of blood volumes has been recently reviewed by Erlanger (4). In the present paper, only such results as seem to concern this work will be mentioned. The findings of the various workers seem fairly concordant and indicate that adults tend to have about 50 milliliters of plasma and 83 milliliters of blood per kilogram of body weight, as determined by the dye method (Keith, Rowntree and Geraghty (2) Bock (5), Brown ana Rowntree (6)). Bock has emphasized the fact that the plasma volume is more constant than the blood volume and has found it to be about 50 milliliters per kilogram of body weight in conditions showing such widely varying volumes of red cells as pernicious anemia and polycythemia. However, a minimum volume of red cells is necessary to maintain the plasma volume. 243