The Determination of Packed Cell Volume from Blood and Plasma Gravities in Indian Soldiers.

The object of this investigation was to find out how far this method could be employed usefully in India Command in place of the usual haematocrit technique, which requires equipment not always available. Assessments of mean corpuscular volume based on an inspection of dry. blood films or of the cells in the counting chamber cannot be expressed in figures, and it has thus been difficult to obtain information as to the improvement or deterioration in individual cases or to compare the blood state of different groups of population. Seventy-five samples of venous blood were taken, the red cell concentration, the haemoglobin content, and the packed cell volume were measured, and the mean corpuscular volume and mean corpuscular haemoglobin concentration calculated. The specific gravities of the whole blood and plasma were estimated by the copper sulphate method and the packed cell volume was calculated according to equation (1). The subjects were Indian soldiers, most of whom were healthy. The cases of severe anaemia were hospital patients suffering from post-dysenteric debility.