Originally published in Acta Physiol. Scand, 1, 1 (1940). 



51. A METHOD OF BLOOD VOLUME DETERMINATION 



L. Hahn and G. Hevesy 



From the Institute of Theoretical Physics, Copenhagen 



The method usually applied in the determination of blood volume is 

 that worked out by Rowntree and his colleagues (1929). The principle 

 of the method is that a dyestuff is injected intravenously and its degree 

 of dilution determined^^). As the dye only mixes with plasma, the volume 

 of the plasma alone is thus measured. The relative volume of corpuscles 

 and plasma is determined with the haematocrit. To arrive at the blood 

 volume, the volume of the corpuscles is added to that of the plasma. 



Rowntree gives the following description of the method applied 

 (comp. also Fleischer-Hansen, 1928). A 1.5 per cent solution of vital 

 red in distilled water is prepared. Four centrifuge tubes are provided 

 and 1 cc. of a 1.6 per cent solution of sodium oxalate is placed into 

 each of them. A needle is inserted in the vein of one arm and 10 cc. 

 of blood are removed. 5 cc. are placed into each of two centrifuge tubes 

 for standard plasma colour. The dye is then injected. After 3 to 6 min, 

 10 cc. of blood are withdrawn from the vein of the other arm and 5 cc. 

 placed into each of the two remaining centrifuge tubes. All four tubes 

 are centrifuged and the relative volume of corpuscles and plasma measu- 

 red. The second sample is compared with a known strength of the dye 

 and the degree of dilution of the dye in the plasma is thus obtained. 



When considering the possible errors of this method, the main question 

 at issue is whether, when the second sample is collected, the dye is 

 uniformly mixed in the plasma and none has yet escaped into the tissue 

 spaces or urine, a further possible source of error being the adsorption 

 of a part of the dye by the enormous surface of the capillary wall. 



^^' Instead of a dyestuff, diphteria antitoxin was used in some determinations 

 (v. Behking, 1912; Madsen, 1934). 



