[Concentrations of haptoglobin and free hemoglobin in preserved whole blood].

In bank blood, red blood cells are destroyed and free hemoglobin increases during preservation. Concentrations of haptoglobin and free hemoglobin were measured in 73 packages of preserved whole blood which had been kept for various periods, 1 to 21 days. Those blood samples were divided into 7 groups depending on preserved period, 1 to 3, 4 to 6, 7 to 9 days, and so on. Total haptoglobin decreased to less than 100 mg.dl-1 in the blood preserved over 7 days. Total hemoglobin increased with the passage of preserved period. Free hemoglobin appeared in 40% or more of the blood preserved over 7 days and its concentration increased depending on preserved time. Free hemoglobin of 10 mg.dl-1 or more was detected in the blood preserved over 7 days. It is recommended that for massive blood transfusion the whole bank blood under 7 days of preservation should be used.