MEASURING HEMOGLOBIN CONCENTRATION AFTER TRANSFUSION.

At what point after blood transfusion is it possible to get a reliable measure of the increase in hemoglobin concentration? These researchers tackled this question by measuring hemoglobin concentrations in 39 patients 15 minutes, 1 hour, 2 hours, and 24 hours after the patients received two units of packed red cells. None of the patients had active or recent bleeding.

The mean baseline hemoglobin level was 7.4 g/dl. Fifteen minutes after the transfusion, the mean hemoglobin concentration was 9.4 g/dl, and remained at this level throughout the first 24 hours. Various clinical variables such as body size, recent diuretic use, or duration of transfusion did not influence these results.