Variation in Transfusion Requirements Among Children With Thalassemia on Regular Transfusion Programs: Which Formula Closely Predicts the Actual Requirements?

BACKGROUND: Various different formulae are used to calculate blood transfusion volumes in thalassemia. Using the right formula will avoid iron overload and complications of undertransfusion.

OBSERVATIONS: Five years of transfusion data in 11 children with thalassemia showed that no single formula-calculated transfusion volumes accurately. The formula used in the United Kingdom with a hematocrit of the transfused blood of 0.6: (0.4×body weight×desired raise in hemoglobin [g/L]) yielded a volume closest to empirically determined requirements on average. Transfusion factors ranging from 0.3 to 0.48 were calculated as necessary to achieve the required volume for the individual patient.

CONCLUSIONS: To meet transfusion requirements, individualization of formulas by establishment of the transfusion factor for each patient is helpful.