Table 1

 Existing formulae for calculating the transfusion volume of packed red cells (PRC)

Formula (reference)AssumptionsDerivation
Hb, haemoglobin; Hct, haematocrit; TBV, total blood volume.
Volume(ml)  =  3 × delta Hb(g/dl) × weight(kg)7,8Donor unit Hb 23 g/dl Embedded Image
TBV = 70 ml/kg
Volume  =  4 × delta Hb(g/dl) × weight(kg)6Donor unit Hb 23 g/dl Embedded Image
TBV = 90 ml/kg
Volume  =  1 × delta Hct(%) × weight(kg)3Donor unit Hct 70% Embedded Image
TBV = 70 ml/kg