[Estimation of the blood donation necessary for self-sufficiency of blood products]

To estimate the rates of donations needed to achieve self-sufficiency in haemoderivatives, thought to be at least 50 donations per one-thousand inhabitants.

A method is presented to calculate the donation rate according to the variables that could affect self-sufficiency, namely, the number of blood components prepared and deferred; the mean volume of plasma units; the amount of fresh frozen plasma (FFP) and plasma derivatives used (albumin, factor VIII and intravenous immunoglobulins); the rates of appropriate usage of FFP, red-blood cells (RBC), platelets and plasma derivatives; the use of recombinant factor VIII; the rates of albumin, factor VIII and intravenous immunoglobulin yielded by each litre of plasma; the rate of autologous transfusion; the rate of outdated haemoderivatives, and the litres of plasma obtained from plasmapheresis per donor and year.

The achievement of self-sufficiency without a plasmapheresis programme would imply a donation rate of 59 to 143 per one-thousand inhabitants, with simultaneous outdating or RBC from 79% to 49%, respectively. With such a programme the blood donations needs would be 32 to 26 per one-thousand inhabitants, those of plasmapheresis would be 29.9 to 9.1 per one-thousand inhabitants, and the outdated RBC would range from 7.6 to 0%.

Because of the great variations in the rates of donation needs in order to achieve self-sufficiency, every Community Blood Centre would have to establish a programme to calculate and monitor all the factors related with blood supplies in its territory.