[Induced normovolemic hemodilution. Calculation of the amount of blood to be withdrawn].

The authors study the variation of the hematocrit during a provoked normovolemic hemodilution. To get a predetermined hematocrit rate they use a simple and original biophysical model which gives the exact blood volume to be extracted. Then they use the same method to evaluate the hematocrit of the extracted blood after its conditionnement in packs.