[Practical value of the measurement of red cell volume in polyglobulia].

The practical interest of the direct measurement of the red blood cell volume in clinical haematology remains a matter of discussion. A retrospective study of 385 cases with high haematocrit values shows that the measurement of RBC volume is useful for the diagnosis between true and spurious polycythemia only when the haematocrit value is slightly increased (until 52 p.cent in women and 55 p.cent in men). At the higher values of haematocrit, the direct measurement of the RBC volume does not help for the diagnosis between primitive and secondary polycythemia, but may be useful for the choice of the treatment.