PHLEBOTOMY OF 500 OR 750 MILLILITERS OF WHOLE-BLOOD FOLLOWED BY ISOVOLEMIC HEMODILUTION OR AUTOLOGOUS TRANSFUSION YIELDS SIMILAR HEMODYNAMIC, HEMATOLOGIC, AND BIOCHEMICAL EFFECTS

The purpose of this study was to evaluate the effects of phlebotomy of 500 or 750 mi of whole blood followed by isovolemic hemodilution or a utologous transfusion on hemodynamic, hematologic, and biochemical par ameters in healthy subjects. Four groups of normovolemic male subjects (n = 6 or 7 per group), aged 18 to 41 years, participated in this In- day study at Upjohn Research Clinics, Kalamazoo, Mich. On day I two gr oups had phlebotomy of 500 mi; of these, one group underwent immediate postphlebotomy autologous transfusion (group I) and the other underwe nt immediate postphlebotomy isovolemic hemodilution and then autologou s transfusion on day 3 (group 2). Two other groups had 750 mi phleboto my, also on day 1; of these, one group underwent immediate postphlebot omy autologous transfusion (group 3) and one underwent immediate postp hlebotomy Isovolemic hemodilution followed by autologous transfusion o n day 3 (group 4). Noninvasive measurement of vital signs, blood press ure, and cardiac function; oximetry; and select hematologic and bioche mical parameters were made. On day I in groups 2 and 4 transient reduc tions in hematocrit, hemoglobin, red blood cell count, fibrinogen, and albumin were seen concurrent with prolongation of coagulation studies . Erythropoietin was increased severalfold on day 3 (groups 2 and 4, p < 0.001). The physiologic response to phlebotomy of 500 or 750 mi was similar and was well tolerated in normal subjects.