Hemodilution during bone marrow harvesting in children.

Eight children (1-17 yr) underwent bone marrow harvesting while in cytostatic-induced remission of their disease (leukemia [n = 6], Ewing sarcoma, and non-Hodgkin lymphoma). After the induction of general anesthesia, all patients were loaded with 10 mL/kg of a 6% high-molecular dextran solution (Macrodex--Pharmacia), which resulted in a significant preoperative decrease in hematocrit (Hct) from 32% +/- 6% to 28% +/- 5% (hypervolemic hemodilution) and also allowed the procedure to be performed without systemic heparinization. The blood aspirated during the harvest (24 +/- 6 mL/kg; mean +/- SD) was replaced with a solution of 6% dextran and Ringer's acetate solution, and the Hct decreased from 28% +/- 5% to a minimum of 18% +/- 3%. Immediately after the harvest, 10 mL/kg of homologous packed red blood cells was transfused, increasing Hct to 25% +/- 3%. Oxygen saturation in the superior caval vein (ScvO2) decreased from 79% +/- 4% before the harvest to 70% +/- 3% (P less than 0.01) at the end of it, and then increased to 74% +/- 3% after the transfusion of homologous packed red blood cells. There was a strong linear correlation between mean values for Hct and ScvO2 during the various stages (r = 0.99). Mean heart rate decreased gradually during the procedure, from 106 +/- 10 to 86 +/- 7 beats/min. There was no significant change in arterial pressure, but cardiac output measured by impedance cardiography was about 30% greater during harvesting than during undisturbed anesthesia. Pulse oximetric saturation was 99% or 100% throughout. Caval venous blood lactate and pyruvate concentrations remained within normal limits in all children.(ABSTRACT TRUNCATED AT 250 WORDS)