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 < 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 beatslmin. 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. Recovery after anesthesia was uneventful, except in one child in whom severe shivering developed. H is concluded that the hemodilution resulted in a statistically but not clinically significant decrease in Scvo2 that was well tolerated by the patients as judged from hemodynamic responses as well as levels of arterial oxygen saturation (Sao2) and blood lactate.