Modified ultrafiltration attenuates dilutional coagulopathy in pediatric open heart operations.

BACKGROUND: Extreme hemodilution caused by relatively large prime volumes required for cardiopulmonary bypass in infants causes a dilutional coagulopathy, characterized by low concentrations of fibrinogen and other circulating coagulation factors. Modified ultrafiltration results in hemoconcentration and is associated with decreases in postoperative bleeding and transfusion requirements in children. This study was undertaken to quantify the effect of modified ultrafiltration on concentrations of fibrinogen, plasma proteins, and platelets in infants and small children. METHODS: Twenty patients less than 15 kg were studied. Cardiopulmonary bypass circuits were primed with crystalloid solutions. Red blood cells were added during cardiopulmonary bypass for hematocrits less than 15%. Colloid solutions were not administered. Concentrations of fibrinogen, plasma proteins, and platelets, and hematocrit were measured before cardiopulmonary bypass, before modified ultrafiltration, and after modified ultrafiltration. RESULTS: Modified ultrafiltration was associated with significant (p < 0.001) increases in hematocrit (19% +/- 6% to 31% +/- 9%), fibrinogen (65 +/- 29 to 101 +/- 45 mg/dL), and total plasma proteins (2.7 +/- 0.3 to 4.9 +/- 0.7 g/dL), but no change (p = 0.129) in platelet count. CONCLUSIONS: We conclude that modified ultrafiltration significantly attenuates the dilutional coagulopathy associated with cardiopulmonary bypass in infants.

Blood conservation during pediatric cardiac surgery: ultrafiltration of the extracorporeal circuit volume after cardiopulmonary bypass.

After separation of pediatric patients from cardiopulmonary bypass (CPB), the authors salvaged red blood cells (RBCs) from the extracorporeal circuit by ultrafiltration and reinfused them to the patients. The purposes of this study were to determine 1) the effects of infusion of hemoconcentrated RBCs on hemoglobin, plasma free hemoglobin, and activated clotting time, and 2) the incidence of perioperative homologous RBC transfusion. Data were collected prospectively from 200 consecutive infants and children undergoing CPB during correction of congenital heart defects. The patients' hemoglobin, plasma free hemoglobin, and activated clotting time were measured both before and after infusion of 10 mL/kg of hemoconcentrate. Guidelines for intraoperative and postoperative transfusion of homologous RBCs were followed, and such transfusions were recorded. Significant increases in hemoglobin concentrations occurred when the hemoconcentrate was infused, as did statistically significant, but clinically manageable, increases in plasma free hemoglobin and activated clotting time. Perioperative homologous RBC transfusion was performed in 67% of patients (56% received intraoperative transfusion). Intraoperative transfusion was more frequent in small infants who were more hemodiluted by the clear CPB priming solution. Postoperative transfusion was more frequent in patients who had operation for cyanotic heart disease. Hemoconcentration by ultrafiltration after CPB is an effective and safe means of salvaging RBCs and reducing homologous RBC transfusion.