Outcomes Using a Conservative Versus Liberal Red Blood Cell Transfusion Strategy in Infants Requiring Cardiac Operation

Background The optimal hemoglobin for infants after cardiac operation is unknown. Red blood cells (RBCs) are commonly transfused to maintain high hemoglobin concentrations in the absence of a clinical indication. We hypothesized that infants can be managed with a postoperative conservative RBC transfusion strategy, resulting in lower daily hemoglobin concentrations, without evidence of impaired oxygen delivery (ie, lactate, arteriovenous oxygen difference [avO 2 diff]), or adverse clinical outcomes. Methods Infants weighing 10 kg or less undergoing biventricular repair or palliative (nonseptated) operation were randomly assigned to either a postoperative conservative or liberal transfusion strategy. Conservative group strategy was RBC transfusion for a hemoglobin less than 7.0 g/dL for biventricular repairs or less than 9.0 g/dL for palliative procedures plus a clinical indication. Liberal group strategy was RBC transfusion for hemoglobin less than 9.5 g/dL for biventricular repairs or less than 12 g/dL for palliative procedures regardless of clinical indication. Results After the operation of 162 infants (82 conservative [53 biventricular, 29 palliative], 80 liberal [52 biventricular, 28 palliative]), including 12 Norwood procedures (6 conservative, 6 liberal), daily hemoglobin concentrations were significantly lower within the conservative group than the liberal group by postoperative day 1 and remained lower for more than 10 days. The percentage of patients requiring a RBC transfusion, number of transfusions, and volume of transfusions were all significantly lower within the conservative group. Despite lower hemoglobin concentrations within the conservative group, lactate, avO 2 diff, and clinical outcomes were similar. Conclusions Infants undergoing cardiac operation can be managed with a conservative RBC transfusion strategy. Clinical indications should help guide the decision for RBC transfusion even in this uniquely vulnerable population. Larger multicenter trials are needed to confirm these results, and focus on the highest risk patients would be of great interest.