OBJECTIVE/STUDY DESIGN: After blood loss, production of erythropoietin in adults increases, which accelerates erythropoiesis and restores the erythroid mass. It is unclear whether preterm infants with large phlebotomy losses have a similar response. We therefore measured serum erythropoietin concentrations in 11 ill preterm infants (1057 +/- 167 gm) as their phlebotomy losses accumulated.
Results: Before the first transfusion, erythropoietin concentrations were 68.9 +/- 36.2 mU/ml (range 0 to 205 mU/ml) at 5 ml/kg blood out, 17.4 +/- 8.9 mU/ml at 10 ml/kg, and 4.8 +/- 2.6 mU/ml at 15 ml/kg. Erythropoietin concentrations did not increase in any patients despite increasing phlebotomy losses.
Conclusion: Serum erythropoietin concentrations in ill preterm infants do not increase in the face of significant blood loss. Although the mechanistic explanation for this failure is unclear, it likely contributes to the transfusion requirements of this population.