(42) Rise in hematocrit with two different dosing regimens of recombinant erythropoietin for anemia of prematurity

Background: Recombinant erythropoietin (EPO) is used in the prevention and treatment of anemia of prematurity, generally for babies beyond DOL 28 as part of efforts to decrease pRBC transfusions and donor exposures to our premature infants. We previously used recombinant erythropoietin (EPO) for anemia of prematurity at a dose of 500 u/kg 3x/week. In creating a new protocol, we discovered this dose was not well-supported by literature and changed to 300u/kg 3x/week.

Objectives: To determine if the 300 u/kg/dose of EPO will result in a similar rise in hematocrit as the previously studied dose of 500 u/kg/dose.

Design/Methods: Data were previously collected and reported for the 500u/kg cohort. We retrospectively collected data for the subsequent cohort of babies who received EPO after the new protocol was implemented, now at 300u/kg. The electronic medical records (EMR) were examined for patient demographics and characteristics, EPO administration records, laboratory results before/during/after the EPO course, morbidities, and interventions (including the need for transfusion after EPO, neutropenia, thrombocytopenia, development of NEC, and mortality). Statistical analysis used paired t-test for continuous normally distributed variables in two groups, or linear regression to compare two continuous variables for significance testing.

Results: The new cohort has 152 infants who received a total of 172 courses of EPO at a dose of 300 u/kg/dose. Eighteen babies had two courses, and two babies had a third course. The average birthweight was 1315 grams with a mean gestational age of 29.7 weeks (Table 1). The mean starting hematocrit (Hct) was 26.85 (SD 2.24), and the mean starting reticulocyte count was 3.9 (SD 1.74). The median increase in Hct after EPO was 6.4 (4.1, 8.9). The mean drop in white blood cell count after EPO was 2.6 (SD 3.14).

Conclusion: The rise in hematocrit was comparable for both doses suggesting the 300u/kg dosing is as effective as the previously used 500u/kg dosing. However, the rise in reticulocyte count was greater in the 500u/kg cohort than in the 300 u/kg cohort. In this new cohort, we also examined the effect on the white blood cell count, which was significantly lower post-EPO (Table 2).