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Reference Library HomeCurrent Controversies in the Management of the Anemia of Prematurity
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Date Posted: Tuesday, March 3rd, 2009
| Semin Perinatol. 2009 Feb;33(1):29-34 Bishara N, Ohls RK |
| Abstract Here |
| Summary |
| In preterm infants, particularly those weighing <1000 g (extremely low birth weight [EBLW]), frequent blood draws are necessary as part of their NICU care. Most of these infants develop the anemia of prematurity (AOP), a hypoproliferative state in which the production of erythropoietin (EPO) is inadequate. Although the number of transfusions has decreased in recent years, these EBLW neonates still receive a significant number of RBC transfusions. Bishara and Ohls review recent studies that have evaluated transfusion guidelines in infants with AOP. Three studies examined the use of liberal or restrictive transfusion strategies and, based on their results, advocated using more restrictive transfusions strategies. Long-term neurodevelopment of these infants randomized to different strategies for transfusion have not been published. One reason EBLW infants receive transfusions is because of the phlebotomy losses associated with the need for frequent hematocrit determinations. These losses can be decreased if the following strategies are used: microsampling, batching of blood labs, cord blood sampling, removing central lines as soon as possible, judicious ordering of labs, careful monitoring of phlebotomy losses, and using of blood-testing or point-of-care devices at the bedside. Studies recently focused on the use of EPO in neonates to overcome the anemia caused by phlebotomy losses and prevent AOP. Although results of early studies varied because of methodological problems, results have indicated that the number of transfusions given to ELBW infants has decreased consistently and the percentage of ELBW infants not receiving transfusions at all has increased. One randomized trial evaluated the effects of vitamin B12, oral folic acid, iron, vitamin E, and EPO on transfusion requirements in ELBW infants. Control infants had a 95% transfusion rate compared with a 62% rate in those in the EPO group. The investigators concluded that using EPO, iron folate, and vitamins E and B12 during the first few weeks of life significantly reduced the risk of transfusion. Bishara and Ohls studied three doses of darbepoetin alfa (2.5, 5, and 10 µg/kg/dose) for its effect on reticulocyte counts in ELBW infants, all of whom also received iron, folate, and vitamin E. They found that the highest dose led to the highest absolute reticulocyte count by day 28 compared with placebo. No adverse effects were seen with any dose. Concerns have been raised about the use of EPO and the development of retinopathy of prematurity. No randomized controlled trials have reported an increased incidence of this outcome in EPO-treated patients. Most morbidities of prematurity are highest in the tiniest, sickest infants and any treatments will be associated with ELBW morbidities. Only randomized, controlled trials will determine if a cause-and-effect relationship exists between a specific treatment and specific morbidity. Such a relationship has not been reported for EPO treatment and retinopathy of prematurity. Another benefit being examined in ongoing studies is the potential neuroprotective effect of EPO in the developing preterm infant. Animal studies have shown a protective effect of EPO and pilot studies have found the same benefit of high-dose EPO in ELBW infants. Use of EPO combined with restrictive transfusion guidelines and a multifactorial approach to minimize RBC loss will have a great impact on reducing transfusion requirements in neonates (preterm or term) with anemia. Such research efforts may eventually improve the developmental outcomes of preterm infants. |