Thrombopoietin following transfusion of platelets in preterm neonates

Medicinal Uses of Hematopoietic Growth Factors in Neonatal Medicine

This review focuses on certain hematopoietic growth factors that are used as medications in clinical neonatology. It is important to note at the chapter onset that although all of the pharmacological agents mentioned in this review have been approved by the US Food and Drug administration for use in humans, none have been granted a specific FDA indication for neonates. Thus, in a sense, all of the agents mentioned in this chapter could be considered experimental, when used in neonates. However, a great many of the pharmacological agents utilized routinely in neonatology practice do not have a specific FDA indication for this population of patients. Consequently, many of the agents reviewed in this chapter are considered by some practitioners to be nonexperimental and are used when they judge such use to be "best practice" for the disorders under treatment.The medicinal uses of the agents in this chapter vary considerably, between geographic locations, and sometimes even within an institutions. "Consistent approaches" aimed at using these agents in uniform ways in the practice of neonatology are encouraged. Indeed some healthcare systems, and some individual NICUs, have developed written guidelines for using these agents within the practice group. Some such guidelines are provided in this review. It should be noted that these guidelines, or "consistent approaches," must be viewed as dynamic and changing, requiring adjustment and refinement as additional evidence accrues.

A consistent approach to platelet transfusion in the NICU

Platelet transfusions are the principal means of treating thrombocytopenia in neonatal intensive care units (NICUs), and are generally used as treatment of thrombocytopenic neonates who have active bleeding and as prophylactic administration in thrombocytopenic neonates who do not have hemorrhage but appear to be at high risk for bleeding. In this article, we summarize the rationale, benefits and risks of platelet transfusions in neonates. We review the importance of choosing the best product available for platelet transfusion, and we emphasize the importance of adopting and adhering to transfusion guidelines.

Thrombocytopenia and bleeding in pediatric oncology patients

Prophylactic platelet transfusions are the standard of care for patients with hypoproliferative thrombocytopenia after receiving chemotherapy or radiation for the treatment of malignancy, for BM replacement by leukemia or solid tumor, or in preparation for a hematopoietic stem cell transplantation.1 During this time of thrombocytopenia, these patients may receive both prophylactic platelet transfusions, which are given to prevent potentially life-threatening bleeding when a patient's platelet count drops below a predetermined threshold, and therapeutic platelet transfusions, which are given to treat active or recurrent bleeding. In the 1950s, the invention of the plastic blood bag allowed for the production and storage of platelet concentrates,2 and in the 1960s, it was recognized that prophylactic platelet transfusions effectively reduced hemorrhagic death in patients with newly diagnosed leukemia.3,4 In 1962, Gaydos published the paper that is frequently credited with the inception of the 20 000/μL platelet transfusion threshold.5 Despite a half-century of experience with prophylactic platelet transfusions, there are still insufficient data to provide clinicians with evidence-based guidelines specific to pediatric oncology and hematopoietic stem cell transplantation (HSCT) patients.

Platelet transfusions in neonates: practices in the United States vary significantly from those in Austria, Germany, and Switzerland

BACKGROUND

Thrombocytopenia affects 20% to 35% of patients admitted to neonatal intensive care units (NICUs). Platelet (PLT) transfusions are usually administered to neonates with thrombocytopenia at higher thresholds than those used for older children or adults, although there is a paucity of evidence to guide these decisions.

STUDY DESIGN AND METHODS

In this study, we used a Web-based survey to investigate the PLT transfusion thresholds used in Level 1 NICUs (equivalent to Level 3 in the US) in three European countries (Austria, Germany, and Switzerland [AUT/GER/SUI]). This survey was identical to the one that was previously sent to US neonatologists, thus allowing for a direct comparison of their responses to 11 case-based scenarios.

RESULTS

In nine of the scenarios, AUT/GER/SUI neonatologists selected substantially lower PLT transfusion thresholds than US neonatologists (p < 0.0001). Transfusion thresholds were more similar when treating neonatal alloimmune thrombocytopenia and before invasive procedures. The clinical impact of these differences was estimated by extrapolating the AUT/GER/SUI versus the US answers to a cohort of neonates with a birth weight below 1000 g. This suggested that, in AUT/GER/SUI, these neonates would receive 167 PLT transfusions per 1000 infants, compared to 299 PLT transfusions in the United States.

CONCLUSION

This first international comparative survey on PLT transfusion practice in neonates reveals substantially higher transfusion thresholds in the United States than in AUT/GER/SUI. Well-designed clinical studies are needed to address the risks and/or benefits of these different approaches.

Platelet transfusion in the neonatal intensive care unit: benefits, risks, alternatives

Platelet transfusions were introduced into clinical medicine about 60 years ago when they were shown to reduce the mortality rate of patients with leukemia who were bleeding secondary to hyporegenerative thrombocytopenia. In modern neonatology units, platelet transfusions are integral and indeed lifesaving for some neonates. However, the great majority of platelet transfusions currently administered in neonatal intensive care units (NICUs) are not given in the original paradigm to treat thrombocytopenic hemorrhage, but instead are administered prophylactically with the hope that they will reduce the risk of spontaneous bleeding. Weighing the risks and benefits of platelet transfusion, although imprecise, should be attempted each time a platelet transfusion is ordered. Adopting guidelines specific for platelet transfusion will improve consistency of care and will also generally reduce transfusion usage, thereby reducing costs and conserving valuable blood bank resources. Initiating specific programs to improve compliance with transfusion guidelines can further improve NICU transfusion practice.