Explain the special transfusion needs related to pediatric size (ie, aliquots) and immaturity of the immune system (ie, irradiation).
Characterize disorders unique to (ie, NAIT-neonatal alloimmune thrombocytopenia) and common in (ie, sickle cell disease) pediatric populations including current methods of transfusion support.
Elucidate common transfusion reactions encountered in pediatric treatment environments.
This chapter is designed to address the common questions and requests a pathology resident or other laboratory trainee might encounter while rotating through a pediatric blood bank. To comprehensively address each issue would be the work of a book, not a chapter. The aim here, therefore, is to provide an immediately acceptable answer. The hope is that you will be intrigued enough by pediatric transfusion medicine to delve further and use the references in finding more complete answers.
Possibly the most frequent request in pediatric transfusion medicine is for a partial unit of a blood product (aliquot or divide) for a smaller patient. While standard doses in adults tend to be in whole units, pediatric dosing is usually done in milliliters per kilogram (mL/kg). Typical packed red blood dosing, for instance, is 10-15 mL/kg of patient weight, which should translate into a 2-3 g/dL increase in hemoglobin.1 Platelets are expected to increase in count by 50-100 thousand with a dose of 5-10 mL/kg. A plasma dose of 10-15 mL/kg should increase circulating clotting factors by 15-20%. Finally, if fibrinogen is selectively needed, 1-2 unit per 10 kg of cryoprecipitated Anti-Hemophilic Factor (AHF) is expected to raise the level 60-100 mg/dL.
Any service providing red cells to patients smaller than 20 kg (300 mL typical additive solution leukoreduced unit2 at dose of 15 mL/kg) must have a way to provide sterilely produced aliquots or divides. Products prepared in such a manner have a 28 day out-date or their original expiration date, whichever comes first. Some blood centers initially process blood products into “pedipacks.” For example, a set of two to three 75 mL each bags of plasma, all from one donor, would expire after 1 year of frozen storage.2 Aliquots and divides prepared using an open system expire 24 hours after being made (see section Whole Blood later).
The purpose of X-ray or gamma irradiation is to prevent transfusion associated graph versus host disease (TA-GVHD). Standard dose (25 Gray) irradiation prevents TA-GVHD by cross-linking the DNA of donor T-cells so they cannot replicate.3 Settings for which irradiated cellular products are indicated include congenital immunodeficiency disorders and intra-uterine transfusions. Oncology patients with hematologic malignancies, undergoing chemotherapy, or receiving bone marrow transplants should also receive irradiated cellular blood products.4 The other clearly indicated group is recipients who are generally immuno-competent but being transfused products from blood relatives or HLA matched individuals. Neonates ...