Page 2052 - Hematology_ Basic Principles and Practice ( PDFDrive )

C H A P T E R 121

PEDIATRIC TRANSFUSION MEDICINE

Cassandra D. Josephson and Steven R. Sloan

A variety of neonatal and pediatric patients require blood component compound that intercalates with nucleic acid and, on activa-
transfusions. This chapter focuses on aspects of blood-bank labora- tion with ultraviolet (UV) light, cross-links pathogen and
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tory testing, blood products and components, transfusion indications, white blood cell DNA, inhibiting replication. Almost all of
and potential adverse events that are specifically relevant to neonates the amotosalen, a potential carcinogen, is removed during
and children. processing. However, INTERCEPT platelets are contraindi-
cated for neonatal patients treated with phototherapy devices
emitting wavelengths <425 nm due to potential erythema
PEDIATRIC BLOOD BANKING from interaction between UV light and amotosalen.
• Platelets stored in a Platelet Additive Solution (PAS). PAS
Blood and Blood Components platelets contain very little plasma, which reduces the risk of
allergic reactions and transfusion-related acute lung injury
Several different blood components, including whole blood, recon- (TRALI), but also lowers the dose of coagulation factors
stituted whole blood, red blood cells (RBCs), platelets, plasma, and contained in the platelet component.
cryoprecipitated antihemophilic factor (CRYO) may be available • Plasma is frozen to retain functional plasma proteins including
from a blood bank for transfusion. Recently, additional components clotting factors. Depending on the timing of freezing and thawing,
have become available in the United States. They are photochemically- the component may be called fresh frozen plasma (FFP) or another
treated INTERCEPT platelets and plasma, and solvent detergent– name. However, all of these plasma components contain all the
treated plasma, Octaplas. The availability of specific component types necessary clotting factors. Two pathogen-inactivated plasma
varies between blood suppliers. products, that had been available in several countries, are now
available in the United States:
• Whole blood is infrequently used and may not be available from • INTERCEPT(Cerus Corporation, Concord, CA) treated
a particular blood bank or blood supplier, but it may be available plasma using the same system as described above.
on request and is used by some pediatric cardiac surgery services. • Octaplas (Octapharma, Hoboken, NJ) is a filtered pooled
Whole blood contains all RBCs, plasma, platelets, and an antico- plasma product that is subjected to solvent/detergent treat-
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agulant preservative solution containing citrate, phosphate, dex- ment to inactivate lipid-enveloped viruses. Its safety and
trose, and possibly adenine. efficacy in pediatric patients has not been evaluated which
• RBC units mostly contain RBCs but also contain some plasma would be important in neonates whose coagulation system
and a preservative solution. Most RBC units contain an additive regulation differs from adults. Specifically, Octaplas contains
preservative solution that includes some combination of adenine, low concentrations of protein S and α2-antiplasmin, two
dextrose, and mannitol. Additive solutions are safe for relatively inhibitors of the coagulation system that are present in low
small (≤20 mL/kg) transfusions. There are concerns over the concentrations in neonates. 3,4
safety of these additives given in large transfusions to neonates, • Cryoprecipitate is prepared from plasma and contains high con-
and their safety in this setting has never been proven in a random- centrations of fibrinogen.
ized clinical trial. In view of this concern, some hospital blood • Because pediatric patients require smaller doses of blood compo-
banks provide nonadditive RBC units or wash additive units nents, they often require only a portion of a component.
intended for large transfusions to neonates. Because many blood • RBCs are stored refrigerated and hence can be prepared in aliquots
centers provide only additive RBC units to hospital blood banks as needed if the blood bank has the necessary equipment. Alter-
and washing an RBC unit takes approximately 1 hour, blood natively the blood center can collect RBC units into a collection
banks have been unable to supply RBC units without additives in system in which additional bags are attached for dispensing ali-
many situations. Thus many institutions now have significant quots. Whole blood is also stored refrigerated, but its use is very
experience transfusing large volumes of additive RBC units to limited and it is almost never prepared in aliquots.
neonates and have not noticed any problems. • All platelet components are stored at room temperature under
• Two general types of platelet units are available in the United constant agitation and can be prepared in aliquots when needed
States, although any one blood bank or hospital may stock only in the blood bank if the blood bank has the necessary equipment
one of these types. These two types, whole blood–derived platelets and supplies. However, 1 unit of whole blood–derived platelets
(platelets) and platelets collected by apheresis (pheresis platelets), does not contain many doses, even for infants, and most blood
differ in their size. A platelet unit contains approximately 5.5 to banks do not aliquot them.
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10 × 10 platelets in about 50 mL, whereas a pheresis platelet • All plasma products are stored frozen, and are not generally ali-
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unit contains at least 3 × 10 platelets in about 200 mL. It is quoted after thawing. However, many blood centers will prepare
often easier to use platelet units for small children because pheresis plasma aliquots before freezing.
platelets usually need to be aliquoted to provide the correct dose. • Because even small infants rarely require less than 1 unit of
However, many blood centers exclusively provide only one type cryoprecipitate, this component is rarely prepared in aliquots.
of platelet component. Recently, two modifications of platelet
components were approved in the United States, although these
had been in use in other countries for several years. Directed Donations
• Platelets that have undergone pathogen inactivation using the
INTERCEPT Blood System (Cerus Corporation, Concord, Families often prefer to donate blood for their children using a
CA) which mixes amotosalen HCl, a synthetic psoralen process known as directed donations, and some blood banks

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