Pediatric emergency medicine trisk 2255 2255
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Reactions to transfused blood products may be acute (during or within 24 hours of
transfusion) or delayed (days to weeks posttransfusion). The most feared, but fortunately
now uncommon transfusion reaction, is an acute hemolytic transfusion reaction. This
type of reaction occurs due to the presence of a complement-fixing RBC antibody that
causes rapid and often severe intravascular hemolysis. The patient will have a newly
positive DAT (Coombs). The uncommon occurrence of this problem is, in large part, a
tribute to careful blood banking practices and close attention to the administration of the
properly identified RBC product to the correct recipient thereby avoiding infusion of
ABO-incompatible red cells. The release of proinflammatory cytokines as a result of
complement activation gives rise to the characteristic symptoms of apprehension, fever,
chills, abdominal or flank pain, chest tightness, and hypotension as well as activation of
the coagulation cascade potentially manifesting as DIC. Other potentially lifethreatening transfusion reactions include transfusion-related acute lung injury (TRALI),
transfusion-associated circulatory overload (TACO), anaphylactic transfusion reaction,
and septic transfusion reaction ( Table 93.14 ). TRALI is defined as acute lung injury
with hypoxemia (PaO2 /FiO2 ≤300 or room air O2 saturation <90%) that occurs within 6
hours of a transfusion in a patient without prior risk factors for acute lung injury.
Respiratory symptoms can be severe and may progress to respiratory failure in some
cases. While symptoms typically resolve within 48 to 72 hours, the associated mortality
is about 10%. TACO should be considered prior to transfusion in patients at risk for
circulatory volume overload such as patients with chronic anemia or those with
compromised cardiac function. Delayed hemolytic transfusion reactions can occur days
to weeks after an RBC transfusion. These reactions may be due to formation of an
antibody in response to a newly encountered RBC antigen or an amnestic response of an
antibody that originally developed in response to a previous transfusion but was
undetectable at the time of the most recent cross-match. The rate of RBC destruction is
usually slower with a delayed hemolytic transfusion reaction than with an acute
hemolytic reaction, so patients may have symptoms of anemia and hyperbilirubinemia,
but not shock and renal insult.
While nonhemolytic and febrile transfusion reactions are more common, they may be
difficult to distinguish from the more dangerous hemolytic reaction prior to laboratory
evaluation. Consultation with the blood bank and/or hematology can provide guidance
regarding assessment for possible transfusion reaction.
Management
In the event of a suspected transfusion reaction, the transfusion should be stopped
immediately. The blood bank should be alerted to the concern for a possible transfusion
reaction. Supportive care to ensure adequate respiratory support and end-organ
perfusion is essential. Evaluation and management considerations by reaction type are
highlighted in Table 93.14 . The name, identification number, and blood type of the
patient should be compared with those on the unit of blood to ensure that the blood was
