A number of conditions may mask the clinical occurrence of a hemolytic transfusion reaction. Usually more than one needs to be present for the reaction to be completely missed.


Pre-existing or coincident conditions:

(1) febrile illness

(2) acute renal failure

(3) hepatic dysfunction with jaundice

(4) coma

(5) hypotension or shock

(6) DIC or other coagulopathy

(7) hematuria

(8) autoimmune hemolytic anemia or other condition of positive direct antiglobulin test

(9) ongoing hemorrhage

(10) resorption of a large hematoma

(11) back or abdominal pain

(12) complete paralysis, neurologic or drug-induced (unable to complain of symptoms)


Drug therapy:

(1) premedication with antipyretic agent

(2) narcotic analgesia

(3) sedation


Ezidiegwu et al showed that use of antipyretic agents reduce the temperature spike in nonhemolytic febrile reactions but failed to mask other signs and symptoms.


The presence of one or more of these conditions should prompt closer monitoring of the patient during and after the transfusion.


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