From the Guidelines
The diagnosis in this patient can be established by a direct antiglobulin test (DAT), also known as a Coombs test, as this patient is experiencing an acute hemolytic transfusion reaction, which occurs when there is incompatibility between donor and recipient blood. The clinical presentation strongly suggests this diagnosis: fever, hypotension, tachycardia, flank pain, nausea, and dark red urine that developed shortly after blood transfusion initiation. The pain and oozing at the IV site further support this diagnosis.
Key Points to Consider
- The DAT will detect antibodies or complement proteins bound to the patient's red blood cells, confirming immune-mediated hemolysis.
- In acute hemolytic transfusion reactions, donor red blood cells are destroyed by preformed antibodies in the recipient's plasma, leading to intravascular hemolysis, which explains the hemoglobinuria (dark red urine) 1.
- This reaction can cause serious complications including disseminated intravascular coagulation, acute kidney injury, and shock.
- Management includes immediately stopping the transfusion, maintaining blood pressure with fluids, and monitoring renal function.
Relevant Statistics
- The risk for fatal hemolysis was estimated to range from 1.3 to 1.7 per million (5.9 to 7.7 per 10 million) transfused RBC units in one report and 1 per 1 800 000 or 8.5 per 10 million in a second report 1.
- More recently, transfusion-related fatalities due to hemolysis reported to the U.S. Food and Drug Administration averaged 12.5 deaths per year from 2005 to 2010 1.
- With 15 million RBC units transfused per year, the estimated risk for death due to hemolysis is 1:1 250 000 or 8 per 10 million RBC units 1.
From the Research
Diagnosis of Hemolytic Transfusion Reaction
The patient's symptoms, including severe nausea, right flank pain, pain and oozing along the IV site, fever, hypotension, tachycardia, and dark red urine, are consistent with a hemolytic transfusion reaction 2, 3, 4.
- The clinical presentation of hemolytic transfusion reactions can be acute or delayed, with acute reactions occurring within 24 hours of transfusion 4.
- The symptoms of acute hemolytic transfusion reactions include fever, flank pain, and red or dark urine, which may not be immediately visible if the patient is under anesthesia 2.
- In addition to these symptoms, the patient may also experience nausea, restlessness, skin flushing, dyspnea, and shock, which are mediated by cleavage products of complement activated by red cell antigen-antibody reaction 4.
- The diagnosis of hemolytic transfusion reaction can be established by laboratory tests, including the direct antiglobulin test (DAT), which detects immunoglobulin and/or complement on the surface of red blood cells 5.
Laboratory Tests for Diagnosis
The direct antiglobulin test (DAT) is a critical step in the evaluation of hemolysis and can help classify causes of hemolysis, including autoimmune hemolytic anemia, transfusion-related hemolysis, and hemolytic disease of the fetus/newborn 5.
- The DAT can detect immunoglobulin and/or complement on the surface of red blood cells, which is a hallmark of immune-mediated hemolysis 5.
- However, false reactions may occur with improper technique, including improper washing, centrifugation, and specimen agitation at the time of result interpretation 5.
- Patient factors, such as spontaneous red blood cell agglutination, may also contribute to false results 5.
Establishment of Diagnosis
The most likely test to establish the diagnosis in this patient is the direct antiglobulin test (DAT) 5, which can detect immunoglobulin and/or complement on the surface of red blood cells.
- The DAT is a critical step in the evaluation of hemolysis and can help classify causes of hemolysis, including transfusion-related hemolysis 5.
- In addition to the DAT, other laboratory tests, such as hemoglobin, hematocrit, and platelet count, may also be useful in establishing the diagnosis of hemolytic transfusion reaction 2, 3, 4.