A 32-year-old woman is evaluated for fever, chills, and weakness. She had a blood transfusion 10 days prior after she underwent an open reduction and internal fixation of the right femur due to a motor vehicle accident. She has had no significant past medical history except for a C-section 2 years ago at which time she successfully received a blood transfusion.
On examination, she has a fever of 100.1°F, blood pressure is 100/64 mm Hg, pulse rate is 110 bpm, and respiration is 20/min. On physical examination, the patient appears uncomfortable and has scleral icterus. The remainder of the examination is unremarkable. There is no evidence of bleeding.
Hemoglobin concentration is 6.2 g/dL compared with a hemoglobin of 8.6 g/dL previously. Platelet and leukocyte count are normal. Direct and indirect Coombs tests are positive. The blood bank identifies a new alloantibody on further testing.
1. What is the most likely diagnosis?
2. What is the next step in management?
Delayed hemolytic transfusion reaction (DHTR).
Specific treatment generally is not necessary. Supplemental transfusion of blood lacking the antigen corresponding to the offending antibody may be necessary to compensate for the transfused cells that have been removed from the circulation.
DHTR is an antibody response to previously sensitized RBC alloantigens, which have a negative alloantibody screen due to low antibody levels. This reaction typically occurs in 7 to 14 days following a transfusion. The alloantibody is detectable 1 to 2 weeks following the transfusion, and the posttransfusion direct antiglobulin test may become positive due to circulating donor RBCs coated with antibody or complement. These reactions are detected most commonly in the blood bank when a subsequent patient sample reveals a positive alloantibody or a new alloantibody in a recently transfused recipient. DHTR is associated with jaundice, low-grade fever, and an otherwise unexplained decrease in hemoglobin levels. Many delayed hemolytic reactions will go undetected because the red cell destruction occurs slowly. Any adverse reaction to the transfusion of blood or blood components should be reported to blood bank personnel as soon as possible.
Anemia is defined as a reduction below normal of the number of erythrocytes in the circulation. The World Health Organization defines anemia as a hemoglobin level <13 g/dL in men and <12 g/dL in women. Anemia is the most common indication for RBC transfusion among patients. It results from at least 1 of the following 3 factors:
Blood loss related to the primary condition or to the operation
Diminished erythropoiesis related to the primary illness
Serial blood draws (totaling, on average, approximately 40 mL per day in an ICU setting)
Acute anemia is due to blood loss or hemolysis. If blood loss is mild, enhanced O2 delivery is achieved through changes in the O2–hemoglobin dissociation curve mediated by a decreased pH or increased CO2 (the Bohr effect). With acute blood loss, ...