Case Presentation: A 58-year-old male presented to the hospital with several days of fatigue and shortness of breath. His vitals were initially stable, and labs showed a hemoglobin of 4.2 (normal 13.5—17.5), white blood cell count WBC 20.1 (4.5—11.0), and platelet count 43 (160—420), BNP 617 (0—900 pg/ml). He received one unit of packed red blood cells and in several hours became hypoxic, tachypneic to 38 breaths a minute, hypertensive to 233/160, and required intubation. Repeat BNP was 1,676. Chest X-ray showed severe pulmonary venous congestion and concern for ARDS. An echocardiogram showed severely reduced systolic function with ejection fraction (EF) of 29% along with grade 2 diastolic dysfunction. Given flash pulmonary edema and a rising WBC count, he was given aggressive diuresis with broad spectrum antibiotics. WBC was as high as 71.7 with worsening creatinine to 2.0 (0.8—1.4 mg/dl), uric acid 11.1 (3.7—7.0 mg/dl) and LDH 2,907 (87-241 units/L). After a negative septic work-up, a bone marrow biopsy showed hypercellular marrow with 21% blasts consistent with acute myeloid leukemia with myelodysplasia related changes (AML-MRC) with positive CD117 stain. Patient was then transferred to the bone marrow unit for treatment of tumor lysis syndrome (TLS) with rasburicase and allopurinol. Repeat echocardiogram showed recovered EF to 55%, and patient was started on Vyxeos (daunorubicin and cytarabine) chemotherapy.
Discussion: Transfusion-associated circulatory overload (TACO) should be suspected in patients who progress into acute respiratory distress and decompensate within several hours of a blood transfusion. TACO is separated from transfusion-related acute lung injury (TRALI) physiologically in development of hydrostatic cardiogenic edema rather than permeability edema. According to the NHSN (National Healthcare Safety Network) 2016-TACO clinical definition, the criteria consists of new onset dyspnea and cough, positive fluid balance, elevation in brain natriuretic peptide (BNP), and radiographic findings of pulmonary edema with evidence of left heart failure. Unfortunately, patients with leukemia, previous stem cell transplants, and other hematologic disorders can be more predisposed to TRALI; the risk factors are unclear although HLA incompatibility is theorized to be associated. Although TRALI has been mentioned in a few case reports for leukemia patients, interestingly TACO has not been described at all.
Conclusions: Signs of volume overload such as shortness of breath can occasionally be the clinical presentation of AML, although other symptoms such as fever and weakness are more common. The onset of dyspnea is this case was triggered by transfusion of packed RBCs; furthermore, this patient suffered acute pulmonary edema that was believed to be cardiogenic in nature that required significant respiratory support. Based on current evidence, this patient fulfilled all criteria of TACO surveillance diagnosis (International Society of Blood Transfusion 2016) including acute respiratory distress within 6 hours of transfusion, pulmonary edema on imaging, cardiovascular changes including hypertension and peripheral edema, positive fluid balance and response to diuretics, and dramatic elevation in BNP after transfusion (617 to 1,676). This case aims to remind the clinician to be cognizant of underlying etiologies that can “tip over’ the threshold for TACO, such as leukemia.