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Transfusion Associated Cardiac Overload

Transfusion-associated cardiac overload, known by the acronym TACO, accounted for 22% of the transfusion-related fatalities reported to the U.S. Food and Drug Administration between 2010 and 2014.1

The recently released National Healthcare Safety Network Surveillance (NHSN) protocol2 defines TACO as:

  • New onset or exacerbation of 3 or more of the following within 6 hours of cessation of transfusion
    • Acute respiratory failure (dyspnea, orthopnea, cough)
    • Elevated brain natriuretic peptide (BNP)
    • Elevated central venous pressure (CVP)
    • Evidence of left heart failure
    • Evidence of positive fluid balance
    • Radiographic evidence of pulmonary edema
  • Imputability
    • Definite
      • No other explanation for circulatory overload
    • Probable
      • Transfusion is likely contributor to circulatory overload and
        • Either the patient received other fluids as well
        • Or the patient has a history of cardiac insufficiency that could explain the circulatory overload, but transfusion is just as likely to have caused the circulatory overload
      • Possible
        • The patient has a history of pre-existing cardiac insufficiency that most likely explains circulatory overload.

An International Society of Blood Transfusion definition (that is currently under consideration) defines TACO3 :

New acute or exacerbation of respiratory distress of 3 or more of the following within 6 hours of transfusion cessation:

  • Primary features
    • Evidence of acute or worsening pulmonary edema with bilateral infiltrates
    • Enlarged cardiac silhouette on chest X ray
    • Evidence of fluid overload
      • Positive fluid balance
      • Response to diuretic therapy combined with clinical improvement
    • Features to support the diagnosis
      • Elevated BNP or NT-pro BNP to more than 1.5 times pre-transfusion value (if available)
      • Increase in mean arterial pressure or increased pulmonary wedge pressure
    • Confirmed cases have at least 2 primary features or one in combination with 2 supporting features
      • Cases with only one primary feature (e.g. without chest X ray) are reported as possible or probable TACO depending on supporting features.

While the two definitions contain differences, they are similar thematically.

In contrast, other adverse events involving respiratory distress such as Transfusion Related Acute Lung Injury (TRALI) and Transfusion Associated Dyspnea (TAD) are defined, respectively, as:

    • Hypoxemia, radiographic evidence of bilateral infiltrates, and no evidence of left atrial hypertension, i.e. circulatory overload within 6 hours of transfusion
  • TAD
    • Acute respiratory distress within 24 hours of transfusion and allergic reaction, TACO, and TRALI definitions are not applicable.

TACO pathophysiology:

Cardiogenic pulmonary edema. TACO arises from fluid overload and associated increased pulmonary capillary hydrostatic pressure with resultant pulmonary edema. Unclear, at this time, is whether other events are involved, e.g. crystalloid and colloid interactions and/or inflammatory and vasoactive mediators such as those involving nitric oxide scavenging.4

TACO incidence and risk factors:

Per patient, TACO occurs in up to 8% of patients receiving transfusions; 4.2% of pediatric patients receiving platelet transfusions (4-6) TACO occurs following red cell, platelet, and plasma transfusions. Severe morbidity and mortality occur in 13%

In a study conducted at the Mayo Clinic and the University of California-San Francisco medical centers in which 47,783 patients received transfusions, 166 (0.35%) TACO cases occurred.7  Risk factors were determined in the last 83 consecutive patients; chronic renal failure (Odds Ratio=27.0), congestive heart failure (OR=6.6), amount of blood product transfused (OR=1.11 per unit), fluid balance per hour (OR=9.4 per liter), and age (inverse with age, OR 0.78 per 10 years). Among the patients with TACO, 8.4% died because of TACO or their underlying condition; Hazard Ratio=3.20 versus the control group.

At two academic medical centers in Canada, risk factors for TACO included a history of congestive heart failure (present in 41% of patients prior to transfusion), renal dysfunction (44%), and age more than 70 years (56%).8 The study identified excessive fluid management (500mL blood and 2200mL crystalloid or colloid administered within 24 hours) as a factor.

Among Medicare beneficiaries in the U.S., TACO occurred at an overall rate of 62.4 per 100,000 patient stays.9 TACO rates increased with advancing age, the number of units transfused, and in persons with congestive heart failure and chronic pulmonary disease.

Differential Diagnosis:

Consideration of the different presenting signs and symptoms may distinguish TACO and TRALI.10

Taco vs Trali

Other adverse events to consider in the differential diagnosis include: allergic reactions (wheezing), air embolus, acute asthma, pulmonary embolism, acute pneumothorax, and cardiac events causing acute cardiac dysfunction (acute myocardial infarction, arrhythmias).

Treatment and Prevention:

The primary intervention remains diligence in avoiding unnecessary transfusions.4

Once TACO is suspected:

  • Discontinue the transfusion
  • Monitor oxygenation status
  • Provide oxygen supplementation as needed
    • Monitor for non-invasive or invasive interventions
    • Ventilator support if necessary
  • Place patient in an upright position
  • Administer diuretics

There is insufficient evidence for determining the clinical evidence of loop diuretic premedication effectiveness in preventing TACO according to a recently published Cochrane review.11 However, prophylactic diuretic administration has been demonstrated to improve pulmonary capillary wedge pressure and fraction of inspired oxygen.

Decreasing the transfusion rate and monitoring total fluid intake reduces TACO occurrence. In one study, TACO incidence was lower in patients receiving transfusions at rates of 164mL per hour compared to those receiving transfusions at a rate of 225mL per hour.12 Note, red cells must be transfused within 4 hours.

A recently published report addressing urgent vitamin K antagonist reversal (major bleeding, requiring urgent surgery or invasive procedure) found an increased incidence of volume overload in patients receiving plasma compared to those receiving four-factor prothrombin complex concentrates (4F-PCC); 9 of 191 patients receiving 4F-PCC vs. 25 of 197 receiving plasma.13 A history of congestive heart failure and renal disease predicted volume overload. This suggests using 4F-PCC instead of plasma when possible.

An essential element involves critical nursing care.14 Patient monitoring to recognize TACO and the need to decrease or stop transfusions includes assessment of increases in systolic and diastolic blood pressure and increases in pulse pressure.



  4. AABB, Association Bulletin #15-02, December 28, 2015
  5. Li N, Williams L, Zhou Z, Wu YY. Incidence of acute transfusion reactions to platelets in hospitalized pediatric patients based on the US hemovigilance reporting system. Transfusion 2014; 54: 1666-72
  6. Clifford L, Jia Q, Yadav H, et al. Characterizing the epidemiology of perioperative transfusion-associated circulatory overload. Anesthesiology 2015; 122: 21-8
  7. Murphy EL, Kwaan N, Looney MR, et al. Risk factors and outcomes in transfusion-associated circulatory overload. Am J Med 2013: 126: e29-e38
  8. Lieberman L, Maskens C, Cserti-Gazdewich C, et al. A retrospective review of patient factors, transfusion practices, and outcomes in patients with transfusion-associated circulatory overload. Transfus Med Rev 2013; 27: 206-12
  9. Menis M, Anderson SA, Forshee RA, et al. Transfusion-associated circulatory overload (TACO) and potential risk factors among the inpatient US elderly as recorded in Medicare administrative databases during 2011. Vox Sang 2014; 106: 144-52
  10. Goldberg AD, Kor DJ. State of the art management of transfusion-related acute lung injury (TRALI). Curr Pharm Des 2012; 18: 3273-84
  11. Sari M, Tejani AM. Loop diuretics for patients receiving blood transfusions. Cochrane Database of Systematic Reviews 2015, Issue 2 Art. No. CD010138
  12. Li G, Rachmale S, Kojicic M, et al. Incidence and transfusion risk factors for transfusion-associated circulatory overload among medical intensive care unit patients. Transfusion 2011; 51: 338-43
  13. Refaai MA, Goldstein JN, Lee ML, et al. Increased risk of volume overload with plasma compared with four-factor prothrombin complex concentrate for urgent vitamin K antagonist reversal. Transfusion 2015; 55: 2722-9
  14. Alam A, Lin Y, Hansen M, et al. The prevention of transfusion-associated circulatory overload. Tranfus Med Rev 2013; 27: 105-12


Author: Jay Menitove, MD

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