Curriculum · Hematology
Transfusion-associated circulatory overload
What it is
Transfusion-associated circulatory overload, TACO, is fluid overload produced by a transfusion. Volume overload raises hydrostatic pressure, and pulmonary edema follows. Onset is within 6 hours of transfusion.
It sits among the other transfusion reactions, febrile non-hemolytic, allergic, anaphylactic, acute hemolytic and TRALI, and most of its value is that it has to be told apart from TRALI, which carries the same 6 hour timing.
Causes and risk
The cause is fluid overload: an excessive rate of transfusion, or a pre-existing heart failure that cannot take the added volume.
The risk factors named are:
- Elderly patients and infants
- Renal or cardiac failure, and pre-existing cardiac dysfunction
- Rapid infusion and high volume transfusions
How it presents
Dyspnea, orthopnea, hypertension and edema, with a raised JVP. Findings reported during transfusion include a desaturated patient, a raised jugular venous pulse, audible crepitations and bilateral inspiratory crackles, pedal edema and an S3. The patient is afebrile: fever is rare in TACO.