Transfusion-related circulatory overload (TACO)

TACO is cause by heart failure leading to pulmonary oedema as a result of rapid infusion or large volumes of blood products.

It is the 2nd leading cause of transfusion-related deaths reported to the FDA, accounting for 21% of all reported fatalities.(1) 

TACO is also responsible for most deaths and major morbidity reported to SHOT including 24 deaths over the last 5 years and 88 cases of major morbidity.(2)

When to suspect this adverse reaction?

The ISBT criteria for diagnosis of TACO states that it is characterized by any of the 4 of the following within 6 hours of transfusion:

  • Acute respiratory distress
  • Tachycardia
  • Raised blood pressure
  • Acute or worsening pulmonary oedema on CXR
  • Evidence of positive fluid balance

The cardiac marker, brain natriuretic peptide (BNP) is often elevated in TACO. (3)

Usual causes?

This is usually due to rapid or massive transfusion of blood in patients with diminished cardiac reserve or chronic anaemia.

Patients over 60 years of age, infants and severely anaemic patients are particularly susceptible.(4,5)

TACO occurs in approximately 1:100 transfused patients.(4)


TACO is frequently confused with TRALI (3) as a key feature of both is pulmonary oedema and it is possible for these complications to occur concurrently. Hypertension is a constant feature in TACO whereas it is infrequent and transient in TRALI.


What to do?

Stop transfusion immediately and follow other steps for managing suspected transfusion reactions.

Place the patient in an upright position and treat symptoms with oxygen, diuretics and other cardiac failure therapy.

How to prevent?

In susceptible patients at risk for TACO (paediatric patients, patients with severe anaemia and patients with congestive heart failure), transfusion should be administered slowly and consideration given to use of a diuretic. 

  1. Fatalities reported to the FDA following blood collection and transfusion:Annual summary for fiscal year 2012.  Available from:
  2. Bolton-Maggs PH, Cohen H.  Serious Hazards of transfusion (SHOT) haemovigilance and progress in improving transfusion safety.  Br J Haematol 2013, 163(3):303-314.
  3. Popvsky M, Robillard P, Schipperus M, Stainsby D, Tissot J, et al.  ISBT Working Party on haemovigilance.  Proposed standard definitions for surveillance of non infectious adverse transfusion reaction 2013.  Available from:
  4. Fung MK, Grossman BJ, Hillyer CD, Westhoff CM (ed). Non-infectious complications of blood transfusion. Chapter 27, AABB Technical Manual, 18th edition. AABB, Bethesda, 2014.
  5. Callum JL, Pinkerton PH, Lima A, Lin Y, Karkouti K, Lieberman, L, et al. Chapter 5, Transfusion Reactions. Bloody Easy 4: Blood Transfusions, Blood Alternatives and Transfusion Reactions: A Guide to Transfusion Medicine, 4rd edition. Canada: Ontario Regional Blood Coordinating Network, 2016.