Definition
Acute dyspnoea with hypoxia and clear evidence of pulmonary oedema on imaging developing within 6 hours of transfusion, where the patient's respiratory state in the last 12 hours was considered as stable or improving and circulatory overload is not thought to be a major contributor to the reaction.
May be due to antibodies in the donor which react against recipient white blood cells.
Frequency
Very Rare (<1/10,000).
Most cases reported are in patients already unwell with a pre-existing inflammatory insult (e.g. sepsis, trauma). Patients at risk are likely to have multiple co-morbidities, with inflammatory and fluid balance issues.
Reducing the risk
It is vitally important to undertake a TACO pre-transfusion risk assessment and mitigating actions for all patients at risk of pulmonary complications.
As anti-leucocyte antibodies are most likely to form following pregnancy, plasma components (FFP, cryoprecipitate) in the UK are only sourced from male donors.
Female platelet donors are screened for these antibodies.
Further information/ resources
SHOT Transfusion-Associated Circulatory Overload (TACO) Cumulative Data
NHSBT TRALI information sheet