27th May 2023

Non-immune transfusion reactions

Transfusion Associated Circulatory Overload (TACO)

TACO is defined as acute or worsening pulmonary oedema within 6 hours of transfusion and presents with respiratory distress, tachycardia, and clinical evidence of a positive fluid balance. Patients with heart failure, renal impairment, low albumin and fluid overload should have appropriate volume and flow rate prescribed to reduce the risk of TACO. Treatment includes stopping the transfusion, oxygen and diuretic therapy. TACO remains the leading cause of transfusion-related combined mortality and major morbidity. In stable-non-bleeding anaemic patients, medical management of anaemia must be first considered.

Transfusion transmitted infection

Bacterial contamination of blood products is extremely rare. It is more likely to occur with platelet components, stored at 22-24°C degrees, compared to red cells, which are kept refrigerated at 2-6°C and for this reason all platelet donations undergo bacterial culture prior to use. Typical signs include rigors, fever, hypotension and rapid onset shock. The blood component pack may appear normal but should be visibly inspected for clumps and discolouration. Blood cultures should be taken, and intravenous broad-spectrum antibiotics delivered to cover both gram-negative and gram-positive bacteria. The blood component should be sealed and returned to the transfusion laboratory for further investigation so that any associated component can be withdrawn.

Rigorous pre-donation assessment and testing of donated products minimises the risk of transmission of viral infections. All blood donations are screened for hepatitis B, hepatitis C, hepatitis E, HIV and HTLV I and II.

Some blood products are tested for cytomegalovirus (CMV) as CMV-negative blood components are indicated in pregnant women and neonates. In immunocompromised individuals, standard components can be administered as leucodepletion alone is sufficient to reduce the risk of CMV infection. All blood components, apart from granulocytes, are leuco-depleted.