Acute haemolytic and febrile transfusion reactions

Treat the patient's new symptom, not the label initially proposed. Stop the component for fever, rigors, pain, breathlessness, hypotension, hypertension, rash or distress and perform ABCDE. Severe reactions overlap clinically during the first minutes. Acute haemolysis, bacterial contamination, anaphylaxis, TRALI and TACO all require different definitive care, but stopping exposure, maintaining access, checking identity and calling the transfusion laboratory are shared first steps. Record the volume infused, timing, observations and every associated feature.

The classic acute haemolytic transfusion reaction follows ABO-incompatible red-cell exposure. Naturally occurring recipient anti-A or anti-B binds donor cells and activates complement, producing rapid intravascular lysis, vasoactive mediator release and coagulation activation. Only a small volume may cause catastrophe. Most events arise from human-system failures before the laboratory result: wrong blood in tube, incorrect collection, failure of bedside identity checks or administration to the wrong patient. A technically compatible label cannot protect a component attached to someone else.

Clinical expression varies. An awake patient may report heat, apprehension, nausea, infusion-site pain, chest tightness or loin pain before fever and shock. Haemoglobinuria can turn urine dark; haemoglobinaemia, rising bilirubin and LDH and falling haptoglobin follow. Under anaesthesia, unexplained hypotension, diffuse operative bleeding and haemoglobinuria may be the only clues. Extravascular reactions to non-ABO antigens can be less abrupt but still occur within 24 hours and require the same initial response.

At the bedside, stop the transfusion without disconnecting or discarding evidence. Use new tubing and compatible saline to maintain access. Verify the patient, pack and documentation with another trained member of staff and contact the laboratory urgently. The laboratory repeats ABO and compatibility testing, performs DAT and inspects pre- and post-reaction plasma. A new sample must be collected using full positive identification; relying on the original sample could reproduce the original error. Return the implicated pack and administration set under the local chain of custody.

Investigate severity and alternatives simultaneously. Repeat full blood count, renal and liver profile, potassium, LDH, bilirubin, haptoglobin, coagulation and fibrinogen; examine urine for haemoglobin. Obtain patient blood cultures and arrange component culture whenever bacterial contamination is possible, especially with high fever, severe rigors or shock. Compare the pretransfusion sample, post-reaction sample and unit segment. A positive DAT supports immune coating but can be negative after complete destruction and is not sufficient alone to classify the event.

Supportive treatment is physiology led. Give oxygen and careful crystalloid resuscitation, monitor urine output and seek critical-care input for shock. Treat hyperkalaemia immediately if present. Maintain renal perfusion without causing overload; involve nephrology for progressive oliguria, severe electrolyte disturbance or dialysis indications. Manage DIC with source control and targeted components guided by bleeding and results. If sepsis is plausible, give local broad-spectrum intravenous antibiotics promptly after cultures rather than waiting for component culture.

Febrile non-haemolytic reaction commonly presents during or within hours of transfusion with a temperature rise, fever or rigors but no evidence of haemolysis, contamination or another defined reaction. Leucodepletion has reduced incidence but does not abolish it. Review the pretransfusion temperature and underlying infection. A mild isolated rise that resolves after stopping is different from rigors with haemodynamic change. Only after serious causes are excluded may a trained clinician decide under the local protocol whether the same component can safely restart; severe symptoms generally preclude restart.

After stabilisation, close the safety loop. The transfusion team determines imputability and reporting, investigates process failures and blocks unsafe issue if necessary. Document the reaction prominently, update antibody and special-component requirements and provide the patient with an explanation and alert information. Future transfusion remains possible when clinically necessary, but recurrent troublesome febrile reactions may prompt haematology discussion of component choice; routine antipyretic premedication has limited preventive value and can hide an early sign of sepsis or haemolysis.