Bedside Algorithm for Suspected Transfusion Reaction

Any new symptom or sign during a transfusion or in the hours after it must be taken as a possible transfusion reaction until another cause is proven. Acute reactions occur during transfusion or within 24 hours (most within 4 to 6 hours, and the most dangerous within the first 15 minutes). Early recognition depends on baseline observations, careful monitoring and a low threshold for stopping.

Triggers to suspect a reaction.

• Temperature of 38 degrees Celsius or over, or a rise of 1 degree Celsius or more from baseline.

• Rigors, chills, flushing, urticaria, itch, facial swelling or wheeze.

• Chest, back, loin or infusion site pain.

• Dyspnoea, hypoxia, cough, stridor.

• Hypotension (fall in systolic pressure of 30 mmHg or more), tachycardia (rise of 30 beats a minute or more), or hypertension.

• Nausea, vomiting, agitation, sense of doom.

• Haemoglobinuria (dark or red urine), oozing from sites or unexplained bleeding.

Severity.

• Mild: isolated skin reaction (limited urticaria or itch), or fever with a rise under 2 degrees Celsius without other signs.

• Moderate: fever with a rise of 2 degrees Celsius or more, rigors, generalised urticaria, or mild dyspnoea.

• Severe or life-threatening: hypotension, hypoxia, bronchospasm, stridor, severe pain, shock, haemoglobinuria, renal failure or bleeding.

Main reaction types. Acute haemolytic, febrile non-haemolytic, allergic and anaphylactic, transfusion related acute lung injury, transfusion associated circulatory overload, bacterial contamination, hypotensive, and delayed types that appear days later.

Symptom clusters and likely causes.

Quick assessment. Airway, breathing, circulation, disability and exposure, with temperature, pulse, blood pressure, respiratory rate, oxygen saturation, consciousness, skin, urine colour and bleeding. Review the underlying illness, drugs, and anaesthesia (which masks signs).

Other causes to consider. Sepsis unrelated to the transfusion, underlying disease progression, drug reaction, haemorrhage, pulmonary embolism, cardiac event, and in anaesthetised patients unexplained hypotension and bleeding.

Immediate actions in order. Do these for every suspected reaction.

1. Stop the transfusion immediately. Clamp the line. Do not flush blood from the line into the patient.

2. Assess the patient using airway, breathing, circulation, disability and exposure, and call for senior help if the reaction is moderate or severe.

3. Keep intravenous access with a new giving set and 0.9% sodium chloride.

4. Recheck identity of the patient, the wristband, the unit label and the compatibility tag, looking for a clerical error. If a wrong unit is possible, assume another patient may have received the correct unit and alert the ward.

5. Inform the blood bank and the responsible clinician at once, and keep the unit and giving set.

6. Do not restart the transfusion without authorised clinical evaluation.

Treatment by severity.

• Anaphylaxis or severe allergy: adrenaline 500 micrograms intramuscularly (0.5 mL of 1 in 1000) in an adult, repeated after 5 minutes if there is no improvement (children: 300 micrograms at 6 to 12 years, 150 micrograms at 6 months to 6 years).

• Anaphylaxis: high flow oxygen; 0.9% sodium chloride 500 to 1000 mL bolus in an adult (10 mL/kg in a child).

• Anaphylaxis, second line: chlorphenamine 10 mg and hydrocortisone 200 mg intravenously (child doses by age); salbutamol for bronchospasm.

• Suspected haemolysis: aggressive intravenous fluid, maintain urine output over 100 mL/hour (1 mL/kg/hour in children), and treat shock.

• Suspected sepsis: blood cultures, then broad spectrum antibiotic within 1 hour, fluids and vasopressors.

• Circulatory overload: sit upright, oxygen, and furosemide 20 to 40 mg intravenously in an adult (0.5 to 1 mg/kg in a child).

• Lung injury: oxygen, ventilatory support, lung protective ventilation (about 6 mL/kg ideal body weight), and avoid diuretics unless overload is also present.

• Mild febrile reaction: paracetamol 1 g (15 mg/kg in a child), and observe closely.

• Mild urticaria: pause the unit, give chlorphenamine 10 mg, and consider restart only after the clinician authorises when symptoms have fully settled.

Investigations (send for moderate and severe reactions).

• Return the unit, the giving set and all attached fluids to the blood bank.

• New blood samples (not from the infusion arm): group and antibody screen, direct antiglobulin test, repeat crossmatch, full blood count, coagulation screen and fibrinogen, urea, electrolytes, liver function, bilirubin, lactate dehydrogenase, haptoglobin and plasma free haemoglobin.

• Urine for haemoglobin, blood cultures from the patient (and culture of the unit by the blood bank), chest imaging if respiratory signs, electrocardiogram if chest pain, and mast cell tryptase within 1 to 2 hours for anaphylaxis.

Definitive management. Treatment depends on the reaction type, and each type has its own management. Monitor the patient closely for at least 24 hours after any moderate or severe reaction, and longer after anaphylaxis (a biphasic reaction can occur up to 12 hours later).

Further transfusion. If transfusion is still needed, use products selected by the blood bank on the basis of the investigation (washed, plasma reduced, antigen negative or different component), and do not use the same unit.

Reporting. Report every reaction through the hospital transfusion service and the national haemovigilance system, and report serious reactions and near misses at once. Record the type, severity, imputability, products and outcome.

Prevention. Strict bedside identification, correct indication, single units and appropriate rates, observation in the first 15 minutes, training of staff to recognise early signs, and prompt reporting of errors for learning.

Disposition. Document the event in the notes, inform the patient and, where required, the family (an open discussion of any error), and arrange follow up of laboratory results and future transfusion requirements.