Level 2 of 6Must-remember

Transfusion reactions: recognition and immediate management

Assess, manage and stay safe — enough on its own

1 / 8

The card — assess, manage, caution

Assessment— look, ask, measure

Observe deliberately: record a baseline observation set before the unit starts and observe the patient directly for the first 15 minutes of every unit, because most acute reactions declare themselves in that interval.
Know the two time frames: acute reactions occur during the transfusion or within 24 hours; delayed reactions appear at over 24 hours, days to weeks later.
Every serious reaction opens the same way — fever, rigors, a feeling that something is wrong — and the diagnosis is made in the following minutes from the blood pressure, the breathing, the skin, the presence of pain and the colour of the urine.
Re-check identity immediately against the patient's stated name and date of birth, the wristband, the compatibility label and the donation number on the pack: a mismatch means an incompatible transfusion until proven otherwise, and implies a second patient may be receiving the wrong unit at the same moment.
Acute haemolytic reaction (AHTR): onset within minutes, often after as little as 10–15 mL, with rigors, lumbar or loin pain, dyspnoea, hypotension and haemoglobinuria, often with chest or abdominal pain, restlessness, flushing and a sense of impending doom — loin pain during a transfusion is one of the few specific signs in this subject and must never be blamed on positioning.
Febrile non-haemolytic reaction (FNHTR): 30 minutes to 2 hours into the unit, with flushing, tachycardia, fever of 38°C or above or a rise of at least 1°C from baseline, chills and rigors, in a patient who is normotensive, well perfused, not hypoxic and not in pain — a label earned only after hypotension, hypoxia, loin pain and haemoglobinuria are excluded.
Allergic versus anaphylactic: urticaria, itch and flushing within minutes to an hour in an otherwise entirely well patient is a simple allergic reaction; hoarseness, stridor, tongue or lip swelling, wheeze, vomiting, abdominal pain, hypotension or collapse — usually with little or no fever — is anaphylaxis.
Septic (bacterially contaminated) reaction: abrupt, violent and febrile, with temperature often above 39°C, rigors, vomiting, abdominal pain and rapidly progressive hypotension, sometimes with a visibly discoloured, clotted or leaking pack.
TRALI: begins within 6 hours (most often within 1–2) with acute dyspnoea, cough, frothy or pink secretions, fever, tachycardia and hypoxaemia out of proportion to the radiograph — blood pressure normal or low, jugular venous pressure not raised, no response to a diuretic, and transient leucopenia as a useful clue.
TACO: begins during the transfusion or within 6–12 hours with orthopnoea, cough, bibasal crackles, raised JVP, a third heart sound, peripheral oedema and the discriminating vital sign — hypertension with a widened pulse pressure — improving on sitting up and a diuretic.
Acute hypotensive reaction: an isolated fall in systolic pressure of more than 30 mmHg soon after starting, with no fever, rash or respiratory features, resolving within minutes of stopping without further intervention; it is associated with ACE inhibitor therapy and bedside leucodepletion filters.
The delayed reactions: delayed haemolysis at 5–10 days (fatigue, jaundice, falling haemoglobin or simple failure to achieve the expected increment); post-transfusion purpura at 5–12 days (profound thrombocytopenia with bleeding, characteristically in a multiparous woman); TA-GvHD at 1–6 weeks (fever, rash progressing to bullae, watery diarrhoea, deranged liver function and pancytopenia).
The red flags demanding treatment as a life-threatening reaction: systolic pressure falling by more than 30 mmHg or any shock state; loin, back, chest or abdominal pain during a transfusion; red or brown urine; oozing from venepuncture sites, cannula sites or a surgical wound; stridor, hoarseness, tongue or lip swelling, or wheeze; a rising oxygen requirement, respiratory rate above 30 or SpO2 below 92% despite high-flow oxygen; temperature above 39°C or a rise of 2°C, particularly with rigors and hypotension; and any discrepancy on re-checking identity.
The anaesthetised, sedated or unconscious patient loses every symptom that makes the diagnosis easy — no rigor described, no loin pain, no sense of doom; the only signs may be unexplained hypotension, unexpected bleeding from the surgical field or ooze from puncture sites, and dark urine in the catheter bag, and all appear late — so assume the worst diagnosis soonest here.
Age changes the picture: elderly patients are the highest-risk group for TACO (age over 70) and the least likely to complain, fever may be blunted so a modest rise from a low baseline is significant, confusion may be the only feature, and beta-blockade masks the compensatory tachycardia; children maintain blood pressure by tachycardia and vasoconstriction until profoundly shocked, so hypotension in a child is a pre-terminal sign — act on tachycardia, tachypnoea, prolonged capillary refill, mottled peripheries, irritability, unexpected drowsiness and falling urine output.
Look at the urine, and dipstick it: clear red or cola-coloured urine that does not settle is free haemoglobin, and a dipstick strongly positive for blood with no red cells on microscopy means free haemoglobin or myoglobin, not bleeding — the bedside haemolysis test, needing no laboratory.

Management— do this, in order

Stop at the first suspicion, not at the point of diagnosis: severity tracks the volume infused, slowing the rate does not stop the injury, a mild allergic reaction can be restarted, and an incompatible unit cannot be un-transfused.
Preserve venous access: disconnect the giving set at the cannula hub and attach a new set primed with 0.9% sodium chloride — never flush the blood standing in the old tubing into the patient, and do not remove the cannula, because the vein will be needed within seconds and is far harder to obtain once the patient is shut down.Doctor / Nurse
Re-check identity against name, date of birth, wristband, compatibility label and donation number, and alert the transfusion laboratory that a second patient may be at risk.
Airway, breathing, circulation, and oxygen to maintain SpO2 94–98% (88–92% if at risk of hypercapnic respiratory failure).
Acute haemolysis — crystalloid, generously: adult 0.9% sodium chloride 500 mL IV over 15 minutes, repeated against blood pressure, heart rate and urine output (250 mL aliquots in the frail elderly or known cardiac failure); paediatric 10–20 mL/kg IV, reassessing after each bolus, because the kidney is clearing free haemoglobin and needs flow.Doctor / Nurse
Catheterise and measure urine hourly, targeting at least 1 mL/kg/h in an adult and 1–2 mL/kg/h in a child, recording colour as well as volume — volume, not diuretics, protects the kidney, and forced alkaline diuresis, mannitol and low-dose dopamine have been abandoned as ineffective and harmful.Doctor / Nurse
Noradrenaline by infusion, titrated to a mean arterial pressure of about 65 mmHg, if hypotension persists after adequate volume.Doctor / NurseNot available at your setup — Infusion pump.
Treat the predictable hyperkalaemia: adult calcium gluconate 10%, 10 mL IV over 5–10 minutes for ECG changes and repeated as needed, soluble insulin 10 units in 25 g glucose IV over 15–30 minutes, and nebulised salbutamol 10–20 mg; paediatric calcium gluconate 10% 0.5 mL/kg IV over 5–10 minutes (maximum 20 mL), insulin 0.1 unit/kg with glucose 2 mL/kg of 25% or 5 mL/kg of 10%, and nebulised salbutamol 2.5 mg under 5 years, 5 mg thereafter.Doctor / Nurse
Support the bleeding patient in DIC: fresh frozen plasma 15 mL/kg, cryoprecipitate (two adult pools) or fibrinogen concentrate for fibrinogen below 1.5 g/L, and platelets below 50 × 10⁹/L — but do not correct numbers by reflex in a patient who is not bleeding.Doctor / NurseNot available at your setup — Blood & blood products.
If further transfusion is needed: immediately, 2 units of O RhD-negative emergency stock; within 10–15 minutes, ABO- and RhD-identical group compatible blood; within 45 minutes, fully crossmatched blood.Doctor / Nurse
Septic reaction — treat as septic shock: take blood cultures and culture the pack and giving set before antibiotics, then give broad-spectrum intravenous antibiotics within one hour — piperacillin–tazobactam 4.5 g IV 6–8-hourly (paediatric 90 mg/kg IV 6–8-hourly, maximum 4.5 g per dose), or ceftriaxone 2 g IV daily plus metronidazole 500 mg IV 8-hourly, or meropenem 1 g IV 8-hourly where local resistance dictates; avoid ceftriaxone in neonates, using cefotaxime 50 mg/kg IV 6–8-hourly.Doctor / NurseNot available at your setup — Blood culture.
Anaphylaxis — adrenaline first and nothing must delay it: adrenaline 1:1000 IM into the anterolateral thigh — 500 micrograms (0.5 mL) adult and over 12 years, 300 micrograms (0.3 mL) at 6–12 years, 150 micrograms (0.15 mL) at 6 months–6 years, 100–150 micrograms (0.1–0.15 mL) under 6 months — repeated every 5 minutes if there is no improvement; lie the patient flat with legs elevated (sit up only if breathing is the limiting problem), high-flow oxygen, and 0.9% sodium chloride 500–1000 mL IV rapidly in an adult or 20 mL/kg in a child.Doctor / Nurse
Anaphylaxis adjuncts: chlorphenamine IV slowly — 10 mg adult and over 12 years, 5 mg (6–12 years), 2.5 mg (6 months–6 years), 250 micrograms/kg (under 6 months) and hydrocortisone IV — 200 mg, 100 mg, 50 mg, 25 mg by the same age bands; nebulised salbutamol 5 mg (2.5 mg under 5 years) for bronchospasm and nebulised adrenaline 1:1000, 5 mL for stridor while preparing for definitive airway management.Doctor / Nurse
Refractory anaphylaxis: start an adrenaline infusion (intravenous adrenaline is for those experienced in its use, by infusion, with cardiac monitoring), add glucagon 1–2 mg IV if the patient is beta-blocked, and consider vasopressin or methylene blue in refractory vasoplegia.Doctor / NurseNot available at your setup — Infusion pump.
Mild isolated urticaria: interrupt the transfusion, give chlorphenamine 10 mg IV slowly (paediatric doses as above), re-examine specifically for wheeze, stridor, hoarseness, angioedema, vomiting or hypotension — and if truly isolated urticaria settles fully, the transfusion may be restarted at a slower rate under close observation; this is the only reaction in which restarting the same unit is routinely acceptable.Doctor / Nurse
Febrile non-haemolytic reaction, once the dangerous diagnoses are excluded: paracetamol 1 g orally or IV, 6-hourly, maximum 4 g in 24 hours (paediatric 15 mg/kg per dose 4–6-hourly, maximum 60 mg/kg in 24 hours), observe 15-minutely for an hour, and restart cautiously only if the fever was mild and the patient is well.
TRALI: oxygen targeting SpO2 94–98% and early escalation to non-invasive or invasive ventilation with lung-protective settings if intubated (tidal volume 6 mL/kg predicted body weight, plateau pressure below 30 cmH2O); do not give a diuretic unless fluid overload has been positively demonstrated, and treat hypotension with cautious fluid and vasopressors.Doctor / NurseNot available at your setup — Mechanical ventilator. oxygen
TACO: sit the patient upright with legs dependent, high-flow oxygen, stop all intravenous fluids, and give furosemide 20–40 mg IV slowly in an adult with adequate blood pressure, or 40–80 mg IV if already on a loop diuretic or renally impaired (paediatric 0.5–1 mg/kg IV, maximum 20 mg per dose, slowly); CPAP or non-invasive ventilation early in the hypoxic, tiring patient with a maintained blood pressure is transformative, and nitrates may be added for the hypertensive patient with severe oedema.Doctor / Nurse

Caution— what harms

Never slow the rate instead of stopping — severity is broadly proportional to the volume infused, so stopping early is itself a therapeutic act.
Never flush the residual blood in the old giving set into the patient, and never remove the cannula; disconnect at the hub and hang a fresh set primed with 0.9% sodium chloride.
Never take post-reaction samples from the transfused limb: sampling through or downstream of the transfusion line returns donor blood and gives an uninterpretable or falsely reassuring result — use the other arm.
Never give a diuretic in TRALI unless fluid overload has been positively demonstrated: TRALI is not a volume problem, and diuresis compromises an already marginal preload.
Never give generous fluid in TACO — fluid moves in opposite directions in the two commonest lethal reactions, and reversing haemolysis and overload is the classic fatal error; if the patient is hypotensive, reconsider the diagnosis before giving any diuretic.
Never restart a unit after anything except a truly isolated urticarial reaction that has settled completely; where rigors were severe or anything else is abnormal, the unit must not be restarted.
A negative direct antiglobulin test does not exclude haemolysis — it may be negative in fulminant ABO haemolysis because all incompatible cells have already been destroyed; equally, haptoglobin is an acute-phase protein and may be spuriously normal in inflammation.
Do not wait for a fever, a rigor or a complaint in the anaesthetised or unconscious patient: unexplained hypotension, oozing from the surgical field and dark urine in the catheter bag may be the only signs and all appear late.
Do not wait for hypotension in a child — it is a pre-terminal sign; and do not be reassured by a normal-looking temperature in an elderly or beta-blocked patient, in whom fever and tachycardia are blunted.
Never co-infuse hypotonic fluid such as 5% glucose, or any drug, into the transfusion line — osmotic lysis produces a picture indistinguishable from immune haemolysis, and it is entirely preventable.
Never improvise warming: a malfunctioning blood warmer, hot water, a microwave, forced infusion through a narrow-bore needle or a previously frozen unit all destroy red cells thermally or mechanically; massive transfusion mandates a proper blood warmer.
Do not withhold blood from an exsanguinating patient awaiting a perfect crossmatch: SHOT found that delays in transfusion accounted for 23% of transfusion-related deaths — failing to transfuse, or transfusing too late, kills as surely as transfusing wrongly.
Avoid aspirin for transfusion fever in thrombocytopenic patients and in children (paracetamol is the safer first choice), and remember that routine pre-medication of all transfusions is not supported by trial evidence and is discouraged.
Irradiation must be requested explicitly — the laboratory cannot infer the indication from the sample — and TA-GvHD has no effective treatment once established, so prevention is the entire strategy; avoid ceftriaxone in neonates, particularly alongside calcium-containing fluids.

Refer / escalate

Escalate immediately to the transfusion laboratory and to critical care for any shock state, loin or back pain with dark urine, oozing from puncture sites, stridor or airway swelling, SpO2 below 92% or a rising oxygen requirement despite high-flow oxygen, a temperature above 39°C or a 2°C rise with rigors and hypotension, any identity discrepancy, or any reaction occurring in an anaesthetised patient — and return the implicated unit with its giving set, every other pack from the episode and a fresh sample from the opposite arm.

The card — assess, manage, caution

Transfusion reactions: recognition and immediate management — Level 1: CorePrevious Transfusion reactions: recognition and immediate management — Level 3: Core practiceNext

Read the full lesson free

Create a free account to unlock every page, the level exams, and progress tracking.