Septic transfusion reaction

Overview

Symptoms begin during or within hours of transfusion. Speed and severity reflect bacterial load and endotoxin concentration.

•Fever - usually >38.5°C, often with rigors

•Hypotension - key distinguishing feature from non-haemolytic febrile reaction (NHFTR); reflects distributive shock

•Tachycardia - compensatory response

•Abdominal pain, nausea, vomiting - visceral manifestation of systemic inflammatory response

•Rigors - intense shivering from cytokine-mediated hypothalamic resetting

•Confusion/reduced GCS - sign of cerebral hypoperfusion; indicates severity

•Progression to septic shock and multi-organ failure if untreated

🎯

Any fever WITH hypotension during transfusion must be treated as a septic reaction (or acute haemolytic reaction) until proven otherwise. NHFTR causes fever and mild chills but the patient remains normotensive and systemically well.

Investigations

🥇 First-line

•Stop transfusion immediately and retain the blood unit - send for urgent Gram stain and culture

•Blood cultures (x2 peripheral) - before antibiotics if possible, but do not delay treatment

•ABG with lactate - elevated lactate confirms tissue hypoperfusion

•FBC - leucocytosis or leucopenia both possible in sepsis

•U&E/creatinine - AKI is an early complication

•Clotting screen including fibrinogen - DIC can complicate severe reactions

•DAT and repeat group and screen - to exclude concurrent haemolytic reaction

•Urinalysis - haemoglobinuria (pink/red urine) would suggest haemolytic rather than purely septic reaction

🏆 Gold standard

•Culture and Gram stain of the blood product unit - confirms bacterial contamination and identifies organism

⚠️

Do NOT discard the blood unit or giving set - they are critical evidence. Return to blood bank for Gram stain and culture. Discarding delays diagnosis and prevents traceability of the contaminated donation to other recipients.

Differential diagnosis

💡

Septic transfusion reactions are rare due to rigorous blood banking - ABO incompatibility (acute haemolytic reaction) from human error is more common when the clinical picture overlaps. The cardinal differentiating feature of septic reaction vs NHFTR is haemodynamic instability.

Management

Immediate

1. 1Stop the transfusion immediately
2. 2Retain unit and giving set - return to blood bank for Gram stain and culture
3. 3Call for senior/medical help

↓

Resuscitation

1. 1IV fluid resuscitation - crystalloid bolus for hypotension
2. 2High-flow oxygen
3. 3Draw blood cultures x2 peripheral before antibiotics if possible

↓

Treatment

1. 1Start broad-spectrum antibiotics promptly - do not delay for cultures if patient is deteriorating
2. 2Transfer to HDU/ICU if septic shock (lactate >2 mmol/L, persistent hypotension)

Complications

•Septic shock with multi-organ failure - primary cause of death; occurs rapidly if untreated

•AKI - hypoperfusion and direct bacterial toxin effects

•DIC - endotoxin activates coagulation cascade; bleeding and thrombosis simultaneously

•ARDS - diffuse alveolar damage from systemic inflammation

•Death - significant case fatality rate, particularly with Gram-negative organisms and delayed recognition