Massive haemorrhage and major transfusion protocol

Major haemorrhage is bleeding severe enough to threaten life and require coordinated clinical and laboratory response. Definitions based on total units are retrospective; activation should use haemodynamic compromise, ongoing rate, injury pattern, site and failure to respond. The immediate goals are to stop bleeding, restore enough circulating oxygen delivery for perfusion and prevent acquired coagulopathy. A senior leader assigns haemorrhage control, airway, access, monitoring, sampling, component checking, documentation and communication roles.

Source control is the definitive treatment. Use direct pressure, tourniquet, pelvic binder, uterotonic and obstetric manoeuvres, endoscopy, surgery, interventional radiology or damage-control technique according to cause. Avoid spending the patient's remaining clot on repeated diagnostic delays. In trauma, take unstable patients with suspected internal haemorrhage to the fastest definitive pathway; permissive hypotension and restricted crystalloid may reduce clot disruption until control, except when traumatic brain injury requires cerebral perfusion. Individualise for pregnancy, older people and chronic hypertension.

Activate the local protocol and contact the transfusion laboratory directly. Provide unique identifiers, sex and pregnancy potential, location, cause, urgency and known antibodies or special requirements. Take a pretransfusion group-and-screen sample without delaying blood. Use locally designated emergency group O red cells; D-negative is prioritised for children and females with pregnancy potential, while conservation policy may permit D-positive blood for other adults. Switch to compatible group-specific components when the laboratory confirms a secure group.

Empirical packs prevent isolated red-cell resuscitation while results lag. NICE recommends a 1:1 plasma-to-red-cell ratio for adults with active major trauma bleeding, moving to laboratory-guided ratios at the earliest opportunity. Other settings use local BSH-informed pack composition because obstetric, gastrointestinal, cardiac and surgical haemorrhage differ biologically. Platelets are incorporated or requested according to pack stage and count trajectory. Do not administer components automatically after source control or because a pack has arrived.

Send full blood count, PT, APTT, fibrinogen, blood gas with lactate and ionised calcium, electrolytes and renal profile at activation and repeatedly. Results are time-stamped snapshots during rapid change. Viscoelastic testing can shorten targeted decision-making when the institution has validated equipment, trained staff, quality control and a treatment algorithm. Use it to complement clinical source control and conventional tests. Maintain platelets above 50 × 10⁹/L in ongoing major bleeding and higher for traumatic brain or other critical-site bleeding under the specialist protocol.

Fibrinogen is frequently the earliest coagulation substrate to become critically low. In general major bleeding, cryoprecipitate is considered when fibrinogen is below 1.5 g/L; pregnancy begins at a higher concentration and obstetric protocols commonly target at least 2 g/L during major postpartum haemorrhage. Give cryoprecipitate or the locally commissioned fibrinogen product promptly and recheck. Use FFP for multiple-factor deficiency and abnormal coagulation in active bleeding, generally in weight-based effective doses, not as volume expansion.

Physiology determines whether transfused factors work. Warm the patient, blood and environment; minimise exposure and wet clothing. Correct shock and acidosis primarily through haemorrhage control and perfusion rather than bicarbonate. Citrate chelates calcium during rapid transfusion; monitor ionised calcium on serial blood gases and replace calcium under protocol before severe hypocalcaemia impairs myocardium and clot formation. Check potassium because stored red cells, tissue injury and acidosis can produce hyperkalaemia, while resuscitation can also drive later hypokalaemia.

Tranexamic acid reduces fibrinolytic bleeding when given early in appropriate settings. For major trauma, NICE directs treatment as soon as possible and not beyond three hours after injury unless laboratory evidence of hyperfibrinolysis exists. A widely used adult trauma regimen is 1 g intravenously over 10 minutes followed by 1 g over eight hours. Obstetric and surgical regimens differ, so use the corresponding protocol and adjust or avoid repeated exposure in severe renal impairment because the drug is renally eliminated. Never inject tranexamic acid intrathecally.

Anticoagulant reversal runs in parallel. Identify warfarin, factor Xa or thrombin inhibitor, heparin and antiplatelet exposure and last dose. Use four-factor PCC plus intravenous vitamin K for warfarin major bleeding, protamine for unfractionated heparin and the relevant specific antidote or PCC-based DOAC algorithm according to availability, renal function and timing. FFP is not first-line warfarin reversal. Consult haematology for complex thrombosis risk, mechanical valves, pregnancy or uncertain exposure.

De-escalation is an active safety step. Once bleeding is controlled, tell the laboratory, return unused components under approved temperature and traceability conditions and stop empirical packs. Reassess for dilutional overload, pulmonary oedema, hyperkalaemia, hypocalcaemia, hypothermia and thrombosis. Document total components, reactions and wastage; ensure postoperative or critical-care teams know outstanding tests and the haemoglobin, platelet, fibrinogen, temperature, calcium and anticoagulation plan.