Transfusion in Trauma

Haemorrhage is the leading preventable cause of death in trauma. Early control of bleeding, early tranexamic acid and early balanced transfusion reduce mortality. Excess crystalloid, delayed blood, hypothermia and acidosis worsen it. Trauma induced coagulopathy begins within minutes of injury and is driven by shock, tissue injury and hyperfibrinolysis.

Risk context. Penetrating torso injury, unstable pelvic fracture, multiple long bone fractures, major chest or abdominal bleeding, and bleeding in patients on anticoagulants. Head injury raises the stakes, because hypotension and coagulopathy both worsen outcome.

Special groups. Children (compensate then collapse), pregnant women (blood volume expanded, foetal risk), older adults and patients on anticoagulants or beta blockers (blunted signs), and patients with traumatic brain injury. In East Africa, road traffic injuries and penetrating injuries are common, transfer times are long, and blood and surgical capacity are limited, so early tranexamic acid, haemorrhage control and local use of whole blood matter.

Recognition. Systolic pressure under 90 mmHg, heart rate over 120 beats a minute, shock index of about 0.9 to 1 or more, poor perfusion, penetrating mechanism, and a positive focused ultrasound of the abdomen or chest.

Massive transfusion prediction. Penetrating mechanism, positive focused ultrasound, systolic pressure of 90 mmHg or less and heart rate of 120 or more, with two or more positive indicating high risk. Activate the massive haemorrhage plan on any of these or on clinical judgement.

Blood pressure targets. Permissive hypotension (systolic about 80 to 90 mmHg) until bleeding is controlled in penetrating and blunt torso trauma, but not in traumatic brain injury (higher target, usually mean arterial pressure of 80 mmHg or more) or spinal injury.

Haemoglobin and laboratory. Haemoglobin is not a guide early. Targets after control are haemoglobin 7 to 9 g/dL, platelets over 50 x 10⁹/L (over 100 x 10⁹/L in brain injury), fibrinogen over 1.5 g/L and ionised calcium at or over 1.1 mmol/L.

Differential considerations. Tension pneumothorax, tamponade and spinal shock may coexist with or mimic haemorrhage.

Red flags. Rising lactate, worsening base deficit, temperature under 35 degrees Celsius, clinical oozing and failure to respond to the first pack.

Priorities in parallel.

1. Control the source: direct pressure, tourniquet, pelvic binder, haemostatic dressing, damage control surgery, interventional radiology.

2. Give tranexamic acid 1 g intravenously over 10 minutes within 3 hours of injury, then 1 g over 8 hours.

3. Give blood early: low titre group O whole blood if available, otherwise red cells with plasma in balanced proportions.

4. Limit crystalloid to the minimum, and avoid large volume loading.

5. Give calcium, keep warm, and avoid hypothermia and acidosis.

6. Send samples and use laboratory or viscoelastic results to direct fibrinogen, platelets and plasma.

Products. Red cells (or whole blood) and plasma in a ratio of about 1 : 1 to 2 : 1, platelets of one adult dose for about every 6 units of red cells, and cryoprecipitate (two pools) or fibrinogen concentrate (3 to 4 g) when fibrinogen is under 1.5 g/L.

Special groups.

• Brain injury: avoid hypotension and hypoxia, keep platelets over 100 x 10⁹/L, and avoid hypothermia.

• Pregnancy: left lateral tilt, early obstetric input, anti-D immunoglobulin for RhD negative women after trauma, with foetomaternal haemorrhage testing.

• Children: 10 to 20 mL/kg of red cells or 20 mL/kg of whole blood, with matching plasma, and warm all products.

• Anticoagulated patients: prothrombin complex concentrate with vitamin K, or specific reversal agents.

Monitoring. Continuous haemodynamics, temperature and urine output, blood gas with lactate every 30 to 60 minutes, ionised calcium, haemoglobin, coagulation and fibrinogen.

Complications. Hypothermia, acidosis, hypocalcaemia, hyperkalaemia, coagulopathy, overload, lung injury, abdominal compartment syndrome, multi organ failure and sepsis.

Referral and escalation. Trauma surgeon, anaesthetist, intensivist and haematologist early, and transfer to a trauma capable centre when needed.

Disposition. After control, intensive care. Stop the massive haemorrhage plan, return unused products, start thromboprophylaxis as soon as bleeding allows, and treat anaemia with iron.