What is the recommended approach for a patient requiring a blood transfusion due to significant blood loss or trauma?

Blood Transfusion in Trauma and Significant Blood Loss

Immediate Transfusion Strategy

In patients with hemorrhagic shock or life-threatening bleeding, immediately activate massive transfusion protocol with Group O RhD negative red blood cells (RBCs) for women of childbearing potential (<50 years) and children, or Group O RhD positive for other adults, without waiting for crossmatch. 1

Emergency Blood Product Selection

• Group O RhD negative blood should be immediately available and transfused when hemorrhage is life-threatening for women of childbearing potential, children, and patients of unknown sex 1
• Group O RhD positive RBCs are appropriate for adults without childbearing potential in emergency situations 1
• Group-specific RBCs should be rapidly available within 15-20 minutes once the laboratory receives a properly labeled crossmatch sample 1
• Major hemorrhage protocols must result in immediate release of blood components without prior hematologist approval 2

Massive Transfusion Protocol

During massive transfusion protocol activation, transfuse RBCs/plasma/platelets at a 1:1:1 ratio initially, then modify based on laboratory values and point-of-care testing. 1

Component Ratios and Targets

• Start with balanced 1:1:1 ratio of RBCs:plasma:platelets during active massive hemorrhage 1
• Maintain platelet count >50,000/mm³ for general trauma; target ≥75 × 10⁹/L for severe active bleeding 1, 3
• Keep prothrombin time (PT)/activated partial thromboplastin time (aPTT) <1.5 times normal control during emergency interventions 1
• Maintain ionised calcium >1.0 mmol/L, as hypocalcemia impairs coagulation 1

Point-of-Care Testing

• Utilize thromboelastography (TEG) or rotational thromboelastometry (ROTEM) when available to assess and optimize coagulation function in real-time 1
• Serial testing and comparison between tests is more valuable than isolated results for guiding transfusion decisions 1

Hemoglobin Thresholds

For resuscitated trauma patients without active hemorrhage, transfuse RBCs when hemoglobin <7 g/dL; there is no benefit to a liberal strategy (transfusing at Hb <10 g/dL). 1

Specific Clinical Scenarios

• Hemorrhagic shock: RBC transfusion is indicated regardless of hemoglobin level 1
• Active hemorrhage with hemodynamic instability: Transfusion indicated based on clinical status, not hemoglobin alone 1
• Resuscitated trauma patients: Consider transfusion at Hb <7 g/dL 1
• Patients requiring mechanical ventilation: Consider transfusion at Hb <7 g/dL 1
• Acute coronary syndromes: Transfusion may be beneficial if Hb <8 g/dL on admission 1

Critical Caveat

• Never use hemoglobin level alone as a transfusion trigger—base decisions on intravascular volume status, evidence of shock, duration/extent of anemia, and cardiopulmonary parameters 1
• In the absence of acute hemorrhage, give RBC transfusions as single units and reassess 1

Coagulopathy Management

For established coagulopathy with PT/aPTT >1.5 times normal, administer at least 30 mL/kg of fresh frozen plasma (FFP); inadequate dosing of 1-2 units is insufficient. 3

Fibrinogen Replacement

• Administer fibrinogen concentrate or cryoprecipitate if fibrinogen <1.5 g/L 1, 3
• Early high-dose cryoprecipitate (three pools, equivalent to 6 g fibrinogen) showed no mortality benefit in the CRYOSTAT-2 trial, and was associated with higher mortality in penetrating trauma 1
• For rapid fibrinogen replacement, fibrinogen concentrate or cryoprecipitate is more effective than FFP 4, 3

Prothrombin Complex Concentrate (PCC)

• PCC provides rapid reversal of warfarin effect and is superior to FFP for emergency anticoagulation reversal 3
• Target INR <1.5 for major bleeding control with weight-based PCC dosing 3

Haemostatic Resuscitation Principles

The goals are to restore tissue perfusion, maintain hemostasis, and avoid the lethal triad of hypothermia, acidosis, and coagulopathy. 1

Temperature Management

• Apply early measures to reduce heat loss and actively warm hypothermic patients to achieve normothermia 1
• Hypothermia (<35°C) causes a 10% drop in coagulation factor function per 1°C decrease, increases mortality, and worsens blood loss 1
• Temperature <34°C is associated with >80% mortality risk independent of other factors 1

Electrolyte Management

• Treat hyperkalaemia and hypocalcaemia promptly 1
• Maintain ionised calcium >1.0 mmol/L 1

Prehospital and Early Transfusion

Time to initial transfusion is critically important in trauma; prehospital transfusion within minutes of injury is associated with improved 24-hour and 30-day survival. 1

Prehospital Blood Products

• Prehospital combined plasma and RBC transfusion is associated with lower odds of death at 24 hours compared to RBCs alone 1
• Approximately 25% of severe trauma patients present with coagulopathy, which is fatal in 30-50% of cases 1

Tranexamic Acid

• Administer tranexamic acid within 3 hours of injury to reduce mortality in bleeding trauma patients and those with mild-to-moderate traumatic brain injury 1

Monitoring During Resuscitation

Continuously monitor vital signs, tissue perfusion indicators, urine output (target >0.5 mL/kg/hour), and serial hematocrit/platelet counts during transfusion. 4

Hemodynamic Targets

• Maintain mean arterial pressure (MAP) >80 mmHg or systolic blood pressure (SBP) >100 mmHg during bleeding control interventions 1
• For traumatic brain injury patients, maintain cerebral perfusion pressure (CPP) ≥60 mmHg when ICP monitoring is available 1

Critical Pitfalls to Avoid

• Do not use crystalloids alone as primary resuscitation in massive hemorrhage—they worsen dilutional coagulopathy and fail to restore oxygen-carrying capacity 3
• Avoid excessive fluid administration, which can worsen pulmonary edema, particularly during the recovery phase 4
• Do not delay fluid resuscitation in patients showing signs of shock 4
• Never administer aspirin or NSAIDs due to increased bleeding risk 4
• Avoid inadequate FFP dosing (1-2 units)—at least 30 mL/kg is required for established coagulopathy 3

Special Considerations

Simultaneous Multisystem Surgery

• Develop protocols for simultaneous multisystem surgery (including interventional radiology) in patients requiring both hemorrhage control and emergency neurosurgery 1

Intraoperative Cell Salvage

• Consider intraoperative cell salvage (ICS) in trauma laparotomy/thoracotomy for penetrating injuries, which can reduce allogeneic transfusion requirements 1
• No evidence suggests emergency autologous transfusion worsens clinical outcomes 1