What is the current protocol for mass transfusion?

Current Mass Transfusion Protocol Recommendations

Mass transfusion protocols should implement a high-ratio transfusion strategy of 1:1:1 (plasma:platelets:packed red blood cells) for trauma patients with massive bleeding to reduce early mortality and improve hemostasis. 1

Definition and Activation

• Definition of massive transfusion: Typically defined as transfusion of ≥10 units of packed red blood cells (PRBCs) within 24 hours or ≥6 units within 6 hours 1
• Current definition trend: More recent literature defines massive transfusion as transfusion of 3-4 PRBCs within 1 hour 2
• Protocol activation: Hospitals must have a major hemorrhage protocol that can be mobilized immediately when massive hemorrhage is declared 1

Key Components of Current Mass Transfusion Protocols

Immediate Hemorrhage Control

• Immediate control of obvious bleeding is paramount using:
  • Direct pressure
  • Tourniquets
  • Hemostatic dressings 1

Transfusion Ratios

• For trauma patients: High-ratio transfusion strategy (1:1:1 plasma:platelets:PRBCs) is recommended 1
  • This ratio has been shown to reduce 24-hour mortality without increasing morbidity 1
  • The PROPPR trial demonstrated improved hemostasis with this ratio 1
• For non-trauma patients: No definitive recommendation for fixed high-ratio transfusion due to limited evidence and potential differences in pathophysiology 1

Laboratory Targets and Monitoring

• Fibrinogen: Maintain >1 g/L; levels <1 g/L represent established hemostatic failure 1
• Coagulation tests: PT and aPTT >1.5 times normal indicates hemostatic failure 1
• Platelets: Maintain minimum target count of 75 × 10⁹/L 1
• Monitoring: Use viscoelastic testing (TEG/ROTEM) when available to guide product replacement 2

Blood Product Administration

• Early FFP: Administer 15 mL/kg FFP early if massive hemorrhage is anticipated 1
• Established coagulopathy: Will require >15 mL/kg FFP to correct 1
• Fibrinogen replacement: Fibrinogen concentrate or cryoprecipitate is most effective for rapid replacement 1
• Blood type considerations: Group-specific blood can be issued without antibody screening; O-negative blood should only be used if blood is needed immediately 1

Implementation Considerations

Protocol Development

• Hospitals should develop standardized protocols that include:
  • Clinical responses
  • Laboratory testing
  • Logistical coordination 1
• "Shock packs" may be helpful in hospitals where massive hemorrhage is frequent 1

Timing and Coordination

• Faster blood product delivery is associated with better outcomes 3
• Having blood products readily available in the trauma bay improves resuscitation efforts 3
• Coordinated response between emergency department, blood bank, and laboratory is essential 1

Post-Resuscitation Care

• Standard venous thromboprophylaxis should be initiated as soon as possible after hemostasis is secured, as patients develop a prothrombotic state following massive hemorrhage 1

Emerging Trends

• Whole blood: Alternative to component therapy in some settings 2
• Adjuncts: Early use of tranexamic acid, fibrinogen concentrate, and point-of-care coagulation testing 2, 3
• Cryopreserved/cold-stored platelets: Insufficient evidence to make recommendations regarding their use 1

Common Pitfalls to Avoid

• Delayed activation: Failure to activate MTP early enough can worsen outcomes
• Unbalanced ratios: Using too low a ratio of plasma and platelets to PRBCs can lead to worsened coagulopathy
• Overlooking fibrinogen: Failure to monitor and replace fibrinogen early
• Neglecting temperature management: Hypothermia worsens coagulopathy
• Delayed hemostatic interventions: Focusing solely on transfusion without addressing the source of bleeding

Mass transfusion protocols continue to evolve, but current evidence strongly supports the use of balanced high-ratio transfusion strategies particularly for trauma patients, with protocols that emphasize early activation, coordinated response, and aggressive correction of coagulopathy.