What is the protocol for massive blood transfusion, including transfusion ratios, management of complications, and contraindications?

Massive Blood Transfusion Protocol: Management, Complications, and Contraindications

Definition and Activation

Massive blood transfusion (MBT) should follow a 1:1:1 ratio of red blood cells (RBCs), plasma, and platelets to optimize patient survival and minimize complications. 1

Massive transfusion is defined as:

• Loss of one blood volume within 24 hours (approximately 7% of ideal body weight in adults)
• Alternative definition: 50% blood volume loss within 3 hours or bleeding at a rate of 150 ml/min
• Practically defined as transfusion of ≥10 units of RBCs within 24 hours 1

Initial Assessment and Protocol Activation

1. Rapid hemodynamic assessment:

   • Vital signs (heart rate, blood pressure)
   • Capillary refill
   • Skin color
   • Consciousness level
   • Signs of internal/external bleeding 1

2. Laboratory investigations:

   • Complete blood count
   • Coagulation profile (PT, APTT)
   • Clauss fibrinogen level
   • Blood typing and cross-matching
   • Serum lactate and base deficit (better indicators of shock than hematocrit) 1

3. Imaging:

   • For unstable patients: FAST scan to detect free fluid
   • For stable patients: CT scan to identify bleeding source and extent 1

Transfusion Strategy

Blood Product Ratios

The optimal transfusion ratio has evolved over time:

• Historical approach: 1 unit FFP for every 4 units RBCs 2
• Current recommendation: High-ratio transfusion strategy with at least 1 unit plasma per 2 units RBCs, with many centers now using a 1:1:1 ratio (RBC:plasma:platelets) 1

Military and civilian studies show improved survival with higher plasma:RBC ratios approaching 1:1 2, 3. A large retrospective study demonstrated that platelet:RBC ratios of 1:1 were associated with improved early and late survival and decreased hemorrhagic death 4.

Blood Product Administration Order

1. Start with O-negative blood if cross-matched blood unavailable
2. Transition to group-specific blood when available
3. Use fully cross-matched blood as soon as possible 1

Management of Coagulopathy

1. Target parameters:

   • Maintain fibrinogen levels >1.5 g/L using cryoprecipitate or fibrinogen concentrate
   • Keep platelet count >75 × 10⁹/L
   • Monitor PT/APTT (goal <1.5 times normal) 2, 1

2. Coagulopathy prevention:

   • Early FFP infusion to prevent dilutional coagulopathy
   • Consider antifibrinolytic agents (tranexamic acid) 1
   • Correct hypocalcemia and hypomagnesemia associated with massive transfusions 1

3. Anticoagulant reversal (if applicable):

   • Warfarin: Prothrombin Complex Concentrate (PCC) based on INR + IV vitamin K
   • Heparin: Protamine 1

Complications and Management

Acute Complications

1. Transfusion-Related Acute Lung Injury (TRALI):

   • Most commonly associated with FFP and platelet concentrates 2
   • Management: Supportive respiratory care, oxygen therapy

2. Circulatory Overload:

   • Risk increases with rapid transfusion
   • Management: Slow transfusion rate, diuretics if needed

3. Hypothermia:

   • Use blood warmers for all products
   • Monitor core temperature

4. Citrate Toxicity/Hypocalcemia:

   • Monitor calcium levels during massive transfusion
   • Supplement calcium as needed

5. Hyperkalemia:

   • Monitor potassium levels
   • Consider insulin/glucose or other treatments if severe

Delayed Complications

1. Multiple Organ Failure:

   • Higher risk with increased transfusion volume 4
   • Close monitoring in ICU setting

2. Transfusion-Transmitted Infections:

   • Rare but possible risk 2

3. Immunomodulation:

   • May increase susceptibility to infections

Monitoring During Massive Transfusion

1. Laboratory monitoring:

   • Repeat coagulation tests every 30-60 minutes during active bleeding 1
   • Monitor hemoglobin, platelet count, fibrinogen
   • Blood gases and electrolytes (especially calcium, potassium)

2. Clinical monitoring:

   • Vital signs
   • Ongoing blood loss assessment
   • Signs of rebleeding
   • Temperature 1

Post-Transfusion Care

1. Critical care admission for close observation 1
2. Thromboprophylaxis once bleeding is controlled 1
3. Consider temporary IVC filter in high-risk cases 1
4. Monitor for rebleeding, which carries high mortality 1

Pitfalls and Caveats

1. Survival bias in research: Many studies showing benefit of high ratio transfusion excluded patients who died early, potentially overestimating benefit 2

2. One-size-fits-all approach: Some experts argue that the 1:1:1 ratio may not be optimal for all patients and ignores the additional fluids added for anticoagulation and preservation of components 5

3. Delayed traumatic intracerebral hematoma: Early empirical FFP infusion may increase risk in patients with severe head injury 2

4. Transition to goal-directed therapy: Once the crisis phase is averted, transition from fixed-ratio transfusion to goal-directed therapy based on laboratory values 5

5. Protocol implementation: Having a well-defined hospital protocol for managing massive hemorrhage improves communication among staff and facilitates timely delivery of blood products 1