Overview
Definition:
A massive transfusion protocol (MTP) is a predefined, systematic approach to rapidly administer blood products and fluids to patients experiencing severe hemorrhage, aiming to restore oxygen-carrying capacity and hemostasis.
Epidemiology:
Hemorrhagic shock is a leading cause of preventable death in trauma patients
MTP is activated in approximately 5-10% of major trauma cases, with higher incidence in penetrating trauma and severe blunt trauma.
Clinical Significance:
Prompt and appropriate MTP activation and execution are critical for patient survival, reducing mortality and morbidity from exsanguination and hypovolemic shock
It requires a multidisciplinary team approach and efficient resource utilization.
Activation Criteria
Prehospital Signs:
Signs of shock on arrival (e.g., hypotension, tachycardia, altered mental status)
Mechanism of injury suggestive of massive blood loss (e.g., high-speed MVC, GSW to torso)
Presence of pelvic fracture or multiple long bone fractures.
Emergency Department Criteria:
Initial hemodynamic instability (e.g., systolic BP < 90 mmHg, heart rate > 120 bpm, need for >10 mL/kg crystalloid bolus)
Evidence of ongoing major bleeding on imaging or at physical exam
INR > 1.5 or aPTT > 1.5 times normal with suspected coagulopathy.
Laboratory Criteria:
Hemoglobin < 7 g/dL in a hemodynamically unstable patient
Hematocrit < 20% in conjunction with shock
Lactate > 4 mmol/L
Base deficit < -6.
Multidisciplinary Trigger:
Clinical judgment by trauma surgeon, emergency physician, or anesthesiologist
Often involves a "code red" or similar alert system to mobilize resources.
Protocol Execution
Initial Resuscitation:
Administer large-bore IV access (e.g., 14-16G)
Rapid infusion of crystalloids (e.g., 1-2 L warmed isotonic saline or lactated Ringer's) while awaiting blood products
Consider balanced resuscitation approach.
Blood Product Administration:
Initiate MTP with a balanced ratio of packed red blood cells (PRBCs), fresh frozen plasma (FFP), and platelets
Common initial ratio is 1:1:1 (PRBC:FFP:Platelets)
Rapidly infuse PRBCs to achieve adequate oxygen delivery.
Plasma And Platelets:
FFP is crucial for replacing coagulation factors lost during hemorrhage
Platelets are essential for primary hemostasis, especially in thrombocytopenic patients or those with significant platelet dysfunction.
Cryoprecipitate And Fibrinogen:
Administer cryoprecipitate if fibrinogen levels are < 100-150 mg/dL or if there is active bleeding despite adequate PRBC and FFP
Fibrinogen is critical for clot stability.
Monitoring And Reassessment:
Continuous hemodynamic monitoring (BP, HR, CVP, ScvO2)
Frequent laboratory reassessment (Hgb, Hct, PT, PTT, INR, fibrinogen, platelet count, lactate)
Serial FAST scans or DPL to assess for ongoing intra-abdominal bleeding.
Blood Product Management
Packed Red Blood Cells:
Primary goal is to restore oxygen-carrying capacity
Aim for Hgb > 7-8 g/dL
Administer rapidly through pressure bags or rapid infusers.
Fresh Frozen Plasma:
Administer to correct coagulopathy (INR > 1.5, PTT > 1.5x normal) and provide clotting factors
Dose typically 10-15 mL/kg.
Platelets:
Administer to maintain platelet count > 50,000-100,000/µL
Dose typically 1 apheresis unit or 6-10 whole blood-derived units.
Cryoprecipitate:
Administer to replete fibrinogen, von Willebrand factor, and factor XIII
Dose typically 10 units
Indicated for fibrinogen < 100-150 mg/dL.
Blood Bank Coordination:
Effective communication with the blood bank is vital for timely and adequate supply of blood products
Pre-established MTP kits can expedite the process.
Adjunctive Therapies
Calcium Administration:
Citrate in stored blood products can chelate calcium, leading to hypocalcemia and impaired coagulation
Administer calcium chloride or gluconate empirically and monitor ionized calcium levels.
Warm Resuscitation:
Maintain normothermia to prevent hypothermia-associated coagulopathy and improve the efficacy of transfused blood products
Warm all fluids and blood products.
Vasopressors And Inotropes:
May be required to maintain adequate perfusion pressure in the presence of ongoing shock or myocardial depression
Titrate carefully to avoid excessive vasoconstriction.
Recombinant Activated Factor Vii:
Considered in refractory life-threatening hemorrhage, but evidence is controversial
Should be used in conjunction with appropriate hemostatic resuscitation and after exclusion of other reversible causes.
Complications
Transfusion Reactions:
Acute hemolytic reactions, febrile non-hemolytic reactions, allergic reactions, transfusion-related acute lung injury (TRALI)
Monitor closely for signs and symptoms.
Transfusion Associated Circulatory Overload:
Fluid overload, particularly in patients with compromised cardiac function
Administer blood products cautiously and monitor for signs of fluid overload.
Dilutional Coagulopathy And Thrombocytopenia:
Occurs with massive transfusion of PRBCs without adequate replacement of plasma factors and platelets
Balanced resuscitation with FFP and platelets mitigates this risk.
Hypocalcemia And Hyperkalemia:
Hypocalcemia due to citrate binding
Hyperkalemia from stored PRBCs
Monitor electrolyte levels and administer replacements as needed.
Post Transfusion Purpura And Thrombotic Thrombocytopenic Purpura:
Rare but serious complications of transfusion therapy
Suspect if thrombocytopenia recurs despite platelet transfusion.
Key Points
Exam Focus:
MTP activation triggers and components (PRBC:FFP:Platelets ratio)
Management of hemorrhagic shock and coagulopathy
Complications of massive transfusion.
Clinical Pearls:
Think MTP early in severe hemorrhage
Use warmed crystalloids initially
Balance PRBCs with FFP and platelets
Monitor and reassess frequently
Communicate effectively with the blood bank.
Common Mistakes:
Delaying MTP activation
Inadequate resuscitation with crystalloids alone
Failure to administer FFP and platelets in appropriate ratios
Ignoring signs of hypothermia or hypocalcemia
Lack of continuous reassessment.