Massive transfusion protocols

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MTP Initiation - When the Floodgates Open

  • Clinical Triggers: Uncontrolled hemorrhage, hemodynamic instability despite initial fluid resuscitation, or anticipated need for massive transfusion.
  • Scoring Systems (Predictive):
    • ABC Score ≥2 points suggests need for MTP:
      • Penetrating mechanism (1 pt)
      • Positive FAST exam (1 pt)
      • SBP ≤90 mmHg (1 pt)
      • HR ≥120 bpm (1 pt)

Ultrasound FAST scan: Free fluid in Morison's pouch

⭐ The Assessment of Blood Consumption (ABC) score is a simple, rapid tool used in the emergency department to predict the likelihood of requiring massive transfusion. A score of 2 or more has high specificity and positive predictive value.

The Lethal Triad - Vicious Cycle of Doom

A catastrophic cascade in massive hemorrhage where three conditions feed into each other, leading to irreversible shock. Breaking the cycle is a key goal of damage control resuscitation.

  • Hypothermia (<35°C / 95°F)
    • Causes: Environmental exposure, infusion of cold fluids, decreased heat production.
    • Effect: Impairs platelet function and enzymatic activity of coagulation factors.
  • Acidosis (pH <7.2)
    • Causes: Anaerobic metabolism from hypoperfusion (lactic acidosis).
    • Effect: Impairs the function of coagulation enzymes.
  • Coagulopathy
    • Causes: Dilution, consumption, and dysfunction (from acidosis/hypothermia).
    • Effect: Worsens hemorrhage, deepening shock.

⭐ Clotting factor activity decreases by 10% for every 1°C drop in body temperature.

Lethal Triad of Trauma and Massive Transfusion Cycle

The Protocol - Balanced Blood Buffet

  • Activation: Triggered by rapid, significant blood loss (e.g., >4 units PRBCs in 1 hr) or specific trauma scores (e.g., ABC score ≥2).
  • Goal: Prevent or reverse the lethal triad of trauma (acidosis, hypothermia, coagulopathy) by replacing whole blood components.
  • Balanced Ratio (1:1:1):
    • 1 unit PRBCs: For oxygen delivery.
    • 1 unit FFP: Replaces clotting factors.
    • 1 unit Platelets: For primary hemostasis.
  • Critical Additions:
    • Tranexamic Acid (TXA): Antifibrinolytic given within 3 hours of injury.
    • Calcium: Replete aggressively; citrate in blood products binds Ca²⁺, causing hypocalcemia.

⭐ The 1:1:1 ratio of PRBCs:FFP:Platelets is associated with improved survival in massive hemorrhage, primarily by preventing dilutional coagulopathy early on.

MTP Complications - The Aftermath Audit

Lethal Triad of Trauma: Acidosis, Hypothermia, Coagulopathy

  • Metabolic Derangements:
    • Hypocalcemia: Most common. Citrate in pRBCs chelates calcium, causing myocardial depression.
    • Hyperkalemia: From lysis of stored RBCs. Risk of arrhythmias.
    • Acid-Base: Initial metabolic acidosis (lactate) followed by metabolic alkalosis as the liver metabolizes citrate.
  • Coagulopathy & Hematologic:
    • Dilutional coagulopathy and thrombocytopenia.
    • Depletion of labile Factors V and VIII.
  • Hypothermia:
    • Infusion of cold blood products exacerbates acidosis and coagulopathy. Target >35°C.
  • Impaired Oxygen Delivery:
    • Stored RBCs have ↓ 2,3-DPG, causing a left-shift in the oxyhemoglobin curve (↑ O₂ affinity).

High-Yield: The most frequent metabolic complication is hypocalcemia. Citrate preservative chelates ionized calcium, leading to paresthesias, prolonged QT, and myocardial depression. Monitor ionized calcium levels closely.

  • Massive transfusion is >10 units of PRBCs in 24 hours or >4 units in 1 hour.
  • Use a balanced 1:1:1 ratio of PRBCs:FFP:platelets to reconstitute whole blood and prevent dilutional coagulopathy.
  • The lethal triad of trauma consists of acidosis, hypothermia, and coagulopathy.
  • Monitor for hypocalcemia (citrate toxicity) and hyperkalemia (RBC lysis).
  • Goal-directed resuscitation aims to correct these abnormalities, guided by frequent lab monitoring.

Practice Questions: Massive transfusion protocols

Test your understanding with these related questions

A 36-year-old woman is brought to the emergency department 20 minutes after being involved in a high-speed motor vehicle collision. On arrival, she is unconscious. Her pulse is 140/min, respirations are 12/min and shallow, and blood pressure is 76/55 mm Hg. 0.9% saline infusion is begun. A focused assessment with sonography shows blood in the left upper quadrant of the abdomen. Her hemoglobin concentration is 7.6 g/dL and hematocrit is 22%. The surgeon decided to move the patient to the operating room for an emergent explorative laparotomy. Packed red blood cell transfusion is ordered prior to surgery. However, a friend of the patient asks for the transfusion to be held as the patient is a Jehovah's Witness. The patient has no advance directive and there is no documentation showing her refusal of blood transfusions. The patient's husband and children cannot be contacted. Which of the following is the most appropriate next best step in management?

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Flashcards: Massive transfusion protocols

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Massive fluid loss in significant burns can cause acute _____

TAP TO REVEAL ANSWER

Massive fluid loss in significant burns can cause acute _____

gastritis (GI problem)

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