Massive Transfusion

CRNA Study Suite · MTP Reference Card
All Calculators MTP
Definition of Massive Transfusion — any of: • ≥10 units PRBC in 24 hours
• Loss of ≥1 blood volume
• >5 units PRBC in 4 hours with ongoing hemorrhage
1:1:1 Transfusion Ratio (TRAUMA / TXA)
ComponentRatioPearls
PRBC1 unit~300 mL; Hct ~65%
FFP1 unit~250 mL; all coag factors
Platelets1 unit (apheresis)= 6 unit random-donor pool
(Wilson, 2023, p. 405)
Transfusion Triggers (Active Bleeding)
PRBCHgb < 7 g/dL (or 8 if cardiac)
Platelets (most)< 50,000/μL
Platelets (neuro)< 75-100,000/μL
Platelets (prophylactic)< 10,000/μL
FFPINR > 1.5 with active bleeding
CryoprecipitateFibrinogen < 150-200 mg/dL
(Wilson, 2023, pp. 400-407)
Tranexamic Acid (TXA)
• Loading: 1 g IV over 10 min
• Maintenance: 1 g IV over 8 hr (or 10 mg/kg IV bolus in trauma)
• Best within 3 hours of injury; after 3 hr may increase mortality (CRASH-2)
• Indications: trauma, postpartum hemorrhage, cardiac surgery, orthopedic surgery
Calcium Replacement
Citrate in stored blood binds calcium → hypocalcemia after rapid transfusion.
• Calcium chloride 10%: 500-1000 mg per 4 units PRBC (central line preferred)
• Calcium gluconate 10%: 1-2 g per 4 units PRBC
Monitor iCa; target > 1.1 mmol/L.
Complications to Watch For
• Hyperkalemia (old blood, Ca gluconate stabilizes myocardium)
• Hypocalcemia (citrate chelation)
• Metabolic alkalosis (citrate → bicarbonate in liver)
• Hypothermia — always use fluid warmer
• TRALI (within 6 hr; fever, hypoxia, pulmonary edema)
• TACO (circulatory overload; raised JVP, crackles)
• Hemolytic reaction under GA: Classic triad = unexplained hypotension + hemoglobinuria + hemorrhagic episode
(Wilson, 2023, p. 409)
Lab Targets During MTP
• Hgb > 7 (> 8 if cardiac disease)
• Platelets > 50k (> 75-100k for neuro)
• Fibrinogen > 150-200 mg/dL
• INR < 1.5
• iCa > 1.1 mmol/L
• pH > 7.2; temp > 35°C; lactate trending down
Board-High-Yield Mnemonic
"TEN-ONE-FIVE" = definition: TEN units/24h, ONE blood volume, FIVE units/4h with continued hemorrhage.
Also recall: MTP activation thresholds (ABC score, shock index > 1.0, Hgb < 11 on arrival).
(Wilson, 2023, p. 405)
References

Wilson, R. P. (2023). Blood and blood component therapy. In S. Elisha, J. S. Heiner, & J. J. Nagelhout (Eds.), Nurse anesthesia (7th ed., pp. 400-410). Elsevier.

How this works

What massive transfusion means

Massive transfusion is classically more than 10 units of packed red cells within 24 hours, with higher mortality when given within 6 hours (Levy, 2022, p. 2045). Balanced resuscitation uses a fixed 1:1:1 ratio of plasma to platelets to red cells to mimic whole blood. The PROPPR trial found no significant 30 day mortality difference between 1:1:1 and 1:1:2 but showed reduced exsanguination, 9.2% versus 14.6% (Levy, 2022, p. 2057).

Citrate, calcium, and complications

Stored blood contains citrate, which chelates ionized calcium and can cause hypotension, a prolonged QT, and impaired coagulation (Levy, 2022, p. 2047); give calcium chloride 1 g IV (or calcium gluconate 3 g) for roughly every 4 to 6 units of product (Haglund & Phillips, 2023, p. 926). Other complications include hyperkalemia, hypothermia, dilutional coagulopathy, and TRALI (Levy, 2022, p. 2047).

References

Levy, J. H. (2022). Physiology and management of massive transfusion. In Stoelting's pharmacology & physiology in anesthetic practice (6th ed., pp. 2042-2065). Wolters Kluwer.