Massive Blood Transfusion

Aka: Massive Blood Transfusion, Massive Transfusion, Dilutional Coagulopathy, Massive Transfusion Protocol

1. See Also
   1. Hemorrhage Management
   2. Thromboelastography
2. Indications
   1. ABC Hemorrhage Score of 2 or more OR
   2. Hemorrhagic Shock with 2 or more risk factors as below (see Houston protocol below) OR
   3. Trauma with Hemorrhage requiring Transfusion of Packed Red Blood Cells that replace >50% of Blood Volume
      1. More than 50% of Blood Volume in 4 hours (4-6 units replaced in an average adult)
      2. More than 100% of Blood Volume in 24 hours (8-12 units replaced in an average adult)
   4. Calculating total Blood Volume in units
      1. Blood Volume is 70 ml/kg in adults, 80 ml/kg in children, 100 ml/kg in infants
      2. One unit or pint of blood is 450 ml
      3. Blood Volume in Units = wtKg/6.4 in adults, wtKg/5,6 in children, wtKg/4.5 in neonates
   5. Critical Administration Threshold (CAT)
      1. Three or more units pRBC transfused within 60 minutes
      2. CAT+1: 3 units in 1 hour
      3. CAT+2: A second set of 3 units pRBC transfused in 1 hour
      4. CAT+3: A third set of 3 units pRBC transfused in 1 hour
      5. CAT+4: A fourth set of 3 units pRBC transfused in 1 hour
      6. Savage (2015) J Trauma Acute Care Surg 78(2):224-9 +PMID: 25757105 [PubMed]
3. Risk Factors: Predictors of Massive Blood Transfusion (MBT)
   1. Emergency department arrival Heart Rate >120
   2. Emergency department arrival Heart Rate <90 mmHg
   3. Positive FAST Exam
   4. Penetrating Trauma
   5. Uncrossed match blood use in the Emergency Department
4. Diagnosis: Triggers for Massive Blood Transfusion (MBT)
   1. Assessment of Blood Consumption Score
      1. Score >=2 predicts MBT in 40% of cases (100% if score of 4)
   2. Houston Protocol
      1. Two or more criteria suggest need for Massive Blood Transfusion
      2. Test Sensitivity: 86%
      3. PPV: 53%
      4. NPV: 96%
5. Mechanism
   1. Dilutional Coagulopathy
      1. Coagulopathy develops with Massive Blood Transfusion (dilution of Coagulation Factors)
   2. FFP helps treat the Coagulopathy by replacing Fibrinogen, C1 esterase, antiplasmins and other factors
   3. Thromboelastography (TEG or r-TEG)
      1. Measures overall coagulation efficiency and can identify the severity of coagulation defects
      2. Typically limited to large Trauma Centers
6. Protocol: Primary 1:1:1 replacement
   1. Notify the blood bank early regarding need for Massive Transfusion Protocol
   2. Red Blood Cell replacement remain the first priority
      1. Continue Blood Transfusion until bleeding is controlled or patient becomes hemodynamically stable
   3. Ratio of 1:1:1 of Platelets : plasma : Red Blood Cells is preferred (decreased mortality compared with 1:1:2)
      1. Replace 1 unit of Fresh Frozen Plasma for every 1 unit of Packed Red Blood Cells (pRBC)
         1. Typically the limiting factor (insufficient supply)
         2. Available in some centers as Jumbo Plasma (2 to 3 plasma units at 450 to 600 ml)
         3. Ideal universal donor is AB Plasma, which is in short supply
      2. Replace 1 unit of apheresis Platelets for every 6-8 units of Packed Red Blood Cells
         1. Each unit of apheresis Platelets is equivalent to prior Platelet 6-pack
7. Protocol: Other Measures
   1. Consider Cryoprecipitate
      1. Cryoprecipitate primarily replaces Fibrinogen (but also Von Willebrand Factor, Factor VIII)
         1. Fibrinogen is also contained in FFP, which is the primary replacement unit in MBT
      2. Obtain Fibrinogen and r-TEG Level after 12 units pRBC, or bleeding despite 1:1:1 replacement
      3. Cryoprecipitate indications
         1. Fibrinogen level <150 - 180 mg/dl OR
         2. r-TEG Alpha angle shallow (e.g. <50 to 66 degrees)
      4. Cryoprecipitate dosing
         1. Typical adult dose 10 units
         2. One unit Cryoprecipitate per 5 kg wtKg raises Fibrinogen 100 mg/dl
   2. Consider Prothrombin Complex Concentrate (PCC) 1-2 doses
      1. Do not use beyond 6-7 hours from bleeding onset (due to increased bleeding risk)
      2. Consider if bleeding is refractory to multiple units with 1:1:1 replacement
   3. Consider Tranexamic Acid
      1. Also consider in r-TEG LY30 >3%
      2. Give within first 3 hours of injury
         1. Avoid if more than 3 hours after injury (no benefit, and possible harm)
   4. Consider Calcium Supplementation
      1. Blood chelators (e.g. citrate) lower Serum Calcium and may alter hemodynamics
      2. Give 1 g Calcium Chloride (or 2 to 3 g Calcium Gluconate) at start of Massive Transfusion Protocol
      3. Give 1 g Calcium Chloride (or 2 to 3 g Calcium Gluconate) for every 2 to 4 units of transfused
      4. Weingart and Swaminathan in Swadron (2022) EM:Rap 22(7): 2-3
8. Precautions
   1. Avoid Hypothermia (worsens Coagulopathy when <35 C, and especially when <32 C)
      1. Keep Body Temperature >35 C
      2. Warm blood (each unit may lower Body Temperature 0.25 C)
      3. Consider Bair Hugger
   2. Avoid excessive crystalloid (NS, LR)
   3. Prevent acidosis
9. Complications
   1. Dilutional Coagulopathy
   2. Hypothermia
   3. Hyperkalemia
   4. Hypocalcemia
   5. Metabolic Acidosis
10. References
    1. Orman and DeLoughery in Herbert (2017) EM:Rap 17(4): 5-6
    2. Freeman and Bourland (2021) Crit Dec Emerg Med 35(12): 3-11
    3. Holcomb (2012) Arch Surg 15:1-10 [PubMed]
    4. Holcomb (2015) JAMA 313(5): 471-82 +PMID:25647203 [PubMed]