Massive Transfusion with Uncrossmatched Blood
In extreme emergencies requiring immediate transfusion, use group O Rh(D) negative red cells for premenopausal females and group O Rh(D) positive for males and postmenopausal females, limiting uncrossmatched blood to a maximum of 2 units before switching to group-specific blood (typically available within 10 minutes of receiving a blood sample). 1
Blood Selection Algorithm
Initial Blood Product Selection
- Premenopausal females must receive group O Rh(D) negative red cells to prevent Rh sensitization and risk of hemolytic disease in future pregnancies 1
- Males and postmenopausal females should receive group O Rh(D) positive blood to preserve the scarce O negative inventory 1
- Transition to group-specific blood as soon as possible, typically within 10 minutes of blood sample receipt 1
- Limit uncrossmatched O blood to 2 units maximum before transitioning to type-specific or crossmatched blood 1
Safety Profile of Uncrossmatched Blood
- Large trauma series demonstrate that uncrossmatched type-O blood enables rapid red cell administration without discernible risk for transfusion-related complications 2
- The risk of major transfusion reaction from incompatible blood when using uncrossmatched group-specific blood is approximately 1 in 6,000 units 3
- No acute hemolytic transfusion reactions were observed in a series of 161 trauma patients receiving 581 units of uncrossmatched blood 2
- Seroconversion rates in Rh-negative patients receiving Rh-positive blood are lower than historically reported, likely due to immune suppression associated with hemorrhagic shock (only 1 of 10 Rh-negative males developed antibodies) 2
Critical Safety Protocols
Administrative Safeguards
- Most transfusion-related morbidity results from incorrect blood administration, not immunologic incompatibility 1
- Ensure two identification bands are in place on the patient 1
- Perform a final administrative check for every blood component given, even in emergencies 1
- Document the fate of all blood components for 30 years and record all blood use in clinical notes 1
Blood Warming Requirements
- Blood warming is mandatory for all volumes ≥500 mL or flow rates >50 mL/kg/h 1
- Use only approved warming devices with visible thermometer and audible warning 1
- Hypothermia from cold banked blood is aggravated by environmental factors and should be aggressively avoided 4
Component Therapy Thresholds During Massive Transfusion
Red Blood Cell Transfusion
- Transfuse almost always when hemoglobin <6 g/dL 1
- Rarely transfuse when hemoglobin >10 g/dL 1
- Base intermediate values on rate of blood loss, cardiorespiratory reserve, and atherosclerotic disease 1
Platelet Transfusion
- Maintain >50 × 10⁹/L platelets in acutely bleeding patients 1
- Target >100 × 10⁹/L for multiple trauma or CNS injury 1
Fresh Frozen Plasma
Fibrinogen Replacement
- Maintain fibrinogen >1.0 g/L 1
- Critical level of 1.0 g/L is reached after 150% blood loss with plasma-poor red cells 1
- Fibrinogen <0.5 g/L is strongly associated with microvascular bleeding 1
Organizational Requirements
Communication and Coordination
- Designate a coordinator responsible for communication and documentation 1
- Establish a rapid communication cascade 1
- Contact key personnel early: clinician in charge, duty anesthetist, blood bank, and duty hematologist 1
Common Pitfalls to Avoid
- Do not prophylactically administer calcium chloride for presumed citrate toxicity—this is dangerous and unnecessary, as citrate toxicity and hypocalcemia are usually self-limiting 4
- Avoid protocol-driven component therapy; instead, treat coagulopathy based on coagulation studies rather than fixed ratios 4
- Recognize that posttransfusion hyperkalemia and acidosis are more likely related to inadequate resuscitation from shock than to blood administration itself 4