What are the recommendations for managing a massive transfusion with uncrossed (not cross-matched) blood?

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, then switch to group-specific blood as soon as possible (typically within 10 minutes of receiving a blood sample). 1

Blood Selection Algorithm

Immediate Emergency (No Time for Testing)

• Premenopausal females: Group O Rh(D) negative red cells to prevent sensitization and risk of hemolytic disease in future pregnancies 1
• Males and postmenopausal females: Group O Rh(D) positive is acceptable to preserve scarce O negative inventory 1
• Limit to 2 units maximum of uncrossmatched O blood before transitioning 1

Within 10 Minutes (Group-Specific Blood)

• Send blood sample immediately upon patient arrival for ABO/Rh typing 1
• Switch to group-specific blood as soon as grouping is complete (approximately 10 minutes) 1
• This strategy carries minimal risk: patients with massive bleeding have minimal circulating antibodies, making acute reactions unlikely 1
• Risk of major incompatibility is approximately 1 in 6,000 when using group-specific blood 2

Within 45 Minutes (Fully Crossmatched)

• Complete crossmatch typically requires 45 minutes 1
• After replacement of 1 blood volume (8-10 units), further crossmatching is not required 1

Critical Safety Protocols

Patient Identification

• Most transfusion-related morbidity results from incorrect blood administration, not immunologic incompatibility 1
• Maintain strict protocols for blood administration even in emergencies 1
• Ensure two identification bands are in situ 1
• Perform final administrative check for every component given 1

Blood Warming Requirements

• Mandatory for all volumes ≥500 mL or flow rates >50 mL/kg/h 1
• Use approved warming devices with visible thermometer and audible warning 1
• Warm blood to 37°C to prevent hypothermia-induced coagulopathy and mortality 1

Administration Equipment

• Use 14-gauge or larger peripheral cannulae 1
• Standard blood administration sets with 170-200 μm filter 1
• Rapid infusion devices (6-30 L/h capacity) for massive hemorrhage 1

Monitoring and Laboratory Assessment

Initial Blood Samples

• Send for blood grouping, antibody screening, and compatibility testing immediately 1
• Baseline: CBC, PT, APTT, fibrinogen, biochemistry, blood gases 1

Ongoing Monitoring

• Repeat coagulation studies every 4 hours or after each 1/3 blood volume replacement 1
• Recheck after each therapeutic intervention 1
• Monitor for transfusion reactions throughout hospital course 3

Component Therapy Thresholds

Red Blood Cells

• Transfusion almost always indicated when hemoglobin <6 g/dL 1
• Rarely indicated when hemoglobin >10 g/dL 1
• Intermediate values: base decision on rate of blood loss, cardiorespiratory reserve, and atherosclerotic disease 1

Platelets

• Maintain >50 × 10⁹/L in acutely bleeding patients 1
• Target >100 × 10⁹/L for multiple trauma or CNS injury 1
• Anticipate need after 2 blood volumes replaced 1

Fresh Frozen Plasma

• Dose: 12-15 mL/kg (approximately 1 liter or 4 units for adults) 1
• Target PT and APTT <1.5× control mean 1
• Allow 30 minutes for thawing 1

Cryoprecipitate

• Maintain fibrinogen >1.0 g/L 1
• Critical level of 1.0 g/L reached after 150% blood loss with plasma-poor red cells 1
• Fibrinogen <0.5 g/L strongly associated with microvascular bleeding 1

Evidence on Safety

Transfusion Reaction Risk

• No acute hemolytic reactions observed in largest trauma series of 161 patients receiving 581 units of uncrossmatched blood 3
• Zero deaths related to transfusion incompatibility in prospective study of 99 patients receiving 410 units uncrossmatched blood 4
• Seroconversion rate in Rh-negative patients is lower than historically reported, likely due to immune suppression from hemorrhagic shock 3

Common Pitfalls to Avoid

• Do not delay transfusion waiting for crossmatch in life-threatening hemorrhage 1
• Do not over-rely on group O Rh(D) negative blood—it is a scarce resource 1
• Do not administer blood without proper warming equipment in massive transfusion 1
• Do not forget to switch from O blood to group-specific blood once available 1

Organizational Requirements

Coordination

• Designate a coordinator responsible for communication and documentation 1
• Establish rapid communication cascade through Hospital Transfusion Committee 1
• Contact key personnel early: clinician in charge, duty anesthetist, blood bank, duty hematologist 1

Traceability

• Statutory requirement: fate of all blood components must be documented for 30 years 1
• Record all blood use in clinical notes and inform transfusion laboratory 1