Can cross-matched Packed Red Blood Cells (PRBCs) and unmatched Fresh Frozen Plasma (FFP) be given in emergencies?

Emergency Use of Cross-matched PRBCs with Unmatched FFP

Yes, cross-matched packed red blood cells (PRBCs) can be given with unmatched fresh frozen plasma (FFP) in emergency situations, as FFP does not require ABO compatibility testing before administration in life-threatening hemorrhage scenarios.

Rationale for Unmatched FFP in Emergencies

Blood Component Compatibility Requirements

• PRBCs: Require ABO compatibility testing (cross-matching) to prevent potentially fatal hemolytic transfusion reactions
• FFP: Does not require cross-matching in emergencies as it contains minimal red cell antigens 1
  • FFP can be administered without waiting for ABO compatibility testing when time is critical
  • This is particularly valuable in massive hemorrhage scenarios where coagulopathy correction is urgent

Clinical Advantages

• Time-saving benefit: Unmatched FFP can be administered immediately while cross-matched PRBCs are being prepared
• Coagulopathy management: Early FFP administration helps prevent or correct trauma-induced coagulopathy 1
• Volume considerations: FFP offers several advantages over large-volume crystalloid resuscitation, including:
  • Faster reconstitution into smaller volumes
  • Shorter infusion time (20-30 minutes)
  • Reduced risk of transfusion-associated circulatory overload 1

Emergency Transfusion Protocol

Initial Management

1. Insert wide-bore peripheral cannulae (14G or larger) 1
2. Activate major hemorrhage protocol to mobilize resources 1
3. Designate a team leader (senior anesthetist) and coordinator to maintain communication with laboratory 1

Blood Product Administration

1. For PRBCs:

   • Use cross-matched PRBCs when available
   • If immediate transfusion needed before cross-matching:
     • Group O RhD negative for women of childbearing potential (<50 years)
     • Group O RhD positive acceptable for males or postmenopausal females 1

2. For FFP:

   • Can be given unmatched in emergency situations
   • Typical dose: 12-15 ml/kg (approximately 4 units for an adult) 1
   • Allow 30 minutes for thawing if not immediately available

Monitoring and Adjustment

• Repeat coagulation studies (PT, APTT, fibrinogen) after every 1/3 blood volume replacement 1
• Target PT and APTT <1.5x control mean
• Aim for fibrinogen >1.0 g/L

Special Considerations

Balanced Resuscitation

• Evidence suggests that FFP:PRBC ratios of 1:2 to 3:4 may provide maximal hemostatic effect 2
• Higher ratios (≥1:1) may not confer additional hemostatic advantages 2
• The beneficial effects of plasma therapy are primarily limited to patients with coagulopathy 2

Potential Complications

• FFP-related risks: Allergic reactions, transfusion-related acute lung injury (TRALI)
• Volume overload: Less common with FFP than with large-volume crystalloid resuscitation
• Thromboembolic risk: Each unit of FFP may increase VTE risk by 25% in patients requiring <4 units of PRBCs 3

Common Pitfalls to Avoid

1. Delayed transfusion: Don't wait for laboratory hemoglobin results before initiating transfusion in obvious hemorrhagic shock 4

2. Overlooking hypothermia: Use blood warmers when flow rate exceeds 50 ml/kg/h in adults 1

3. Ignoring calcium levels: Monitor and maintain ionized calcium >1.0 mmol/L during massive transfusion 1

4. Fixed ratios without monitoring: Adjust therapy based on patient response and laboratory/viscoelastic testing 4

In summary, the practice of administering cross-matched PRBCs with unmatched FFP is not only acceptable but often necessary in emergency situations involving massive hemorrhage, where rapid correction of coagulopathy is essential for patient survival.