How to Transfuse Cryoprecipitate
Transfuse cryoprecipitate using a standard blood giving set with a 170-200 μm filter, administering the adult dose of two pools (10 units total) at ambient temperature within 4 hours of thawing. 1
Preparation and Storage
Cryoprecipitate is stored at -25°C and must be thawed before administration. Once thawed, it can be kept at ambient temperature for 4 hours maximum and should never be refrigerated again 1. The product is typically available as pooled bags of five units (100-200 ml per bag) in the UK, with each single unit containing 400-450 mg of fibrinogen 1.
Administration Technique
Equipment and Setup
- Use a standard blood giving set with a 170-200 μm filter 1
- Recent evidence demonstrates that rapid infuser devices and pressure bags can be safely used without compromising hemostatic function or causing clumping 2
- Traditional gravity infusion remains acceptable
Dosing
The standard adult dose is two pools (10 units total), which provides approximately 4 grams of fibrinogen 1. This dosing aims to raise plasma fibrinogen concentration by approximately 1 g/L, though the actual increase is modest—approximately 0.55 g/L for 8-9 units, or roughly 0.06 g/L per unit 3.
Clinical Indications for Transfusion
Primary Indications
Transfuse cryoprecipitate when:
- Fibrinogen concentration is <80-100 mg/dl (0.8-1.0 g/L) in the presence of excessive bleeding 4
- Fibrinogen <150 mg/dl (1.5 g/L) during major hemorrhage 1
- Fibrinogen <200 mg/dl (2.0 g/L) in active obstetric hemorrhage 4, 1—note this higher threshold for pregnant patients
- As an adjunct in massively transfused patients when fibrinogen levels cannot be measured timely 4
- When fibrinogen activity testing indicates fibrinolysis 4
Timing in Massive Transfusion
Recent evidence suggests specific transfusion ratios. When using viscoelastic testing (VET) to guide resuscitation, cryoprecipitate is typically needed after 7 units of RBCs/plasma in component-only resuscitation, or after 10 units when whole blood is incorporated 5. For centers using algorithmic protocols without VET, a ratio of approximately 1 unit cryoprecipitate per 7-8 units of RBCs appears optimal 6.
Special Populations
- Congenital fibrinogen deficiencies: Consult hematology whenever possible 4, 7
- von Willebrand disease: Use only if desmopressin or specific VWF/FVIII concentrate unavailable or ineffective 4
Important Caveats
When NOT to Transfuse
Cryoprecipitate is rarely indicated if fibrinogen concentration is >150 mg/dl in non-pregnant patients 4, 7. The evidence shows that 34-42% of cryoprecipitate use occurs outside guidelines, often without appropriate fibrinogen measurement 8.
Blood Group Compatibility
Donor and recipient blood groups should match for cryoprecipitate transfusion 9. If the patient's blood group is unknown, ABO non-identical plasma with low-titre anti-A or anti-B is acceptable. Group O components should only be given to group O recipients 9.
Monitoring Response
Obtain fibrinogen levels before administration when possible 7. The fibrinogen response is modest and variable—expect an increase of approximately 0.5-0.6 g/L with standard dosing 3. Two-step preparation methods may yield slightly higher fibrinogen increases (51 mg/dL vs 36 mg/dL) compared to one-step methods 10.
Clinical Outcomes
High cryoprecipitate ratios (≥1:1 cryoprecipitate to PRBC) are independently associated with decreased 6-hour and 24-hour mortality in massively transfused trauma patients 6. This protective effect persists even after adjusting for FFP, platelets, and whole blood administration.
The key to successful cryoprecipitate transfusion is timely administration at appropriate fibrinogen thresholds using standard filtered blood sets, with higher thresholds maintained in obstetric hemorrhage.