In a bleeding patient (e.g., during major surgery, trauma, or massive transfusion), does a low functional fibrinogen (cFF) on thromboelastography indicate the need for cryoprecipitate?

Does Low Functional Fibrinogen on TEG Indicate Need for Cryoprecipitate?

Yes, a low functional fibrinogen (cFF) on thromboelastography in a bleeding patient indicates the need for fibrinogen replacement with either cryoprecipitate or fibrinogen concentrate. 1

Understanding the TEG/ROTEM Thresholds

The most recent European trauma guidelines (2023) provide clear viscoelastic cutoffs for fibrinogen replacement:

• Very low functional fibrinogen (≤4-6 mm maximum clot firmness on FIBTEM): Fibrinogen replacement is strongly recommended in patients with continuous, significant, non-surgical microvascular bleeding 1
• Borderline functional fibrinogen (6-8 mm FIBTEM-MCF): Replacement may be considered in the same bleeding context 1
• Target level: Maintain physiological fibrinogen function (>9 mm FIBTEM-MCF) but avoid supranormal levels (>14 mm) 1

For TEG functional fibrinogen specifically, the correlation with plasma fibrinogen shows that lower %MA(FF) is associated with coagulopathy and increased transfusion requirements 2. A FIBTEM MCF of 7 mm correlates with approximately 2.0 g/L plasma fibrinogen 1.

Clinical Decision Algorithm

Step 1: Confirm Active Bleeding

• Major bleeding must be present (trauma, surgery, massive transfusion scenario) 1
• Bleeding should be non-surgical and microvascular in nature 1

Step 2: Assess Functional Fibrinogen

• Use viscoelastic testing (TEG functional fibrinogen or ROTEM FIBTEM) for rapid assessment 1
• ROTEM FIBTEM shows better correlation with Clauss fibrinogen (0.27-0.94) compared to TEG FF (0-0.9) and is more widely validated 3
• Viscoelastic methods provide 30-60 minute time savings over conventional laboratory testing 4

Step 3: Initiate Replacement Based on Threshold

• If FIBTEM MCF ≤4-6 mm OR plasma fibrinogen ≤1.5 g/L: Give fibrinogen replacement immediately 1
• Initial dose: 3-4 g fibrinogen concentrate OR 15-20 single donor units cryoprecipitate (approximately 50 mg/kg) 1

Step 4: Reassess and Redose

• Repeat viscoelastic monitoring after administration 1
• Additional doses should be guided by ongoing VEM and laboratory fibrinogen levels 1

Cryoprecipitate vs. Fibrinogen Concentrate

Both products are acceptable for fibrinogen replacement, though they have different characteristics:

Cryoprecipitate advantages:

• Contains Factor VIII, Factor XIII, von Willebrand factor, and α2-antiplasmin in addition to fibrinogen 5
• May provide superior clot stability, improved thrombin generation, and increased fibrinolytic resistance compared to fibrinogen concentrate alone 5
• Associated with improved survival when administered during transfusion in trauma 6

Fibrinogen concentrate advantages:

• Standardized fibrinogen content (vs. variable content in cryoprecipitate units) 1, 7
• Lower volume (50 ml vs. 250 ml) 1
• No need for cross-matching 1
• Viral inactivation processing 1

Important caveat: The 2023 European trauma guidelines note that despite 10+ years of use, no large double-blind RCT has confirmed superiority of either product, and meta-analyses show no difference in mortality, transfusion requirements, or thromboembolic events 1. However, the physiologic rationale and observational data support their use in hypofibrinogenemia with active bleeding.

Critical Pitfalls to Avoid

Do not delay fibrinogen replacement: Fibrinogen is the first coagulation factor to reach critically low levels during massive hemorrhage, depleting before any other factor 4, 6. Early administration is crucial.

Do not rely solely on Clauss fibrinogen: The turnaround time is too long in acute bleeding scenarios 1. Viscoelastic testing provides real-time functional assessment and should guide initial therapy 1.

Do not aim for supranormal levels: Target physiological fibrinogen function (>9 mm FIBTEM-MCF or >1.5 g/L plasma fibrinogen) but avoid very high levels (>14 mm FIBTEM-MCF), as these do not provide additional benefit and may increase thrombotic risk 1.

Recognize in vivo recovery is incomplete: Fibrinogen recovery after cryoprecipitate administration averages only 61.6% 7, meaning you may need more than calculated doses to achieve target levels.

Monitor platelet contribution: Despite fibrinogen's importance, platelets contribute more to clot strength at all time points after injury (69.4% vs. 30.6% at admission) 2. Address both components of coagulopathy.

Special Populations

Cardiac surgery: The same principles apply, with cryoprecipitate significantly increasing FIBTEM A10 and plasma fibrinogen in bleeding patients post-cardiopulmonary bypass 7. A dose of approximately 13.2 mg/kg is required to increase FIBTEM A10 by 1 mm 7.

Cirrhosis: Routine correction of fibrinogen deficiency to decrease procedure-related bleeding is discouraged in non-bleeding cirrhotic patients 1. However, in actively bleeding cirrhotic patients, a threshold of >120 mg/dl (1.2 g/L) is commonly used 1.