Management of Low TEG Max Amplitude and Functional Fibrinogen MA
Immediate Fibrinogen Replacement is Required
Your patient has critical hypofibrinogenemia with impaired clot formation requiring immediate fibrinogen replacement with either fibrinogen concentrate (3-4 grams) or cryoprecipitate (50 mg/kg, approximately 15-20 single donor units in a 70 kg adult). 1
Interpretation of Your TEG Results
Your TEG demonstrates a functional fibrinogen deficit:
- Rapid TEG Max Amplitude of 49 mm (Low): Indicates overall impaired clot strength 2, 3
- Functional Fibrinogen MA of 22 mm (Low): This is critically low and correlates with plasma fibrinogen levels well below the 1.5-2.0 g/L threshold required for adequate hemostasis 1, 3
- Normal Reaction Time (6.2-7.7 min): Suggests preserved thrombin generation, meaning the primary defect is fibrinogen, not clotting factor deficiency 1
The functional fibrinogen MA of 22 mm is particularly concerning, as this represents severe hypofibrinogenemia requiring urgent correction. 3, 4
Step-by-Step Management Algorithm
1. Immediate Fibrinogen Replacement
- First-line therapy: Administer fibrinogen concentrate 3-4 grams IV OR cryoprecipitate 50 mg/kg (15-20 units for 70 kg patient) 1
- Target: Achieve fibrinogen level ≥1.5-2.0 g/L or functional fibrinogen MA >9 mm on repeat TEG 1
- Rationale: Fibrinogen is the first coagulation factor to critically decrease during bleeding, and your patient's functional fibrinogen MA of 22 mm indicates severe depletion 1, 5
2. Repeat TEG After Fibrinogen Replacement
- Recheck TEG 15-30 minutes after fibrinogen administration 3, 4
- If functional fibrinogen MA remains <9 mm: Give additional fibrinogen (repeat dosing guided by TEG) 1
- If functional fibrinogen MA normalizes but overall MA remains low: Consider platelet transfusion, as platelets contribute approximately 70% to clot strength 2, 3
3. Assess for Additional Coagulation Factor Deficiency
- Only if fibrinogen level is normalized (>1.5 g/L or functional fibrinogen MA >9 mm) AND reaction time remains prolonged: Consider prothrombin complex concentrate (PCC) for factor deficiency 1
- Do NOT give PCC first: Your normal reaction time indicates preserved thrombin generation; fibrinogen is the primary deficit 1
4. Monitor for Bleeding and Transfusion Requirements
- **If active bleeding with platelet count <50 × 10⁹/L**: Transfuse platelets to maintain >50 × 10⁹/L 1
- If massive transfusion anticipated: Maintain plasma:RBC ratio of 1:2 to 3:4 alongside fibrinogen replacement 1
Critical Thresholds to Remember
- Fibrinogen <1.5 g/L (or functional fibrinogen MA <9 mm): Immediate replacement required 1
- Fibrinogen <2.0 g/L: Associated with 100% positive predictive value for severe hemorrhage progression 1, 5
- Functional fibrinogen MA <22 mm: Your patient is at this critical threshold requiring urgent intervention 3
Common Pitfalls to Avoid
Do Not Rely on PT/INR Alone
- Conventional coagulation screens (PT/INR, aPTT) only monitor coagulation initiation and may appear normal while fibrinogen is critically depleted 5
- Your patient's reaction time is normal, which could falsely reassure if you ignore the functional fibrinogen deficit 5
Do Not Delay for Laboratory Fibrinogen Results
- TEG functional fibrinogen provides real-time assessment with 30-60 minute time savings over Clauss fibrinogen 5, 4
- Act on the TEG results immediately rather than waiting for laboratory confirmation 5
Do Not Overuse PCC
- PCC is only indicated if fibrinogen is normal AND reaction time is prolonged 1
- Inappropriate PCC use increases thrombotic risk without addressing the primary fibrinogen deficit 1
Avoid Artificial Colloids
- Hydroxyethyl starch (HES) causes laboratory fibrinogen assays to overestimate actual levels and should be avoided 1, 6, 5