How do I use ROTEM (rotational thromboelastometry) results to guide transfusion of plasma, platelets, fibrinogen, and other blood components?

ROTEM-Guided Transfusion Strategy

Use ROTEM to guide targeted blood component therapy in major hemorrhage by following specific thresholds: FIBTEM CA5 < 10 mm for fibrinogen replacement, EXTEM CA5 – FIBTEM CA5 < 30 mm for platelets, and EXTEM CA5 > 40 mm plus EXTEM CT > 80 s for fresh frozen plasma. 1

Core ROTEM Parameters and Transfusion Thresholds

The 2025 Association of Anaesthetists guidelines provide the most current algorithmic approach 1:

Fibrinogen Replacement

• Trigger: FIBTEM CA5 < 10 mm
• Treatment: 2 pools cryoprecipitate (equivalent to 4 g fibrinogen) or fibrinogen concentrate
• Context-specific thresholds: In obstetrics, use FIBTEM A5 < 12 mm as the cutoff, with target fibrinogen > 2.0 g/L 2

The FIBTEM test isolates fibrinogen contribution by eliminating platelets with cytochalasin D, providing results faster than Clauss fibrinogen and correlating strongly with fibrinogen levels (r = 0.82) 2. FIBTEM A5 is superior to Clauss fibrinogen in predicting progression to severe hemorrhage 2.

Platelet Transfusion

• Trigger: EXTEM CA5 – FIBTEM CA5 < 30 mm
• Treatment: 1 pool platelets
• This calculation isolates the platelet contribution to clot strength by subtracting the fibrinogen component 1

Fresh Frozen Plasma (FFP)

• Trigger: EXTEM CA5 > 40 mm plus EXTEM CT > 80 s
• Treatment: 4 units FFP
• Important caveat: Avoid FFP for isolated hypofibrinogenemia if fibrinogen concentrate or cryoprecipitate are available 1

Antifibrinolytic Therapy

• Trigger: EXTEM LI30 < 85% (indicating hyperfibrinolysis)
• Treatment: Additional 1 g tranexamic acid
• Critical warning: Do NOT withhold tranexamic acid while waiting for ROTEM results in trauma—give empirically 1

Clinical Context and Evidence Strength

Strongest Evidence Base

The British Society of Haematology recommends ROTEM use in:

• Cardiac surgery (strongest evidence)
• Liver surgery (strongest evidence)
• Obstetric hemorrhage (cautious recommendation)
• Trauma hemorrhage (cautious recommendation) 1

Trauma-Specific Considerations

A 2023 RCT (iTACTIC trial, n=396) found no difference in primary outcomes between ROTEM-guided and conventional approaches in the intention-to-treat analysis 1. However, ROTEM showed benefit in coagulopathic patients (INR > 1.2) and those with traumatic brain injury 3. The 2023 European trauma guidelines support VEM use with moderate evidence 3.

Obstetric Hemorrhage

ROTEM-guided strategies in postpartum hemorrhage demonstrated:

• Reduced transfusion requirements (P < 0.001)
• Decreased cesarean hysterectomy rates (25.0% vs 53.5%, P = 0.013)
• Fewer ICU admissions (3.6% vs 43.1%, P < 0.001)
• Shorter hospitalizations 2

Cardiac and Liver Surgery

A 2026 Cochrane review (35 RCTs, n=3096) found ROTEM may reduce mortality (RR 0.76,95% CI 0.63-0.92), but evidence certainty is very low 4. Studies in liver transplantation showed reduced FFP use and blood loss with ROTEM guidance 5, 6.

Critical Limitations and Pitfalls

What ROTEM Cannot Detect

• Von Willebrand disease or endothelial dysfunction
• Antiplatelet agents (aspirin, clopidogrel)—ROTEM bypasses primary hemostasis 2
• Hyperfibrinolysis in trauma—less sensitive than expected, hence the mandate to give tranexamic acid empirically 1

Standardization Issues

• Poor inter-center standardization beyond manufacturer reference ranges 1, 7
• No universal algorithms—each institution must optimize protocols locally 1
• Limited interchangeability between TEG and ROTEM devices 7

Operational Requirements

• Requires trained user present at all times 1
• Always pair with conventional coagulation tests—send simultaneous samples for PT, APTT, fibrinogen, platelet count 1

Practical Implementation Algorithm

1. Activate ROTEM immediately when major hemorrhage protocol initiated
2. Give tranexamic acid empirically (1 g) without waiting for results in trauma 1
3. Run EXTEM and FIBTEM simultaneously (fastest turnaround)
4. Apply thresholds sequentially:
   • First: Check FIBTEM CA5—if < 10 mm, give fibrinogen
   • Second: Calculate EXTEM CA5 – FIBTEM CA5—if < 30 mm, give platelets
   • Third: Check EXTEM CA5 and CT—if both elevated, consider FFP
   • Fourth: Check EXTEM LI30—if < 85%, give additional tranexamic acid
5. Recheck ROTEM after each intervention to guide further therapy
6. Use conventional targets as backup: Hb 70-90 g/L, platelets > 50×10⁹/L (> 75 in obstetrics), fibrinogen > 1.5 g/L (> 2.0 in obstetrics), PT < 1.5× normal 1

Special Populations

Obstetrics: Use lower FIBTEM A5 threshold of 12 mm and higher fibrinogen target of 2.0 g/L 2

Traumatic brain injury: Higher hemoglobin thresholds (80-100 g/L) may be appropriate until ongoing trials complete 1

Liver failure: ROTEM particularly useful given baseline coagulopathy; reduces prophylactic transfusions before procedures 8

The evidence base remains limited by low certainty across outcomes, with most data from cardiac surgery 4. Optimize your institutional algorithm based on local resources and patient population, but use the thresholds above as starting points 1.