Can ROTEM (Rotational Thromboelastometry) be used for assessing platelet function?

ROTEM Cannot Be Reliably Used for Platelet Function Assessment

Standard ROTEM is not recommended for testing platelet function because it bypasses primary hemostasis and is insensitive to antiplatelet agents and platelet dysfunction. 1

Why Standard ROTEM Fails to Assess Platelet Function

The fundamental limitation stems from how ROTEM works:

• ROTEM uses reagents that activate coagulation, bypassing primary hemostasis entirely, making it insensitive to antiplatelet agents or any kind of platelet inhibition 1
• ROTEM cannot detect disorders of primary hemostasis because it does not assess the contribution of endothelium to coagulation 1
• Studies have demonstrated that standard TEG (similar technology to ROTEM) was incapable of detecting platelet dysfunction in severe preeclampsia, unlike the PFA-100 1

Indirect Platelet Assessment Methods (Not Validated)

Some investigators have attempted workarounds, but these remain unvalidated:

• Calculating platelet contribution by subtracting FIBTEM maximum clot elasticity from EXTEM has been suggested, but this metric has not been validated in clinical practice 1
• The platelet-specific thromboelastometry (PLTEM) calculation (A10 EXTEM – A10 FIBTEM) showed correlation (r = 0.80) with platelet count in postpartum hemorrhage patients, but more studies are needed for confirmation 1

Newer ROTEM Platelet Systems

Newer versions including the ROTEM platelet system may allow assessment of platelet function, but these assays are relatively new and still need validation 1:

• The ROTEM platelet system with thrombin activation (TRAP-tem) showed improvement after platelet transfusion in cardiac surgery, suggesting it may detect platelet dysfunction 2
• However, ROTEM platelet demonstrated inadequate detection of clopidogrel compared to light transmission aggregometry, though it could detect aspirin 3
• Specificity was low in both ROTEM and TEG platelet mapping assays 4

Clinical Implications and Recommendations

If platelet function testing is needed, ROTEM must be supplemented with other, more sensitive platelet tests 1:

• The ASA guidelines recommend obtaining platelet count alongside viscoelastic assays when coagulopathy is suspected 1
• For detecting antiplatelet therapy in trauma patients, the European trauma guidelines recommend avoiding routine use of POC platelet function devices due to mixed results and limited value when platelet counts are low 1

Critical Pitfall to Avoid

Previous studies suggesting the safety of neuraxial anesthesia in pregnant women with platelet counts as low as 56,000/mm³ based on normal TEG profiles need to be interpreted with extreme caution, as TEG/ROTEM are not adequate measures of platelet function 1

What ROTEM Actually Measures Well

While ROTEM cannot assess platelet function, it excels at:

• Detecting hypofibrinogenemia (FIBTEM A5 ≤12 mm correlates with fibrinogen ≤2 g/L) 1, 5
• Assessing fibrinogen-platelet interaction and overall clot strength 6
• Detecting hyperfibrinolysis and heparin effects 6