What is ' trauma -induced coagulopathy'?

Trauma-induced coagulopathy (TIC) is a disorder of the blood clotting process that can occur soon after trauma injury that can lead to the patient bleeding to death. A diagnosis of TIC on admission to hospital is associated with increases in death rates, blood transfusions, risks of complications and length of stay in hospital.

How is TIC diagnosed?

Current testing for TIC normally involves coagulation tests on the patient's blood.

What are thromboelastography (TEG) and rotational thromboelastometry (ROTEM)?

Thromboelastography (TEG) and rotational thromboelastometry (ROTEM) are tests which involve a group of assessments that can be used to diagnose TIC. In some centres TEG and ROTEM are used routinely to test patients' blood, but in the UK their use is usually restricted to experimental and research settings.

The purpose of this research

The purpose of this research was to determine how good the TEG and ROTEM assessments are at diagnosing TIC in adult trauma patients who are bleeding. The accuracy of TEG and ROTEM was compared against another test that is currently used (the reference standard), which was the prothrombin time/international normalized ratio (PTr/INR).

What we discovered

We identified 3 studies (with 300, 90 and 40 participants; 430 in total) that compared the diagnostic test accuracy of TEG or ROTEM for identifying TIC in bleeding adult trauma patients within the emergency setting against PTr/INR. We recognise that the reference standards of PT and INR are imperfect, but in the absence of embedded clinical consensus these are judged to be the best reflection of current clinical practice. Readers should note that the assessment of test accuracy was not the single purpose of any of these 3 included studies.

None of the 3 studies investigated the accuracy of the TEG assessment; they all investigated the ROTEM assessment. The 3 studies provided very little evidence on the accuracy of ROTEM, and provided results for only one potential indicator of TIC (clot amplitude (CA) at 5, 10 and 15 minutes (CA5, CA10 and CA15)), although other indicators could have been used.

The overall reliability of the estimates of accuracy for CA was undermined by the low number of studies (2 for CA5 measurements and 1 each for CA10 and CA15 measurements), as well as concerns that the studies might be subject to bias concerning aspects of the ROTEM test and the PTr/INR test being used as the reference standard.

There was not enough research available on the test accuracy of TEG or ROTEM for the researchers to determine whether these assessments provide a good test for diagnosing TIC in bleeding adult trauma patients.