Trauma to the lower limbs requiring orthopedic immobilisation (plaster cast or splint) is
a frequent reason for seeking emergency care. Because of the venous stasis caused by
immobilisation, hypercoagulability and vascular lesions induced by the trauma, these
patients are at risk of developing a venous thromboembolic event (VTE). This risk is
estimated at around 2% (95% CI 1.3 to 2.7). To reduce the risk of thrombosis, preventive
anticoagulants, mainly low molecular weight heparins (LMWH) and fondaparinux, have been
shown to be beneficial. However, not all patients have the same thromboembolic risk
factors. A targeted strategy should therefore be used to avoid prescribing treatment to
low-risk patients and to prescribe it to the sub-group of patients at high risk. The
TRiP(cast) score has been developed and validated for this purpose.
In the CASTING study (randomised stepped-wedge trial), patients not receiving
thromboprophylaxis on the basis of a TRiP(cast) score <7 had a 3-month rate of
symptomatic thromboembolic events of 0.70% (95% CI: 0.21-1.17). Use of the TRiP(cast)
score reduced the rate of anticoagulation prescriptions by 26% (24.5% versus 50.4%)
without increasing the rate of thromboembolic events at 3 months. Since this study,
French recommendations concerning the prescription of anticoagulation treatments have
been updated.
Since this study, French recommendations concerning the prescription of preventive
anticoagulant treatment have been updated by the SFMU (French Society of Emergency
Medicine) and the SFMV (French Society of Vascular Medicine). They were presented in June
2023 and are now applied in all emergency facilities. During the review for the
publication of the CASTING study, it was discussed whether it would be useful to evaluate
the reliability of this score.
However, the reliability of the measurement and the reproducibility of the score have
never been assessed. Given the importance of assessing the risk of venous thromboembolism
in patients with lower-limb trauma when deciding whether or not to prescribe
thromboprophylaxis, this assessment is essential.
Although this score appears to be objective, there are still items where interpretation
may be different. For example, the type of immobilisation cannot be transposed perfectly
to all existing immobilisation methods. This study will also be carried out in other
European countries. The types of immobilisation vary considerably from one country to
another, and the interpretation of certain items could be different. The interpretation
of patient characteristics may also vary.
Furthermore, this score has never been compared with the clinician's implicit "gestalt"
probability, which is used to define patients at risk of venous thromboembolic events.
It is a real challenge when implementing scores to assess their added value compared with
clinical intuition. The use of scores has an initial educational objective, but it is
important to know whether clinical intuition would be sufficient to assess this venous
thromboembolic risk.
The aim of the study is to evaluate the inter-observer reliability of the assessment of
venous thromboembolic risk using the TRiP(cast) score in patients presenting with trauma
to a lower limb requiring immobilisation, and of the clinicians' assessment using the
physician's implicit probability (gestalt) compared with the use of the TRiP(cast) score.
