When to Skip and When to Use Anticoagulation in Patients Getting Casts or Splints

This robust randomized trial introduces a new, slick, and effective predictive tool for assessing clotting risk

When to Skip and When to Use Anticoagulation in Patients Getting Casts or Splints

What’s the Claim?

A large, multicenter trial evaluated the efficacy of anticoagulation in patients with lower extremity injuries who were given immobilization for ≥ 7 days (cast, splint, or brace, with or without weightbearing restrictions) and who were deemed to be at low risk of DVT/PE according to the TRiP(cast) score. TRiP(cast) takes about 10 seconds to calculate either by looking at Table 1 here or by using a free app.

The study compared “usual care,” in which physicians used anticoagulation according to their routine approaches (in this study, about half the patients received it during the control phase), to withholding anticoagulation during the intervention phase for those whose TRiP(cast) score was < 7.

(A 50-year-old male patient with no other risk factors for clotting who is immobilized below the knee for a bimalleolar fracture awaiting surgery a week later — a common scenario — would have a score of 6 points, and so would’ve been eligible to participate.)

The authors found that more than three-quarters of the patients were deemed low risk on that scoring rubric; their risk of symptomatic venous thromboembolism without thromboprophylaxis was 0.7% (95% CI 0.35% to 1.4%). There were no differences between the control and intervention phase of the study in terms of clotting risk.

  • Perhaps as interesting, 2.7% of patients with a TRiP(cast) score of ≥ 7 experienced symptomatic thromboembolic events despite receiving prophylactic anticoagulation.
    • And it doesn't take much to get a score of 7 points on TRiP(cast) — a 50-year-old male patient with an Achilles tendon rupture treated for a week with a short-leg boot scores 7 points!

How’s It Stack Up?