Advice
- Clinical Aid: The Wells' criteria aids decision-making but should not force management.
- Prerequisites: Apply only after a detailed history and physical exam.
- Appropriate Use: Use only for patients deemed at risk for DVT. No risk stratification is needed if there is no concern for DVT.
Management Strategy
Patients are stratified into risk groups to guide D-dimer and Ultrasound (US) utilization.
Score ≤ 0: DVT Unlikely (Low Risk)
Prevalence ~5%. Proceed to D-dimer testing.
- Negative D-dimer: Probability <1%. No further imaging required.
- Positive D-dimer: Proceed to Ultrasound.
- US Results: Negative US rules out DVT. Positive US requires anticoagulation consideration.
Score 1-2: Moderate Risk
Pretest probability ~17%. Proceed to High-Sensitivity D-dimer.
- Negative High-Sens D-dimer: Sufficient to rule out DVT (prob <1%).
- Positive High-Sens D-dimer: Proceed to Ultrasound.
- US Results: Negative US rules out DVT. Positive US requires anticoagulation consideration.
*Moderate sensitivity D-dimer is insufficient for rule-out without US in this group.
Score ≥ 3: DVT Likely (High Risk)
Pretest probability 17-53%. All patients should receive Ultrasound.
D-dimer helps with risk stratification:
- Negative D-dimer + Negative US: Sufficient to rule out DVT.
- Positive D-dimer + Negative US: Still concerning. Repeat US in 1 week.
- Positive US: Treat for DVT.
Critical Actions
Clinical Decision Making: No decision rule supersedes clinical judgement. High suspicion for DVT warrants imaging regardless of the Wells score.