Key Points
- Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
- Use system-specific risk tools to guide testing and disposition.
- Order high-yield tests first; escalate imaging when indicated.
- Start evidence-based initial therapy and reassess frequently.
Algorithm
- Primary survey and vitals; IV access and monitors.
- Focused history/physical; identify red flags and likely etiologies.
- Order system-appropriate labs and imaging (see Investigations).
- Initiate guideline-based empiric therapy (see Pharmacology).
- Reassess response; arrange consultation and definitive management.
Clinical Synopsis & Reasoning
DVT should be considered in unilateral limb swelling, pain, and erythema, particularly with recent surgery, immobility, cancer, or prior VTE. Use Wells score to categorize probability and apply D‑dimer in low/intermediate risk; duplex ultrasonography confirms diagnosis. Evaluate for PE symptoms and bleeding risk to plan therapy.
Treatment Strategy & Disposition
Anticoagulate with DOACs for most patients, LMWH for cancer, and heparin/warfarin when DOACs are unsuitable. Consider catheter‑directed therapy for limb‑threatening iliofemoral DVT (phlegmasia). Plan duration based on provoking factors; provide compression for symptom control and counsel on recurrence risks. Outpatient management is appropriate for reliable, low‑risk patients; admit if extensive clot burden, high bleeding risk, or comorbidity.
Epidemiology / Risk Factors
- Risk factors vary by condition and patient profile
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|---|---|---|
| CBC | Baseline hematology | Abnormal counts | |
| BMP | Electrolytes/renal | Derangements |
Scan Points
| Site | Landmark |
|---|---|
| Common femoral | Just distal to inguinal ligament |
| Popliteal | Midline fossa posterior knee |
Pharmacology
| Medication | Mechanism | Onset | Role in Therapy | Limitations |
|---|---|---|---|---|
| Unfractionated heparin (IV) | Antithrombin-mediated Xa/IIa inhibition | Immediate | Initial AC when lysis/cath possible or renal failure | Bleeding, HIT; monitor aPTT; ED use |
| Catheter-directed therapy | Localized fibrinolysis/thrombectomy | Rapid | When systemic lysis high risk or ineffective | Bleeding; expertise required; ED use |
| Apixaban/Rivaroxaban | Direct factor Xa inhibition | Hours | First-line for most stable PE/DVT | Bleeding; interactions; ED use |
| Alteplase (systemic) | Plasminogen activation (fibrinolysis) | Rapid | Massive PE with shock or arrest | ICH/major bleed; contraindications; ED use |
| Enoxaparin (LMWH) | Xa>IIa inhibition | Hours | Preferred initial AC in many stable cases; cancer VTE | Avoid severe renal failure; ED use |
Prognosis / Complications
- Prognosis depends on severity, comorbidities, and timeliness of care
Patient Education / Counseling
- Explain red flags and when to seek emergent care.
- Reinforce medication adherence and follow-up plan.
Notes
Use color doppler as adjunct; avoid excessive pressure causing vein collapse artifact; consider calf DVT limitations.
References
- ACEP DVT Ultrasound — Link