Deep Vein Thrombosis (DVT)

Related Subjects: | Assessing Breathlessness | Respiratory Failure | Pulmonary Embolism | Deep Vein Thrombosis | DVT/PE in Pregnancy | CTPA

🦵 Initial DVT Management Summary

ℹ️ About DVT

• Most pulmonary emboli (PE) originate from pelvic or leg DVTs.
• Untreated DVT ➝ PE 🫁 + Post-thrombotic syndrome.
• Hospital prevention: 🚶‍♂️ early mobilisation, 💉 LMWH, 🧦 TED stockings.

⚠️ Risk Factors

• 🛌 Immobility (stroke, illness, neurological disease)
• 🔪 Surgery (pelvic, orthopaedic, gynae), postoperative states
• 🎗️ Malignancy
• 🤰 Pregnancy, postpartum, COCP use
• 🧬 Inherited thrombophilia (Factor V Leiden, Protein C/S deficiency)
• 👵 Age >60, 🚬 smoking, ⚖️ obesity
• ✈️ Travel >4h (within past 2 weeks)
• ❤️ CCF, 💉 HONK (Hyperosmolar non-ketotic coma)

💊 COCP & Risk

• ❌ No pill: 5 DVT/PE per 100,000
• 💊 2nd gen pill: 15/100,000
• 💊 3rd gen pill: 25/100,000
• 🤰 Pregnancy: 60/100,000

🩺 Clinical Presentation

• Calf pain, erythema, dilated veins
• 🦶 Homan’s sign (pain on dorsiflexion)
• Positive tibial tap
• Asymmetry: calf circumference ↑ >3 cm

🔍 Investigations

• 🧪 D-dimer (only if low suspicion)
• 🩻 Compression ultrasound (good for proximal DVT)
• 🧵 Venography (rare, gold standard)
• 🧲 MRI in select cases
• 🧬 Thrombophilia screen (selected cases)

🔄 Differentials

• Calf haematoma
• Ruptured Baker’s cyst
• Cellulitis / soft tissue infection
• Lymphatic obstruction
• CCF / cor pulmonale
• Gastrocnemius rupture
• Low albumin states

📊 Wells Score Criteria

• Paralysis/paresis/recent leg cast (1)
• Bedridden >3 days or major surgery <4w (1)
• Localised tenderness along deep veins (1)
• Swelling of entire leg (1)
• Calf swelling >3 cm vs other leg (1)
• Pitting oedema in affected leg (1)
• Collateral superficial veins (1)
• Active cancer (<6 months) (1)
• Alternative diagnosis more likely (-2)

Risk of PE with DVT - Key Points

• Proximal DVT (popliteal, femoral, iliac)
  • Without anticoagulation → ~40–50% risk of PE (days–weeks).
  • With anticoagulation → risk falls to ~3–5%.
• Distal (calf) DVT
  • Lower embolic risk overall.
  • <5% progress to PE if untreated.
  • Selected low-risk cases may be managed with ultrasound surveillance (per guidelines).
• Pathophysiology
  • Embolisation risk rises with clot bulk and mobility.
  • Free-floating proximal tail → higher risk; small calf thrombi → lower risk.
• Clinical pearl
  • The main danger is silent/fatal PE, not the leg swelling.
  • Start anticoagulation promptly when suspicion is high, sometimes before definitive imaging.

📌 Interpretation

• 🚨 3–8 points → High probability
• ⚠️ 1–2 points → Moderate probability
• ✅ -2–0 points → Low probability

⚖️ Clinical judgement always overrides scores. If suspicion is high ➝ proceed to imaging regardless of Wells score.

💊 Management

• 🏥 Most ambulatory patients → Outpatient care.
• 💉 Start weight-adjusted LMWH (e.g., Enoxaparin 1 mg/kg BD) if DVT suspected.
• ➡️ Confirm DVT → Add Warfarin (3–5 mg daily) until INR therapeutic; overlap with LMWH for ≥5 days.
• 🧨 Streptokinase / thrombolysis for massive iliofemoral DVT with limb-threatening risk.
• 📆 Below-knee DVT → 6 weeks Warfarin.
• 📆 Unprovoked DVT/PE → 6–12 months anticoagulation.
• 📆 Provoked DVT (surgery, trauma) → 3 months anticoagulation.
• ♾️ Recurrent DVT/PE → Consider lifelong anticoagulation.

📚 Reference

• Wells PS et al. Lancet. 1997;350(9094):1795–8.

🧑‍⚕️ Case Examples - Deep Vein Thrombosis (DVT)

• Case 1 (Post-operative DVT): 🏥 A 65-year-old woman develops unilateral calf swelling, erythema, and tenderness 1 week after total hip replacement. Analysis: Major risk factor = recent surgery with immobility → high suspicion of provoked DVT. Diagnosis: Wells score high; Doppler ultrasound confirms proximal DVT. Management: Start therapeutic anticoagulation (LMWH bridging or DOAC if suitable), encourage early mobilisation, monitor for pulmonary embolism. Review need for 3–6 months anticoagulation.
• Case 2 (Unprovoked DVT in young adult): 🧬 A 32-year-old man develops painful swollen left leg after a long-haul flight. No PMH. Analysis: Temporary provoking factor (immobility during flight) but still considered relatively “unprovoked” in a young patient. Must exclude thrombophilia or occult malignancy. Diagnosis: Duplex ultrasound confirms femoral DVT. Management: DOAC first-line (unless contraindicated), minimum 3 months anticoagulation. Thrombophilia screen considered after treatment; lifestyle advice (hydration, mobility).
• Case 3 (Cancer-associated DVT): 🎗️ A 70-year-old man with pancreatic cancer presents with right leg swelling and pain. Analysis: Malignancy = hypercoagulable state (Trousseau’s syndrome). High risk of recurrence. Diagnosis: Duplex ultrasound shows iliofemoral DVT. Management: Anticoagulation with LMWH or DOAC (e.g., apixaban), balancing bleeding risk. Oncology and palliative input for long-term plan. Duration of treatment usually indefinite while cancer is active.
• Case 4 (Pregnancy-related DVT): 🤰 A 28-year-old woman at 28 weeks gestation has unilateral leg swelling and pain. Analysis: Pregnancy = high VTE risk (Virchow’s triad: hypercoagulability, venous stasis, vascular injury). Diagnosis: Doppler ultrasound confirms femoral DVT (Wells score not validated in pregnancy). Management: LMWH is the treatment of choice (safe in pregnancy, no placental transfer). Continue throughout pregnancy and at least 6 weeks postpartum. Warfarin/DOAC contraindicated in pregnancy.
• Case 5 (Recurrent DVT): 🔄 A 60-year-old man with obesity and hypertension presents with his third DVT in 5 years. Analysis: Recurrent VTE indicates persistent risk factors and likely need for long-term therapy. Diagnosis: Confirmed by Doppler ultrasound. No evidence of malignancy. Management: Lifelong anticoagulation (DOAC preferred), compression stockings to reduce post-thrombotic syndrome, weight loss and cardiovascular risk management.