Management of Extensive Proximal DVT (Iliofemoral + Long/Short Saphenous) in an 80-Year-Old with Hb 6 g/dL

Step 1 - Immediate Risk Assessment & Stabilisation

• Phlegmasia cerulea dolens - massive iliofemoral DVT can cause venous gangrene (blue, congested, painful leg). This is a limb-threatening emergency requiring urgent intervention.
• Pulmonary embolism - proximal DVT has high embolism risk; check for dyspnoea, tachycardia, hypoxia, right heart strain. Do CTPA or at minimum D-dimer + ECG + ABG if clinically suspected.
• Cause of Hb 6 - this is severe anaemia and must be investigated urgently. It directly affects anticoagulation decisions.

• CBC with peripheral smear, reticulocyte count
• Iron studies, B12/folate, renal function, LFTs
• PT/INR, aPTT (baseline before anticoagulation)
• Blood group and crossmatch (for transfusion)
• CTPA if PE suspected
• Serum creatinine/eGFR (critical for DOAC/LMWH dosing in elderly)
• Thrombophilia screen (Factor V Leiden, prothrombin mutation, antiphospholipid antibodies) - ideally before anticoagulation, though results won't change acute management
• Consider malignancy workup (CA-125, CT abdomen/pelvis) given age - DVT can be the presenting feature of occult cancer

Step 2 - Address Severe Anaemia (Hb 6 g/dL)

• Transfuse packed red cells to a target Hb of at least 8-9 g/dL before or concurrent with anticoagulation initiation. In an elderly patient with possible cardiovascular disease, transfuse slowly (1 unit at a time with furosemide cover if needed).
• Investigate the cause - iron deficiency anaemia (most common in elderly) vs. GI bleed (which would further elevate bleeding risk with anticoagulation) vs. chronic disease vs. haematological cause.
• If active GI bleeding is the cause of Hb 6, this substantially changes the anticoagulation risk-benefit calculus - seek GI input and consider IVC filter (see below).

Step 3 - Anticoagulation (Cornerstone of DVT Treatment)

Option A: LMWH (Preferred initial agent in most cases)

• Enoxaparin 1 mg/kg SC twice daily (or 1.5 mg/kg once daily)
• Key advantage: outpatient treatment possible, predictable pharmacokinetics, lower HIT risk vs. UFH
• Dose-adjust for renal impairment: CrCl 10-30 mL/min → reduce to 1 mg/kg once daily. Monitor anti-Xa levels in the elderly.
• "Numerous well-designed trials demonstrate a decrease in thrombotic complications, bleeding, and mortality with LMWHs" compared to UFH - Schwartz's Principles of Surgery 11th Edition

Option B: Unfractionated Heparin (UFH) - if renal failure or high bleeding risk where rapid reversal may be needed

• IV infusion, titrated to aPTT 60-100 seconds (1.5-2.5× control)
• Easily reversed with protamine sulfate - an important advantage in this elderly, anaemic patient
• Monitoring: aPTT every 6 hours initially

Option C: Direct Oral Anticoagulants (DOACs) - can be used as monotherapy

• Rivaroxaban: 15 mg twice daily with food for 21 days, then 20 mg once daily
• Apixaban: 10 mg twice daily for 7 days, then 5 mg twice daily
• These can be started directly without initial parenteral anticoagulation
• Caution in the elderly: renal clearance is significant - check eGFR before prescribing. Avoid rivaroxaban if CrCl <15 mL/min.
• No reliable reversal agent widely available for most (andexanet alfa reverses factor Xa inhibitors but is expensive and not universally available) - this matters given Hb 6.

1. Readily reversible (protamine for UFH/LMWH)
2. Easy dose adjustment with real-time monitoring
3. Safe bridge while anaemia is being investigated and treated

Step 4 - Duration of Anticoagulation

Step 5 - Consider Catheter-Directed Thrombolysis (CDT)

• Iliofemoral DVT - fits the profile
• Progressive limb-threatening swelling
• Young-onset or high functional need (less relevant at 80 years)

• Hb 6 = high bleeding risk - CDT significantly increases haemorrhagic complications (RR 1.73 in systemic thrombolysis trials)
• Age 80 - increased bleeding risk
• If cause of anaemia is GI or internal bleeding, CDT is absolutely contraindicated

Step 6 - IVC Filter

• Absolute contraindication to anticoagulation (e.g., active serious bleeding, intracranial haemorrhage)
• Recurrence of PE despite therapeutic anticoagulation
• Inability to achieve therapeutic anticoagulation

Step 7 - Supportive Measures

• Compression stockings (graduated elastic compression, 30-40 mmHg) once acute swelling allows - reduces post-thrombotic syndrome (PTS)
• Limb elevation - reduces oedema acutely
• Mobilisation - bed rest is not required; early ambulation is encouraged once anticoagulation is therapeutic
• Intermittent pneumatic compression devices for the contralateral leg during hospitalisation to prevent new DVT

Step 8 - Monitoring & Follow-Up

Summary Algorithm

Hb 6 + Extensive Proximal DVT (Iliofemoral)
          |
          ├── Investigate & transfuse (target Hb ≥8-9)
          |
          ├── Assess cause of anaemia (GI bleed? → IVC filter if anticoag contraindicated)
          |
          ├── Start anticoagulation:
          |    - UFH (IV) if severe renal failure or rapid reversal needed
          |    - LMWH (dose-adjusted for renal function) in most cases
          |    - DOAC (rivaroxaban/apixaban) once Hb stabilised and no active bleeding
          |
          ├── CDT: defer until Hb corrected; re-evaluate if phlegmasia develops
          |
          ├── IVC filter: only if true contraindication to anticoagulation
          |
          └── Compression stocking + elevation + early mobilisation
              Duration: min 3 months (extend if unprovoked/cancer)

• Phlegmasia cerulea dolens (blue, painful, pulseless leg) - emergency thrombectomy/CDT regardless of Hb
• Haemodynamic collapse - consider massive PE, urgent CTPA
• Progressive drop in Hb despite transfusion - find and control source before anticoagulation