What is the appropriate management for an elderly male presenting with sudden onset right lower extremity edema and pain, increased warmth, inability to bear weight, and tachycardia, without a history of injury?

Acute Limb Ischemia: Immediate Management Protocol

Immediate Clinical Assessment and Action

This patient has acute limb ischemia (ALI) until proven otherwise, and you must initiate systemic anticoagulation with intravenous unfractionated heparin immediately while simultaneously arranging emergent vascular surgery consultation and CT angiography. 1, 2

The clinical presentation—sudden onset unilateral lower extremity edema, pain, increased warmth, inability to bear weight, and tachycardia in an elderly patient without trauma—represents a vascular emergency requiring intervention within 4-6 hours to prevent permanent tissue damage and limb loss. 1, 2

Critical Diagnostic Features

Assess the "6 Ps" immediately at bedside to determine limb viability: 1, 2, 3

• Pain: Present (patient unable to bear weight)
• Pallor: Assess skin color compared to contralateral limb
• Pulselessness: Check femoral, popliteal, dorsalis pedis, and posterior tibial pulses with handheld Doppler (pulse palpation alone is unreliable) 1
• Paresthesias: Test sensory function in foot and toes
• Paralysis: Assess motor strength—any motor weakness indicates Category IIb (immediately threatened limb) requiring intervention within 6 hours 1, 2
• Poikilothermia (Polar): The "increased warmth" described is atypical for ALI and raises concern for concurrent infection or alternative diagnosis, but does not exclude arterial occlusion 1

Immediate Management Steps (Within Minutes)

1. Start anticoagulation NOW: Administer intravenous unfractionated heparin bolus and continuous infusion immediately to prevent thrombus propagation during the inevitable delay while arranging imaging and intervention. 1, 2

2. Call vascular surgery emergently: Do not delay consultation for imaging—if motor weakness or paralysis is present, the patient requires immediate surgical intervention even before imaging. 2, 3

3. Order CT angiography of entire lower extremity: CTA is the preferred initial imaging modality, providing rapid anatomic detail of the entire arterial circulation including the level of occlusion, degree of atherosclerotic disease, and below-knee vessel patency—all critical for immediate revascularization planning. 1, 2, 3

Differential Diagnosis Considerations

While ALI is the primary concern, the "increased warmth" is unusual and warrants consideration of: 4

• Deep venous thrombosis (DVT): Can present with unilateral leg swelling, warmth, and pain, but typically does not cause inability to bear weight or tachycardia unless massive or complicated by pulmonary embolism. 4
• Septic arthritis or necrotizing soft tissue infection: The tachycardia and low-grade fever (99.1°F) could suggest infection, but the distribution from calf to foot and inability to bear weight favor vascular etiology. 4
• Phlegmasia cerulea dolens: Massive DVT causing arterial compromise from venous hypertension—presents with severe pain, edema, and cyanosis.

However, the acute presentation with inability to bear weight and systemic signs (tachycardia) in an elderly patient mandates treating this as ALI first. 1, 2

Imaging Strategy

CT angiography with IV contrast is the diagnostic test of choice: 1, 2, 3

• Provides rapid diagnosis (scan time <5 minutes)
• Evaluates entire arterial tree from aorta to pedal vessels
• Identifies occlusion level and underlying atherosclerotic disease
• Guides revascularization strategy (endovascular vs. surgical)
• Can be performed even with renal dysfunction—the benefit of limb salvage outweighs nephrotoxicity risk in this emergency 2, 3

Do NOT order: 2, 3

• Ankle-brachial index (ABI) as primary diagnostic test—it only confirms arterial occlusion but provides no anatomic detail for intervention planning 1
• Duplex ultrasound—operator-dependent, time-consuming, and inadequate for acute limb ischemia evaluation 3

Revascularization Planning

Once CTA confirms arterial occlusion: 1, 2

• Endovascular-first approach is preferred for most patients (catheter-directed mechanical thrombectomy ± thrombolysis), with similar 1-year limb salvage and survival rates compared to open surgery but lower 30-day mortality 1, 2
• Surgical thromboembolectomy is indicated if endovascular approach fails or if patient has Category IIb/III ischemia with motor deficit requiring immediate flow restoration 1
• The goal is prompt restoration of direct pulsatile flow to at least one pedal artery 2

Critical Pitfalls to Avoid

• Do not delay anticoagulation while obtaining imaging or awaiting vascular consultation—heparin should be started within minutes of presentation. 1, 2
• Do not dismiss this as cellulitis or DVT based on warmth and edema—the inability to bear weight and acute presentation demand arterial evaluation. 3, 4
• Do not wait for "complete workup" if pulses are absent or diminished—time is tissue, and delays beyond 4-6 hours dramatically increase amputation risk. 1, 2
• Do not order echocardiography acutely—while useful later to identify embolic sources (atrial fibrillation, ventricular thrombus), it is not part of the acute workup and delays definitive treatment. 3

Post-Revascularization Management

After successful revascularization: 2, 3

• Continue anticoagulation with warfarin (target INR 2.0-3.0) or direct oral anticoagulant for at least 3-6 months depending on etiology 5
• Add antiplatelet therapy (aspirin 75-100 mg daily) unless contraindicated 1, 2
• Optimize cardiovascular risk factors: statin for LDL <55 mg/dL, blood pressure <130/80 mmHg, glycemic control if diabetic 2
• Follow-up within 2 weeks to assess limb perfusion, wound healing, and renal function 2