CV

Acute Limb Ischemia

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Acute Limb Ischemia, Critical Limb Ischemia, Limb Threatening Ischemia

  • See Also
  1. Peripheral Vascular Disease Management
  2. Peripheral Arterial Disease
  3. Arterial Ulcer
  • History
  1. Rest pain or rest Claudication
  2. Onset rapid, sudden (embolic) or slowly progressive
  3. Cardiovascular disease (CAD, aneurysms, longstanding Diabetes Mellitus)
  4. Confounding diagnoses (e.g. raynaud's phenomena)
  • Exam
  1. Cold, painful or pale extremity
  2. Decreased or absent pulses
    1. Obtain proximal and distal pulses (bedside doppler as needed)
  3. Neurologic changes (nerves are most sensitive to ischemia)
    1. Motor weakness
    2. Sensory loss
  4. Comorbid infection findings
    1. Distinguish wet gangrene (aggressive management) from dry gangrene (chronic, outpatient management)
  • Precaution
  • Rapid evaluation and management is critical
  1. Involve Intervention Radiology and vascular surgery early in suspected Acute Limb Ischemia
  2. Irreversible neuromuscular damage occurs within 4-6 hours of warm ischemia (room Temperature)
    1. Warm ischemia for 6 hours: 10% of patients with irreversible Muscle and nerve damage
    2. Warm ischemia for 12 hours: 90% of patients with irreversible Muscle and nerve damage
  • Evaluation
  1. Focused history and exam as above
  2. Ankle-Brachial Index <0.3 (or <0.5 with other findings suggestive of Acute Limb Ischemia)
    1. Obtain arterial doppler, Ankle-Brachial Index (ABI) and Toe Pressures
    2. First-line study for most vascular surgeons
    3. False Negatives in stiff, non-compressible vessels (does not effect toe pressures)
  3. CTA Abdomen and Pelvis with limb runoff
    1. May be preferred definitive study in some centers if available (consult vascular surgery)
    2. However, additional contrast load may be significant if emergent angiogram to immediately follow
  4. Assign Rutherford Classification (see above)
  • Management
  1. Medications
    1. Aspirin 325 mg orally
    2. Unfractionated Heparin (weight based Heparin)
  2. Emergent surgical interventions
    1. Intervention Radiology for directed arterial Thrombolysis or percutaneous thrombectomy
      1. Indicated for Rutherford Class I and IIa (see above)
    2. Vascular surgery
      1. Indicated for Rutherford Class IIb and III (see above)
  • References
  1. Lin in Herbert (2014) EM:Rap 14(4): 5-7
  2. Guest and DuBose (2024) EM:Rap, 9/16/2024