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What Are the Stages of Ischemia?

There are three main stages of acute limb ischemia, which include Stage 1 (limb is not immediately threatened, no sensory loss), Stage 2 (limb is salvageable), and Stage 3 (limb has major tissue loss or permanent nerve damage inevitable).
There are three main stages of acute limb ischemia, which include Stage 1 (limb is not immediately threatened, no sensory loss), Stage 2 (limb is salvageable), and Stage 3 (limb has major tissue loss or permanent nerve damage inevitable).

Limb ischemia is a severe blockage in the arteries of the lower extremities, which significantly reduces blood flow. Acute limb ischemia is a sudden and rapid decrease in lower limb blood flow. 

There are three main stages of acute limb ischemia: 

  • Stage 1: Viable
    • Limb is not immediately threatened
    • No sensory loss
    • No muscle weakness
    • Doppler signals of arteries and veins are audible
  • Stage 2: Threatened 
    • Stage 2a: Marginally threatened 
      • Limb is salvageable if promptly treated
      • Minimal sensory loss (toes) or no sensory loss
      • No muscle weakness
      • Doppler signals of arteries are often inaudible; veins are audible
    • Stage 2b: Immediately threatened 
      • Limb is salvageable with immediate revascularization
      • Sensory loss is more than toes, associated with rest pain
      • Mild to moderate muscle weakness
      • Doppler signals of arteries are usually inaudible; veins are audible
  • Stage 3: Irreversible 
    • Limb has major tissue loss or permanent nerve damage inevitable
    • Profound sensory loss, numbness
    • Profound weakness, paralysis 
    • Doppler signals of arteries and veins are inaudible

What Are Symptoms of Acute Limb Ischemia?

Symptoms of acute limb ischemia are often referred to as the “six Ps” and include: 

  • Pain that is located in the extremity and gradually increases in severity, but may eventually decrease due to progressive ischemic sensory loss
  • Pallor: pale or mottled skin 
  • Poikilothermia: cool skin
  • Pulselessness: diminished or absent pulse
  • Paresthesia: numbness and tingling
  • Paralysis

What Causes Acute Limb Ischemia?

Causes of acute limb ischemia include: 

  • Blockage in a blood vessel (embolism) by such as by a blood clot, a fat globule, a bubble of air or other gas, or foreign material
  • Blood clot (thrombosis)
  • Peripheral artery disease due to atherosclerosis
  • Tear in the lining of an aortic or peripheral artery (dissection)
  • Major trauma
  • Conditions that cause vasospasm 

How Is Acute Limb Ischemia Diagnosed?

Acute limb ischemia diagnosed with a patient history and physical examination. The blockages associated with limb ischemia are located using one or more of the following methods:

What Is the Treatment for Acute Limb Ischemia?

Immediate treatment is needed for limb ischemia to re-establish blood flow to the affected area and to preserve the limb.

Treatments for acute limb ischemia include: 

  • Intravenous (IV) injection of unfractionated heparin 
  • Surgical treatment 
    • Thromboembolectomy
    • Bypass surgery
  • Endovascular treatment 
    • Catheter-directed thrombolysis (CDT)
    • Percutaneous thrombus aspiration
    • Stent placement
  • Hybrid treatment that combines both therapies
References
Image Source: iStock Images

https://www.uptodate.com/contents/clinical-features-and-diagnosis-of-acute-lower-extremity-ischemia#H403210236

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326052/