Info PAD Severity

• PAD severity:

  • PAD continuum of disease progression:
  • non-critical limb ischaemia:
  • predominant S&S = ischaemic pain
  • critical limb ischaemia:
  • predominant S&S = rest pain & tissue loss or ulceration
  • we want to prevent non-critical limb ischaemia from progressing onto critical limb ischaemia
• How severity of PAD can be measured

  • Fontaine classification
  • thermal imaging
  • ankle brachial pressure index (ABPi)
  • pulse presence/absence/character - weaker pulse = more severe PAD
  • doppler & pulse volume recordings
  • angiogram (CAT, MRI or xray)
• How severity of PAD can be measured - Fontaine classification:

  • 4 levels:
  • 1: subclinical
  • subtle changes e.g. paraesthesia
  • cold extremities
  • diminished pulses
  • restless leg syndrome
  • 2: characterised by intermittent claudication - angina like pain on activity
  • 2a: intermittent claudication > 200 metres
  • 2b: intermittent claudication < 200 metres
  • 3: rest pain (initially at night)
  • 4: ischaemic ulcers or gangrene/necrosis

  
• How severity of PAD can be measured - Thermal Imaging:

  • red means warm, so shows which bits of the leg is being supplied with blood
  • blue indicates parts of the body not being supplied with blood due to a block in the artery

  
• How severity of PAD can be measured - Ankle-brachial Pressure Index = ABPi

  • systolic pressure leg artery/systolic pressure brachial artery = ABPi
  • for the leg artery you can use either the posterior tibial artery or the dorsalis pedis
  • want the SBP to be similar, but a ABPi < 90 = positive diagnosis of PAD

  
• Expected Clinical status & ABPi scores:

  • symptom free = ~ 1
  • intermittent claudication = 0.95 to 0.5
  • rest pain = 0.5 to 0.3
  • gangrene and ulceration = < 0.2
  • a score > 1.2 is a false negative - indicative of non-compressible vessel structure e.g. severe arteriosclerosis
• How severity of PAD can be measured - Doppler & Pulse Volume Recordings

  • there will be distortion in wave recordings where there is obstruction in an artery

  
• How severity of PAD can be measured - angiogram (CAT, MRI or xray)