Peripheral artery disease

Revision as of 16:48, 8 June 2015 by Rossdonaldson1 (talk | contribs) (Differential Diagnosis)

Background

  • Peripheral artery disease = ABI <0.9 (normal ≥1.0)[1]
  • >70% of pts are either former or current smokers[2]
  • 33% of deaths are from reperfusion injury
    • Myoglobinemia, ARF, incr CK
  • Thrombosis accounts for >80% of lower limb ischemia
  • PAD indicates systemic atherosclerosis[3]

Clinical Features

6 P's

  • Paraesthesia - With weakness are early findings and preservation of light touch is good guide to viability
  • Paralysis - impending gangrene
  • Pain - claudication or pain with leg elevation
  • Pallor
  • Pulselessness - helpful only if accompanies by skin changes
  • Poikilothermia

Physical Exam

  • Shiny, hyperpigmented skin, hair loss
  • Ulceration
    • Tend to be on foot/toes, more painful than venous ulcers
  • Cap refill >3sec

Differential Diagnosis

Foot diagnoses

Acute

Subacute/Chronic

Diagnosis

ABI

  • Measuring
    1. Position patient supine
    2. Measure SBP from both brachial arteries using cuff and handheld Doppler over the AC fossa
    3. Measure SBP from both DP and PT arteries using cuff placed just proximal to the malleoli with Doppler over artery (5-8% of normal patients have absent DP pulse)
    4. Calculate ABI on each leg by taking the highest ankle SBP divided by the highest brachial SBP and record to 2 decimal places
  • Using calculation
    • 0.91–1.30: normal
    • 0.70–0.90: mild occlusion
    • 0.40–0.69: moderate occlusion
    • <0.40: severe occlusion
    • >1.30: poorly compressible/calcified vessels

Imaging

  • Xray
    • Little use or benefit
  • Ultrasound
    • Accurate for detecting obstruction in femoral/popliteal/bypass grafts
      • Sn declines at/below the calf
    • Quality of signal (triphasic, biphasic, monophasic) is important to note
  • CTA
    • Sensitivity similar to that of conventional angiography
  • MRI
    • Limited utility in the ED setting
    • Detailed images of vasculature can be taken and plaques identified

Management

  • Chronic PAD can recieve outpatient management (by vascular)

Acute Limb Ischemia

  • Unfractionated Heparin
    • 80 units/kg bolus; then infuse 18units/kg/hr
  • ASA
  • Dependent positioning
  • Pain control
  • Fluid resuscitation and treatment of heart failure as needed to improve limb perfusion
  • Vascular surgery consultation (clot retrieval, balloon angioplasty, intraarterial tPA, stenting, bypass)

Disposition

  • Acute limb ischemia requires inpatient management
  • Chronic PAD can be managed as an outpatient

See Also

External Links

References

  1. Heald CL, et al. Ankle Brachial Index C. Risk of mortality and cardiovascular disease associated with the ankle-brachial index: systematic review. Atherosclerosis. 2006;189:61–69.
  2. Ng EL, et al. Prevalence of and risk factors for peripheral arterial disease in older adults in an Australian emergency department. Vascular. 2014; 22(1):1-12.
  3. Levy PJ. Epidemiology and pathophysiology of peripheral arterial disease. Clin Cornerstone. 2002;4:1–15.