Difference between revisions of "Peripheral artery disease"

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== Background ==
 
== Background ==
*Peripheral artery disease = ABI <0.9
+
*Peripheral artery disease = ABI <0.9 (normal ≥1.0)<ref>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.</ref>
*>80% of pts are either former or current smokers
+
*>70% of pts are either former or current smokers<ref>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.</ref>
 
*33% of deaths are from reperfusion injury
 
*33% of deaths are from reperfusion injury
 
**Myoglobinemia, ARF, incr CK
 
**Myoglobinemia, ARF, incr CK
 
*Thrombosis accounts for >80% of lower limb ischemia
 
*Thrombosis accounts for >80% of lower limb ischemia
 +
*PAD indicates systemic atherosclerosis<ref>Levy PJ. Epidemiology and pathophysiology of peripheral arterial disease. Clin Cornerstone. 2002;4:1–15.</ref>
  
== Diagnosis ==
+
==Clinical Features==
History
+
===6 P's===
*6 P's: Pain, pallor, paralysis, pulselessness, paresthesias, polar
+
*'''P'''araesthesia - With weakness are early findings and preservation of light touch is good guide to viability
**Paresthesia and weakness are early findings
+
*'''P'''aralysis - impending gangrene
**Preservation of light touch is good guide to tissue viability
+
*'''P'''ain - claudication or pain with leg elevation
**Anesthesia and paralysis = impending gangrene
+
*'''P'''allor
**Absence of pulse in pt w/ chronic disease only helpful if accompanied by skin changes
+
*'''P'''ulselessness - helpful only if accompanies by skin changes
**Pain with leg elevation
+
*'''P'''oikilothermia
*Leg claudication
+
 
Physical Exam
+
===Physical Exam===
 
*Shiny, hyperpigmented skin, hair loss
 
*Shiny, hyperpigmented skin, hair loss
 
*Ulceration
 
*Ulceration
 
**Tend to be on foot/toes, more painful than venous ulcers
 
**Tend to be on foot/toes, more painful than venous ulcers
 
*Cap refill >3sec
 
*Cap refill >3sec
 
== Work-Up ==
 
*ABI
 
**Ratio of sBP of post tibial or DP to highest brachial pressure in either arm
 
**<0.40 = potentially limb-threatening vascular disease
 
**0.41-0.90 = claudication
 
**>1.3 = noncompressible vessel (severe vascular calcification)
 
*Imaging
 
**Ultrasound
 
***Accurate for detecting obstruction in femoral/popliteal/bypass grafts
 
****Sn declines at/below the calf
 
**CTA
 
***Sensitivity similar to that of conventional angiography
 
  
 
==Differential Diagnosis==
 
==Differential Diagnosis==
 
*[[Phlegmasia Alba Dolens]]
 
*[[Phlegmasia Alba Dolens]]
 
*[[Phlegmasia Cerulea Colens]]
 
*[[Phlegmasia Cerulea Colens]]
 +
*[[Ankle fracture]]
 +
*[[Venous thromboembolism]]
  
==Treatment==
+
==Management==
 +
===Workup===
 +
====ABI====
 +
*Measuring
 +
*#Position patient supine
 +
*#Measure SBP from both brachial arteries using cuff and handheld Doppler over the AC fossa
 +
*#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)
 +
*#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
 +
 
 +
===Treatment===
 
Acute Limb Ischemia
 
Acute Limb Ischemia
 
*[[Unfractionated Heparin]]
 
*[[Unfractionated Heparin]]
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*Pain control
 
*Pain control
 
*Fluid resuscitation and treatment of heart failure as needed to improve limb perfusion
 
*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==
 
==See Also==
 
*[[Foot Diagnoses]]
 
*[[Foot Diagnoses]]
  
== Source ==
+
==External Links==
Tintinalli
+
*[http://stanfordmedicine25.stanford.edu/the25/ankle.html Stanford Medicine 25: Measuring ABI]
 +
 
 +
==References==
 +
<references/>
  
 
[[Category:Trauma]]
 
[[Category:Trauma]]
 
[[Category:Surg]]
 
[[Category:Surg]]

Revision as of 12:47, 8 June 2015

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

Management

Workup

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

Treatment

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.