Rosen & Barkin's 5-Minute Emergency Medicine Consult (533 page)

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Authors: Jeffrey J. Schaider,Adam Z. Barkin,Roger M. Barkin,Philip Shayne,Richard E. Wolfe,Stephen R. Hayden,Peter Rosen

Tags: #Medical, #Emergency Medicine

BOOK: Rosen & Barkin's 5-Minute Emergency Medicine Consult
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CODES
ICD9
  • 356.9 Unspecified hereditary and idiopathic peripheral neuropathy
  • 782.0 Disturbance of skin sensation
ICD10
  • G62.9 Polyneuropathy, unspecified
  • R20.0 Anesthesia of skin
  • R20.2 Paresthesia of skin
PERIPHERAL VASCULAR DISEASE
Sally A. Santen
•
Samantha R. Hauff
BASICS
DESCRIPTION
  • Obstruction of ≥1 of the peripheral arteries secondary to embolism or thrombus
  • Caused by atherosclerosis or embolus
  • Patients with PAD may also have coronary artery and cerebrovascular disease.
  • Epidemiology:
    • Risks factors (selected):
      • Age
      • Smoking
      • Diabetes
      • Hyperlipidemia
      • HTN
    • Associated with morbidity and mortality from other forms of atherosclerosis (coronary artery disease, stroke)
    • Complications:
      • Aneurysm
      • Thrombosis
      • Ulceration
      • Limb loss
  • Chronic arterial insufficiency (CAI):
    • Progressive obstructing atherosclerotic disease causing subacute ischemia and pain (claudication)
    • 10% develop critical leg ischemia.
  • Acute arterial insufficiency (AAI):
    • Caused by arterial thrombosis (50%) or embolism
    • Causes acute limb ischemia with signs and symptoms of the 6 Ps (below)
  • Atheroembolism:
    • Caused by rupture or partial disruption of an atherosclerotic plaque (aorta, femoral, iliac)
    • Gives rise to cholesterol emboli that shower and obstruct arteriolar networks
    • May be precipitated by invasive arterial procedures such as cardiac catheterization
ETIOLOGY
  • Obstruction by atherosclerotic plaques (CAI)
  • Arterial thrombosis
  • Arterial emboli:
    • Cardiac emboli from dysrhythmias, valvular heart disease, or cardiomyopathy (80%)
    • Aneurysms
    • Infection
    • Tumor
    • Vasculitis or foreign body
    • Thrombosis of plaques from pre-existing CAI
  • Atheroembolism
DIAGNOSIS
SIGNS AND SYMPTOMS
History
  • CAI:
    • Claudication:
      • Aching pain in the calves (femoropopliteal occlusion) or buttocks and thighs (aortoiliac region)
      • Occurs with activity and slowly relieved by rest or dependent positioning
      • Classic claudication presents in about 1/2 of patients with PVD.
    • Severe disease presents with limb pain at rest:
      • Usually starting in the foot
      • Rapidly progressive claudication or ulceration
  • AAI:
    • Extremity pain:
      • Sudden onset
      • Gradual increase in severity
      • Starts distally and moves proximally over time
      • Decrease in intensity once ischemic sensory loss occurs
  • Atheroembolism:
    • Complaint of cold and painful fingers or toes
    • Small atherosclerotic emboli may affect both extremities.
    • Usually related to recent arteriography, vascular or cardiac surgery
    • Multiorgan involvement is common (renal, mesentery, skin, others)
Physical-Exam
ALERT

Sudden onset of pain and pallor in extremity is limb and life threatening.

  • CAI:
    • Absent or decreased peripheral pulses
    • Delayed capillary refill with cool skin
    • Increased venous filling time
    • Bruits
    • Pallor and dependent rubor of the leg
    • Muscle and skin atrophy
    • Thickened nails and loss of dorsal hair
    • Ulcerations (especially toes or heels) or gangrene with severe disease
  • AAI:
    • 6 Ps:
      • Pain (1st, sometimes only symptom)
      • Pallor
      • Pulselessness
      • Poikilothermic
      • Paresthesias (late finding)
      • Paralysis (late finding)
    • Identification of a source of a possible embolic process is crucial (atrial fibrillation, cardiomegaly).
  • Atheroembolism:
    • Ischemic and painful digits
    • “Blue toe syndrome”
    • Livedo reticularis
ESSENTIAL WORKUP
  • CAI:
    • Ankle–brachial index (ankle systolic BP divided by higher arm systolic BP)
    • Bedside test to determine whether CAI is present (see NEJM video reference)
    • Ratio of <0.9 is abnormal and <0.4--5 indicates severe disease.
    • Calcific arteries (diabetes) can have false negative ABI or elevated ABI (>1.3).
  • AAI:
    • Physical diagnosis using the 6 Ps
    • Those with acute-on-chronic arterial insufficiency tolerate limb ischemia better than those without CAI, due to well-developed collateral circulation.
  • Atheroembolism:
    • Clinical diagnosis: Affected areas painful, tender, and may be either dusky or necrotic
    • Workup may investigate source of emboli with duplex US, CT angiogram, EKG.
DIAGNOSIS TESTS & NTERPRETATION
Lab
  • CBC and platelets
  • Electrolytes, BUN, creatinine, glucose
  • Coagulation studies
  • Creatine phosphokinase to evaluate for ischemia.
  • Special tests for suspected etiologies:
    • Hold blood for hypercoagulable studies
    • Sedimentation rate, CRP for vasculitis
    • Blood cultures for endocarditis
Imaging
  • Doppler US:
    • Visualizes both venous and arterial systems
    • Identifies level of arterial occlusion, as well as thrombosis and aneurysm
    • Sensitivity and specificity >80–90% for occlusion of vessels proximal to the popliteal vessels
  • Plethysmography/segmental pressure measurements:
    • Uses measurements of the volume and character of blood flow to detect areas of CAI
    • Less widely available than US, therefore requires an experienced technician
    • Approximates US in sensitivity and specificity
  • Angiography:
    • Determines details about the anatomy, including the level of occlusion, stenosis, and collateral flow
    • Useful where the diagnosis of AAI is uncertain or before emergent bypass grafting
    • Advantage is intervention (atherectomy, angioplasty, or intraluminal thrombolytics) can be done at the time of diagnosis.
  • CT angiogram:
    • CT is useful for diagnosis of occlusive aortic disease or dissection.
    • Rapidly available and reliable
    • Many centers have moved to CT angiogram as the 1st-line diagnostic tool. The decision for operative or angiographic intervention is based on the CT angiogram.
    • Requires contrast, therefore may not be 1st line for patients with renal insufficiency
  • MRI:
    • Sensitive for evaluation of CAI and dissection
    • Disadvantages are that MRI is time consuming and expensive.
DIFFERENTIAL DIAGNOSIS
  • Acute thrombosis or emboli
  • Arterial dissection
  • Deep venous thrombosis
  • Venous insufficiency
  • Compartment syndrome
  • Buerger disease
  • Spinal stenosis
  • Neuropathy
  • Bursitis
  • Arthritis
  • Reflex sympathetic dystrophy
TREATMENT
PRE HOSPITAL
  • Maintain hemodynamic stability with fluids.
  • Apply cardiac monitor.
  • Place the ischemic limb at rest and in a dependent position.
  • Provide oxygen if low oxygen saturation or pulmonary symptoms.
INITIAL STABILIZATION/THERAPY
  • IV fluid bolus for hypotension
  • EKG, monitor, pulse oximetry
  • Supplemental oxygen
  • Pain control
  • Avoid temperature extremes
ED TREATMENT/PROCEDURES
  • CAI:
    • Antiplatelet therapy with 75 or 325 mg of aspirin or clopidogrel (75 mg/day) may be used as 1st-line treatment. Dual therapy has not been shown to improve outcomes, although may be indicated in other forms of atherosclerosis.
    • Other approved drugs include: Cilostazol 100 mg BID, dipyridamole 200 mg BID, pentoxifylline 400 mg TID
    • Revascularization depending on the severity and location of obstruction:
      • Balloon angioplasty
      • Atherectomy
      • Bypass grafting
    • Risk-factor modification:
      • Tobacco cessation
      • Aggressive management of hyperlipidemia, HTN, diabetes
      • Exercise therapy
  • AAI:
    • Limit further clot propagation with IV heparin.
    • Do not anticoagulate patients suspected of having an aortic dissection or symptomatic aneurysm.
    • Emergent consultation with vascular surgery or interventional radiology:
      • To determine which diagnostic study is best to make the diagnosis
      • To begin arrangements for possible operative therapy or other intervention
      • Options for operative therapy include thrombectomy, embolectomy, angioplasty, regional arterial thrombolysis, bypass grafting.
      • Blood flow to the affected limb must be re-established within 4–6 hr after onset of ischemic symptoms.
    • Complications of AAI include:
      • Compartment syndrome
      • Irreversible ischemia requiring amputation
      • Rhabdomyolysis, renal failure
      • Electrolyte disturbances
  • Atheroembolism:
    • Treat conservatively if a limited amount of tissue is involved and renal function is not significantly compromised.
    • No clear therapy for the ischemic digits besides supportive wound care and analgesia
    • Some studies have tried corticosteroids to decrease inflammation, statins to stabilize plaque, aspirin, or dipyridamole
    • Amputation for irreversibly necrotic toes
    • Vascular surgeon referral within 12–24 hr of ED visit
    • Prevent further embolic events by a thorough investigation and correction of the source of atheroemboli.

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