| Pulseless ExtremityFirst Things First (assess & treat for the following) - Is extremity irreversible, threatened or viable?
- Irreversible
- Cyanotic/blue
- Absent capillary refill
- Mottled/marbled
- Anesthesia/insensate
- No motor function
- No arterial or venous Doppler signals in foot
- Threatened: treat w/ sense of urgency
- Waxy/white color
- Slow capillary refill
- Moderate to severe pain
- Mildly decreased sensory & motor function
- Absent arterial Doppler signals in foot
- Venous Doppler signals present in foot
- Viable
- Pale/pallor
- Normal or mildly slowed capillary refill
- Cool
- Minimal or no pain
- Normal sensory & motor function
- Is there a palpable pulse or Doppler signal or absent Doppler signals?
- Palpate pulses in the dorsalis pedis (mid-dorsal foot) & posterior tibial (posterior to medial malleolus) positions.
- If nonpalpable, interrogate for Doppler signals w/ a continuous wave Doppler.
- Definitions
- Claudication: pain, usually in the calf or calves w/ exertion (subsides w/ rest)
- Rest pain: pain at rest, usually at night & usually over the metatarsal heads or distal foot
- Tissue loss/gangrene: usually develops in the distal watershed areas or in the immediate site of traumatic injury
 History and Physical (assess for the following): - Trauma to the extremity, sudden onset vs. long history of claudication, rest pain or tissue loss
- Embolic: 80% cardiac origin, 20% other arterial sources
- Cardiac origin of embolic sources: myocardial infarction, arrhythmia, prosthetic heart valve, endocarditis, rheumatic heart disease, cardiomyopathy, right-to-left shunts, intracardiac neoplasm
- Arterial origin of embolic sources: thrombus on plaque, aneurysm, neoplasm, cervical rib, penetrating trauma
- Thrombotic: history of underlying atherosclerosis, previous vascular surgery, previous trauma, clotting defects or hypercoagulable state, spontaneous abortions in females
- Hypovolemia w/ history of peripheral vascular disease: dry mucous membranes, decreased skin turgor, orthostatic BP changes
- Decrease in systolic pressure 10 mmHg or more or increase in pulse 15 bpm or more
- Decreased urine output (0.5 ml/kg/hr or less)
- Meds: anticoagulants (& compliance or appropriate monitoring of levels), estrogens or other prothrombotic agents
- Thorough head-to-toe pulse exam w/ comparison to contralateral limb (helps localize level of stenosis or occlusion)
- Obtain ankle-brachial index (ABI) for both lower extremities.
- Take the highest dorsalis pedis or posterior tibial systolic pressure w/ a BP cuff on the calf divided by the highest brachial artery systolic pressure.
- Normal ABI >0.9, w/ a difference or change of 0.15 between extremities considered abnormal
- Examine & note changes in tissue color, temp & neurosensory/motor function.
Diagnostic Tests - Lab studies
- PT/PTT/INR (if pt on anticoagulants or suspected coagulopathy)
- CBC
- Assess for thrombocytosis, polycythemia or indicators for possible hypercoagulable states.
- Coagulation screen
- Indicated for idiopathic or unknown etiology in a suspected hypercoagulable state
- Includes protein C, protein S, antithrombin III, anticardiolipin antibodies, resistance to activated protein C, prothrombin gene mutation, heparin-induced antibodies
- Draw prior to administration of anticoagulants.
- Renal panel
- Required if possible need for angiography or IV contrast administration (serum creatinine)
- Assists in assessing fluid/renal status
- CPK to assess degree of myonecrosis
- Noninvasive & radiographic studies
- ECG
- Evaluate cardiac rhythm & signs of ischemia.
- Compare w/ previous studies.
- Echocardiography
- If suspicious for cardiogenic source in acute embolic disease
- Transthoracic (TTE) study initially & obtain transesophageal (TEE) study if visualization inadequate, especially left atrial appendage
- Bubble study may be helpful in identifying presence of right-to-left shunt (possible path for paradoxical emboli).
- Segmental studies (noninvasive vascular lab)
- In cases of chronic claudication or known peripheral vascular disease in viable limbs
- Helps identify level of occlusion or stenosis
- Duplex scanning of aorta, iliac & femoral arteries versus CT arteriography
- Helps identify aneurysms & sources of intra-arterial thrombus/emboli
- For pts w/out cardiac history or symptoms & w/ normal ECG
- Arteriography
- Indicated if echocardiogram is negative
- Helps localize responsible arterial source of emboli & provides a map of distal arterial circulation
General Management Principles - First determine limb viability.
- Thorough history & physical as previously outlined
- If limb is irreversibly ischemic, it is an unlikely candidate for embolectomy or other thrombolytic or endovascular procedure.
- If limb is threatened, proceed w/ urgency.
- If limb is viable, may be able to follow the above diagnostic regimen
- Anticoagulation
- Usually w/ IV unfractionated heparin sodium to achieve systemic anticoagulation
- Screen pts for contraindications for anticoagulation (GI bleed, intracranial hemorrhage, recent major surgery, heparin antibodies).
- Used to prevent distal propagation of thrombus & occurrence of additional embolic events
Specific Treatment - Thrombolytic therapy
- Limited to pts in whom the embolic debris is thrombus
- Tissue plasminogen activator (t-PA) most commonly used
- These agents do not dissolve atherosclerotic plaque or cholesterol emboli, although it may not be clear prior to therapy whether embolic debris is dissolvable thrombus or atherosclerotic plaque.
- Interventional percutaneous mgt
- No prospective studies exist that document the superiority of percutaneous interventional therapy over open surgical therapy for acute emboli.
- Mechanical thrombectomy devices employ various suction or fragmentation techniques for thrombus removal.
- Percutaneous transluminal angioplasty (PTA) employs small catheter-based balloons w/ or w/out the combination of stent placement for treatment of select pts w/ limited or focal disease of the iliac arteries (limited use for infrainguinal disease).
- Surgical mgt
- Balloon catheter embolectomy after cutdown & exposure of femoral or popliteal arteries is used to quickly remove emboli & restore in-line blood flow to extremity.
- In vessels w/ underlying atherosclerosis, further therapy may be required.
- Arterial bypass w/ autogenous vein or prosthetic graft may be required if there is severe underlying disease in affected vessel.
- Direct endarterectomy & patch angioplasty may be employed to treat a focal atherosclerotic stenosis or occlusion.
- Four-compartment fasciotomy (anterior, lateral, deep & superficial lower extremity compartments) if indicated for compartment syndrome secondary to prolonged ischemia
Ongoing Assessment - What to follow:
- Carefully examine & document distal extremity blood flow (pulses, Doppler signals, ABI’s).
- Follow clinical exam & course for symptoms of reperfusion injury (see “Complications” section).
- Careful & frequent assessment of limb for evidence of compartment syndrome (by clinical exam or individual compartment pressure measurements)
- Continue or initiate workup for underlying etiology or embolic source if not already initiated.
Complications - Irreversibly ischemic limbs
- Gangrene/severe tissue loss
- May necessitate limb amputation to a viable level
- Sepsis/infection
- Amputation may be required emergently for ascending infection (wet gangrene vs. necrotizing fasciitis vs. sepsis).
- Reperfusion syndrome/injury
- Manifestations
- Abrupt & rapid metabolic acidosis
- Release of oxygen radicals
- Treatment
- Anticipate acidosis intraoperatively & generously administer fluid & bicarbonate.
- Administer mannitol as oxygen/hydroxy radical scavenger.
- Administer fluids, glucose & insulin to drive potassium intracellularly.
- Maintain high hourly urine output w/ alkalinization of urine (pH >6.5) in early reperfusion period to reduce or prevent myoglobinuria & renal failure.
- Compartment syndrome
- Manifestations
- Neuro findings include pain out of proportion to the initial injury or surgical pain, paresthesias or hypesthesias.
- Muscular findings include weakness, paralysis, tenderness or pain w/ passive stretching.
- Vascular findings include diminished or absent distal pulses (but normal pulses do not preclude the presence of compartment syndrome).
- Occurs when interstitial pressure exceeds capillary perfusion pressure, creating inadequate tissue perfusion
- Compartment pressures >30-40 mmHg are confirmatory.
- Treatment
- Immediate four-compartment fasciotomy
Author - Written by Andy C. Chiou, MD
- Revised by Jason S. Lees, MD
Pulseless Extremity is a sample topic found in
Anesthesia Central.
To find other Anesthesia Central topics
please login or purchase a subscription. | |
CrossLinks