■ Paralysis (indicates limb-threatening ischemia)
■ Presence of light touch sensation indicates tissue viability.
DIFFERENTIAL
■ Atheroembolism:Microembolifrom proximal atherosclerotic plaques or
aneurysms
■ Lodge in distalsmall vessels
■ “Blue toe syndrome”is classic presentation
■ Arterial pulses are maintained
■ Acute thrombotic occlusion (thrombosis-in-situ)
■ Arterial vasospasm
■ Raynaud’s disease:
■ Vasospasm of distal small arteries
■ Characteristic bilateral triphasic response to cold or emotion:Fingers
become white, blue, then red
■ Resolves spontaneously, benign course
■ Vasculitis
DIAGNOSIS
■ Clinical diagnosis based on history and examination
■ Doppler ultrasonography
■ Normal doppler arterial signal is triphasic.
■ Angiography is confirmative.
■ Abrupt cutoff in disease-free artery
TREATMENT
■ Immediate heparinization
■ Surgical embolectomy
■ The likelihood of return to normal limb function is minimal after
4–6 hours of occlusion.
ACUTETHROMBOTICOCCLUSION(THROMBOSIS-IN-SITU)
Acute thrombotic occlusion is associated with advanced atherosclerotic disease
the vast majority of the time. Because these patients have developed collateral
circulation, the obstruction is less commonly limb-threatening.
PATHOPHYSIOLOGY
■ Plaque rupture or endothelial erosion →thrombus formation →distal
ischemia.
■ Degree of ischemia is determined by extent of collateral flow, duration of
obstruction, extent of obstruction.
■ Other less common causes include trauma, vasculitis.
SYMPTOMS/EXAM
■ Limb ischemia as described above.
■ Symptoms are often less dramatic and less intense because of collateral
arterial flow.
DIFFERENTIAL
■ Most important diagnosis to exclude is arterial thromboembolism.
■ Other diagnoses include atheroembolism, arterial vasospasm, vasculitis.
CARDIOVASCULAR EMERGENCIESThe five Ps of acute
arterial occlusion:
Pain
Pallor
Paresthesias
Pulselessness
ParalysisNormal doppler arterial signal
is triphasic.In acute arterial occlusion,
surgical embolectomy must
occur within 4—6 hours.