Question 3 of 36

Which statement concerning arterial disease is true?

To develop an acutely ischemic limb, either thrombosis in situ or embolic obstruction must occur.

You must start anticoagulant therapy in all patients who present with acute limb ischemia.

90% of emboli causing acute lower extremity ischemia arise in the abdominal aorta.

The most common site of an embolus of an upper extremity is the distal radial artery.

The diagnosis of arterio-arterial emboli may be confused with a vasculitis.

Low cardiac output may result in acute extremity ischemia without initial thrombosis or embolus. The duration of symptoms is an important prognostic determinant. Limb salvage is poor if ischemic sensory-motor deficits have been present for more than 3 hours. Antithrombotic therapy is not indicated for the nonsalvageable or gangrenous limb. Up to 90% of peripheral emboli arise in the heart. The most common upper extremity vessel involved is the brachial artery. Aneurysms of the aorta or major vessels may dislodge arterio-arterial microemboli, resulting in muscle tenderness from infarcts, skin lesions, and gangrenous toes. Endocarditis and systemic vasculitis have a different distribution of lesions and physical signs.