Peripheral Embolism

An otherwise stable patient with atrial fibrillation who suddenly develops severe unilateral leg pain, pallor, and a cool foot may have a limb emergency, not a musculoskeletal problem. A clot or other embolic material can travel from the heart or aorta and lodge at an arterial narrowing, abruptly cutting oxygen delivery. The immediate question is whether the limb is viable, threatened, or irreversible; sensory and motor loss plus arterial and venous Doppler findings establish the Rutherford stage and set the clock. Start IV unfractionated heparin unless contraindicated, involve vascular surgery, and do not let imaging delay emergency revascularization of a Rutherford IIb limb. After flow returns, the priority shifts to detecting reperfusion injury and compartment syndrome. In Canadian practice, activate the local provincial and hospital vascular-emergency pathway; prescribing authority and the heparin nomogram follow applicable provincial and institutional policy.