A patient who injects drugs is at risk for limb amputation.
Reasons for limb amputation:
(1) ischemic gangrene
(2) necrotizing cellulitis or gas gangrene
Sites of injection:
(1) inguinal region (groin)
(2) antecubital fossa
Reasons for ischemia:
(1) mycotic aneurysm/pseudoaneurysm
(2) arterial thrombosis
(3) distal emboli
(4) arteriovenous fistula
Risk factors for limb amputation:
(1) repeated injections
(2) suboptimal needle
(3) bacterial contamination of injected material, including spores of Clostridium species
(4) failure to clean the skin surface before injections
(5) coma or reduced level of consciousness
(6) delay in seeking healthcare
(7) loss of collateral circulation
(8) hypercoagulable state
