Ischemic Disorders

Question 1

Dry gangrene

Answer 1

Due to insufficient blood flow to tissue, typically from atherosclerosis

Early signs are a dull ache, cold and pallor of flesh. As necrosis sets in, tissue (usually toe) becomes bluish-black, dry, and shriveled. Diabetes, vasculopathy, and smoking are risks

Question 2

Wet gangrene

Answer 2

Involves bacterial infection usually with skin flora

Tissue appears bruised, swollen or blistered with pus

Question 3

Gas gangrene

Answer 3

Due to C. perfringens infection

Typically at site of recent injury or surgery. Presents with swelling around injury and with skin that turns pale and then dark red.

Bacteria are rapidly destructive of tissue, producing gas that separates healthy tissue and exposes it to infection.

Medical emergency

Question 4

Tx of gangrene

Answer 4

1) Surgical debridement, with amputation if needed. ABX alone do not suffice by virtue of inadequate blood flow, but they should be given as adjuvant to surgery
2) Gas gangrene can be treated with hyperbaric O2 which is toxic to the anaerobe. Susceptible patients should maintain careful foot care and should avoid trauma.