Gangrene

Question 1

Define gangrene.

Answer 1

Gangrene is a complication of necrosis characterised by the decay of body tissues. There are two major categories: infectious gangrene (wet gangrene) and ischaemic gangrene (dry gangrene).

Question 2

Explain the aetiology/risk factors of gangrene.

Answer 2

Diabetes
Smoking
Atherosclerosis
Renal disease
Drug and alcohol abuse
Malignancy
Trauma or abdominal surgery
Contaminated wounds
Malnutrition
Hypercoagulable states
Prolonged use of tourniquets

Question 3

Summarise the epidemiology of gangrene.

Answer 3

Gangrene occurs equally in men and women. Type I necrotising fasciitis occurs most commonly in patients with diabetes and patients with peripheral vascular disease. It is the most common form of necrotising fasciitis in the general population.

Question 4

Recognise the presenting symptoms of gangrene. Recognise the signs of gangrene on physical examination.

Answer 4

Pain
Oedema
Skin discoloration
Crepitus (gas gangrene)
Diminished pedal pulses and ankle-brachial index (ischaemic gangrene)
Low-grade fever and chills (infectious gangrene)

Question 5

Identify appropriate investigations for gangrene and interpret the results.

Answer 5

FBC
Comprehensive metabolic panel
Serum LDH
Coagulation panel
Blood cultures
Serum C-reactive protein
Plain x-rays
CT of affected site
MRI of affected site
Doppler ultrasonography