Gas gangrene

Question 1

Wet gangrene

Answer 1

infectious gangrene, necrotic area is poorly demarcated from the surrounding tissue and patients are pyrexial/septic.

Includes
- necrotising fasciitis (infection of the subcutaneous fascia and fat)
- gas gangrene (caused by Clostridium)
- gangrenous cellulitis (in the immunocompromised).

Mx: Surgical debridement/amputation + broad-spectrum intravenous antibiotics

Question 2

Define dry gangrene

Answer 2

ischaemic gangrene and occurs secondary to chronically reduced blood flow

Question 3

Dry gangrene: causes

Answer 3

1. atherosclerosis (in association with peripheral arterial disease)
2. thrombosis (in association with vasculitis and hypercoagulable states)
3. vasospasm (in association with cocaine use and Raynaud’s)

Answer 4

a clinical condition of ischemic and necrotic tissue, often circumferential around a digit or extremity

Question 5

Define gangrene

Answer 5

a clinical condition of ischemic and necrotic tissue, often circumferential around a digit or extremity

Question 6

Presentation of dry gangrene

Answer 6

necrotic area is well demarcated from the surrounding tissue and patients are do not show signs of infection
Auto-amputation occurs in most cases (self-detachment)

Question 7

Gas gangrene: pathophysiology

Answer 7

gas production is caused by the bacterial growth and its resulting greater carbohydrate break-down causes acid and gas creation in the affected area

Question 8

Gas gangrene: complications

Answer 8

Toxic shock
Amputation
Death

Question 9

Gas gangrene: most common bacterium

Answer 9

Clostridium perfringens

Question 10

Gas gangrene: clinical features

Answer 10

acute onset of severe localised pain
skin is darkened and there is a spreading erythema, while the patient is hot to touch and the infected area gives off a distinctive and potent smell.

Answer 11

Debridement + abx
If amputation –> large margin to avoid redevelopment of GG
Hyperbaric O2 chamber as bacteria are anaerobic and O2 may be lethal to them