Gangrene and necrotising fasciitis

Question 1

define gangrene?

Answer 1

• tissue necrosis can be either wet or dry

Question 2

what is necrotizing fasciitis?

Answer 2

• a life-threatening disease that spreads rapidly across the fascial places

Question 3

what is the aetiology of gangrene?

Answer 3

caused by

• tissue ischemia
• physical trauma
• thermal injury
• gas gangrene is caused by clostridia perfingens

Question 4

what is the aetiology of necrotizing fasciitis?

Answer 4

• polymicrobial involving streptococci, staphylococci, Bacteroides, and coliforms

Question 5

what are the risk factors for both necrotizing fasciitis and gangrene?

Answer 5

Diabetes
Peripheral vascular disease
Leg ulcers
Malignancy
Immunosuppression
Steroid use
Puncture/surgical wounds

Question 6

what is the epidemiology of gangrene and necrotizing fasciitis?

Answer 6

• gangrene is common

- necrotising fasciitis and gas gangrene are uncommon

Question 7

presenting symptoms of gangrene?

Answer 7

• pain
• discoloration
• often affecting extremities

Question 8

what are the presenting symptoms of necrotizing fasciitis?

Answer 8

• pain

- often seems severe and out of proportion to the physcial signs

Question 9

general signs of gangrene on examination?

Answer 9

• painful

- gangrenous tissue is black due to hemoglobin breakdown

Question 10

signs of wet gangrene?

Answer 10

• the tissue becomes boggy with associated ous and has a very strong odor

Question 11

signs of dry gangrene?

Answer 11

• the spreading infection and destruction causes overlying oedema, discoloration and crepitus

Question 12

what are the signs of necrotizing fasciitis?

Answer 12

• area of erythema and oedema
• Haemorrhagic blisters may be present
• signs of systemic inflammatory response

Question 13

investigations for gangrene and necrotizing fasciitis?

Answer 13

• bloods (FBC, Us and Es, glucose, CRP, blood culture)
• wound swabs
• x-ray of the affected area (can show the gas in gas gangrene)