Necrotising fasciitis

Question 1

What is nec fasc

Answer 1

severe and rapidly progressive soft tissue infection that causes necrosis of the subcutaneous tissues and fascia, sometimes also affecting the muscle.

Question 2

What is fourniers gangerne

Answer 2

Nec fasc of genitals

Question 3

Management of nex fasc

Answer 3

Surgical debridement and antibiotics

Question 4

Ass comorbidities with necfasc

Answer 4

Diabetes - 60%
CKD - higher mortality
Cirrhosis
Chronic HF
Obesity
Alcohol abise
SLE
immunodeficiency eg HIV, chemo

Question 5

What often pre disposes nec fasc

Answer 5

Deep traumatic wound allowing bacterial entry

Question 6

Type I nec fasc

Answer 6

Polymicrobial
Multiple anaerobic species
Esp affects multiple comorbidities
Trunk or perineum
Majority of cases

Question 7

What is type II nec fasc

Answer 7

Monomicrobial - Strep pyogenes
Younger patients, limbs

Question 8

TypeIII nec fasc

Answer 8

Monomicrobial - clostridium species (normally vibrio)
IVDUs

Question 9

Type IV nec fasc

Answer 9

Fungal NF, mainly candida
Immunocompromised patients
Particuarly aggressive and extensive

Question 10

Progression of Nec fasc signs

Answer 10

Ischaemia from thrombosis -> intense pain -> hypotheria/anaesthesia as progresses

Question 11

Early clinical features of necrotising fascitis

Answer 11

Swelling (80%)
Pain (79%)
Erythema (70%)
Induration

Question 12

How is NF characterised

Answer 12

Pain severe and exaggerated from what normally expect from soft tissue infection

Question 13

Features of nec fasc later stage

Answer 13

Rapid progression of lesion
Blister and bullae (serous then blood)
Failure to respons to broad spec antibiotics
Grey, dusky skin = necrosis
Skin crepitus
Diarrhoea and vomitting
Systemic features - tachycardia, fever, hypotension, tachypnoea
Signs of sepsis and organ dysfunction incl altered mental status

Question 14

Score for NF

Answer 14

Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC)
Based on serum values

Question 15

What Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) score suggests high risk for nec fasc

Answer 15

> 8
6-7 = intermediate risk

Question 16

What criteria tested in Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC)

Answer 16

Hb (g/dL) <11 = 2, >13.5 = 0
White cell count (x10^9/L) >25 = 2, <15 = 0
Sodium (mmol/L) <135 - 2
Creatinine (µmol/L) >141 - 2
Glucose >10 - 1
C-reactive protein >150 - 4

Question 17

Investigations nec fasc

Answer 17

Bloods - used in scorinG - Hb, WCC, Na, creatinine, glucose, CRP
Wounf culture
Palin X rays - SC gas
CT and MRI - asymmetrical fascial thicking w fluid collection and gas tracking
Incisional biopsy w frozen section evaluation - necrosis, microroganisms

Question 18

What is polyderma gagrenosum and how does it differ form NF

Answer 18

AI ulcerative skin condition - necrosis and bullae formation
Progresses in days not hours
Ass w AI conditions

Question 19

Antibiotic therapy regime for NF

Answer 19

Based on microoganisms found and local guidleines
General:
IV Flucloxacillin
IV Benzylpenicillin
IV Metronidazole
IV Clindamycin
IV Gentamicin