Necrotising fasciitis Flashcards
What is nec fasc
severe and rapidly progressive soft tissue infection that causes necrosis of the subcutaneous tissues and fascia, sometimes also affecting the muscle.
What is fourniers gangerne
Nec fasc of genitals
Management of nex fasc
Surgical debridement and antibiotics
Ass comorbidities with necfasc
Diabetes - 60%
CKD - higher mortality
Cirrhosis
Chronic HF
Obesity
Alcohol abise
SLE
immunodeficiency eg HIV, chemo
What often pre disposes nec fasc
Deep traumatic wound allowing bacterial entry
Type I nec fasc
Polymicrobial
Multiple anaerobic species
Esp affects multiple comorbidities
Trunk or perineum
Majority of cases
What is type II nec fasc
Monomicrobial - Strep pyogenes
Younger patients, limbs
TypeIII nec fasc
Monomicrobial - clostridium species (normally vibrio)
IVDUs
Type IV nec fasc
Fungal NF, mainly candida
Immunocompromised patients
Particuarly aggressive and extensive
Progression of Nec fasc signs
Ischaemia from thrombosis -> intense pain -> hypotheria/anaesthesia as progresses
Early clinical features of necrotising fascitis
Swelling (80%)
Pain (79%)
Erythema (70%)
Induration
How is NF characterised
Pain severe and exaggerated from what normally expect from soft tissue infection
Features of nec fasc later stage
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
Score for NF
Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC)
Based on serum values
What Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) score suggests high risk for nec fasc
> 8
6-7 = intermediate risk
What criteria tested in Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC)
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
Investigations nec fasc
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
What is polyderma gagrenosum and how does it differ form NF
AI ulcerative skin condition - necrosis and bullae formation
Progresses in days not hours
Ass w AI conditions
Antibiotic therapy regime for NF
Based on microoganisms found and local guidleines
General:
IV Flucloxacillin
IV Benzylpenicillin
IV Metronidazole
IV Clindamycin
IV Gentamicin
