Infection Flashcards
What is Newman’s classification of septic arthritis?
A = pathogen isolated from joint B = pathogen isolated from blood in context of a red, hot joint C = no pathogen isolated but presence of histiological/radiological evidence of infection OR turbid fluid aspirated from joint D = post-mortem isolation of pathogen
Give some risks for septic arthritis.
- RA
- OA
- immunocompromised
- iatrogenic trauma
- trauma
- joint prostheses
- IVDU
- alcoholism
- cutaneous ulcers
What is the aetiology of septic arthritis?
4-10/100,000p-y
Most common organism = Staph. aureus
Sickle-cell anaemia = Salmonella spp.
What investigations are needed in septic arthritis?
BLOODS:
- ESR/CRP
- WCCs
- blood culture
- U&Es
- LFTs
- serum procalcitonin
BIOPSY:
- joint fluid aspirate for Gram staining
IMAGING:
- radiographs
- Tch bone scan
- CT
- MRI
What is the management of septic arthritis?
Admit for supportive care
IV Abx = flucloxacillin/gentamicin + clindomycin
Aspirate fluid +/- washout
What are the Kocher criteria?
Differentiate septic arthritis from transient synovitis in children
Non-weightbearing on affected side = +1
ESR>40 = +1
Temp>38.5 = +1
WCCs > 12,000 = +1
1 = 3% likelihood of septic arthritis 2 = 40% 3 = 93% 4 = 99%
What is osteomyelitis?
Progressive inflammatory destruction due to bone infection
- most commonly Staph. aureus
- joint prosthesis infection forms biofilm
- extent: superficial (one cortex involved) to localised (one cortex + medulla) to diffuse/segmented (two cortices + medulla)
O/E:
- pain
- fever
- erythema
- tenderness
- oedema
- chronic limp
- sinus
What is the aetiology of chronic fasciitis?
- diabetes
- immunocompromised
- alcoholism
- peripheral vascular disease
- trauma
What is Fournier’s gangrene?
Necrotising fasciitis/gangrene usually affecting the perineum
What is a Brodie’s abscess?
Type of subacute osteomyelitis which may persist for years before converting to a frank osteomyelitis.
Abscess is moving away from epiphysis, therefore not affecting growth
Contained to localised area and walled off by fibrous granulation tissue
What is the most common organism implicated in dog bites?
Pasturella multocida
What are the BAPRAS guidelines for Abx cover for leg fractures?
Within 3hrs of injury give 1.2g of co-amoxiclav OR cefuroxime 1.5g 8hrly OR clindomycin 600mg 6hrly in penicillin allergy
