Orthopaedic Infection / Week 4 Elective Surgery Flashcards
the most common bacteria to infect an arthoplasty
its a draw —– staph epidermidis and staph aureas
name 2 soft tissue infections
cellulitis
necrotizing fasciitis
what is the anaerobic infection that may occur in an open fracture in a muddy farm accident?
Gram positive bacilli – clost perfringens .
Metronidazole (penicillin potentially too). Gentamicin wouldn’t work.
how do you test for osteomyelitis?
bone biopsy
pathogenesis of tetanus?
The spastic paralysis induced by the toxin is due to the blockage of neurotransmitter release from spinal inhibitory interneurons
Tx of a dog bite causing tetanus?
Debridement
IV Penicillin +/- metronidazole
Antitoxin (Ig) + Booster vaccination
alpha haemolytic strep (2)
what colour?
strep viridans
strep pneumoniae
GREEN
what type of haemolysis is Group B Strep?
What the other name for Group B strep?
What type of infection does it cause?
beta haemolysis (clear)
“Agalactiae”
Group B strep causes neonatal meningitis
what is Corynebacterium diphtheriae?
a aerobic small bacilli causing diptheria
what is Listeria monocytogenes? what does it cause
a small aerobic bacilli that can cause meningitis
2 different large aerobic bacilli?
bacillus cereus (food poisoning) bacillus anthracis (anthrax)
aeorobic bacteria : coccia and bacilli
within bacilli there are 3 types of clostridium, what are they?
Cl. tetani (tetanus)
Cl. perfringens (gas gangerene)
Cl. difficile (antibiotic associated colitis)
what is involucrum?
new bone that forms round an area of necrosis
what is sequestrum?
a fragment of dead bone
what is brodie’s abscess?
subacute osteomyelitis, that has an incidious onset
basically there is an abscess which is surrounded by thin rim of sclerotic bone
2 main sites of chronic osteomyelitis?
spine (mainly lumbar) and pelvis
infection can spread to bone causing osteomyelitis. where does it typically come from?
- lung - including pulmonary TB –> spine
2. UTI
how long does it take for debrided bone to become vascularised again?
6 weeks
if you have been giving IV fluclox for staph aureas but you want to switch to oral, what do you give?
oral Doxycycline
what if they have a strep infection but are allergic fluclox?
IV vancomycin
antibiotic for gram negatives?
gentamicin
what are SAPHO and CROMO?
types of recurrent MULTIFOCAL osteomyelitis, associated with systemic upset
Sapho - adults
chromo - kids
vertebral osteomyelitis can be a confusing presentation. why?
what additional features can occur?
only half have fever, and in 90% the pain is slow onset
there may be psoas/ epidural abscesses.
drain and give 6 weeks of antimicrobials
what is pyomyositis?
a tropical bacterial skeletal muscle infection
tropical in geographical sense - the actual causing bacteria is staph aureas in 90% of cases. normally have an abscess.
what is myositis?
NON BACTERIAL SKELETAL MUSCLE INFECTION…ie
viral - diffuse
fungal - focal
parasitic eg schistosomiasis.
What is Pott’s disease?
Another name for Vertebral TB, which can cause Vertebral Osteomyelitis.
not infectious + no cough
treatment of Staph aureas’ PVL??????
linezoid and clindamycin
what type of haemolysis is Group A strep?
what is it’s other name?
Beta haemolysis (clear) Strep pyogenes
the duration of antibiotics given for staph aureus infection depends on where it is….
skin / soft tissue ?
blood?
bone?
skin = 7 days blood = 14 days bone = 6 weeks
flucloxacillin is given for staph aureus. what is given for MRSA?
Vancomycin
which bone is most commonly targeted by haematogenous spreading osteomyelitis?
what other part of the body is at risk of infection?
the femur
the heart valves, causing endocarditis
what bacteria is most common in haematogenous spreading osteomyelitis?
staph aureus
what specific groups of people get osteitis pubis infections (OM) ?
- athletes (acute)
2. post-urogynae operations
sickle cell anaemia patients get osteomyelitis, caused by staph aureas and what other infection
clue: common food bacteria
salmonella
what is the “empirical” treatment of septic arthritis
- in adults
- in children
Flucloxacillin (as staph aureus is most common)
Add Cefriaxone to cover H.influenza in children
Gram + strictly anaerobic rods with spores - what am I ??
tetanus
clostridium tetani
