MSK Infections Flashcards Preview

RB Y2 MSK 02 - Rheumatology > MSK Infections > Flashcards

Flashcards in MSK Infections Deck (71)
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1
Q

gram positive penicillin allergic

A

vancomycin

2
Q

staph epididermis treatment

A

vancomycin

3
Q

h influenzae treatment

A

ceftriaxone

4
Q

anaerobes treatment

A

metronidazole

5
Q

anaerobes example

A

clostridium and bacteriocides

6
Q

gram negative treatment

A

gentamicin

7
Q

gram negative examples

A

bordatella, h influenza, coliforms, h pylori, campylobacter

8
Q

adult osteomyelitis

A

inflammation of the bone and medullary cavity, usually located in one of the long bones

9
Q

how can adult osteomyelitis be classified

A

acute/chronic conitguous/haematogenous host status eg presence of vascular insufficiency

10
Q

what forms of adult osteomyelitis can progress to chronic

A

ALL

11
Q

how long must the antibiotic course for adult osteomyelitis be

A

minimum 6 weeks as can recur after treatment

12
Q

clinical approach to infection

A

clinical suspicion - history is key examination confirmation treatment

13
Q

how can infection be confirmed

A

indirect - CT scan and MRI (best) direct - bone biopsy gold standard, also surgical sample, histology wound swabs and blood cultures are not very useful except in septic patients

14
Q

what is the gold standard direct investigation for infection

A

bone biopsy

15
Q

what is the best indirect investigation for infection

A

MRI

16
Q

predispoing conditions

A
  • Sickle cell anaemia
  • IV drug user
  • DM
  • Immunosuppression
  • alcohol excess
17
Q

open fractures

A

early management is key - debridement, fixation and soft tissue cover the clinical clue is non union and poor wound healing

18
Q

infection of open fractures

A

3-25% get infected - tends to be S aureus and aerobic gram negative bacteria

19
Q

name 2 aerobic gram negative bacterias

A

pseudomonas and legionella

20
Q

diabetes/vascular insufficiency

A

are often polymicrobial and the diagnosis can be challenging are difficult to clear once infection is established

21
Q

CF of diabetes/vascular insufficiency

A

Microneurovascular dysfunction with loss of nociceptive reflex and inflammatory response - diminished sensation in feet - ischaemic toes - pressure ulcers - diabetic foot ulcer

22
Q

treatment of diabetic foot ulcers

A

debridement and antimicrobials

23
Q

what is the likely bacteria in mild to moderate diabetic foot ulcer

A

s aureus - flucloxacillin

24
Q

who is haematogenous osteomyelitis seen in

A

prepubertal children, PWID,, central lines/dialysis/elderly

25
Q

haematogenous osteomyelitis - PWID

A

can be contiguous, haematolgoical or direct inoculation. often seen at unusual sites

26
Q

haematogenous osteomyelitis - PWID organisms

A

staph and strep and often unusual pathogens

27
Q

dialysis patients with haematogenous osteomyelitis

A

high staphlocccal colonisation rates there are often co morbidities present

28
Q

osteitis pubis

A

inflammation of the pubic symphysis. well known complication of invasive procedure about pelvis, may also occur as an inflammatory procedure in athletes

29
Q

clavicle osteomyelitis

A

v unusual, risk factors are neck surgery or subclavian vein catheterisation

30
Q

typical causative organism of sickle cell osteomyelitis

A

12% of people with sickle cell disease get it

salmonella

31
Q

gaucher’s disease

A

lysosomal storage disease that may mimic bone crisis and often affects the tibia

32
Q

bone crisis

A

severe bone pain as a result of infarction

33
Q

pathogens in gaucher’s disease

A

if it is bone crisis - sterile if infected - s aureus

34
Q

SAPHO and CRMO

A

SAPHO in adults, CRMO in kids causes general constitutional symptoms and multifocal osteitis. there is a genetic role

35
Q

how does vertebral osteomyelitis occur

A

mostly haematogenous, but can be associated with local spread from epidural or psoas abscess

36
Q

how does one confirm vertebral osteomyelitis

A

MRI

37
Q

CF of vertebral osteomyelitis

A

fever and inc WCC and inflammatory markers insidious pain and tenderness neurological symptoms and signs

38
Q

clinical approach to infection: treatment

A

debridement antimicrobials - AFTER microbial diagnosis unless there s acute presentation or sepsis

39
Q

treatment of vertebral osteomyelitis

A

large abscesses need to be drained 6 week minimum antimicrobials

40
Q

when to repeat MRI in vertebral osteomyelitis

A

increasing pain, inc in inflammatory markers or new signs/symptoms

41
Q

skeletal TB

A

pott’s disease - often no systemic symptoms - some have skin and soft tissue infection - less than half have pulmonary TB

42
Q

treatment of pott’s disease

A

check reduced receptors in kids for IFN gamma etc offer HIV test in adults

43
Q

what are the risk factors for infection in prosthetic joints

A

rheumatoid arthritis (IS drugs?), diabetes, malnutrition and obesity

44
Q

why are prosthetic joints difficult to treat

A

a biofilm (layer of bugs lying on top of joint) forms and antibiotics struggle to penetrate it

45
Q

how do bugs get into joints

A

during surgery (can take a month to present) or through blood stream

46
Q

when is s epididmeris colonisation considered serious

A

only when multiple showings of it - normal commensal of skin

47
Q

planktonic bacteria

A

free in the blood - causes bacteraemia

48
Q

sessile bacteria

A

sits on joint/metal/plastic and forms a biofilm a phenotypic transformation of planktonic bacteria

49
Q

diagnosis of prosthetic joint infection

A

is difficult as it is caused by organisms that are common contaminants culture of tissue is taken

50
Q

treatment of prosthetic joints

A

epididmeris- vancomycin ideally the prosthetic joint is removed, in some elderly people it is just derided but this has a poor prognosis

51
Q

septic arthritis

A

inflammation of the joint space caused by infection

52
Q

when should septic arthritis be considered

A

in any acutely inflamed joint as it can destroy a joint in under 24 hours

53
Q

where does septic arthritis commonly affect

A

knee - 50% cases

54
Q

how does the joint become infected in septic arthritis

A

blood borne, direct inoculation, or extension of local infection

55
Q

what severe thing is occasionally seen in septic arthritis

A

PVL producing S aureus - increases virulence

56
Q

cause of septic arthritis in prosthetic joints

A

coagulase negative staphylococci eg staph epidermidis

57
Q

cause of septic arthritis in sexually active ppl

A

Neissera gonorrhoea (aerobic gram negative diplococci)

58
Q

cause of septic arthritis in pre school children

A

H influenzae - less common now due to vaccination

59
Q

key investigation for septic arthritis

A

joint aspiration for synovial fluid microscopy and culture

60
Q

what must be excluded in septic arthritis

A

gout - can present in same way

61
Q

<5 with septic arthritis treatment

A

Ceftriaxone (h infuenzae)

62
Q

pyomyositis

A

bacterial infection of the skeletal muscles that result in a pus filled abscess

63
Q

cause of pyomyositis

A

90% staphylococcal

64
Q

what is often the cause of pyomyositis in contaminated wounds

A

clostridial infection

65
Q

myositis

A

canbe viral, protozoic or fungal

66
Q

what is tetanus caused by

A

clostridium tetani - gram postiive anaerobic rods forms spores

67
Q

clinical features of tetanus

A

exotoxin causes muscle spasms and rigidity spasms can be induced by bright lights and loud noises

68
Q

classical description of tetanus

A

locked jaw

69
Q

incubation period for tetanus

A

4 days to several weeks

70
Q

tetanus treatment

A

surgical debridement antitoxin supportive measure antibiotics not that useful as due to toxin

71
Q

what do tetanus survivors need

A

booster vaccine - not immune