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Flashcards in MSK microbiology Deck (30):
1

what is septic arthritis?

infection of joint space

2

what is septic arthritis caused by?

MSSA, strep
rare - h. influenza, neuseria gonorrhoea

3

how is septic arthritis spread

blood. contagious. direct

4

what investigations should be done in suspected septic arthritis

blood culture if fever
CRP, FBC, U&Es, lactate etc
joint fluid washout for culture, microscopy - crystals, WCC, gram stain
US
x-ray
MRI
bone scan
CT

5

what are the symptoms of septic arthritis

acute monoarrhtropathy (inflammation on one joint at a time)
decreased movement, swelling, systemic upset, increased WCC, increased inflam markers

6

what is osteomyelitis and where does it occur

inflammation/infection of bone and medullary cavity
long bone, vertebrae
may reoccur if treatment suboptimal

7

what are the causes of osteomyelitis

acute - mssa, strep
chronic - tb, psuedomonaks aeruginosa, salmonella esp in sickle cell patients, brucella - goats/cows milk, coliforms

8

how is osteomyelitis spread

blood, contiguous, PVD associated, prosthetic valve associated

9

what is the treatment of septic arthritis

if SA - flucoxacilllin high dose (IV)
in under 5 add ceftriaxone for HI and kingella cover
change when blood cultures come out
2-4 weeks

10

acute osteomyelitis - how long does it last for, what do infants have more of a risk of, what spread and where

few days to 2 weeks
infants are more at risk of septic arthritis
blood spread more likely
femur, tibia, shoulder, able, hip, elbow

11

chronic osteomyelitis - why, how long, treatment

if acute is not treated may progress
over 2 wks
is SIRS absent (usually is) then no need for immediate antibiotic treatment - wait till cultures

12

investigations for osteomyelitis

blood culture if fever
bony biopsy/wahsout

13

treatment of osteomyelitis

high flucox
modify w culture results
4-8 weeks of antibiotics

14

PJI risk factors

rheumatoid, diabetes, malnutrition, obesity

15

PJI 0-3 months is called what, symptoms and causes

early post op
fever, effusion, warmth drainage
SA, strep, enterococci

16

PJI 3-24 months is called what, symptoms and causes

delayed (low-grade)
persistant pain, device loosening, fistula
coag -ve staph

17

PJI >24 months. spread. types. causes

blood spread. can be acute or subacute. SA, e.coli

18

what ix for PJI

3 blood cultures
CRP
WCC
radiological investigations

19

treatment of PJI

retention of prosthesis - clean off boils and give gent
or replace 1 op
or 2 operations prosthetic removed, ABs, new prosthetic
or AB in high dose for long time

20

how many minimum weeks of ABs required before clean surgery for PJI

6

21

Prophylaxis - when is the first dose given, how long after surgery should dose not continue

first dose given within 60 mins of start of surgery
should not continue >24 hours after surgery
co-amox 1.2g peri op and 2 doses post op. PA co-trimoxazole

22

what should patients be screened for before op PJI

MRSA

23

What is given for PVL

clindamycin

24

what are the causes of BJI

SA, strep like group A, coliform, kingella in

25

presentation of BJI

temp/systemic signs
pain/redness/swelling over area
reduced mobility
children - listless, cranky, not feeding, not playing

26

SIRS

2 or more of
temp >38 or 90
RR>20 or PaCo2 12000 or under

27

presentation of cellulitis, causes, treatment

pain, swelling, erythema
B haemolytic strep, staph
rest, elevation, analgesia, split, panicillin

28

what is gas gangrene caused by? how does the process happen

clostridium perfringens - gram +ve strictly anaerobic rods which produces spore
spores get into tissues and germinate -> accumulate of gas bubbles in tissues 'crepitus'

29

treatment of gas gangrene

urgent debridement
penicillin, metro - either or both
+/- hyperbaric oxygen in extreme cases

30

what is tetanus caused by? how does it present? treatment

clostridium tetanis. gram +ve strictly anaerobic rods. spore are found in soil, gardens, animal bites
lock jaw, muscle spasm due to toxins (non-invasive)
surgical debridement, anti toxins
penicillin/metro
booster vaccination - toxoid