Osteomyelitis (+infection basics)

Question 1

What antibiotic is 1st line against staphylococcus aureus?

Answer 1

Flucloxicillin

Question 2

What antibiotic is 1st line against staphylococcus epidermidis?

Answer 2

Vancomycin

Question 3

What antibiotic is 1st line against streptococcus pyogenes?

Answer 3

Doxycycline

Question 4

What antibiotic is first line against gram -ve bacteria?

Answer 4

Clindamycin (4C)

Question 5

What antibiotic is 1st line against anaerobes?

Answer 5

Metronidazole

Question 6

What antibiotics are used in cases of MRSA?

Answer 6

Vancomycin
Teicoplanin
Daptomycin

Question 7

What is osteomyelitis?

Answer 7

An infection of the bone

Question 8

What are some methods of contracting acute osteomyelitis?

Answer 8

Trauma (Open fracture)
Haematogenous spread

Question 9

What are some risk factors for developing osteomyelitis?

Answer 9

Diabetes
PWID
Young age
Immunosuppressed

Question 10

What are the most common causative bugs in osteomyelitis?

Answer 10

• Staphylococcus aureus (1st)
• Group A Streptococcus (2nd)
• Haemophilus (Children)

Question 11

In what cases should gram -ve osteomyelitis be suspected?

Answer 11

If there is also a UTI

Question 12

What is the cause of chronic osteomyelitis?

Answer 12

Untreated acute osteomyelitis

Question 13

How does chronic osteomyelitis occur?

Answer 13

Untreated osteomyelitis goes on to affect the metaphysis, causing bone death, abscess formation and spread to the space beneath the periosteum
This causes formation of an involucrum (New layer of bone outside of the pus

Question 14

What is an involucrum?

Answer 14

A new layer of bone that forms outside of the pus-filled layer beneath the periosteum

Question 15

How will osteomyelitis usually present?

Answer 15

Localised pain
Slight fever

Question 16

What are some other infections that may occur in osteomyelitis?

Answer 16

Skin infections such as necrotising fasciitis

Question 17

What tests are required in diagnosis of osteomyelitis?

Answer 17

Probe to bone test (Culturing)
Blood testing

Question 18

How will staphylococcus test under culturing?

Answer 18

Gram positive
Cocci
Coagulase positive
Gold on blood agar

Question 19

What are some toxins that staphylococcus aureus can produce?

Answer 19

• Enterotoxin - Food poisoning
• SSSST - Staphylococcal Scalded Skin Syndrome Toxin
• PVL - Panton Valentine Leukocidin

Question 20

Why can antibiotics alone not be used in osteomyelitis?

Answer 20

Open fractures are often poly-microbial and have very little vascularisation, meaning that antibiotics alone cannot control all organisms or reach some centre of bone

There can also be pus in the bone, which antibiotics cannot clear

Question 21

What treatments are required in osteomyelitis?

Answer 21

Antibiotics to culture
Debridement
Pus release

Question 22

What antibiotics are used in staphylococcus aureus in osteomyelitis?

Answer 22

IV flucloxacillin is given first, followed by oral doxycycline

Question 23

What is the treatment used in vertebral osteomyelitis?

Answer 23

drainage of para-vertebral or epidural abscesses, with 6 weeks minimum antibiotics given