Osteomyelitis- Schoenwald Flashcards
Infection and inflammation of the bone is called what?
Osteomyelitis
Name three sources of osteomyelitis?
- Hematogenous spread through blood
- Invasion from a contiguous focus of infection- diabetic foot
- Skin breakdown- vascular insufficiency or trauma
What is bacteremia?
Presence of bacteria in the bloodstream
Sickle cell is from what organism
Salmonella
Who are at risk for hematogenous spread of osteomyelitis?
Sickle cell, elderly, IV drug users
__________ is a risk factor to hematogenous spread of osteomyelitis
Diabetes
What symptom is not a good indicator of osteomyelitis?
Fever because most don’t have it
Name two symptoms related to osteomyelitis and what labs would be elevated
bone or joint tenderness/pain and elevated acute phase reactants (Sed rate and CRP)
You can suspect osteomyelitis if…
- bone can be probed with swab from wound site
- Wound > 6 weeks in duration
What is the most common sickle cell organism?
Salmonella
Name some diseases that cause a weakening of the immune system and lead to osteomyelitis?
- Diabetes
- Organ transplant
- Chemo
- AIDS
What imaging test is used to diagnose osteomyelitis?
Plain film xray of suspected area
What findings do you expect to see on an xray of a patient with osteomyelitis?
- cortical bone abnormalities
- cortical erosion, periosteal reaction, and lucency or osteolysis.
However, these abnormalities may not be apparent until 7-15 days after the onset of acute clinical osteomyelitis
Bone abnormalities on an xray of a patient with osteomyelitis may not be apparent until _______ days after onset of acute clinical osteomyelitis
7-15 days
If osteomyelitis is suspected and xray is negative, what is the next test that should be done?
MRI
B/c abnormalities may not be apparent until 7-15 days after the onset of acute clinical osteomyelitis
What bloodwork would help us diagnose osteomyelitis?
Sed rate, CRP, CMP, WBC, CBC
What is the first step of treatment of osteomyelitis?
Debridement of bone & culture
In patients with osteomyelitis, they must be on IV abx for at least how many weeks?
Six
It is important to consider what when choosing an antibiotic for ostemyelitis?
Keep in mind bone penetration ability of chosen antibiotic
Name the empiric abx choices for osteomyelitis? (empiric means when antimicrobials are given to a person before the specific bacterium or fungus causing an infection is known)
Vanco +/- rifampin (which helps entry into the bone) AND Ceftriaxone (if no MRSA risk)
Which medicine should not be given as a single agent in osteomyelitis because of resistance to __________?
Rifampin, staph
____________ is the preferred med for MSSA
Nafcillin
_________ are bone abscess that can be walled off by body’s immune defenses for years
Brodie’s abscess
Most commonly isolated organism of brodie’s abscesses is?
Staph aureus
Most commonly affected bone in Brodie’s abscesses?
Tibia (BroTie) T for Tibia
What is the most commonly associated
organism in non diabetics?
Staph
Best treatment for MRSA?
Vanco
To treat diabetics for osteomyelitis, what do you do?
Debride and get cultures (usually no empiric tx). Start doxy until you get them back
This medication is used in diabetics when waiting for cultures to come back and can penetrate bone well
Doxycycline
Usual treatment duration is _____ weeks of IV antibiotic therapy
6
A patient complains that he was walking yesterday and a nail went through his tennis shoe into foot. WHat is the most likely organism?
Pseudomonas
A patient complains that he was walking yesterday and a nail went through his tennis shoe into foot. What is the best treatment?
Fluroquinolone (Cipro)
A patient complains that he was walking yesterday and a nail went through his tennis shoe into foot. What is an important thing to ask the patient?
If he got a tetanus shot and is UTD
Septic arthritis is also known as ___________
infectious arthritis
Infectious arthritis causes direct invasion of the _________ space by _______
joint, bacteria
What population is more at risk for infectious arthritis?
Elderly >65 and mostly male
Mc organism that causes infectious arthritis?
Staph
In younger, more sexually active patients, what is the mc organism of infectious arthritis?
Neisseria gonorrhoeae
Mechanism of infectious arthritis?
- Direct inoculation (trauma)
- Contiguous spread (from another site of focus)
- Bacteremia-most common
- Previously damaged joints,especially in RA, most susceptible
What is the mc mechanism of infectious arthritis?
Bacteremia
When there has been an infection and the infection clears and a patient gets arthritis, this is called _________
Reactive arthritis
Reactive arthritis is mc in those patients who have this gene __________
are HLAB27 +
Mc organisms involved in reactive arthritis?
Chlamydia trachomatis & various GI bugs (Salmonella, Yersinia, Campylobacter, C diff)
Name three mc joints involved in reactive arthritis?
- knee
- hip
- shoulder
Disseminated bacteria from cervix, urethra or pharynx makes you think of what type of arthritis?
Gonococcal arthritis
Arthralgias of multiple joints & Asymetric tenosynovitis make you think of what type of arthritis?
Gonococcal arthritis
With this type of arthritis, you need to be really careful when looking at the skin because… “Typically hands with progression to other joints- skin pustules any location”
Gonococcal arthritis
An enlarged, warm and red knee would be a sign of what type of arthritis?
Septic arthritis
How to diagnose gonococcal arthritis?
Fluid aspirate and culture, blood cultures, XRAY
A patient who is > 35 probably has arthritis from _______ and a patient who is <35 probably has arthritis from _________
Name the organisms
staph, gonococcal
What antibiotics for non gonococcal arthritis (septic)?
Staph directed so vancomycin if MRSA risk & cephalexin for no MRSA risk
What antibiotics for gonococcal arthritis?
Ceftriaxone + doxy
