Sstis & Join Infx

Front 1

Considerations for decolonization of MRSA skin infections

Back 1

Considerations:
==> Recurrent infections despite adequate therapy
==> Transmission to household

Front 2

Medication options for decolonization of MRSA skin infections

Back 2

==> Mupirocin
• 1 swab in each nare twice daily x 5 to 10 days or first 5 days of each month
==> Chlorhexidine
• Use as body wash 2 to 3 times per week
==> Dilute bleach baths
• 1 tsp bleach per 1 gallon of water or ¼ cup bleach per ¼ tub
• Soak 15 minutes twice weekly

Front 3

Clinical features associated w/ osteomyelitis

Back 3

• Fever
• Pain and tenderness
• Inflammation
• Erythema
• Drainage-contiguous route of infection only


•Elevated WBC
o (+) with acute infection
o (+/-) with chronic
•Elevated ESR/CRP
oHematogenous
oVertebral

Front 4

Majority of acute osteomyelitis is caused by what type of organisms?

Back 4

gram positive

Front 5

Majority of chronic osteomyelitis caused by what type of organism?

Back 5

polymicrobial

Front 6

possible routes of infection in osteomyelitis

Back 6

o Hematogenous – spread of bacteria via bloodstream from a distant infection site
o Contiguous – direct infection of the bone from an adjacent source of infection or direct inoculation of the bone (trauma, puncture, surgery)
o Vascular – diabetes mellitus, peripheral vascular disease, generally contiguous

Front 7

Duration of infection in acute and chronic osteomyelitis

Back 7

o Acute – less than 1 week
o Chronic – greater than 1 month

Front 8

Organism associated with hematogenous osteomyelitis

Back 8

• Single organism almost always recovered, Staphylococcus aureus

Front 9

Hematogenous most often seen in what age group?

Back 9

children

Front 10

Vertebral osteomyelitis most often seen in what group?

Back 10

adults greater than 50 years and IVDU

Front 11

Organisms associated with vertebral osteomyelitis

Back 11

Single organism most often involved
o Normal adult-Staphylococcus aureus
o IVDU-Pseudomonas aeruginosa or MRSA
o Known concomitant infection

Front 12

Organisms associated with contiguous osteomyelitis

Back 12

Most commonly involves multiple organisms
o Gram-positive-Staph. aureus, Streptococci, Enterococcus
o Gram-negative
o Anaerobes

Front 13

Is contiguous usually acute or chronic?

Back 13

chronic

Front 14

Predisposing factors for contiguous osteomyelitis in pts with normal vasculature

Back 14

• Surgical reduction and internal fixation of fractures
• Prosthetic devices
• Open fractures
• Chronic soft tissue infections

Front 15

Predisposing factors for contiguous osteomyelitis in pts with abnormal vasculature

Back 15

DM & CAD

Front 16

What area is most commonly involved in contiguous osteomyelitis w/ vascular insufficiency?

Back 16

Small bones of feet
-Inadequate tissue perfusion predisposes pt to infx

Front 17

Pts with contiguous osteomyelitis w/ vascular insufficiency usually present with what signs/sxs

Back 17

ingrown toenail, foot ulcer or cellulitis

Front 18

What is often necessary for tx of contiguous osteomyelitis w/ vascular insufficiency?

Back 18

majority will have recurrence of infection. So, resection of involved area is often necessary

Front 19

Labs involved in diagnosis of osteomyelitis

Back 19

o Microbiologic – cultures of blood and bone
• Identification of causative microorganisms is essential (blood cultures)
• Surgical cultures, needle biopsy (bone cultures)
o WBC – leukocytosis or may be normal
o ESR/CRP – elevated (nonspecific, best for monitoring therapeutic response)

Front 20

Radiographic studies used in osteomyelitis

Back 20

o Conventional X-ray – bone changes do not appear for 10-21 days
o Nuclear imaging - see changes in 2 days
• Technitium99m (triple phase bone scan)
• Indium111 (labeled leukocyte scan)
o CT or MRI - most consider MRI gold standard
o PET

Front 21

Empiric tx of osteomyelitis in a neonate (likely pathogen and antibiotic choice(s))

Back 21

Likely pathogen: S. aureus, group B Strep, E.coli
Abx: Oxacillin/nafcillin or cefazolin or vancomycin
+/- cefotaxime

Front 22

Empiric tx of osteomyelitis in a child <5 yo (likely pathogen and antibiotic choice(s))

Back 22

Likely pathogen: S. aureus, group A Strep, H. flu Abx: Oxacillin/nafcillin or cefazolin or cefuroxime or clindamycin or vancomycin
Alternatives: vancomycin + gentamicin

Front 23

Empiric tx of osteomyelitis in a child >5 yo (likely pathogen and antibiotic choice(s))

Back 23

Likely pathogen: S. aureus
Abx: Oxacillin/nafcillin or cefazolin or clindamycin or vancomycin

Front 24

Empiric tx of osteomyelitis in an adult (likely pathogen and antibiotic choice(s))

Back 24

Likely pathogen: S. aureus
Abx: Vancomycin or Oxacillin/nafcillin or cefazolin or clindamycin

Front 25

Empiric tx of osteomyelitis in an IVDU (likely pathogen and antibiotic choice(s))

Back 25

Likely pathogen: P. aeruginosa, S. aureus (MRSA), other Gram (-) rods
Abx: Anti-pseudomonal B-lactam + vancomycin or
FQs + tobramycin or
ceftazidime + tobramycin

Front 26

Empiric tx of osteomyelitis in a Post-op/post-trauma pt (likely pathogen and antibiotic choice(s))

Back 26

Likely pathogen: Gram (+), Gram (-)
Abx: BL/BLI or 3rd gen Ceph or FQ + Clindamycin all +/- Vancomycin

Front 27

Empiric tx of osteomyelitis in a sickle cell pt (likely pathogen and antibiotic choice(s))

Back 27

Likely pathogen: Salmonella, S. aureus, S. pneumonia
Abx: Cefotaxime/Ceftriaxone or FQ + Vancomycin

Front 28

Empiric tx of osteomyelitis in a pt w/ vascular insufficiency (likely pathogen and antibiotic choice(s))

Back 28

Likely pathogen: Gram (+), Gram (-), anaerobes
Abx: BL/BLI or Carbapenems or 3rd Gen Ceph or FQ + metronidazole/clindamycin all +/- vancomycin
Anaerobes: Cefoxitin or Clindamycin + ceftazidime

Front 29

Duration of abx tx of osteomyelitis

Back 29

o Prolonged therapy 4-6 wks

Front 30

Monitoring parameters for

Back 30

• Clinical signs and symptoms
• CBC (WBC) – one or two times weekly until within normal range
• ESR and/or CRP – weekly or every other week (may take several weeks to normalize)
• MRI – repeat at end of therapy
• Chemistry panel – Follow BUN/SCr for agents eliminated renally
• Serum drug levels
• Adherence – critical for treatment success, both IV and oral, reinforce at every chance

Front 31

Which antimicrobials have bone penetration?

Back 31

o Clindamycin and rifampin
o Fluoroquinolones, linezolid, vancomycin, nafcillin/oxacillin, cephalosporins

Front 32

What pts are candidates for IV abx in tx of osteomyelitis?

Back 32

• Standard of care for adults
• Data lacking for PO therapy
• Limited data with fluoroquinolones and linezolid

Front 33

What pts are candidates for PO abx in tx of osteomyelitis?

Back 33

•Acceptable for pediatrics (more data to support)
• Suitable candidates
o Children with response to IV therapy
o Adults without DM or PVD

Front 34

Requirements for PO tx of osteomyelitis

Back 34

• Requirements for oral therapy
o Confirmed osteomyelitis
o Known C & S results
o Demonstrated improvement with IV therapy
o Suitable oral agent available
o Surgery performed (if needed)
o Adherence assured

Front 35

Principles of therapy of osteomyelitis

Back 35

o Need for surgical drainage must be assessed
o Remove foreign material (hardware)
o Must obtain C&S; empiric therapy → definitive therapy when results become available
o IV agents recommended (may be able to switch to oral)
o Bactericidal agents preferred
o Adequate bone penetration
o Prolonged therapy 4-6 wks
o Agent with long t1/2 and good tolerability (will be on home therapy)