Osteomyelitis

PEBC

osteomyelitis

• inflammation of the bone marrow and surrounding bone caused by infection

hematogenous infection

• through the blood

• typically monomicrobial: Staph tried stinky salmonella poo

  • S. aureus

  • Streptococci

  • IV drug user = pseudomonas

  • sickle cell anemia = Salmonella

  • tuberculosis

• age of onset = <20 yr (children), > 50 yr

• sites = long bones, vertebrae

• risk factors:

  • bacteria travel via blood to certain bone areas, colonize and cause infection

contiguous

• next to (adjacent site)

• common pathogens: Sick Guys Prefer Pretty Klean Environments Barefoot

  • S. aureus

  • G- bacilli:

    • Pseudomonas

    • Proteus,

    • Klebsiella,

    • E coli

  • anaerobic = B. fragilis

• age of onset = >40

• location = femur, tibia, skull, mandible

• clinical presentation:

  • pain, tenderness, swelling, erythema and drainage in area of infection

  • fever (can be absent)

  • unstable joint

• risk factors:

  • surgery

  • trauma (penetrating injury/ open fractures)

  • cellulitis/ abscess

vascular insufficiency

• most common - when blood doesnt get to an area or pools in an area

• polymicrobial: Some Bad Circulation Gets Abscessed

  • S. aureus

  • Beta hemolytic streptococci

  • Coagulase negative staphylococci

  • Gram negative and anaerobic organisms

  • Usually mixed infections

• age of onset = >40

• location = feet

• clinical presentation:

  • localized pain

  • swelling

  • drainage

  • ulcer formation

  • fever and leukocytosis may be absent

• risk factors:

  • diabetes

  • PVD (peripheral vascular disease)

goals of therapy

• cure infection

• eliminate undesirable signs and symptoms

• prevent complications of disease and therapy

• reduce recurrence risk of infection

non pharm

• surgical incision and drainage/ debridement

principles of therapy

• empiric therapy

  • NOT INDICATED UNLESS: sepsis, Inability to culture

• duration of therapy:

  • 4 - 8 weeks antibiotics (longer if retained hardware)

  • switch to oral abx once pt stabilized = normal labs, decreased pain, no complications (no necrosis)

    • need to have high bioavailability and bone penetration and should be tolerated

• Pain management

  • acetaminophen, NSAIDs, Opioids

empiric therapy options

treatment for hematogenous and contiguous osteomyelitis

• targeted initial tx:

  • Staph aureus (MSSA) = Cefazolin, cloxacillin

  • Staph aureus (MRSA) = Vancomycin, daptomycin, linezolid

    • long term therapy of linezolid has been associated with thrombocytopenia, anemias, peripheral neuropathy! not really a good option

  • P. aeruginosa = Ceftazidime, Pip/tazo, Cefepime, Meropenem, Imipenem/Cilastin

• IV therapy x 7-10 days

  • if pt responds, consider step down to oral x 6 weeks

  • generally avoid PO beta lactams

• duration = at least 4-6 weeks (oral or IV) or until ESR/ CRP normalized

• shorter course in children = 20 days

treatment of vascular insufficiency osteomyelitis

• empiric treatment:

  • Pip-Tazo +/ - Vanco

  • [Clindamycin or Metronidazole] + [Ceftriaxone/ Cefotaxime] +/ - Vanco

  • Carbapenem + / - Vanco

• IV tx or oral therapy for ≥6 weeks

• example oral options:

  • cephalexin, cefadroxil, cloxacillin (not preferred)

  • clindamycin or Metronidazole + Levofloxacin

  • Moxifloxacin

  • Amoxicillin/ clavulanate

  • TMP/SMX + / - Clindamycin or Metronidazole

  • Doxycycline + FQ

  • Linezolid + FQ

therapeutic alternatives

• await microbiology prior to treatment

• surgical removal of necrotic bone and poorly vascularised tissue b/c you cant cure it otherwise

• IV antibiotics post-surgery - antibiotics selection based on the infection site

• Parenteral therapy for 6-8 weeks, then 3-12 months oral

• must monitor for side effects since will use for very extended period

• surgeon must also do regular re-evaluations

monitoring

• ensure pt responding to IV antibiotic (WBC, fever decreased, less drainage, reduced CRP)

• monitor Cr, trough levels q7 days if using vancomycin to avoid nephrotoxicity

• if using aminoglycosides: monitor levels and avoid long term use due to nephrotoxicity and ototoxicity