Osteomyelitis

Background

• Infection of the bone by bacteria or fungus
• Etiology
  • Contiguous spread (80%)
  • Hematogenous spread (20%)
    • More common in peds (long bones)
    • Less common in adults (spine)

Risk Factors

• Diabetic pts with one or more of the following:
  • Skin ulceration >2cm
  • Positive probe-to-bone test
  • ESR >70 (83-92% Sn)
  • Abnormal x-ray

Diagnosis

• Pain at the site
  • May also have warmth, swelling, erythema
• X-ray
  • May be normal early in the course
  • Later will show bone demineralization, periosteal elevation, lytic lesions
• Blood culture
• Bone scan

Treatment

Risk Factor	Likely Organism	Initial Empiric Antibiotic Therapy
Elderly, hematogenous spread	MRSA, MSSA, gram neg	Vanco 1gm + (piperacillin-tazobactam 3.375 grams OR imipenem 500mg)
Sickle cell disease	Salmonella, gram-negative bacteria	Ciprofloxacin 400mg, consider vanco 1gm
DM or vascular insufficiency	Polymicrobial: Staph, strep, coliforms, anaerobes	Vanco 1gm + (piperacillin-tazobactam 3.375 grams OR imipenem 500mg)
IV drug user	MRSA, MSSA, pseudomonas	Vanco 1gm
Newborn	MRSA, MSSA, GBS, gram-negative	Vanco 15mg/kg load, then reduce dose, AND ceftazidime 30mg/kg IV q12 h
Children	MRSA, MSSA	Vanc 10mg/kg q6 h AND ceftazidime 50mg/kg q8hr
Postoperative (ortho)	MRSA, MSSA	Vanco 1gm
Human bite	Strep or anaerobes	Piperacillin-tazobactam 3.375gm OR imipenem 500mg
Animal bite	Pasteurella, Eikenella	Piperacillin-tazobactam 3.375gm OR imipenem 500mg

Source

Tintinalli