What is the recommended treatment for suspected infected olecranon bursitis?

Management of Suspected Infected Olecranon Bursitis

Suspected infected olecranon bursitis requires immediate aspiration for diagnosis followed by empiric antibiotic therapy targeting Staphylococcus aureus while awaiting culture results.

Diagnostic Approach

Clinical Assessment

• Look for cardinal signs of infection:
  • Erythema, warmth, tenderness over the olecranon process
  • Fluctuant swelling of the bursa
  • Systemic symptoms (fever, malaise)
  • Recent trauma or skin breakdown over the elbow

Immediate Diagnostic Steps

1. Aspiration of the bursa is mandatory

   • Provides definitive diagnosis by distinguishing septic from non-septic bursitis 1
   • Allows for Gram stain and culture to guide antibiotic therapy
   • Therapeutic benefit of decompressing the bursa

2. Laboratory evaluation

   • Send bursal fluid for:
     • Cell count and differential (WBC >3000/mm³ with neutrophil predominance suggests infection)
     • Gram stain
     • Aerobic and anaerobic cultures
     • Crystal analysis to rule out gout/pseudogout

Treatment Algorithm

Initial Management

1. Empiric antibiotic therapy

   • Start immediately after aspiration
   • Target Staphylococcus aureus (most common pathogen) and streptococci 1
   • First-line regimen:
     • Oral: Cephalexin 500mg QID or Dicloxacillin 500mg QID
     • IV (for severe cases): Cefazolin 1-2g q8h or Nafcillin/Oxacillin 2g q4-6h

2. Supportive measures

   • Rest and elevation of the affected limb
   • Ice application to reduce inflammation
   • NSAIDs for pain and inflammation
   • Avoid pressure on the affected elbow

Follow-up Management

1. Adjust antibiotics based on culture results

   • Modify therapy once organism and sensitivities are identified
   • Continue antibiotics for at least 14 days 1

2. Serial aspirations

   • Repeat aspiration every 3-5 days if reaccumulation occurs
   • Continue until minimal fluid collection remains

3. Monitoring response

   • Assess for clinical improvement within 48-72 hours
   • If worsening after 48-72 hours or no improvement after 3-5 days, consider alternative management 2

Indications for Escalation of Care

1. Consider hospitalization for:

   • Systemic symptoms (high fever, chills)
   • Immunocompromised patients
   • Failed outpatient management
   • Surrounding cellulitis or abscess formation

2. Surgical consultation for:

   • Failure to respond to repeated aspirations and appropriate antibiotics
   • Development of localized abscess
   • Presence of foreign body
   • Chronic infected bursitis unresponsive to conservative measures

Special Considerations

Antibiotic Resistance

• If MRSA is suspected (prior MRSA infection, high local prevalence):
  • Oral: Trimethoprim-sulfamethoxazole DS BID or Doxycycline 100mg BID
  • IV: Vancomycin 15-20mg/kg q12h

Recurrence Prevention

• Address underlying mechanical factors:
  • Recommend protective padding over the elbow
  • Modify activities that cause repetitive trauma
  • Avoid direct pressure on the elbow

Pitfalls to Avoid

1. Failure to aspirate the bursa

   • Aspiration is essential for diagnosis and guides appropriate treatment
   • Empiric antibiotics without aspiration may lead to treatment failure 1

2. Premature corticosteroid injection

   • Never inject corticosteroids into a potentially infected bursa
   • Can worsen infection and lead to serious complications

3. Inadequate antibiotic duration

   • Shorter courses (<14 days) are associated with higher failure rates 1
   • Complete the full course even if symptoms improve quickly

4. Delayed surgical referral

   • Persistent infection despite appropriate medical therapy requires surgical evaluation
   • Chronic infection may necessitate bursectomy

While some recent research suggests empiric antibiotic treatment without aspiration may be successful in select cases 3, 4, the current standard of care remains aspiration for diagnosis followed by targeted antibiotic therapy, as this approach provides definitive diagnosis and allows for tailored treatment based on the causative organism.