Infectious Disease Compendium

Subdural empyema

Diagnosis

Infection in the subdural space, often present like bacterial meningitis. Can be missed on CT, especially unenhanced, or MRI as it is often just a thin rim of pus between the brain and the skull.

Epidemiologic Risks

Trauma, sinusitis, otitis.

Microbiology

Otitis and sinusitis source: Often polymicrobial with streptococci, anaerobes, S. aureus and/or aerobic gram-negative bacilli.

Postoperative source: S. aureus, gram negative rods like Pseudomonas aeruginosa, and Proprionibacterium acnes (esp years after the surgery).

Empiric Therapy

Drain drain drain, its an emergency.

Sinusitis/Otitis: vancomycin PLUS a third generation cephalosporins PLUS metronidazole OR carbapenems PLUS vancomycin.

Post-op/trauma: vancomycin PLUS a third generation cephalosporins (esp ceftazadime or cefepime) OR carbapenems PLUS vancomycin.

Pearls

I would avoid the penicillin/beta-lactamase inhibitors as they do not cross the blood brain barrier well.

Rants

ICD9 Codes (Soon to be supplanted by ICD10)

subdural empyema 324.9.