Aug 20 - vertebral osteomyelitis and epidural abscess

This mornings case was a 51 year old man presenting with one month of progressive back pain (thoracic) associated with low grade fevers, leukocytosis, and weight loss.  Imaging via CT at an outside facility revealed degenerative changes, spinal stenosis, and not much else.  He presented here febrile with some lower extremity spasticity but no bowel or bladder dysfunction.  he did have decreased sensation in the lower legs.  There was point tenderness over the mid thoracic spine.

There are multiple red-flag symptoms in this back pain presentation.  This recent evidence based guideline from Annals identifies some common alert signs and presents an algorithm for workup:

In this case the patient was found to have vertebral osteomyelitis an epidural abscess due to methicillin susceptible Staphylococcus aureus and was taken for surgical decompression.  He is in the early stages of an 8 week course of IV antibiotics. 

Some key points:

Medical therapy with IV antibiotics alone is appropriate therapy for select patients with epidural abscess according to this Arch Int Med study.  This is a bit of a change from previous dogma.

There are no practice guidelies dictating duration of therapy, with differing opinions regarding duration of therapy.  I generally choose 8 weeks, but this NEJM review from March 2010 suggests a duration of 6 weeks for most patients.

Regarding the efficacy of vancomycin compared to nafcillin for MSSA - see these articles:

AAC Jan 2008 - mortality with vanco 37% compared with 18% treated with beta-lactams.
Medicine Sep 2003 - study of MSSA bacteremia without endocarditis - failure rate with vanco near 20% compared with no failures in the nafcillin group.

The bottom line is beta lactams are clearly superior to vancomycin in S aureus infections, and in the case of serious or life threatening S aureus infections I feel it is worthwhile to desensitize to beta lactams in order to use these agents if at all possible.