Epidural Abscess (quick review)

5 Dec

Epidemiologyhttps://i1.wp.com/www.jaaos.org/content/12/3/155/F1.large.jpg

Relatively rare disease process, affecting 0.2-1.2 patients per 10,000 hospital admissions.

-Incidence has increased over the past 25 years

Causative Organisms

Staphylococcus aureus is present in up to 70% of cases

Steptococcus is the second most common, with a rate of about 7% of cases

Gram negative bacilli can be found in patients with Epidural Abscesses associated with IVDA

Mycobacterium tuberculosis

Factors that Predispose Patients to Epidural Abscesses

  • DM has a very high risk for forming epidural abscess
  • ESRD
  • HIV
  • Malignancy
  • IVDA
  • Indwelling catheter
  • Distant site of infection

Pathophysiology: Three primary methods for forming Epidural Abscess

Hematogenous spread from distant infection sites

  • skin and soft tissue is a common source but other sites can include infective endocarditis, respiratory infections, and genitourinary systems infections

Direct Extension

  • Usually originate from osteomyelitis of the spine but can also originate from paravertebral, retropharyngeal, or psoas abscesses.

Iatrogenic inoculation-

  • Some studies have shown rates as high as 14-22% of all epidural abscesses originate from spine surgeries or spinal procedures.

Clinical Manifestations/Exam Findings

  • Back/neck pain
  • Fever
  • Bowel/bladder dysfunction
  • Paresis/paraplegia (Up to 71% of patients have abnormal neurological exams on presentation)
  • Sepsis
  • Note: Classic triad of Back pain, fever, and neurologic deficit is present in only 8-37% of cases

Diagnosis:

  • ESR and CRP are best laboratory tests
  • WBC is less helpful than ESR and CRP
  • Blood cultures are positive in about 60% of cases, likely because most cases of Epidural Abscesses originate from sources outside of the vertebral canal
  • MRI with contrast is the study of choice
  • CT is less specific

Treatment

Emergent laminectomy, drainage of abscess, and appropriate antibiotic coverage

Prognosis

-Many studies have shown that preoperative neurologic status is the major prognostic factor

Submitted by J. Grover.

References: Cheng-Hsien L, et al. “Adult Spinal Epidural Abscess: Clinical Features and Prognostic Factors.” Clinical Neurology and Neurosurgery. September 2002. 104:4;306-310.  Tompkins M et al. “Spinal Epidural Abscess.” Journal of Emergency Medicine. September 2010. 39:3;384-390. Uptodate. Epidural Abscess; picture

Advertisements

One Response to “Epidural Abscess (quick review)”

  1. Mary M. Saltz, MD, CMO December 10, 2012 at 03:54 #

    Very important, as you state, to check the blood cultures. This is a reliable and inexpensive, non-invasive was to evaluate possible significant spinal infection.

    In a quality review at Emory,

    http://hospitalradiologypartnersblog.com/2012/09/24/142/

    in Sept 2012, only 5% of patients who underwent spine biopsy to confirm/diagnose spinal osteomyelitis had care changed by the results of the biopsy. Over $100K was spent on unnecessary invasive spine biopsies. Going forward, with changing reimbursement models, we will have to do better.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: