Spinal epidural abscess

OVERVIEW

  • Spinal epidural abscess is considered a neurosurgical emergency
  • morbidity and mortality is worse with delayed diagnosis, and the worse the neurological deficit at the time of surgery the worse the outcome
  • surgery within 24 hours of symptom onset is associated with the best prognosis
  • Absent fever and absent neurological deficit does not rule out spinal epidural abscess, an MRI may be indicated

PATHOPHYSIOLOGY

  • The epidural space is between the dura and the vertebral column

Source of infection

  • often unknown
  • haematogenous spread
    • skin/ soft tissue infections
    • infected prostheses e.g. IV catheters
    • bacterial endocarditis
    • pneumonia
    • UTI
  • contiguous spread
    • Vertebral osteomyelitis
    • Retropharyngeal abscess
    • Overlying skin infections or pressure sores
    • Psoas abscess
    • Penetrating injury
    • Epidural injections or catheters
    • Spinal stimulators

Complications

  • death from generalized septicemia/ meningoencephalitis
  • Adjacent spread: osteomyelitis, paraspinal abscess
  • Spinal cord dysfunction including paralysis: direct compression, spinal ischemia from local thrombosis

CAUSE

Typical causative organisms:

  • Staphylococci
  • Streptococci
  • Gram negative anaerobes

Risk factors

  • IV drug abuse
  • Immunocompromise, including diabetics, alcoholics and HIV
  • Infection of adjacent structures (e.g, vertebral osteomyelitis, infected pressure sores)
  • Recent perispinal procedures (e.g. epidurals, lumbar puncture, spinal operations)

CLINICAL FEATURES

Typical progression of symptoms is:

  • Localized back pain with or without fever: 50% afebrile, most have local tenderness
  • nerve root irritation corresponding to the involved segments
  • early neurological deficits: motor weakness, sensory deficits, bowel or bladder dysfunction
  • late neurological deficits: paralysis (very poor prognosis if complete paralysis >24 hours)
  • other complications (see above)

The diagnosis is often missed at first presentation, when neurological deficits may be absent

INVESTIGATIONS

Laboratory tests

  • FBC: WBC increased with neutrophilia
  • CRP can be elevated before abnormalities in WBC are seen (suspect SEA if raised CRP and point tenderness in back)
  • Blood cultures

Imaging

  • Spine XR usually unhelpful
  • CT scan: high false negative rate but may be diagnositc; can be used for CT-guided diagnostic aspirate for cultures
  • MRI: gold standard for diagnosis; ideally perform before the onset of neurological symptoms; routinely scanning the entire spine is the safest approach although some radiologists prefer to image the preseumed affected segment and adjacent segments

MANAGEMENT

  • IV antibiotics (typically prolonged for 4-6 weeks, due to associated osteomyelitis)
    • cefotaxime
    • flucoxacillin, or vancomycin if MRSA is suspected
  • Urgent neurosurgical referral for consideration of early decompressive laminectomy and drainage
  • Selected cases may be managed by aspiration and/ or medical management alone
  • Supportive care and monitoring including analgesia, attention to bowel and bladder cares, pressure injury prophylaxis and other issue relevant to spinal cord compromise

References and Links

Journal articles

  • Darouiche RO. Spinal epidural abscess. N Engl J Med. 2006 Nov 9;355(19):2012-20. PMID: 17093252.
  • Sendi P, Bregenzer T, Zimmerli W. Spinal epidural abscess in clinical practice. QJM. 2008 Jan;101(1):1-12. PMID: 17982180.
  • Shah NH, Roos KL. Spinal epidural abscess and paralytic mechanisms. Curr Opin Neurol. 2013 Jun;26(3):314-7. PMID: 23511442.
  • Tompkins M, Panuncialman I, Lucas P, Palumbo M. Spinal epidural abscess. J Emerg Med. 2010 Sep;39(3):384-90. PMID: 20060254.

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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