When Back Pain is More Than Musculoskeletal: The Red Flags of Spinal Epidural Abscesses

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Author: Kaitlin M. Fries, OMSIV
Ohio University Heritage College of Osteopathic Medicine

Originally Published: Modern Resident April/May 2015

As an emergency medicine physician it is important to always think about the worst-case scenario. What is the worst thing that could explain this patient’s symptoms? What could potentially kill this patient if not quickly identified and appropriately managed? For common complaints such as back pain, this mindset can easily be over looked. No matter how simple and straightforward a case of back pain may seem, it is still important to ensure there are no red flags. One of the most concerning worst-case scenarios of low back pain is that of a spinal epidural abscess.

Recent studies have shown that the number of cases of spinal epidural abscesses is rising due to an increase in IV drug abuse and spinal surgeries.[2,3] If overlooked, this infection can cause a rapid decline and lead to sepsis, meningitis and permanent paralysis.[3] With a mortality rate as high as 20%, it is vital to catch this infection on the patient’s first presentation.[2,3] Diagnostic delays are far too common in these patients. In 2003, a retrospective study looked at 63 cases of spinal epidural abscesses. It was found that 75% of these cases had multiple ED visits or were admitted without a clear diagnosis.[1]
The classic triad of symptoms for a spinal epidural abscess is fever, back pain and neurological deficits.[1,4] However, in the study mentioned above, 63 cases of spinal epidural abscess were studied and this classic triad was only seen in 13% of the patients.[1,4] A more reliable predictor of the diagnosis was having one or more risk factors for spinal epidural abscess, which had a sensitivity of 98%.[1,4] Consequently, it is important to ask about recent invasive procedures, immunocompromised states, spinal implants/devices, IV drug abuse, alcohol abuse, distant sites of infection, recent spine fracture, chronic renal failure or cancer.[4] The first step when suspecting spinal epidural abscesses is to obtain an ESR level, as this is elevated in greater than 90% of cases.4 Next, or concurrently (depending on the degree of suspicion), order a MRI. This is the gold standard for diagnosis and will reveal the precise location of the infection.[5] Treatment of choice in these individuals is emergent surgical consultation for decompression and debridement.[5] Long-term antibiotic therapy directed at Staphylococcus aureus is also recommended.[4]

References:

1. Davis D, Wold R, Patel R, Tran A, Tokhi R, Chan T, Vilke G. (2003). The clinical presentation and impact of diagnostic delays on emergency department patients with spinal epidural abscess. The Journal of Emergency Medicine, 2003; 26(3), 285-291.
2. Felton B, Dao T, Gerstner B, and Letarte S. Diagnosis of spinal epidural abscess by abdominal plain-film radiography. West J Emerg Med, 2014; 15(7), 885-886.
3. Schoenfeld A, Hayward, R. Predictive modeling for epidural abscess: What we can, can't, and should do about it.The Spine Journal, 2014; 15(1), 102-104.
4. Tintinalli J. Neck and back pain. Tintinalli's emergency medicine: A comprehensive study guide (7th ed.). New York: McGraw-Hill; 2011.
5. Tompkins M, Panuncialman I, Lucas P, Palumbo M. Spinal Epidural Abscess. The Journal of Emergency Medicine, 2010; 39(3), 384-390. Retrieved March 15, 2015.