Spinal Epidural Abscess: Early Suspicion in Emergency Department Using C-Reactive Protein and Erythrocyte Sedimentation Rate Tests.

Background: Spinal epidural abscess (SEA) is an uncommon but serious differential diagnosis of acute spinal pain with high paralysis and mortality rate. This study aims to provide local data on its bioclinical characteristics and evaluate potential strategies to enhance its diagnostic rate in accident and emergency department (AED).

Methods: A retrospective case study from 2013 to 2019 was conducted in United Christian Hospital. SEA cases were classified as study group, spinal pain due to non-SEA cases were classified as control group. Data collected from study group included symptoms, radiological diagnosis, microbiological culture, treatment, and outcome. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) of both groups were compared to analyze their diagnostic power.

Results: In the study group (n = 42), 93% of patients had spinal pain, 55% had fever, 60% had neurological deficits, and only 26% had the classic triad on presentation. Seventy-four percent of patients presented with spinal cord or cauda equina compression in their first magnetic resonance imaging. Mortality rate was 23.8%, and paralysis rate was 7.1%. Diagnostic accuracy in AED was 12%. Admission to orthopedic ward (n = 23) resulted in a significantly lower mean time-to-imaging (4.39 days vs. 14.58 days) and mean time-to-treatment (6.56 days vs. 16.9 days) as compared to other specialties. The area under curves of CRP and ESR were 0.893 and 0.874 respectively, the optimal threshold levels were 45.9 mg/L (sensitivity 82.9%, specificity 79%) and 59.5 mm/hr (sensitivity 87.2%, specificity 80.4%), respectively.

Conclusion: Diagnosis of SEA in emergency department based on clinical symptomatology is not reliable due to low incidence of the classic triad, despite a more advanced disease on presentation. We proposed incorporating CRP and ESR tests into evaluation of patients with spinal pain since both tests demonstrated excellent discriminative power in diagnosing SEA.