Predictors of failure for nonoperative management of spinal epidural abscess

Abstract

Study Design: Retrospective cohort study. Objectives: The aim of this study is to identify predictive factors associated with failure of nonoperative management of spinal epidural abscess (SEA). Methods: Between January 2007 and January 2017, there were 97 patients 18 years or older treated for SEA at a tertiary referral center. Of these, 58 were initially managed nonoperatively. Details on presenting complaint, laboratory parameters, radiographic evaluation, demographics, comorbidities, and neurologic status (Frankel grades A-E) were collected. Success of treatment was defined as eradication of infection with no requirement for further antimicrobial therapy. Diagnosis of SEA was made via evaluation of imaging and intraoperative findings. Patients with repeat presentation of SEA, children, and those who were transferred for immediate surgical decompression were excluded. Results:Fifty-eight patients initially treated nonoperatively were included. Of these, 21 failed nonoperative management and required surgical intervention. The mean age was 60 years, 66% male, and 19% of Maori ethnicity. Abscess location was predominantly dorsal, and in the lumbar region (53%). Multivariate analysis identified Maori ethnicity, multifocal sepsis, and elevated white cell count as predictors of failure of nonoperative management. With 1 predictor the risk of failure was 44%. In the presence of 2 predictive variables, failure rate increased to 60%, and if all 3 variables were present, patients had a 75% risk of failure. Conclusion: Thirty-six percent of patients treated nonoperatively failed nonoperative management—the failure rate was significantly increased in patients with multifocal sepsis, in patients with elevated white cell count, and in patients of Maori ethnicity.