Background

Deep spinal infection is a devastating complication after epidural injection. This study aimed to investigate the incidence of deep spinal infection primarily after outpatient single-shot epidural injection for pain. Secondarily, this study assessed the national trends of the procedure and risk factors for said infection.

Methods

Using South Korea’s National Health Insurance Service sample cohort database, the 10-yr national trend of single-shot epidural injections for pain and the incidence rate of deep spinal infection after the procedure with its risk factors were determined. New-onset deep spinal infections were defined as those occurring within 90 days of the most recent outpatient single-shot epidural injection for pain, needing hospitalization for at least 1 night, and receiving at least a 4-week course of antibiotics.

Results

The number of outpatient single-shot epidural injections per 1,000 persons in pain practice doubled from 40.8 in 2006 to 84.4 in 2015 in South Korea. Among the 501,509 injections performed between 2007 and 2015, 52 cases of deep spinal infections were detected within 90 days postprocedurally (0.01% per injection). In multivariable analysis, age of 65 yr or more (odds ratio, 2.91; 95% CI, 1.62 to 5.5; P = 0.001), living in a rural area (odds ratio, 2.85; 95% CI, 1.57 to 5.0; P < 0.001), complicated diabetes (odds ratio, 3.18; 95% CI, 1.30 to 6.7; P = 0.005), multiple epidural injections (three times or more) within the previous 90 days (odds ratio, 2.34; 95% CI, 1.22 to 4.2; P = 0.007), and recent use of immunosuppressants (odds ratio, 2.90; 95% CI, 1.00 to 6.7; P = 0.025) were significant risk factors of the infection postprocedurally.

Conclusions

The incidence of deep spinal infection after outpatient single-shot epidural injections for pain is very rare within 90 days of the procedure (0.01%). The data identify high-risk patients and procedure characteristics that may inform healthcare provider decision-making.

Editor’s Perspective
What We Already Know about This Topic
  • Deep spinal infection after outpatient epidural injections is a rare yet devastating complication

  • The incidence of and risk factors for deep spinal infection remain unclear

What This Article Tells Us That Is New
  • A deep spinal infection was defined as an infection recorded in South Korea’s national insurance database, occurring within 90 days of an outpatient epidural injection, and requiring 4 weeks of antibiotic therapy

  • In a randomly sampled population of adults between 2007 and 2015, 501,509 injections performed in 95,551 individuals were associated with 52 deep spinal infections (1.0 infections per 100,000 injections)

  • Multivariable analysis demonstrated that age of 65 yr or more, living in a rural area, complicated diabetes, repeated epidural injections (three times or more) within 90 days, and recent use of immunosuppressants or systemic steroids were associated with the diagnosis of a deep spinal infection after epidural injection

You do not currently have access to this content.