­­­­ A research team at Seoul National University Hospital (SNUH) has presented an accurate report of deep spinal infection's frequency and risk factors, one of the fatal side effects occurring after epidural injection.

The researchers, led by Professor Moon Jee-youn of the Department of Anesthesiology and Pain Medicine, received an award for their achievement at a conference held by the Korean Pain Society on Nov. 20.

Herniated discs in middle-aged and spinal musculoskeletal disorders increasing in younger generations are classified as pain disorders. As a result, practitioners often perform epidural injections on patients to treat spinal-related pain.

Such adverse effects could lead to permanent damage to the patient if appropriate measures are not taken early. However, it was almost impossible to determine the exact frequency of occurrence or risk factors through existing single-center studies as the side effects rarely occurred.

The research team observed the annual frequency of reimbursement for spinal epidural injection requested to the Health Insurance Review and Assessment Service from 2006 to 2015. Researchers conducted the study via bootstrap validation by regression analysis of the increasing trend, the incidence of deep spinal infection within 90 days after the procedure, and risk factors of deep spinal infection after the procedure.

The study showed that the frequency of epidural injection performed for pain increased more than twice from about 40.8 per 1000 people in 2006 to 84.4 in 2015, almost double that of cases reported in the U.S.

The incidence of deep spinal infection, which is very rare among complications after epidural injection but causes fatal results such as surgery and death, was found to be around 0.01 percent.

About 65 percent of patients with deep spinal infection had to have their abscesses surgically removed despite long-term antibiotic treatment after hospitalization, and 27 percent of them died within six months.

"Until now, we lacked accurate study on the frequency of deep spinal infection, one of the fatal side effects that can occur after the procedure. However, we have discovered risk factors for the first time in the world through the recent study," Moon said, "We hope the study results help establish a more cautious treatment plan considering the frequency and risk factors of the side effects when treating patients' spinal pain."

The study was published in the latest issue of Anesthesiology, one of the most prestigious journals in anesthesiology and pain medicine.