Epidural steroid injections: efficacy and safety

Epidural steroids give a small, short-term benefit for lumbosacral radicular pain. Their rare catastrophic risks are embolic, so use nonparticulate dexamethasone for transforaminal injections, and do not do high-risk levels without contrast.

1. Expect modest, short-lived benefit. A Cochrane review of 25 placebo-controlled trials found epidural steroids probably slightly reduce leg pain and disability at short-term follow-up, by less than 10 points on a 0–100 scale ¹.
2. Particulate steroid is the embolic hazard. Catastrophic cord and brain infarctions after cervical transforaminal injection are attributed to particulate steroid entering a vertebral or radicular artery; an FDA-convened working group advised nonparticulate steroid ².
3. Steroid labels carry a warning. Triamcinolone labeling warns of spinal cord infarction, paraplegia, quadriplegia, cortical blindness and stroke after epidural use, with and without fluoroscopy, and states epidural use is not approved ³.
4. Contrast unavailability changes the plan. Transforaminal injections at L2 and above, atlanto-axial and atlanto-occipital joint injections and sympathetic blocks should be postponed without contrast because of radiculomedullary artery risk ⁴.
5. Below L2, only nonparticulate steroid without contrast. If a lower transforaminal injection proceeds without contrast, use only a nonparticulate steroid such as dexamethasone ⁴.
6. Interlaminar without contrast: drop the local anesthetic. Consider omitting local anesthetic to avoid a high or total spinal if dura is breached; this is strongly recommended for cervical interlaminar injections ⁴.

Gadolinium is not a safe substitute for iodinated contrast in epidural injections: intrathecal gadolinium is neurotoxic and can be catastrophic ⁴.

• The 2015 working group combined the FDA Safe Use Initiative, an expert panel and 13 societies, producing 17 clinical considerations ².
• Lumbar interlaminar injections and medial branch blocks are lowest-importance procedures that may proceed without contrast ⁴.
• Without contrast, consider preservative-free dexamethasone because preservative-containing steroid given intrathecally is linked to arachnoiditis ⁴.
• Do not draw contrast from the same vial for multiple patients, because of infection risk ⁴.
• Minor adverse events reported after epidural steroids included post-dural puncture headache, vasovagal reactions and hypotension ¹.
• The Cochrane effects were judged too small to be clinically important for many patients and clinicians ¹.
• One trial reported a retroperitoneal hematoma in a patient on anticoagulant therapy ¹.
• Cervical transforaminal injections and stellate blocks may be done without contrast only by experts using ultrasound to see arteries ⁴.

• Choosing particulate triamcinolone for a cervical transforaminal injection ².
• Switching to a transforaminal approach when contrast is unavailable ⁴.
• Assuming fluoroscopy alone prevents catastrophic events; label reports occurred with and without it ³.
• Promising long-lasting relief from a single epidural steroid ¹.