Epidural steroid injections (ESIs) are a common treatment option for many forms of low back pain and leg pain. They have been used for low back problems since 1952 and are still an integral part of the non-surgical management of sciatica and low back pain. The goal of the injection is pain relief; at times the injection alone is sufficient to provide relief, but commonly an epidural steroid injection is used in combination with a comprehensive rehabilitation program to provide additional benefit.
An epidural steroid injection delivers steroids directly into the epidural space in the spine. Sometimes additional fluid (local anesthetic and/or a normal saline solution) is used to help ‘flush out’ inflammatory mediators from around the area that may be a source of pain.
The epidural space encircles the dural sac and is filled with fat and small blood vessels. The dural sac surrounds the spinal cord, nerve roots, and cerebrospinal fluid (the fluid that the nerve roots are bathed in). Typically, a solution containing cortisone (steroid) with local anesthetic (lidocaine or bupivacaine), and/or saline is used.
A steroid, or cortisone, is usually injected as an anti-inflammatory agent. Inflammation is a common component of many low back conditions and reducing inflammation helps reduce pain. Triamcinolone acetonide, Dexamethasone, Methylprednisolone acetate and Celestone are commonly used steroids.
Lidocaine (also referred to as Xylocaine) is a fast-acting local anesthetic used for temporary pain relief. Bupivacaine or Sarapin a longer lasting medication, may also be used. Although primarily used for pain relief, these local anesthetics also act as ‘flushing’ agents to dilute the chemical or immunologic agents that promote inflammation.
Saline is used to dilute the local anesthetic or as a ‘flushing’ agent to dilute the chemical or immunologic agents that promote inflammation.