Epidural injections have been used as a means to provide pain relief since 1901 (Waurick & Waurick, 2015). This treatment involves injecting a substance directly into the epidural space, the fluid-filled area around the spinal nerves.

This substance may be an analgesic or a steroid, which is used depending on why the epidural injection is being considered. This may range from controlling chronic pain to managing pain during and after surgery. The most common reason for getting an epidural is childbirth.

The epidural space is the region between the spine bones and the nerves of the spine and is filled with a liquid called cerebral spinal fluid (CSF) (Hakim &  Munakomi, 2023). When a substance is injected into it, it will react based on the medication used, the dosage, and the placement of the person receiving it.

Some medications are heavier than the CSF, causing them to spread down and affecting more nerves below the initial entry point. Others are lighter and will flow upwards, similarly affecting nerves above the initial entry point.

Epidural injections can be a one-time thing, such as during surgery or childbirth, or it can be an ongoing treatment, such as for chronic back pain. It must always be performed by a qualified medical professional in an appropriate environment.

An epidural steroid injection describes the act of injecting a steroid medication into the epidural spinal space (Carassiti et al., 2021).

While the overall procedure for an epidural steroid injection is the same as any other epidural injection, this type of injection uses a steroid or corticosteroid medication that aims to reduce inflammation in the spine. This inflammatory reduction can allow nerves to heal through neuroplasticity and help heal injuries or reduce pain caused by back and spine issues.

These injections can be made into the epidural space, the spinal muscles, or the spinal joints.

Epidural steroid injections can be used for a variety of medical conditions that involve an inflammatory injury within the spine or spinal area (Kaye et al., 2015).

The most common use is to treat lumbar radiculopathy (sciatica), and arthritis or osteoarthritis back pain. Some other conditions that can be treated include spinal disk(s) hernia, fused or ruptured spinal disk(s), coccydynia, spinal stenosis, lumbago, chronic pain from a back injury, cervical radiculopathy, spinal bursitis, and back muscle tendonitis.

Epidural steroid injections are considered a safe and minimally invasive procedure that can help reduce and control back pain caused by an inflammatory injury. However, as it is an injection, it is not currently recommended as a primary treatment option.

Furthermore, its efficiency is increased by the addition of additional pain treatments, such as physiotherapy.

Spinal stenosis is the abnormal narrowing of the spine, most commonly found in the lower back (Comer et al., 2022). This narrowing increases the pressure on the nerves at the stenosis site, leading to irritation and/or damage to them. The main symptom of spinal stenosis is severe pain, often described as a shooting or burning pain going down from the affected area.

Spinal stenosis, which worsens over time, can become a chronic pain condition that requires extensive and regular treatment in order to reduce and/or control the pain it causes. Other symptoms of this disorder are weakness or loss of control of muscles below the spinal stenosis, numbness, and a loss of balance.

Research has determined several risk factors that increase the chances of having spinal stenosis. These can range from poor posture, bad lifting habits, a previous spinal injury, and/or smoking.

A caudal epidural injection indicates the location of the epidural injection, namely that the injection will be performed in the caudal area of the spine. The caudal area, also known as cauda equina, is located in the lower back, known as the lumbar area. The nerves there primarily affect the legs and pelvis.

As the lower back is the most common area to develop spinal stenosis, caudal epidural injections are a recurring treatment option when other non-invasive treatments do not provide sufficient help. However, Akram et al. (2021) found that while caudal epidural injections can provide pain relief, interlaminar lumbar epidural injections provide a more consistent and wide-ranging effect.

The use of interlaminar epidural injections may not be widely available as it requires the use of fluoroscopy to guide the placement of the injection (Hakim & Munakomi, 2023).

Caudal epidural injections have some side effects associated with them, the most common being redness, soreness, discomfort, or an infection at the injection site (NHS, 2023). Additionally, as the injection happens within the caudal epidural space of the spine, there are rare risks of a temporary or permanent nerve injury, pain or paralysis, muscle weakness, or a cerebrospinal fluid leak.

To reduce these risks, injections are usually done under the direction of an ultrasound or another guidance tool.

Steroids have their own side effects, the most common ones being benign and will pass within a few days. These side effects include headaches, dizziness, gastrointestinal issues, increased appetite or weight gain, and flushing of the face. The following side effects are more serious but rarely happen: fainting, severe nausea or vomiting, changes in sleeping patterns, changes in the state of the skin, sudden blood sugar level changes, or unusual hair growth.

The long-term use of steroids can increase the risk of serious complications such as Cushing syndrome, meningitis, adrenal insufficiency, seizures, or swelling of the limbs. These side effects are rare but require immediate medical intervention.

Akram, M., Farooqi, F. M., Baluch, T. A., & Jabbar, S. (2021). Comparison of Caudal Epidural Steroid Injection with Interlaminar Lumbar Epidural Injection in treating Spinal Stenosis. Pakistan Journal of Medical and Health Sciences, 15(9), 2168–2170. https://doi.org/10.53350/pjmhs211592168

Carassiti, M., Porcellini, G., Strumia, A., Russo, F., Papalia, G. F., Cataldo, R., Gargano, F., Costa, F., Pierri, M., De Tommasi, F., Massaroni, C., Schena, E., & Agrò, F. E. (2021). Epidural steroid injections for low back pain: A narrative review. International Journal of Environmental Research and Public Health, 19(1), 231. https://doi.org/10.3390/ijerph19010231

Comer, C., Ammendolia, C., Battié, M. C., Bussières, A., Fairbank, J., Haig, A. J., Melloh, M., Redmond, A., Schneider, M. J., Standaert, C. J., Tomkins-Lane, C., Esther, W., & Wong, A. Y. (2022). Consensus on a standardised treatment pathway algorithm for lumbar spinal stenosis: an international Delphi study. BMC Musculoskeletal Disorders, 23(1). https://doi.org/10.1186/s12891-022-05485-5

Hakim, B. R., & Munakomi, S. (2023, May 1). Interlaminar epidural injection. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK545197/

Kaye, A. D., Manchikanti, L., Abdi, S., Atluri, S., Bakshi, S., Benyamin, R., Boswell, M. V., Buenaventura, R., Candido, K. D., Cordner, H., Datta, S., Doulatram, G., Gharibo, C., Grami, V., Gupta, S., Jha, S. S., Kaplan, E. D., Malla, Y., Mann, D. P., . . . Hirsch, J. A. (2015). Efficacy of epidural injections in managing chronic spinal pain: A best evidence synthesis. Pain Physician, 6;18(6;11), E939–E1004. https://doi.org/10.36076/ppj.2015/18/e939
NHS. (2023, April 26). Steroid injections. nhs.uk. https://www.nhs.uk/conditions/steroid-injections/

Waurick, K., & Waurick, R. (2015). Epiduralanästhesie – Geschichte und Technik der Epiduralanästhesie. Anasthesiologie Intensivmedizin Notfallmedizin Schmerztherapie, 50(07/08), 476–483. https://doi.org/10.1055/s-0041-100845