Caudal Epidural Injection Information

Paul Dreyfuss, MD
Clinical Professor
University of Washington
Seattle, WA, USA

What is the epidural space and what is an epidural injection?
The covering over the nerve roots in the spine is called the dura. The sleeve-like space surrounding the dura is called the epidural space. Nerves travel through the epidural space before they travel into your legs. The nerves leave the spine from small nerve holes. These nerves may become inflamed due to irritation from a damaged disc or from contact with a bone spur. Inflammation of these nerves may cause pain in your low back, hip, buttock and legs.

An epidural injection places anti-inflammatory medicine (cortisone) into the epidural space to reduce nerve inflammation, and hopefully reduce your symptoms. By stopping or limiting nerve inflammation we may promote healing, and speed up “mother nature”, thereby reducing your pain. Although not always helpful, epidural injections reduce pain and improve symptoms in most people within 3-7 days. They may provide permanent relief or provide a period of pain relief that will allow other treatments like physical therapy to be more effective.

Your doctor may order up to three epidural injections spaced approximately 2-4 weeks apart. Performing a repeat injection depends on your response to the prior injection. If you obtain excellent relief from an epidural, you do not need to have it repeated. If you have partial sustained benefit (>35% relief) the epidural can be repeated for possible additive benefit. If an epidural injection provides minimal benefit (<35 % relief), the physician may choose another injection be performed with a change in technique and/or cortisone used.

What will happen to me during the procedure?
First, an IV is started so that you may be given medicine for relaxation if you so desire. Next, while lying face down on a x-ray table your skin will be well cleansed with an antiseptic. The physician will numb a small area of skin where the epidural needle will be inserted. The injection will occur at the top of the buttock crease where there is a small opening to the epidural space. Next, the physician will use x-ray guidance to direct a small needle into the epidural space. There will be pressure felt with this part of the procedure. He will then inject contrast dye to confirm that the medicine spreads to the affected nerve(s) in the epidural space. After this, the physician will inject a combination of numbing medicine (anesthetic) and time released anti-inflammatory (cortisone).

What should I do and expect after the procedure?
You may have some partial numbness in your buttocks and/or legs from the anesthetic after the injection. This may last several hours but you will be able to function safely as long as you take precautions. You will report your remaining pain (if any) and also record the relief you experience over the next week in a “pain diary” which we will provide. *Mail or fax the completed pain diary in the envelope provided, so that your treating physician can be informed of your results and plan future tests and/or treatment if needed.

You may notice an increase in your pain lasting for several days. This occurs after the numbing medicine wears off but before the cortisone has a chance to work. Ice will typically be more helpful than heat during this time. You may begin to notice an improvement in your pain 3-5 days after the injection. Improvements will generally occur within 10 days after the injection.

On the day of the injection, you should not drive, and should rest and avoid any strenuous activities. You may take your regular medications at their usual times after the procedure including your pain medicine if needed. On the day after the procedure, you may return to your regular activities. When your pain was improved, start your regular exercise in moderation. Even if you are significantly improved, gradually increase your activities over 1-2 weeks to avoid recurrence of your pain.

*SpineUniverse Editorial Comment: Dr. Dreyfuss has provided excellent information for patients who undergo this procedure. Instructions and information provided by your physician may vary.

Article written 01/01/2008
Published online 03/07/2008
Last updated 03/07/2008

Epidural Injections can be a very helpful adjunct in rehabilitation of patient's the spine pain that radiates into an arm or leg or in the thoracic spine around the chest or trunk. They work by placing cortisone (a potent anti-inflammatory medication) close to an inflamed nerve. This allows the patient to be fully able to regain full motion and increase the muscular support of the spine critical in the recovery and prevention of future episodes. They are generally not indicated in spine pain that does NOT radiate from an irritated spinal nerve. Most patients actually respond to just 1-2 injections; therefore, they should not be routinely performed in a "series of three". In my experience, 60 % of patients require only one injection and only 10-20 % will require 3 injections. Certainly, if there is little or no pain relief after trying 2 injections, it is unlikely that the third injection will be of benefit. In addition, most patients can be treated with a local anesthetic without the need for sedation which requires an IV and a longer recovery immediately after the procedure.

Gerard Malanga, MD

Epidural glucocorticoid injections are commonly given to relieve pain and improve mobility without surgery, buying time for healing to occur or as an attempt to avoid surgery after other conservative approaches failed. Those injections have a good theoretical rationale, but they do not help every patient. Who then should receive an epidural glucocorticoid injection and how many? For leg pain greater than the back pain, guidelines from a respected source (Abram S. Anesthesiology 91:1937-1942, 1999) suggest that patients who had full pain relief from the first epidural injection should not receive another one but to be re-evaluated in 4 weeks and followed thereafter. Those patients who still have some residual pain after the first injection should receive a second and third injection and patients who did not get any benefit from the first injection should not receive another one. Patient selection is very important in deciding on the type of injections patients should receive. Transforaminal injections (different approach to the epidural space) may produce longer pain relief and may also predict whether a patient might benefit from surgery or not (for details, see review McLain et al, Spine Journal 2005). For patients with the diagnosis of lumbar canal stenosis, improvement after such injections may be longer lasting than it was initially thought (Kapural et al., 2005).

Leonardo Kapural, MD, PhD

Epidurals, and more particularly selective nerve root blocks, have been extremely helpful in our practice. Of note, people on blood thinners such as Coumadin need to be off of these prior to a spinal injection and have a PT/PTT (prothrombin time/partial thromboplastin time) check prior to having a needle placed into the epidural space. Also, diabetics should be counseled to watch their blood sugar carefully up to 24 hours after the injection, as steroid medication can increase their blood sugar.

Todd Albert, MD

Epidural injections can be done at any level of the spine: cervical (neck), thoracic (mid-back), lumbar (low back), and sacral (tailbone area). The thoracic epidural may be a valuable tool in the treatment of mid-back and chest wall pains. These problems might be caused by disc problems, arthritis of the spine, or even shingles.

Steven Richeimer, MD

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