The idea of a caudal epidural is to inject a mixture both of local anaesthetic and hydrocortisone around the areas of inflammation in the spinal canal. This is generally aimed at nerves which are inflamed either by narrowing such as spinal stenosis or irritation from a disc prolapse. Not only does this reduce inflammation caused by a mechanical events such as compression or rubbing but also neutralises some of the noxious chemicals produced during disc herniation or from leaking and torn discs.
These procedures are carried out generally as day cases under sedation to avoid any discomfort. They are carried out through the caudal hiatus which is a small hole in the bottom of the sacrum which is just up from the coccyx. The idea of injecting here is that it is safer than injecting around the nerves in the spine higher up. Immediately after the injection due to the local anaesthetic, there is often numbness around the groin area and into the legs. This wears off as the local wears off in a matter of hours. The hydrocortisone itself is chemically active itself for about six weeks and therefore the effects of the injection are not known usually until the end of this time period. Epidurals can be repeated in the effect has been substantial and prolonged but clearly if it has not been effective then other forms of treatment may need to be discussed.
The risks and complications of this sort of procedure are infection at the injection site. There is a small risk of a headache due to the puncture of the sleeve surrounding the nerves in this technique it would be a rare complication.