Epidural injections are often used to treat radicular pain, also called sciatica , which is pain that radiates from the site of a pinched nerve in the low back to the area of the body aligned with that nerve, such as the back of the leg or into the foot. Inflammatory chemicals (. substance P, PLA2, arachidonic acid, TNF-α, IL-1, and prostaglandin E2) and immunologic mediators can generate pain and are associated with common back problems such as lumbar disc herniation or facet joint arthritis . These conditions, as well as many others, provoke inflammation that in turn can cause significant nerve root irritation and swelling.
The caudal approach to the epidural space involves the use of a Tuohy needle, an intravenous catheter, or a hypodermic needle to puncture the sacrococcygeal membrane . Injecting local anaesthetic at this level can result in analgesia and/or anaesthesia of the perineum and groin areas. The caudal epidural technique is often used in infants and children undergoing surgery involving the groin, pelvis or lower extremities. In this population, caudal epidural analgesia is usually combined with general anaesthesia since most children do not tolerate surgery when regional anaesthesia is employed as the sole modality.