Patient: My friend has a budging disc – On the same day the Doctor tried twice to do a epidermal and hit a nerve. She did not let him try a third time. The Doctor is now going to sedate her to do this procedure. She is worried what happens when and if he hits a nerve. Can this cause damage. Should she worry about this? She can not have surgery because of a heart problem. Thank you
Doctor: The correct technique for a Epidural procedure is as follows: first of all the skin is infiltrated with local anaestheti c over the identified space. The insertion point is usually in the midline. The needle tip passes along a shelf of vertebral bone called the lamina until just before reaching the ligamentun flavum and the epidural space. ‘Walking’ the needle tip off this lamina allows the doctor to be confident that is close to the epidural space. This is particularly important in the thoracic spine, where the spinal cord is larger (than in the lumbar spine) and nearly fills the spinal canal increasing the risk of dural puncture and cord damage. The most common complication is the accidental dural pucture with headache. The epidural space in the adult lumbar spine is only 3-5mm deep, which means it is comparatively easy to cross it and accidentally puncture the dura (and arachnoid) with the needle. This may cause cerebrospinal fluid (CSF) to leak out into the epidural space, which may in turn cause a post dural puncture headache (PDPH). This can be severe and last several days, and in some rare cases weeks or months. It is caused by a reduction in CSF pressure and is characterised by postural exacerbation when the patient raises their head above the lying position. If severe it may be successfully treated with an epidural blood patch (a small amount of the patient’s own blood given into the epidural space via another epidural needle which clots and seals the leak). Most cases resolve spontaneously with time.