Before the injection procedure begins, topical anesthesia is applied to the skin. Next, in order to prevent healthy nerve roots from being exposed to too much medication, the physician will use imaging technology such as fluoroscopy to guide the insertion of the needle and to confirm its correct placement in the epidural space. In addition, contrast dye is typically injected in order to observe where the medication will be administered and to ensure that it will be properly distributed throughout the targets areas. The administration of steroids and an anesthetic such as Lidocaine directly onto the nerves roots results in dramatic or complete pain relief. The steroid decreases inflammation, while the anesthetic disrupts pain signal transmission.
This is a rare complication that may occur if a small hole is made in the fibrous sac and does not close up after the needle puncture. These small holes are only made in less than 1% of epidural injections and usually heal on their own. The spinal fluid inside can leak out, and when severe, the brain loses the cushioning effect of the fluid, which causes a severe headache when you sit or stand. These types of headaches occur typically about 2-3 days after the procedure and are positional - they come on when you sit or stand and go away when you lie down. If you do develop a spinal headache, it is OK to treat yourself. As long as you do not feel ill and have no fever and the headache goes away when you lay down, you may treat yourself with 24 hours of bed rest with bathroom privileges while drinking plenty of fluids. This almost always works. If it does not, contact the radiologist who performed the procedure or your referring physician. A procedure (called an epidural blood patch) can be performed in the hospital that has a very high success rate in treating spinal headaches.