University of Maryland Rehabilitation & Orthopaedic Institute
410-448-2500 or 1-888-453-7626

Programs and Services

Pain Management Center

Frequently Asked Questions

Nerve Root Block

What is a nerve root block?

A nerve root block is an injection of local anesthetic (numbing medicine) and steroid injected under X-ray guidance into the area where the nerve exits the spinal column. A nerve root block is usually ordered by your doctor for pain in the arm or leg that follows the path of a single nerve. A nerve root block may be diagnostic (a test to determine the source of your pain) and/or therapeutic (to relieve your pain). If you get a period of sustained pain relief from the injection, the block may be repeated. Sometimes the block is done to help identify whether or not surgery might be helpful and at what level such surgery might be most helpful.

Note: The procedure cannot be performed if you have an active infection, flu, cold, fever, very high blood pressure or if you are on blood thinners. Please make your doctor aware of any of these conditions. This is for your safety!

How do I prepare for my procedure?

No solid food or fluids after midnight prior to the procedure unless directed otherwise. You may take your medications with a small amount of water. Diabetics should not take their medication for diabetes until after the procedure is complete. Please check your blood sugar at home before arriving at the PMC. If you are taking any blood thinners such as Coumadin, Warfarin, Plavix, or any others, these medications must be discontinued well before the procedure. You will be directed by our staff as to when you should stop this medication. Please make your Pain Management doctor aware that you are taking a blood thinner, and contact your primary care physician or prescribing physician before stopping this medication.

What are the risks of the procedure?

As with most procedures there is a remote risk of bleeding, infection, nerve injury, or allergic reaction to the medications used. Some short-term side effects may also occur. You should feel some numbness that follows the path of the nerve that was blocked. You may feel some temporary weakness as well. If this weakness interferes with your ability to walk, you will have to remain in the Pain Management Center until it resolves - usually several hours. You may have increased pain for a few days after the injection, including localized pain at the injection site. Diabetics may have short-term elevation of blood sugars because of the steroid medication.

Will the injection hurt a lot?

Most people say the stinging/burning of the numbing medicine is the most uncomfortable part of the procedure; however, each person's response to any procedure will differ. Although rare, it is possible to get a temporary "electric-shock" sensation during the procedure, since the injection is close to a nerve.

What happens during the actual procedure?

After signing a consent form and checking your vital signs, the procedure will be done in the fluoroscopy (X-ray) room with you lying on your stomach. You may have an intravenous (IV) line started in your hand or arm to provide you with fluids and medication to help you relax. Your back is cleansed thoroughly with an antiseptic soap and sterile drapes are placed around the area. The skin is anesthetized (numbed) with a local anesthetic, which may produce a brief stinging or burning sensation that goes away in about 15 seconds. Using X-ray guidance, a needle is advanced to the proper location. A dye may be injected at this point (Please let the doctor know if you have any allergies to X-ray dye or shellfish!). A mixture of local anesthetic (numbing medicine) and steroid is then injected through the needle, and then the needle is removed. Your skin will be cleansed and a Band-Aid will be applied (the Band-Aid can be removed the next morning). Your blood pressure will be monitored in the recovery area for an appropriate time (usually 20-30 minutes) and you may be offered juice/soda and graham crackers. You will be given written and oral discharge instructions, and you may go home with your driver after your doctor authorizes discharge.

How will I feel after the injection?

Your pain may be improved immediately after the injection from the local anesthetic. The steroid usually takes two or three days to have an effect in most people, peaking in about two weeks. You may experience some local tenderness for a couple of days after the injection. Using an ice pack three or four times a day will help alleviate this. You may take your usual pain medication after the injection. It is important that you keep track of the amount of pain relief you received as well as how long the pain relief lasted.

Will I have any restrictions on the day of the procedure?

You may not drive for the remainder of the day after your procedure. A responsible adult (over 18 years old) must be present to drive you home or to accompany you in a taxi. The procedure will be cancelled if you don't have a responsible adult with you! This is for your safety. No heat is to be used on the injected area for the remainder of the day. No tub bath, shower or soaking in water (i.e., pool, hot tub, etc.) for the remainder of the day. You may resume normal diet and medications after the procedure unless told otherwise by your doctor.

When should I call the Pain Management Center?

We would like speak to you the day after your procedure regarding your response. Specifically, we would like to know if you experienced pain relief (if so, how long did it last), your current pain score, and if you are experiencing any problems. If you experience severe pain, new numbness or weakness of your arms or legs, a temperature of 100.5 or greater, a severe headache that doesn’t go away with your usual headache medication, or signs of infection in the area of the injection (redness, swelling, heat, discharge), you should call the Pain Management Center immediately at 410-448-6824 during business hours, and 410-448-2500 after hours to have the pain management physician on call paged to your number.

For more information or to make an appointment, call the University of Maryland Pain Management Center at 410-448-6824 or email us at paininfo@anes.umm.edu