Sympathetic Nerve Block

What are the sympathetic nerves?

The sympathetic nerves run on the front surface of the spinal column (not in the spinal canal with the nerves from the central nervous system). The sympathetic nerves are part of the autonomic nervous system which basically controls functions. In other words, the autonomic nervous system is responsible for controlling things people do not have to think about or have direct control concerning their function. However, there is a connection between the central and autonomic nervous systems. Sometimes arm or leg pain is caused by a malfunction of the autonomic system secondary to an injury.

What is a sympathetic nerve block and why is it helpful?

A sympathetic nerve block involves injecting medicine around the sympathetic nerves in a lumbar or cervical area. By doing this, the system is temporarily blocked in hopes of reducing or eliminating pain. If the initial block is successful, then additional blocks are generally repeated in 7-10 days and repeated again until the pain diminishes.

What happens during the procedure?

An IV will be started so that relaxation medication can be given. The patient is placed on the X-ray table on their back for a cervical block and on their side for a lumbar block. The skin on the neck or the skin on the low back is scrubbed using 2 types of sterile scrub (soap). Next, the physician numbs a small area of skin with numbing medicine. This medicine stings for several seconds. After the numbing medicine has been given time to be effective, the physician directs a very small needle, using x-ray guidance to the area of the sympathetic nerves. A small amount of contrast (dye) is injected to insure proper needle position. Then, a small mixture of numbing medicine (anesthetic), normal saline and anti-inflammatory (cortisone/steroid) is injected.

What happens after the procedure?

Immediately after the procedure, the patient will go back to the recovery area where they are monitored for 30 – 60 minutes. The recovery room nurse checks the patient periodically to see if they get good arm/hand or good leg/foot warming. Patients are then asked to report the percentage of pain relief and record the relief experienced during the next week on a post injection evaluation sheet (“pain diary”). This will be given to the patient when they are discharged home.

The arm(s) or leg(s) may feel weak or numb for a few hours. This is fairly common and happens following a sympathetic nerve block.

General Pre/Post Instructions

Patients can eat a light meal within a few hours before the procedure. If a patient is an insulin dependent diabetic, they must not change their normal eating pattern prior to the procedure. Patients may take their routine medications. (i.e. high blood pressure and diabetic medications). Patients should not take pain medications or anti-inflammatory medications the day of their procedure. Patients have to be hurting prior to this procedure. They may not take medications that may give pain relief or lessen their usual pain. These medicines can be restarted after the procedure if they are needed.