Sympathetic Block FAQs from a Colorado Pain Management Center

Sympathetic Nerves

Sympathetic nerves run on the front surface of the spinal column, and not in the spinal canal with the nerves that Lumbar Sympathetic Chainoffers strength and sensation to the legs.  The sympathetic nerves are a portion of the autonomic nervous system, and basically control many functions such as temperature regulation and flow of blood to the legs and arms, heart rate, sweating, blood pressure and digestion.  

This autonomic nervous system is responsible for controlling functions of the body that a human does not have to think about or have any direct control over.  But there is an association between the CNS or central nervous system and the autonomic nervous system.  Regulation of the connection can become changed, usually secondary to some type of injury.  When the regulation of the sympathetic is changed, various pain states can happen including a complex regional pain syndrome which is also known as Reflex Sympathetic Dystrophy or RSD.

What is a Sympathetic Block and why is it Helpful?

A sympathetic nerve block includes injecting medication that has a numbing effect around the sympathetic nerves in the low back.  Doing this causes the sympathetic nervous system in that area to for the time being be “switched” off to aid with reducing or eradicating pain.   If pain is significantly improved after the block, then a diagnosis of “sympathetically mediated pain” is customary.  The therapeutic properties of the block can last, at times, longer than would be generally expected.  The goal of this block is to reset the sympathetic tone to a normal state of regulation. If the block is successful, then added blocks might be repeated if the pain continues to be relieved.

What Will Happen During the Procedure?

An IV may be started for sedation if necessary.  After lying on an x-ray table, the skin over the area to be injected will be sterilized.  Next, the physician will numb a small part of skin with numbing medication or anesthetic which will sting for only a few seconds.  The physician will use x-ray guidance to direct a needle to the sympathetic plexus of nerves.  The physician will then inject contrast dye to insure the medication only goes over the targeted sympathetic nerves.  Once this occurs, numbing medication and possibly some steroid will then be injected slowly.

What Should I Do and Expect after the Procedure?

You may or may not achieve improvement in the first few hours following the injection depending on if the sympathetic nerves are carrying pain indicators. You may notice amplified warmth in the affected extremity for 4-18 hours following the block. If the sympathetic nerves in the neck are those injected (stellate ganglion), you usually will also note an insignificant drooping of the eyelid as well as redness of the eye for several hours. This is all typical, and will get better over 4-16 hours.

You should report any remaining pain (if any) and record the relief you experience throughout the next week in a “pain diary”.  You might notice an insignificant intensification in your pain lasting for several days as the numbing Sympathetic Blockmedication wears off. You might also have mild pain at the injection site for several days. Ice will normally be more helpful than heat in the first 2-3 days after the injection. You may take your regular medications following the procedure, but try to limit your pain medications the first 4-6 hours after the procedure so that the diagnostic information gained is precise.

On the day of the injection, you should not drive and should evade any vigorous activities. On the day after the procedure, you may return to your regular activities. If your pain is improved from this procedure, start your regular exercise/activities in moderation. Even if you are considerably improved, progressively increase your activities over 1-2 weeks to avoid relapse of your pain.

The key with a lumbar sympathetic block is to “break the cycle” of RSD, and it is often very successful. Colorado Clinic offers lumbar sympathetic blocks with Board Certified pain doctors who are highly experienced in the procedure. There are three Colorado pain management locations available for scheduling in Boulder, Greeley and Loveland. Call today for scheduling!