A sympathetic nerve block is an injection of an anesthetic near the affected sympathetic nerves to block pain. It is performed to determine if damage to the sympathetic nerves is the cause of the patient’s pain. If the block provides temporary pain relief, your physician may recommend a series of blocks to provide longer pain relief.
Sympathetic nerves originate from the front of the spine and are part of the autonomous nervous system that controls several involuntary body functions including blood pressure, heart rate and digestion, and sweating. Sometimes the nerves can continue to transmit pain even after an injury is healed.
A sympathetic nerve block may be recommended for the following:
- Pain related to amputation, frostbite, shingles, chronic regional pain syndrome, reflex sympathetic dystrophy, Reynaud’s syndrome, cancer, coccydynia (chronic tail bone pain), peripheral vascular disease, pelvic pain and pain in arms or legs.
- To increase blood circulation in diabetic neuropathy and to improve healing in slow-healing wounds
- As a diagnostic tool to determine whether the pain involves the sympathetic nerves
You will be taken to the pre-op area where trained nursing staff will get you ready for the procedure by taking vitals and reviewing your medications. Your blood sugar and coagulation status may also be checked if needed.
Then you will enter the procedure room where you will lie, usually, face down on a table. For the stellate ganglion block in the neck, you will lie on your back.
The injection site is then cleansed and injection of a local numbing agent is given in the area so that you don’t feel pain during the procedure.
The location of the injection will depend on which sympathetic nerves are being blocked. To block pain in the upper part of the body a stellate ganglion nerve block is given in the neck, for abdominal pain the block is given in the celiac plexus, for pelvic pain the hypogastric plexus is blocked and for pain in the lower back a lumbar sympathetic block is administered.
A thin hollow needle is then inserted around the nerves to be blocked or numbed. The doctor is guided by fluoroscopic X-ray to place the needle in the correct position. This system gives real time X-ray images of the position of the needle in the spine on a monitor for the physician to view.
A contrast material is then injected through the hollow needle to confirm that the drug flows to the affected nerve when injected.
When the doctor is satisfied with the position of the needle, the anesthetic drug is injected through the same needle.
The needle is then removed and the injection site is covered with a dry, sterile bandage.
You may feel some pressure during the injection but mostly the procedure is not painful and usually takes about 15-20 minutes to complete.
Risks and Complications
The sympathetic nerve block procedure is generally safe. With the use of live imaging through X-ray machines, contrast dye, and physicians trained in the latest interventional techniques, complications are rare. But with all medical procedures, complications can occur. These may include:
Infection: Your pain physician cleans and sterilizes your back before every procedure to prevent this from occurring. On rare occasions oral antibiotics may be needed.
Allergic Reaction: This may occur if you have allergies to any medication used. Typically this is pre-treated and on occasion your physician may recommend medications for you to take after the procedure. Pay close attention to any rashes and difficulty breathing because that may indicate need for emergency attention.
After the procedure you should not drive or operate machinery for the next 12 hours as the procedure can cause drowsiness, temporary numbness, weakness and soreness.
Some temporary side effects following the block may include warmth and weakness in the affected extremities. If a stellate ganglion block is given in the neck area you may notice drooping of the eyelid, redness of the eye, difficulty in swallowing or temporary voice change which will go away after a while.
To help minimize risk and complications please follow all directions given to you by your care provider. Have all your treatment options explained, so you are aware of the risks and benefits of these procedures.
The effect of the sympathetic nerve block varies from person to person and can take a few days to 2 weeks to feel the effects. If you obtain pain relief with the first injection usually a series of 3-6 injections are recommended to break the pain cycle and provide longer pain control.
As always, follow the instructions of your care provider and have your questions answered prior to the procedure.
Sympathetic nerve blocks are a safe procedure used to diagnose and treat pain disorders originating from the sympathetic nervous system.