Sympathetic Nerve Blocks
Stellate Ganglion Block (SGB)
What is a Stellate ganglion block and why is it helpful?
A Stellate ganglion block involves injecting numbing medicine around the sympathetic nerves in the neck. The sympathetic nerves run on the front surface of the spinal column, and not in the spinal canal with the nerves that provide sensation and strength to your limbs. The sympathetic nerves are part of the autonomic nervous system, which basically controls functions such as blood flow and temperature regulation to limbs, sweating, heart rate, digestion, and blood pressure.
The autonomic nervous system is responsible for controlling bodily functions that you do not think about or have direct control over. However, there is a connection between the central nervous system (that you have control over) and the autonomic nervous system. Regulation of the connection can become altered, usually secondary to an injury. When regulation of the sympathetic nervous system is altered, various pain states can occur, including CRPS (complex regional pain syndrome), previously known as RSD (Reflex Sympathetic Dystrophy) (Dreyfuss, 2008).
By doing this, the sympathetic nervous system in that area is temporarily ‘switched’ off in hopes of reducing or eliminating pain. If pain is substantially improved, then a diagnosis of sympathetically-mediated pain is established. Therapeutic effects of the anesthetic can occur, at times, longer than would be normally expected. The goal is to reset the sympathetic tone to a normal state of regulation. If the initial block is successful, then additional blocks may be repeated if the pain continues to improve each time (Dreyfuss, 2008).
How long does the injection take, and does it hurt?
It usually takes up to 30 minutes. Some mild discomfort is involved because the procedure involves inserting a needle through the skin and deeper tissues, which we will numb first.
How is the injection performed?
The procedure is performed while lying on your back. Your blood pressure, heart rate, and oxygen saturation will be monitored during the procedure and you may be offered medication to help relax. The skin is cleaned with antiseptic solution prior to the injection. It may be done using landmarks, ultrasound, or X-ray guidance to guide the needle(s) into the proper position.
What should I expect after the injection?
Immediately after the injection, you may feel your affected limb getting warm. This is a good sign. You may notice that your pain may be gone or lessened. You may notice weakness and/or numbness in the limb – if it does happen, this is temporary.
What are the risks and side effects?
Stellate Ganglion Block
Generally this procedure is safe, however, risks include bruising, tenderness or bleeding at the injection site and rare allergic reaction (to local anesthetic or contrast dye), nerve damage, infection, or seizure. SGBs often also numb other nerves in the nearby areas, resulting in temporary side effects lasting up to 24 hours. These include: a drooping eye lid, stuffy nose and blood shot eye on the same side; hoarseness or change in voice; “frog in your throat” and difficulty swallowing; headache. Rarely, the numbing spreads from the nerves to the arm resulting in a numb arm for 12-24 hours.
Puncture of the lung is a rare (1 in 1000 or less) complication of this block. It is far less common when we use the ultrasound or X-ray machine for needle guidance, but still possible. Usually, puncture happens during the block and the patient complains of a strong urge to cough, or chest discomfort.
If you develop worsening shortness of breath over the first 6 hours, and you are having trouble breathing even when at rest, please go to emergency room immediately. You can take this sheet with you and show it to the doctor. A chest X-ray should be ordered, since it will show air in your chest cavity if a lung puncture has occurred.
What can I do after the procedure?
You should arrange for a ride home. We advise that you take it easy for a day or two. Perform your daily activities as tolerated. You can apply ice on the injection site on and off for approximately 15 minutes at a time. Use mild analgesics for pain, such as Tylenol or Advil. Avoid soaking the injection site for at least 24 hours.
How long do the effects of the medication last?
The local anesthetic wears off in a few hours. The nerve blockade may last for many hours or days. Usually the duration of relief gets longer after each injection.
Note: We highly recommend that the Stellate ganglion block is done in conjunction with physical therapy. Our therapists have a great deal of experience in providing treatment following injections.
How many injections do I need to have?
If you respond to the first injection, a series of injections is usually needed to treat the problem. The response for such injections varies from patient to patient; therefore the number of injections varies.
Who should not have this injection?
If you are allergic to any of the medications involved in the procedure, if you are taking any blood thinners, or if you have an active ongoing infection, you should not have the injection. Ask about stopping any medications. If you are pregnant, the required X-rays may injure the fetus.
Lumbar Sympathetic Nerve Block
What are the sympathetic nerves and why are sympathetic blocks helpful?
The sympathetic nerves run on the front surface of the spinal column and not in the spinal canal with the nerves that provide sensation and strength to your legs. The sympathetic nerves are part of the autonomic nervous system, which basically controls functions such as blood flow and temperature regulation to limbs, sweating, heart rate, digestion, and blood pressure.
The autonomic nervous system is responsible for controlling bodily functions that you do not think about or have direct control over. However, there is a connection between the central nervous system (that you have control over) and the autonomic nervous system. Regulation of the connection can become altered, usually secondary to an injury. When regulation of the sympathetic nervous system is altered, various pain states can occur, including CRPS (complex regional pain syndrome), previously known as RSD (Reflex Sympathetic Dystrophy) (Dreyfuss, 2008).
What is a sympathetic block and why is it helpful?
A lumbar sympathetic nerve block involves injecting numbing medicine around the sympathetic nerves in the lower back using X-ray guidance. By doing this, the sympathetic nervous system in that area is temporarily ‘switched off’ in hopes of reducing or eliminating pain. If pain is substantially improved, then a diagnosis of sympathetically-mediated pain is established. Therapeutic effects of the anesthetic can occur, at times, longer than would be normally expected. The goal is to reset the sympathetic tone to a normal state of regulation. If the initial block is successful, then additional blocks may be repeated if the pain continues to improve each time (Dreyfuss, 2008).
What are the risks and side effects?
Generally, this procedure is safe, however, risks include bruising, tenderness or bleeding at the injection site, and rare allergic reaction (to local anesthetic or contrast dye), nerve damage, infection, or seizure.
How long does the injection take and does it hurt?
It usually takes up to 30 minutes. Some mild discomfort is involved because the procedure involves inserting a needle through the skin and deeper tissues, which we will numb first.
How is the injection performed?
The procedure is performed while lying on your stomach. Your blood pressure, heart rate, and oxygen saturation will be monitored during the procedure and you may be offered medication to help relax. The skin is cleaned with antiseptic solution prior to the injection. Fluoroscopy (X-rays) will be used to guide the needle(s) into the proper position, followed by contrast dye injection to confirm.
What should I expect after the injection?
Immediately after the injection, you may feel your affected limb getting warm. This is a good sign. You may notice that your pain may be gone or lessened. You may notice weakness and/or numbness in the limb – if it does happen, this is temporary.
What can I do after the procedure?
You should arrange for a ride home. We advise that you take it easy for a day or two. Perform your daily activities as tolerated. You can apply ice on the injection site on and off for approximately 15 minutes at a time. Use mild analgesics for pain, such as Tylenol or Advil. Avoid taking a bath or soaking for at least 24 hours.
How long do the effects of the medication last?
The local anesthetic wears off in a few hours. The nerve blockade may last for many hours or days. Usually, the duration of relief gets longer after each injection,
Note: We highly recommend that the sympathetic block is done in conjunction with physical therapy. Our therapists have a great deal of experience in providing treatment following injections.
How many injections do I need to have?
If you respond to the first injection, a series of injections is usually needed to treat the problem. The response for such injections varies from patient to patient; therefore the number of injections varies.
Will the lumbar sympathetic blocks help me?
The patients who present early during their illness tend to respond better. Patients in the advanced stages of disease may not respond adequately. It is difficult to predict if the injections will help or not.
Who should not have this injection?
If you are allergic to any of the medications involved in the procedure, if you are taking any blood thinners, or if you have an active ongoing infection, you should not have the injection. Ask about stopping any medications. If you are pregnant, the required X-rays may injure the fetus.