Introduction:
The human body has a network of nerves called the nervous system. The autonomic nervous system regulates the body's involuntary processes, like respiration, digestion, and blood pressure. The autonomic system is further divided into the parasympathetic and sympathetic nervous systems. The sympathetic nervous system activates during stress or danger, and the parasympathetic works opposite to the sympathetic one. This topic explains the use, procedure, risks, and benefits of sympathetic nerve block.
What Is a Sympathetic Nerve?
Sympathetic nerves are the nerves that arise from the gray matter of the spinal cord and run through the backbone. They provide sensation and strength to the legs. They are part of the autonomic nervous system. They control the function that is directly controlled by the body (involuntary). The autonomic nervous system regulates functions like blood pressure, digestion, respiration, sweating, and temperature. Sympathetic nerves get activated at the time of need in stress or anxiety, or danger. Thus, they are the fight-or-flight nerves of the body.
What Is the Purpose of the Sympathetic Nerves?
The sympathetic nervous system is a network of nerves activated automatically in dangerous or stressful situations. These neurological effects facilitate fast thinking or action. In addition, the sympathetic nervous system affects the immune system, the eyes, the heart, the lungs, the digestive system, and the liver. It also works when the body is sick or exercising.
What Is a Sympathetic Nerve Block?
A sympathetic nerve block blocks the action of the sympathetic nerves. It is done by injecting the medicine in or around the lower back. On injection, the medicine reduces the activity of the sympathetic nerves. As a result, it temporarily provides relief from chronic pain. The goal of the block is to reset the sympathetic action to normal regulation. If required, more than one injection is also delivered to block the activity or the pain messages.
When to Use Sympathetic Nerve Block?
A sympathetic nerve block is used to block the nerves having pain in the sympathetic nervous system. Its use is also for diagnostic purposes. It is administered to overcome pains due to lack of blood in tissues, organs, nerve pain, and shooting or burning sensations. Some uses of sympathetic nerve block are:
- Pain from spasms in the blood vessels.
- Complex regional pain syndrome includes arm or leg pain after the surgery or injury.
- Raynaud syndrome is when some area of the body feels numb, cool, and relaxed.
- Chronic stomach pain.
- Excess sweating.
Where Is the Sympathetic Nerve Block Administered?
The injection is administered into the ganglions. Ganglions are the nerve bundles controlling the sympathetic effects. These ganglions are present in the spine in the spinal nerves. These ganglions extend their nerve fibers in the body to control functions. After locating the area to block the pain, an injection is given. Sometimes, it needs a repeated injection dose to provide long-term relief.
How to Prepare for Sympathetic Nerve Block?
Following are some preparations for sympathetic nerve block:
- The doctor takes the patient's medical history.
- If any medication patient takes, like blood thinning medication, it is made to stop.
- The patient is asked to fast for nearly six hours before the procedure.
- Any allergy, if the patient is having.
What Are the Steps to Perform the Sympathetic Nerve Block?
The steps to perform sympathetic nerve block are:
- Relax the patient first.
- The patient is made to lie on the bed.
- The site of injection is made clean with the antiseptic solution.
- An injection is delivered to numb the area near the nerves.
- X-ray guidance is used to direct the location of the needle to the ganglion.
- The doctor can use contrast media to locate the nerves and ganglia.
- After locating the area, an injection containing anesthesia is delivered directly to the nerve slowly.
What Happens After the Procedure?
After the injection, the patient may feel painless till the effect of anesthesia works. But after 4 to 18 hours, the patient feels warm in the nerves affected. The patient may start feeling pain again when the anesthesia effect wears off. So, steroids are used along with anesthesia for long-term results. Steroids can work from a few weeks to a few months. Some symptoms can also get displayed on injecting block, but they are normal. Icing can be helpful in cases of warmth for two to three days after injection. For example, when the sympathetic nerve in the neck with the stellate ganglion is injected, drooping of the eyelid with redness is noticed. But the symptoms visible are usual and eventually go after 4 to 18 hours.
What Are the Risks Related to Sympathetic Nerve Block?
Risks related to sympathetic nerve block are:
- Pain on injecting.
- Swelling over the site of injection.
- Bleeding.
- Infection.
- Warmth in the area of injection.
- Weakness.
- Difficulty in swallowing, eyelid drooping, and temporary voice change in cases of the stellate ganglion.
What Are the Benefits Related to Sympathetic Nerve Block?
Benefits related to sympathetic nerve block are:
- It helps to control chronic pain.
- It helps restore the mobility of the area.
- Used to diagnose the pain.
- Local pain treatment.
What Are the Precautions Taken After the Procedure?
Precautions after the procedure are:
- The patient should avoid driving for 24 hours.
- The patient should avoid heavy work or activities.
- They should take small bites of food in cases of stellate ganglion or injection at the neck as difficulty in swallowing can occur for a few hours.
Is Sympathetic Nerve Block a Safe Procedure to Perform?
Yes, a sympathetic nerve block is a safe procedure to perform and the procedure's primary role is to relieve the pain, which is safely performed. The patient can go home after the procedure and can work on everyday activities for a day. A full day's rest is required before starting normal day-to-day activities.
Conclusion:
A sympathetic nerve block is delivered to provide pain relief. It is administered by injecting injection at the ganglion present in the spine. The sympathetic nerve block is a safe procedure performed by the doctor to relieve chronic pain. It can be used in Raynaud’s syndrome and excessive sweating. The effect of the block can be seen as the pain in the area is relieved. But it is a temporary relief; in the long term, the doctor uses steroids and anesthesia. The risks and benefits of the block are also presented above.
