What is Sympathetic Nerve Block

Sympathetic nerve block is a procedure to numb these nerves. Your sympathetic nerves control certain processes in your body that happen without your thinking about them, like sweating.

It may be done to check if pain is caused by damaged sympathetic nerves. It may also be done to relieve pain that is caused by damaged sympathetic nerves.

During this procedure, a health care provider will inject a numbing medicine (anesthetic) into a clump of sympathetic nerves. The place where he or she injects the medicine will depend on where you have pain:

• If your pain is in your upper body, the medicine may be injected into nerves in your neck.
• If your pain is in your abdomen, the medicine may be injected into nerves in the middle of your back.
• If your pain is in your lower body, the medicine may be injected into nerves in your lower back.

Pain that is caused by damaged sympathetic nerves will go away for a period of time after the block. The pain relief usually ends when the medicine wears off, but sometimes it continues for longer.

Tell a health care provider about:

• Any allergies you have.
• All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
• Any problems you or family members have had with anesthetic medicines.
• Any blood disorders you have.
• Any surgeries you have had.
• Any medical conditions you have.
• Whether you are pregnant or may be pregnant.

What are the risks?

Generally, this is a safe procedure. However, problems may occur, including:

• Failure of the procedure to relieve your pain.
• Feeling worse pain than you did before.
• Bleeding.
• Allergic reactions to medicines.
• Infection.
• Blood vessel damage.
• Nerve damage.

What happens before the procedure?

Medicines

Ask your health care provider about:

• Changing or stopping your regular medicines. This is especially important if you are taking diabetes medicines or blood thinners.
• Taking medicines such as aspirin and ibuprofen. These medicines can thin your blood. Do not take these medicines before your procedure if your health care provider instructs you not to.

Staying hydrated

Follow instructions from your health care provider about hydration, which may include:

• Up to 2 hours before the procedure – you may continue to drink clear liquids, such as water, clear fruit juice, black coffee, and plain tea.

Eating and drinking restrictions

Follow instructions from your health care provider about eating and drinking, which may include:

• 8 hours before the procedure – stop eating heavy meals or foods such as meat, fried foods, or fatty foods.
• 6 hours before the procedure – stop eating light meals or foods, such as toast or cereal.
• 6 hours before the procedure – stop drinking milk or drinks that contain milk.
• 2 hours before the procedure – stop drinking clear liquids.

General instructions

• Plan to have someone take you home from the hospital or clinic.

What happens during the procedure?

• An IV tube will be inserted in one of your veins.
• You will be given one or more of the following:
  • A medicine to help you relax (sedative).
  • A medicine to numb the area (local anesthetic).
• A needle will be inserted into the numbed area.
• An imaging tool, like an X-ray or CT scan, will be used to help your health care provider put the needle in the right position.
• The anesthetic for the block will be injected into the nerves.
• The needle will be removed.
• The IV tube may be removed next.
• Small bandages (dressings) may be placed over the area where the needle was put in.

The procedure may vary among health care providers and hospitals.

What happens after the procedure?

• Your blood pressure, heart rate, breathing rate, and blood oxygen level will be monitored until the medicines you were given have worn off.
• You may notice redness in the area where the medicine was injected.
• Do not drive for 24 hours if you received a sedative.

Sympathetic Nerve Block, Care After

These instructions provide you with information about caring for yourself after your procedure. Your health care provider may also give you more specific instructions. Your treatment has been planned according to current medical practices, but problems sometimes occur. Call your health care provider if you have any problems or questions after your procedure.

What can I expect after the procedure?

After your procedure, it is common for the area where the medicine was injected to be:

• Sore.
• Warm.
• Weak.
• Numb.

If the injection was made in your neck, you may also have:

• Voice changes.
• A droopy eyelid.
• Trouble swallowing.
• A stuffy nose.

Follow these instructions at home:

• For the first 24 hours after your procedure:
  • Do not drive.
  • Rest.
  • Avoid activities that require a lot of energy.
• Keep track of the amount of pain relief that you feel and how long it lasts.
• Do not apply heat near or over the injection sites.
• Do not take a bath or soak in water, such as in a pool or lake, until your health care provider approves.
• Take over-the-counter and prescription medicines only as told by your health care provider.
• If you have trouble swallowing, take small bites when eating and small sips of water when drinking until you are able to swallow normally.
• Keep all follow-up visits as told by your health care provider. This is important.

Contact a health care provider if:

• You have numbness that lasts longer than 8 hours.
• You continue to have pain for more than 24 hours after your procedure.
• You have worsening pain or swelling around an injection site.
• There are red streaks around an injection site.

Get help right away if:

• You cannot swallow.
• You have chest pain.
• You have trouble breathing.