Health Library

An interscalene nerve block is a shot of numbing medicine that's delivered into a group of nerves in the neck called the brachial plexus. These nerves control feeling and movement in the shoulder and upper arm.

This procedure may be done to:

1. Numb your shoulder and upper arm during surgery.
2. Help relieve pain in your shoulder or upper arm.

The interscalene nerve block may be given as a single shot or as a continuous block. For a continuous block, a soft tube (catheter) is used to deliver numbing medicine to the nerves over a longer period.

Tell a health care provider about:

1. Any allergies you have.
2. All medicines you take. These include vitamins, herbs, eye drops, and creams.
3. Any surgeries you have had.
4. Any anesthesia you have had.
5. Any problems you or family members have had with anesthesia.
6. Any medical conditions you have, including any lung disease or bleeding problems.
7. Whether you're pregnant or may be pregnant.
8. Whether you smoke, drink alcohol, or use drugs, such as marijuana.

What are the risks?

Your health care provider will talk with you about risks. These may include:

1. Damage to nearby structures or organs. These include damage to nerves, blood vessels, other neck structures, or lungs. Lung damage can cause lung collapse (pneumothorax).
2. Bleeding.
3. Infection.
4. Numbness, tingling, or weakness of the shoulder or arm.
5. Numbing of other nerves near the brachial plexus. This may cause hoarseness, eye droop, dry eye, eye redness, shortness of breath, or chest tightness.
6. Allergies to medicines.
7. Other reactions to medicines. These may cause seizures or heart problems.

What happens before?

When to stop eating and drinking

Eat and drink only as you've been told. If you don't, your interscalene nerve block procedure may be delayed or canceled. You may be told this:

a. 8 hours before:

1. Stop eating most foods. Do not eat meat, fried foods, or fatty foods.
2. Eat only light foods such as toast or crackers.
3. All liquids are OK except energy drinks and alcohol.

b. 6 hours before:

1. Stop eating.
2. Drink only clear liquids, such as water, clear fruit juice, black coffee, plain tea, and sports drinks.
3. Do not drink energy drinks or alcohol.

c. 2 hours before:

1. Stop drinking all liquids.
2. You may be allowed to take medicines with small sips of water.

Medicines

a. Ask about changing or stopping:

1. Any medicines you take.
2. Any vitamins, herbs, or supplements you take.

b. Do not take aspirin or ibuprofen unless you're told to.

Surgery safety

For your safety, you may:

1. Need to wash your skin with a soap that kills germs.
2. Get antibiotics.
3. Have hair removed at the surgery site.

General instructions

a. Do not smoke, vape, or use nicotine or tobacco for 3–6 weeks before your surgery.

b. Ask if you'll be staying overnight in the hospital.

c. If you'll be going home right after the surgery, plan to have a responsible adult:

1. Drive you home from the hospital or clinic. You won't be allowed to drive.
2. Stay with you for the time you're told.

What happens during an interscalene nerve block?

a. An IV will be inserted into one of your veins, usually in the arm on the side that will not receive the block.

b. You may be given:

1. A sedative to help you relax.
2. Anesthesia to keep you from feeling pain.
3. Analgesic to help reduce pain.

c. You'll rest on your back. Your provider will find the muscles over your brachial plexus.

d. You'll be given a shot on your neck to numb the skin where the block will be placed (local anesthetic).

e. A needle will be inserted through your skin, toward the brachial plexus. Your shoulder or arm may twitch.

f. The block will be put in as follows:

1. If you're having a single-shot nerve block, the shot will be given. The needle that was used for the shot will be removed.
2. If you are having a continuous block, a catheter may be placed to deliver medicine to the nerves nonstop, often for 1–2 days.

g. A clear bandage may be placed over the area where the shot was given. For a continuous block, more dressings may be added to keep the tubing in place.

These steps may vary. Ask what you can expect.

What happens after?

You'll be watched closely. The effect of the block will be checked. Your shoulder and upper arm should be numb. Your fingers may tingle and may feel numb.

If you have a surgery right after you have the block, these things may happen after the surgery:

a. You'll be watched closely until you leave. This includes checking your pain level, blood pressure, heart rate, and breathing rate.

b. Your arm may remain numb for several hours. If you have a continuous block catheter in place, your arm may remain numb for longer.

c. You may have to wear a sling to:

1. Keep your arm safe from injury while it's numb.
2. Support your arm after surgery.

d. As the nerve block medicine wears off:

1. You may begin to feel pain at the surgery site. You may be given pain medicine for this.
2. You may have tingling in your shoulder, arm, and fingers.
3. Your muscle strength and feeling will return within hours.

e. Do not drive or use machines until you're told it's safe.

This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.