What is a median nerve block procedure?

A median nerve block is a procedure to anesthetize part of the palm and fingers by injecting an anesthetic solution to numb the median nerve of the forearm. The median nerve block is often performed along with an ulnar and radial nerve block to anesthetize the whole hand and the palm. The median nerve, along with the ulnar and radial nerve, provides sensation to the hand and fingers.
The median nerve provides sensation to the palm side (palmar/volar aspect) of the thumb, index and middle fingers, half of the ring finger and the palm area from the thumb to the middle of the ring finger.
The median nerve also provides sensation to a part of the index, middle and half of the ring finger on the back of the hand. The median nerve is also responsible for the motor function of the forearm and the thumb.
The median nerve block may be administered on the inside of the elbow, forearm or the wrist, but it is most often performed in the wrist, as the numbing effect may be more effective when administered via this approach.
Why is a median nerve block performed?
A median nerve block is performed to provide local anesthesia during surgical procedures involving the hand and fingers. The anesthetic blocks the transmission of pain signals to the brain.
A median nerve block may be performed solely or in combination with an ulnar and radial block:
- To treat simultaneous injury to several fingers
- For surgical repair of
- large abrasions or torn off tissue (avulsions),
- fractures and dislocations,
- complex lacerations,
- nail infections and
- nail injuries
- To lance and drain abscesses or cysts
- During surgical procedures on the hand and fingers such as
- Carpal tunnel release
- Correction of Dupuytren’s contracture
- Wrist keyhole surgery (arthroscopy, or laparoscopic joint surgery)
- Finger joint replacement (arthroplasty)
Median nerve block is not performed in patients who have:
- Allergy to the local anesthetic
- Anatomical distortion due to injury or from previous surgeries in the wrist
- A surgical connection (fistula) between an artery and a vein for hemodialysis
- Additional injuries in other parts of the arm that require a greater area of anesthesia
- Infection or cellulitis in the injection site
- Liver disease or failure
Benefits of median nerve block over other local anesthesia procedures include:
- Immediate pain relief
- Low requirement of anesthetic agent
- Low risk of systemic toxicity

SLIDESHOW
8 First Aid Kit Essentials for Scrapes, Cuts, Bug Bites, and More See SlideshowHow is a median nerve block performed?
A median nerve block is performed as an outpatient procedure and often in an emergency room. A hand surgeon usually performs a median nerve block for surgical procedures involving the hands.
The anesthetic agents commonly used for a median nerve block are lidocaine and bupivacaine depending on the length of time that anesthesia is required. The injection is administered between the two flexor tendons in the middle of the wrist.
Preparation
- The patient lies flat with the hand appropriately positioned.
- The doctor does a physical examination of the hand to assess its neurovascular function.
- The injection site is sterilized with an antiseptic solution.
Procedure
The doctor
- May use ultrasound guidance to position the needle.
- Inserts the needle up to 2 cm into the skin at a perpendicular angle.
- Aspirates the needle to ensure that it is not inside a blood vessel.
- Injects 3-5 ml of the anesthetic solution.
- Injects another tiny quantity of anesthetic in the tissues under the skin to form a small bump (wheal) while withdrawing the needle.
- Massages the injection site gently to help the solution spread in the tissues.
- Waits for up to 10 minutes for the nerve block to take effect.
Post-procedure
The doctor will instruct the patient on caring for the hand because anesthetized extremities are at a greater risk of injury, especially with long-lasting anesthetics.
Latest MedicineNet News
Daily Health News
How long does a median nerve block last?
The duration of the median nerve block’s effects depends on the kind and quantity of anesthetic agent used.
Approximate duration of effects:
- Lidocaine: Two to five hours
- Bupivacaine: Five to 15 hours
The patient may experience tingling, discomfort or pain as the median nerve block wears off. Residual pain may be resolved with oral painkillers.
What are the risks and complications of a median nerve block?
Median nerve blocks are generally safe and effective for surgical procedures involving the hand. Potential complications include:
- Infection at the injection site
- Pain at the injection site
- Bleeding at the injection site
- Hematoma
- Nerve injury
- Injury to blood vessel
- Allergic reaction to the local anesthetic
- Local anesthetic systemic toxicity
- Unsuccessful nerve block

QUESTION
Emotional trauma is best described as a psychological response to a deeply distressing or life-threatening experience. See AnswerHealth Solutions From Our Sponsors
Top How Long Does a Median Nerve Block Last Related Articles
Spiders Slideshow
Know your spiders and stay safe. Learn to ID a black widow spider and a brown recluse spider though this photo guide. See medical images of dangerous spider bites that can turn deadly. Get first aid instruction for spider bites.Burns (First Aid)
Burn types are based on their severity: first-degree burns, second-degree burns, and third-degree burns. First-degree burns are similar to a painful sunburn. The damage is more severe with second-degree burns, leading to blistering and more intense pain. The skin turns white and loses sensation with third-degree burns. Burn treatment depends upon the burn location, total burn area, and intensity of the burn.
First Aid and CPR
First aid is providing medical assistance to someone a sick or injured person. The type of first aid depends on their condition. Preparedness is key to first aid, like having basic medical emergency kits in your home, car, boat, or RV. Many minor injuries may require first aid, including cuts, puncture wounds, sprains, strains, and nosebleeds. Examples of more critical first aid emergencies include heart attacks, strokes, seizures, and heatstroke.First Aid: Bandaging Injuries and Wounds From Head to Toe
Bandaging a wound like a burn, cut, or scrape requires different techniques depending on which part of the body was hurt. Ace bandages, liquid bandages, bandage wraps, waterproof bandages, elastic bandages, and other types are available to cover and protect your wound from dirt and water.First Aid: Wound Care for Cuts and Scrapes
Wound care treatment at home involves performing cuts and scrapes first aid including cleaning the injury and applying antibiotic ointment and a bandage. Use wound care products like adhesive bandages, hypoallergenic bandages, sprays, tape, and gauze. If cuts and scrapes don’t heal, see your doctor.First Aid Essentials
Are you always prepared for a first aid crisis? See which basic first aid items to pack to treat minor scrapes, cuts, and stings when you're on the go.Hand Picture
Intricate in design and function, the hand is an amazing work of anatomy. See a picture of Hand Anatomy and learn more about the health topic.Trauma/First Aid Quiz
What should be in your first-aid kit? Take this quiz to understand trauma and learn the truth about how to administer first aid.