Reported November 2007

BACKGROUND: Nerve blocks involve the injection of a local anesthetic into or near a peripheral nerve or local pain-sensitive trigger point. Nerve blocks relieve pain by interrupting the body’s pain sensory pathways and preventing chemical signals indicating pain from reaching the brain. They are a convenient way to numb targeted areas of the body for specific surgeries, and are thus the ideal anesthetic for surgeries on extremities such as the legs and arms.

HOW IT WORKS: Using ultrasound, doctors can identify the location of the nerves. Once the anesthetic is injected around the nerves, the limb becomes progressively numb. They can be given in a single injection, a continuous infusion, or used to completely destroy the nerve for more permanent pain relief. A single injection can last several hours or up to one day. Unlike general anesthesia, patients receiving a nerve block can breathe on their own with no additional support. Patients do not experience nausea, vomiting, or sore throat. Patients recover more quickly and require less pain medication after surgery. Nerve blocks also provide effective anesthesia and pain relief for joint replacement surgery, major orthopedic trauma, severe burns, hernia repair, breast surgery, removal of kidney stones, and vascular surgery.

CAVEATS: Nerve blocks can provide temporary pain control but they are just one component of a pain management program. There can be side effects, such as allergic reactions to the local anesthetics. If steroids are used with the anesthetics to reduce inflammation, they can cause fluid retention, fluctuations in blood pressure and blood sugar, and mood swings. If nervous tissue is destroyed, a patient can experience partial loss of motor or sensory functions in the affected area. And patients who are taking anticoagulants such as heparin should not have a nerve block as the medications used can increase the risk of bleeding.

If you would like more information, please contact:

Jackie Carr, Health Sciences
Communications & Public Affairs
UCSD Medical Center
(619) 543-6427
jcarr@ucsd.edu

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