Topic Overview

Regional anesthesia is the use of local anesthetics to block sensations of pain from a large area of the body, such as an arm or leg or the abdomen. Regional anesthesia allows a procedure to be done on a region of the body without your being unconscious.

Major types of regional anesthesia include:

• Peripheral nerve blocks. A local anesthetic is injected near a specific nerve or bundle of nerves to block sensations of pain from the area of the body supplied by the nerve. Nerve blocks are most commonly used for surgery on the arms and hands, the legs and feet, the groin, or the face.
• Epidural and spinal anesthesia. A local anesthetic is injected near the spinal cord and major nerves that enter the spinal cord to block sensations of pain from an entire region of the body, such as the lower abdomen, the hips, or the legs.

For regional anesthesia, the anesthetic is injected close to a nerve, a bundle of nerves, or the spinal cord. Skill and experience are needed for the anesthesia specialist to inject the anesthetic at the proper location, because the site of injection of the anesthetic has a significant impact on its effect. Careful technique is needed to reduce the risk of rare complications, such as infection or nerve damage.

The site of the injection also strongly affects how quickly the anesthetic is absorbed into the rest of the body. People who receive regional anesthesia are carefully watched, because the anesthetics used may affect the central nervous system, cardiovascular system, and respiratory system (airway and lungs). This is particularly important with spinal and epidural anesthesia, because they may affect blood pressure, breathing, heartbeat, and other vital functions.

Regional anesthesia may be given with other medicines that make you relaxed or sleepy (sedatives) or relieve pain (analgesics). These other medicines are given through a vein (intravenously, IV).

Regional anesthesia is most often used when the procedure:

• Is confined to a specific region of the body.
• Involves a large area of the body where injection of large amounts of an anesthetic might cause side effects that affect the entire body.
• Does not require general anesthesia.

Risks and complications from regional anesthesia

For regional anesthesia, an anesthetic is injected close to a nerve, a bundle of nerves, or the spinal cord. In rare cases, nerve damage can cause persistent numbness, weakness, or pain.

Regional anesthesia also carries the risk of systemic toxicity if the anesthetic is absorbed through the bloodstream into the body. Other complications include heart or lung problems, and infection, swelling, or bruising (hematoma) at the injection site.

Spinal anesthesia medicine is injected into the fluid that surrounds the spinal cord (cerebrospinal fluid). The most common complication of spinal anesthesia is a headache caused by leaking of this fluid. It is more common in younger people. A spinal headache may be treated quickly with a blood patch to prevent further complications. A blood patch involves injecting a small amount of the person’s own blood into the area where the leak is most likely occurring to seal the hole and to increase pressure in the spinal canal and relieve the pull on the membranes surrounding the canal.