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.