BlocksBlocks are usually done by a specially trained physician. The blocks may be diagnostic, prognostic, or therapeutic. Diagnostic blocks are done to help find the source of the pain and the pathway involved. Prognostic blocks are done before more invasive procedures to predict how they might work. The purpose of therapeutic blocks is to relieve pain. Blocks and trigger point injections can help interrupt the negative cycle of pain-muscle tension-pain that occurs in the body. Blocks may be done in one session or in series. The most common blocks used in the diagnosis and treatment of pain are sympathetic, intravenous (IV) regional and somatic nerve blocks.
Sympathetic blocks may provide permanent or short-term relief of pain. This type of block can help determine if part of the pain is being caused by a problem with the sympathetic nervous system. In addition, a physician gets information about how well other treatments may work based on the patient’s response to the sympathetic block. A sympathetic block of the upper extremity is called a stellate ganglia block. A sympathetic block of the lower extremity is called a lumbar sympathetic block.
Intravenous regional blocks, or Bier blocks, use a tourniquet to keep the injected drug in one area.
Nerve blocks may also be used for diagnostic and treatment purposes. An anesthetic is injected directly into, or near, specific nerves. The anesthetic helps block the pain signal to the brain.
An epidural block can be used to treat pain in the lower part of the body. An epidural catheter is placed in the spinal column to administer a local anesthetic. This treatment may cause weakness in the legs, which makes walking dangerous.
Trigger point injections involve the injection of a local anesthetic into various point-tender spots in the muscles (trigger points). Trigger points usually occur around the area of the muscle where the nerves are sending the most intense pain signals.