The lumbar sympathetic block is an injection of local anesthetic into or around the sympathetic nerves. These nerves are a part of the sympathetic nervous system. They are located in the lower back on the either side of spine. These nerves control basic functions like regulating blood flow.
A lumbar sympathetic block is used to block the sympathetic nerves that go to the leg on the same side as the injection. The injection may reduce pain, swelling, color, sweating and other unusual changes in the lower extremity and may improve mobility. It is done as a part of the treatment of Reflex Sympathetic Dystrophy (RSD), Sympathetic Maintained Pain, Complex Regional Pain Syndrome and Herpes Zoster (shingles) involving the legs.
The injection consists of a local anesthetic and takes from 10 to 30 minutes.
There is some pain involved as the procedure involves inserting a needle through skin and deeper tissues. The skin and deeper tissues are numbed with a local anesthetic using a very thin needle before inserting the actual block needle. Most of the patients also receive intravenous sedation making the procedure easier to tolerate.
If you respond to the first injection, you will be recommended for repeat injections. Usually, a series of such injections is needed to treat the problem. Some may need only 2 to 4 and some may need more than 10. The response to such injections varies from patient to patient.