Lumbar Sympathetic Block What is a lumbar sympathetic block? A lumbar sympathetic block is an injection of local anesthetic that temporarily interrupts activity in the sympathetic nerves in the lower back. These nerves influence and help control the size of blood vessels, and thus, the flow of blood to the legs. What are the goals of a lumbar sympathetic block? The goals of a lumbar sympathetic block are: To provide diagnosis To reduce and possibly eliminate pain To increase function How will a lumbar sympathetic block help my condition? A lumbar sympathetic block temporarily interrupts activity of lumbar sympathetic nerves. This interruption will reduce pain as well as improve blood flow. You may require repeated injections for optimal pain relief. What happens during a lumbar sympathetic block? You will remain awake for the entire procedure. An intravenous (IV) line will be started prior to the injection. Once in the procedure suite: You will be positioned lying face down. The area for the injection will be washed with an antiseptic solution. A local anesthetic will be used to numb the injection site. You will be asked to remain as still as possible. You may feel pressure while the medication is injected. How long is the procedure? The entire procedure lasts about 25 minutes. What happens after the procedure? You will be monitored for approximately 15 minutes, because the medication takes some time to act. A nurse will review discharge and follow-up instructions with you. You will need to carefully monitor the degree and duration of your pain relief. The day after your procedure, you may resume your normal daily activities.