A lumbar sympathetic block is an injection of local anesthetic into or around the sympathetic nerves, which are located on the side of spine, in the lower back. The sympathetic nervous system is responsible for the body’s response during times of stress or danger, such as causing the heart to beat faster and adrenaline to be secreted in preparation for our response to a stressful situation. In addition, sympathetic nervous impulses cause the constriction of peripheral blood vessels (those in arms and legs).
Sometimes a sympathetic nerve may be unnecessarily stimulated because of injury or other trauma to the body. This may cause the blood vessels in the arm or leg to constrict and remain constricted, resulting in poor circulation to that limb. The patient may then experience pain and possibly swelling, skin and nail changes, unusual color of the skin and temperature changes in the limb.
A lumbar sympathetic block is performed to block the sympathetic nerves that go to the leg on the same side as the injection. This may in turn reduce pain, swelling, color, sweating and other unusual changes caused by the nerve, and may improve mobility.
All injections are performed under fluoroscopy (x-ray) or ultrasound-guidance or both.
What can you expect after the injection?
Immediately after the injection, you may feel your lower extremity getting warm. In addition, you may notice that your pain may be gone or quite less.