Lumbar plexus block is sometimes performed at Hospital for Special Surgery to help alleviate hip pain. It can be used alone or in combination with epidural anesthesia for postoperative pain control in patients after hip replacement surgery.
Once you arrive in the operating room, the anesthesiologist will provide some sedatives to make you feel drowsy. Your vital signs will be taken and you will receive oxygen via a small nasal tube. You will be asked to turn on your side. After you are properly positioned, the anesthesiologist will thoroughly clean your back in preparation for the block. The lumbar plexus, which is a set of nerves that go to the front part of the hip and thigh, is identified with a long thin needle along with a small electric current. Sometimes patients may recall feeling involuntary leg twitching - that is the response that your anesthesiologist seeks.
The Novocain-like medication that your anesthesiologist injects will gradually make your hip and thigh numb. Your thigh and leg will also feel heavy or be difficult to move. The pain relief, along with the numbness and heaviness, typically lasts for 12 to 24 hours, depending on the medications used.
The nerves of the lumbar plexus do not cover the posterior portion of the hip, so blocking these nerves alone will not provide adequate anesthesia for hip surgery. Your anesthesiologist will often combine this block with a spinal or epidural anesthesia to provide complete coverage for your surgery.
As with any anesthetic, there are risks and benefits to lumbar plexus blocks. These particulars can be discussed with your anesthesiologist before the procedure.