Regional nerve blockade, or more commonly nerve block, is a general term used to refer to the injection of local anesthetic onto or near nerves. Nerve blocks are used to help control pain, but also offer diagnostic benefits by helping to identify specific nerves as pain generators.
Nerve blocks in humans
Nerve blocks can help patients who suffer from lower back pain, neck pain, sciatica (from a herniated disc), spinal stenosis, reflex sympathetic dystrophy (a complex regional pain syndrome), shingles, cancer, and painful peripheral vascular disease. Proper patient selection is important.
Nerve blocks combine a local anesthetic (such as lidocaine) with a steroid (corticosteroid) and/or opioids. Steroids can help to reduce inflammation and opioids are painkillers. Depending on the purpose of the nerve block, other drugs or methods used include alcohol or phenol to selectively destroy nerve tissue, cryoanalgesia to freeze nerves, and Radiofrequency ablation to destroy nerve tissue using heat. Injection nerve blocks can be either single treatments, multiple injections over a period of time, or continuous infusions.
Nerve blocks are sterile procedures that are usually performed in an outpatient facility or hospital. The procedure can be performed with the help of ultrasound or fluoroscopy (a live X-ray), which enable the physician to view the placement of the needle. In addition, electrical stimulation can provide feedback on the proximity of the needle to the target nerve. Nerve blocks, like other medical procedures, are not risk-free. There is a possibility of side effects and complications from the procedure, needle puncture, and medications used. The most critical factor in the efficacy of a nerve block is the proper location of the target nerve.