Diagnostic, prognostic, and therapeutic nerve blocks.

During the past three quarters of a century, nerve blocks have been used with varying success as a primary treatment technique for patients with acute and chronic pain. However, practicing dolorologists soon realized that, in certain individuals, anesthetic blocking of noxious, peripheral afferent sensations did not always amelliorate pain complaints and at times even exaggerated them. The recent advent of the multidisciplinary approach to the management of pain, including neurosurgical procedures, new drugs, electrical stimulation and psychosocial intervention, has helped to clarify the indications for, limitations of, and disadvantages of the use of nerve blocks. The purpose of this article is to place nerve blocks in proper perspective and to define their role among the many methods currently available for the evaluation and control of severe pain.