Prevention of pain.

Pain is a multistep process originating in the peripheral nervous system at the site of injury, transmitted by the peripheral nervous system, processed at several levels within the central nervous system, and finally perceived at the level of the cerebral cortex. Each of these steps in pain transmission is subject to intervention, with the possibility of reducing or blocking the nociceptive information to result in decreased pain. In general, therapeutic strategies that attempt to prevent the initiation or transmission of nociceptive information are more effective and safer than attempts to minimize pain after it occurs. Analgesic strategies based on knowledge of pain processes and results of controlled clinical trials should result in the prevention of pain in most patients, with fewer adverse effects than traditional analgesic therapy.