Abstract
It is well known that respiratory depression ensues after major surgery due to post-operative pain. Although opioid can produce good analgesia, it sometime causes resoiratory depression postoperative patients. Epidural analgesia improve respiratory function by means of maintaining deep breathing and cough reflex. Those offects lead to prevent atelectasis and other lung complications. However, some patients require vasopressor due to significant sympathetic block when large doses of local anesthetics were used to obtain complete analgesia.
Clinical practice of epidural administration of opioids for analgesia was introduced in 1979. Although the epidural opioids excellent pain relief, the incidence and severity of side effects such as resoiratory depression associated with large doses limits its safty use. It is recommended the concurrent use of low dose of opioids and low concentration of local anesthetics since the combination of those agents, can produce the synergistic analgesia.
Recently, in the field of pain management, a lot of studies regarding opioids agonists and antagonists have been done. It is important to continue such investigation and elucidate analgesia system to develop safer pain control methods.
