The clinical use of spinal opioids,part 1

Spinal opioids are effective analgesics for surgical and non-surgical pain. Central and systemic side effects are less frequent than with epidural local anaesthetics or parenteral opioids. This review focuses on the analgesic efficacy of spinal opioids and their combination with local anaesthetics for postoperative analgesia, including patient-controlled epidural analgesia. Intrathecal administration of opioids has some advantages over their administration by the epidural route. Several factors may influence selection of the opioid; however, in most situations morphine is the drug of choice. Thoracic epidural administration of opioids seems to have no clinically important advantages over the lumbar route in terms of quality of analgesia, adverse effects, doses required or pulmonary function. However, evidence suggesting that effective postoperative analgesia can significantly improve postoperative morbidity in patients at risk is accumulating. In such patients, combined use of epidural local anaesthetics and opioids may become the technique of choice for postoperative analgesia. However, there is no evidence that this would have any clinically relevant benefit in low-risk patients.