Hypothesis:~We hypothesize that 0.2 mg/kg of methadone will result in decreased postoperative hydromorphone consumption compared to hydromorphone alone in opioid naïve patients or patients who are taking less than the equivalent of 15 mg IV morphine a day undergoing lumbar interbody fusion.~We hypothesize that the incidence of opioid related postoperative side effects will not be increased by the administration of methadone in the operating room.
What is the influence of methadone on postoperative analgesia after lumbar interbody fusion in opioid naïve patients or patients who are taking less than equivalent of 15 mg IV morphine each day? What is the incidence of opioid related postoperative side effects after the administration of methadone in the operating room?