The Effect of Choice of Intraoperative Opioid on Postoperative Pain

The primary aim of this randomized, double-blind study is to examine the effect of a single intraoperative dose of methadone on postoperative pain and analgesic requirements in patients undergoing cardiac surgery with cardiopulmonary bypass. These patients will be compared to subjects receiving a standard dose of the "traditional" intraoperative opioid (fentanyl). Secondary outcome measures to be assessed will include standard recovery variables (such as length of postoperative intubation, ICU length of stay, incidence of nausea or vomiting, level of sedation). In addition, patients will be assessed for the development of chronic postoperative pain.