Examining Effects of Methadone in CPB

Background: Postoperative pain control following cardiopulmonary bypass (CPB) is usually managed with short- to medium-acting opioids such as fentanyl, hydromorphone, and morphine. Methadone is a long-acting synthetic opioid that can help mitigate pain from the sternotomy but its pharmacodynamics in the setting of CPB are poorly understood. How should methadone be dosed for CPB? Objective: To describe the pharmacokinetics of an IV bolus of methadone racemate in adult patients undergoing heart surgery with CPB. Design/Participants: Prospective clinical study of patients undergoing CPB to understand the pharmacodynamics of IV methadone and CPB. Methods: 29 patients aged 45 and 75 years were included in the study. On induction, 3 to 5 µg/kg of fentanyl was given Then each patient received 0.2 mg/kg of methadone after induction but prior to initiation of CPB. Additionally, boluses of fentanyl could be given up to a total of 10 µg/kg. No other opioids were administered during more...