Response to letters regarding article, perioperative dexmedetomidine improves outcomes of cardiac surgery

We thank Hyder and colleagues for their careful, insightful reviews and thoughtful comments on our study that demonstrated that perioperative dexmedetomidine use is associated with better outcomes after cardiac surgery.1 We reported on the impact of a dexmedetomidine infusion started in the operating room after patients were separated from cardiopulmonary bypass. Because this was a retrospective, single-center study, all of the patients in both groups were managed in a similar fashion throughout the perioperative period. Intraoperative anesthesia management was consistent among our cardiac anesthesiologists, with an institutional standard of a moderate dose of narcotic (fentanyl or sufentanil) supplemented by a volatile anesthetic agent. Similarly, postoperative sedation in the intensive care unit was at the discretion of the intensive care unit care team, but the institutional protocol is infusions of fentanyl or midazolam supplemented by propofol when necessary for patient comfort. This protocol was used for patients who did not receive dexmedetomidine and those who required intubation and sedation for >24 hours. We initiated the dexmedetomidine infusion at the rate of 0.24 to 0.60 g/kg per hour to minimize the potential for bradycardia or hypotension that might be associated with loading doses or higher infusion rates. Previous studies have demonstrated that, even with loading doses and higher infusion rates, bradycardia and hypotension are not significant complications in this setting. …