Effects of Fixed-Dose Postoperative Dexmedetomidine on Delirium and Early Clinical Outcomes After Cardiovascular Surgery: A Retrospective Cohort Study of 408 Patients.

OBJECTIVES

Postoperative delirium (POD) is a frequent and serious complication after cardiovascular surgery and is associated with impaired recovery and worse clinical outcomes. Dexmedetomidine has been suggested to reduce delirium risk; however, evidence from real-world cardiac surgery cohorts remains inconsistent. This study evaluated the association between a fixed-dose postoperative dexmedetomidine infusion and delirium incidence, sedation depth, and early clinical outcomes.

DESIGN

Single-center retrospective cohort study.

SETTING

Tertiary cardiovascular surgery center.

PARTICIPANTS

A total of 408 adult patients undergoing elective cardiovascular surgery between January 2022 and December 2023.

INTERVENTIONS: Patients received either a fixed-dose dexmedetomidine infusion (0.2 μg/kg/h for 24 hours, n = 188) or no dexmedetomidine (control group, n = 220) in the postoperative period.

MEASUREMENTS AND MAIN

RESULTS

POD was assessed using the Confusion Assessment Method for the ICU at 6 and 24 hours, and sedation depth was assessed using the Richmond Agitation-Sedation Scale. Dexmedetomidine use was associated with a lower incidence of POD at 6 hours (2.1% v 7.0%, p = 0.032) and 24 hours (0.5% v 3.6%, p = 0.042). Multivariable logistic regression identified dexmedetomidine as an independent factor associated with reduced delirium risk at 6 hours (adjusted odds ratio, 0.25; 95% confidence interval, 0.07-0.88). In addition, patients receiving dexmedetomidine demonstrated deeper and more stable sedation profiles and shorter extubation times (6.85 ± 1.49 hours v 9.47 ± 5.61 hours, p < 0.001), with reduced postoperative analgesic requirements. Hemodynamic adverse events, major complications, and early and 30-day mortality rates were similar between groups.

CONCLUSIONS

In this retrospective cohort study, fixed low-dose dexmedetomidine infusion after cardiovascular surgery was associated with a lower observed incidence of early POD, improved sedation profiles, faster extubation times, and reduced analgesic requirements without increased adverse events. These findings suggest that dexmedetomidine may be associated with improved early postoperative recovery in selected cardiac surgery patients. Prospective studies are needed to confirm these findings and further clarify the role of dexmedetomidine in perioperative care.