Dexmedetomidine as a Perioperative Adjunct in Valvular Cardiac Surgery

Background: Valvular heart surgery is associated with considerable perioperative risks including hemodynamic instability, arrhythmias, renal dysfunction and prolonged ICU stay. Dexmedetomidine a selective α2-adrenoceptor agonist, provides sedation and sympatholysis and has been investigated as a cardioprotective adjunct. Objectives: To evaluate the effects of dexmedetomidine on intraoperative hemodynamic stability and postoperative outcomes in adult patients undergoing valvular replacement surgery. Methods: In this retrospective study, 154 patients who underwent valvular surgery under cardiopulmonary bypass between January 2022 and June 2023 were analyzed. Patients were divided into Group C (control, n=77) and Group D (dexmedetomidine, n=77). Group D received a continuous infusion of dexmedetomidine (0.5 μg/kg/hr) from induction until the end of surgery. Hemodynamic and depth of sedation parameters (HR, MAP, CVP, NIRS, entropy) were measured at predefined intraoperative time points. Postoperative outcomes included time of extubation, atrial fibrillation (AF), acute kidney injury (AKI), Type 2 neurological injury, reintubation, reoperation, ICU readmission, ICU length of stay (LOS), and 30-day mortality. Results: Baseline demographics were similar between groups. Group D exhibited significantly lower HR and MAP at post-induction, sternotomy, and pericardiotomy (p<0.001 for HR; p<0.05 for MAP). ICU LOS was significantly shorter in Group D (7.23 +/- 2.96 vs. 8.68 +/- 3.88 days, p=0.010). Time to extubation was also significantly reduced in Group D (74.78 +/- 215.30 vs. 192.10 +/- 352.61 hours, p=0.014). AF (2.6% vs. 13.0%, p=0.031), AKI (2.6% vs. 14.3%, p=0.017), reintubation (0% vs. 10.4%, p=0.006), reoperation (2.6% vs. 13.0%, p=0.031), Type 1 neuro injury (2.6% vs. 13.0%, p=0.031), and ICU readmission (2.6% vs. 13.0%, p=0.031) were all significantly reduced in Group D. Thirty-day mortality was also lower (2.6% vs. 14.3%, p=0.021). Conclusion: Dexmedetomidine use during valvular cardiac surgery was associated with improved intraoperative hemodynamic stability, reduced postoperative complications including atrial fibrillation, acute kidney injury, and neurological injury, shorter ICU stay, faster extubation, and lower 30-day mortality. These findings suggest that dexmedetomidine may provide comprehensive organ protection in high-risk surgical patients. Confirmation in larger multicenter randomized controlled trials is required