Effect of intraoperative dexmedetomidine on postoperative mental health in cardiac surgery: a randomized controlled trial

BACKGROUND: Dexmedetomidine was widely used in anesthesia management during cardiac surgery. The purpose was to evaluate the safety and efficacy of intraoperative dexmedetomidine in the treatment of postoperative depression in adult patients undergoing cardiac surgery. MATERIALS AND METHODS: A randomized trial was conducted to enroll patients undergoing elective cardiac surgery between April and August 2024. Patients aged 18-85 with an American Society of Anesthesiologists classification of I-IV were randomized in a 1:1 ratio to receive intraoperative dexmedetomidine (following a 10 min 0.6 μg/kg loading dose, 0.4 μg/kg/h maintenance infusion) or placebo (normal saline). The primary outcome was the positive screening rate for depression assessed by the Patient Health Questionnaire-9 (PHQ-9) scale at postoperative 7 days. Secondary outcomes encompassed the incidence of delirium, anxiety, sleep disturbance, pain, and quality of life. All participants, care providers, and investigators remained blinded to treatment allocation throughout the study. Analyses were done by intention-to-treat populations. RESULTS: A total of 313 patients provided informed consent, of whom 200 were randomized (100 assigned to dexmedetomidine and 100 assigned to placebo). Dexmedetomidine demonstrated favorable tolerability and safety profiles. The incidence of depression at postoperative 7 days was significantly lower in the dexmedetomidine group than in the placebo group [11.0% vs 31.0%; adjusted relative risk (aRR): 0.29; 95% CI: 0.08-0.48; P < 0.001]. The incidence of delirium (5.0% vs 19.0%; aRR: 0.17; 95% CI: 0.06-0.54; P = 0.001), anxiety (8.0% vs 21.0%; aRR: 0.22; P = 0.005), sleep disturbance (32.0% vs 42.0%; aRR: 0.67; P = 0.022), and pain during movement (31.0% vs 59.0%; aRR: 0.38; P = 0.001) at postoperative 7 days was also significantly lower in the dexmedetomidine group than in the placebo group. The EQ-5D-5L score of the dexmedetomidine group was significantly higher than that of the placebo group at postoperative 7 days. However, there were no significant differences in depression, anxiety, sleep disturbance, pain incidence, and quality of life scores between the two groups at postoperative 30 days. CONCLUSIONS: Intraoperative dexmedetomidine significantly reduced the incidence of depression, delirium, anxiety, sleep disturbance, and pain and improved quality of life in adult cardiac surgery patients at postoperative 7 days. But dexmedetomidine did not reduce depression, anxiety, pain and sleep disturbance in patients undergoing cardiac surgery at postoperative 30 days.