Objective To investigate the effect of 24-hour perioperative application of dexmedetomidine on the occurrence of postoperative atrial fibrillation and delirium in patients undergoing aortic root reconstruction.

Methods A total of 600 patients scheduled for elective cardiac surgery under cardiopulmonary bypass were selected as the study subjects. Eventually, 584 patients were included in the randomized grouping, with 292 patients in treatment group and 292 patients in control group. The treatment group received dexmedetomidine treatment, while the control group received saline placebo treatment. The occurrence of atrial fibrillation and delirium events, as well as other clinical indicators, in the two groups of patients within 5 days after surgery were observed, and the differences in atrial fibrillation and delirium events among different subgroups were analyzed.

Results The incidence rates of atrial fibrillation and delirium events within 5 days postoperatively in the treatment group were lower than those in the control group,with statistically significant differences (P＜0.05). Subgroup analysis showed that for atrial fibrillation events, dexmedetomidine had a protective effect when the cardiopulmonary bypass time was >180 min, the aortic cross-clamping time was >120 min. For delirium events, dexmedetomidine had a protective effect when the cardiopulmonary bypass time was ≤180 min, the aortic cross-clamping time was ≤120 min, there was no significant increase in creatinine, no significant decrease in left ventricular ejection fraction (LVEF), the European System for Cardiac Operative Risk Evaluation Ⅱ score at low risk, and the allogeneic red blood cell transfusion volume was ≤2 U.

Conclusion The 24-hour perioperative application of dexmedetomidine inpatients undergoing aortic root reconstruction can reduce the incidence of postoperative atrial fibrillation and delirium.