BACKGROUND: Postoperative delirium (POD) is a common neurocognitive complication after type A aortic dissection (TAAD), which seriously affects the recovery of patients, and the current intervention timing and treatment methods are still uncertain. This prospective observational cohort study aimed to discuss the effect of dexmedetomidine on POD in patients undergoing TAAD surgery. METHODS: Between February 2022 and March 2023, 167 eligible patients aged 18 to 85 years who underwent TAAD surgery participated in this study. The patients were assigned to either the dexmedetomidine or the control group, which did not receive dexmedetomidine treatment. The primary outcome of interest was the incidence of delirium within five days following surgery. Secondary outcomes included intubation duration, length of stay in the intensive care unit (ICU), total postoperative hospital stay, incidence of non-delirium complications, and all-cause mortality within seven days. To account for differences in baseline characteristics between the groups, propensity score matching (PSM) was utilized. RESULTS: Before PSM, the dexmedetomidine group was made up of 120 patients, whereas the control group comprised 47. The occurrence rate of POD increased from 35.0% in the dexmedetomidine group to 42.6% in the control group, but there was no significant difference [odds ratio (OR) 0.73
95% confidence interval (CI): 0.37-1.45
P=0.36]. After 1:1 PSM, there were 42 patients in each of the dexmedetomidine and control groups. The occurrence of POD was 28.6% and 45.2% in the dexmedetomidine and control groups, respectively, with no statistically significant difference observed (OR 0.48
95% CI: 0.20-1.20
P=0.12). The dexmedetomidine group showed a shorter ICU hospitalization time and postoperative hospital stay than the control group, but the differences were not statistically significant. Furthermore, the two groups had no statistical differences in other secondary outcomes. CONCLUSIONS: Intraoperative dexmedetomidine did not decrease the occurrence rate of POD in TAAD patients. Additionally, no significant differences were observed between the dexmedetomidine and control groups regarding the occurrence of non-delirium complications, intubation time, ICU hospitalization time, and postoperative hospital stay.