Dexmedetomidine and postoperative dementia risk in older patients.

Background: Postoperative cognitive decline (POCD) and dementia are significant risks in older patients after surgery. Dexmedetomidine, an α2-adrenergic agonist, has shown neuroprotective properties in preclinical models, but its role in preventing dementia in postoperative patients remains unexplored.

Methods: We conducted a retrospective cohort study using data from Taiwan's National Health Insurance Research Database from 2012 to 2020. The cohort included 59 194 older patients (≥70 years) who underwent hip fracture surgery. Patients were categorised based on postoperative dexmedetomidine use. The primary outcome was the incidence of dementia, including Alzheimer's disease (ad) and vascular dementia (VaD), assessed using multivariable Cox regression models adjusted for confounders. Competing risk analysis was also performed.

Results: Patients administered dexmedetomidine postoperatively had a significantly lower risk of dementia compared to those who did not receive the drug [adjusted hazard ratio (aHR) 0.53, 95% confidence interval (CI) 0.45-0.60]. The reduction in ad risk was more pronounced (aHR 0.38, 95% CI 0.30-0.47) compared to VaD (aHR 0.58, 95% CI 0.49-0.68). These effects persisted after adjusting for confounders, including age, sex, comorbidities, and socioeconomic factors.

Conclusions: This study is the first to provide clinical evidence supporting dexmedetomidine's potential in reducing dementia risk, particularly ad, in older postoperative patients. Further randomised trials are needed to confirm these findings and determine the optimal use of dexmedetomidine in postoperative care. If validated, dexmedetomidine could become a critical strategy in reducing the long-term cognitive burden in ageing populations.