The impact of dexmedetomidine on postoperative delirium and early postoperative cognitive impairment in elderly patients undergoing general surgery: a systematic review and meta-analysis.

Anesthetic management in general surgery poses substantial risks in elderly patients because age-related physiologic decline and preexisting comorbidities increase vulnerability to peri-operative complications. Older adults have reduced physiological reserve, impaired organ function, and slower recovery from surgical and anesthetic stress, placing them at increased risk for postoperative delirium and early postoperative cognitive impairment. Dexmedetomidine, a selective α2-adrenergic receptor agonist, has sedative, anti-inflammatory, and opioid-sparing properties that may influence early postoperative cognitive outcomes without significant respiratory depression. This systematic review and meta-analysis evaluated the association between dexmedetomidine and 24-h postoperative delirium/early postoperative cognitive impairment in elderly patients undergoing general surgery. Four studies involving 479 patients met the inclusion criteria. Across the included studies, dexmedetomidine was generally administered as a 1 µg/kg loading dose followed by continuous intraoperative maintenance infusion of 0.2-0.7 µg/kg/h. Pooled analysis showed that dexmedetomidine was associated with significantly lower odds of 24-h postoperative delirium/early postoperative cognitive impairment compared with control treatment (pooled OR 0.38, 95% CI 0.24-0.61; p < 0.001). These findings suggest that dexmedetomidine is associated with lower odds of early postoperative cognitive outcomes in elderly surgical patients compared with control treatment. Larger, long-term studies are needed to confirm these findings and establish standardized dosing protocols.