One hundred twenty-six older adults undergoing lower-extremity orthopedic surgery under spinal anesthesia were randomized in a single-blind, parallel-group trial to receive intraoperative sedation with either remimazolam or dexmedetomidine. All patients received standardized spinal anesthesia with hyperbaric bupivacaine. The primary outcome was the incidence of hemodynamic fluctuations, specifically hypotension and bradycardia. Secondary outcomes included cumulative norepinephrine and atropine use, serial measurements of mean arterial pressure and heart rate, and adverse events such as post operative nausea and vomiting (PONV), postoperative delirium, and hypoxemia. Overall, the results of the study revealed that remimazolam significantly reduced the incidence of hypotension and bradycardia, required less vasoactive support, and demonstrated faster recovery of hemodynamic parameters compared with dexmedetomidine, while maintaining similar rates of non-cardiovascular adverse events. These findings suggest remimazolam offers superior hemodynamic stability for sedation in older patients undergoing spinal anesthesia.