Abstract: Background　Although numerous anesthetic methods are currently available for endoscopic
dacryocystorhinostomy (En-DCR), research on sedative anesthesia remains relatively scarce. Objective　To investigate the efficacy of continuous dexmedetomidine infusion for sedative and analgesic anesthesia in endoscopic dacryocystorhinostomy. Methods　 Patients with chronic dacryocystitis who underwent endoscopic dacryocystorhinostomy at Shanxi Eye Hospital from 2021 to 2025 were enrolled and randomly assigned via block randomization to either the dexmedetomidine group (Group D) or the control group (Group C). Group D received a continuous infusion of dexmedetomidine hydrochloride at 1 μg/(kg·h) combined with propofol and remifentanil, while Group C received an equal volume of 0.9% sodium chloride injection combined with propofol and remifentanil. After 10 min of intravenous infusion, the dexmedetomidine dose in Group D was reduced to 0.6 μg/(kg·h), and the sodium chloride infusion in Group C was adjusted to an equal volume, with both infusions discontinued 5 min before the end of surgery. The primary outcome was the Fromme score during bone removal. Secondary outcomes included noninvasive mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), Ramsay Sedation Scale (RSS), as well as plasma norepinephrine and serum cortisol concentrations at the following time points: upon calm arrival to the operating room (T0), 10 min after drug administration (T1), 30 min after the start of surgery (T2), and 10 min after the end of surgery (T3). Results　In Group D, there were 40 cases (5 males and 35 females), with age ranging from 40 to 69 (56.80±7.56) years. In Group C, there were 40 cases (5 males and 35 females), with age ranging from 41 to 70 (54.15±8.11) years. There was no statistically significant difference in general data between the two groups (P＞0.05). Group D showed superior Fromme scores compared to Group C 2.00 (2.00, 3.00) vs 3.00 (2.25, 3.00), P=0.001. Significant reductions in MAP were observed in Group D at T1 and T2 when contrasted with Group C (T1: 60.88±3.80 bpm vs 64.75±4.32 bpm, P＜0.001;T2: 64.85±4.37 bpm vs 70.35±4.32 bpm, P＜0.001). At T1, T2, and T3, there was no significant difference in respiratory rate between the Group D and the Group C (P>0.05). At T1 and T2, the Ramsay score in the Group D was higher than that in the Group C T1: 4.00 (4.00, 4.00) vs 3.50 (3.00, 4.00), P＜0.001; T2: 4.50 (4.00, 5.00) vs 4.00 (4.00, 4.00), P＜0.001. The plasma norepinephrine concentration in the Group D was lower than that in the Group C at T2 and T3 (T2: 299.82±5.62 pg/mL vs 349.45±4.90 pg/mL, P＜0.001;T3: 249.49±5.08 pg/mL vs 300.29±5.31 pg/mL, P＜0.001). At T2 and T3, the serum cortisol concentration in the Group D was lower than that in the Group C (T2: 299.76±5.23 nmol/L vs 400.42±5.28 nmol/L, P＜0.001; T3: 400.25±5.51 nmol/L vs 500.62±5.41 nmol/L, P＜0.001). Conclusion　Continuous dexmedetomidine infusion for sedative and analgesic anesthesia in endoscopic dacryocystorhinostomy provides excellent sedative and analgesic effects, reduces blood pressure and heart rate, decreases intraoperative bleeding, attenuates the stress response, exerts minimal impact on respiratory rate, and demonstrates a high safety profile, making it suitable for clinical application.