Abstract: Objective To investigate the efficacy of dexmedetomidine combined anesthesia on postoperative delirium in elderly patients undergoing radical resection of esophageal cancer. Methods Seventy patients with selective radical resection of esophageal cancer were selected and randomly divided into dexmedetomidine group(n=35)and control group(n=35)by random number table method. The dexmedetomidine group was intravenously pumped 0.8 μg/kg dexmedetomidine for 15 min before anesthesia induction, and was continuously infused at a speed rate of 0.4 μg/(kg·h)until 30 min before surgery completion. Patients in the control group received the same dosage of saline in the same way. Delirium-rating Scale-98 Revised(DRS-R-98)was used to assess the occurrence of delirium within 48 hours after operation. Percutaneous oxygen saturation(SpO₂), heart rate(HR)and mean arterial blood pressure(MAP)before anesthesia induction(T₀), at 1 hour after single lung ventilation(T₁), at the end of the operation(T₂)and at the time point of tracheal extubation(T₃), were recorded. Blood samples for 2 mL were collected from the jugular bulb before anesthesia induction(T₀), tracheal extubation(T₃)and at 48 h after operation(T₄)to determine the serum concentrations - of hypersensitive C reactive protein(hs-CRP). Results Compared with control group, the incidence of postoperative delirium was significantly decreased(P<0.05). Compared with T₀, the concentrations of hs-CRP at T₃ and T₄ in the two groups increased(P< 0.05); the concentrations of hs-CRP at T₃ and T₄ in dexmedetomidine group showed significant differences compared to the control group(P<0.05). Conclusion Continuous infusion of dexmedetomidine can significant decrease incidence of postoperative delirium in elderly patients undergoing radical resection of esophageal cancer. Its mechanism is related to stabilizing hemodynamics, and inhibiting inflammatory responses.