Objective  To explore the effect of dexmedetomidine combined with comprehensive body temperature protection on postoperative delirium and the levels of serum S100 beta(S100β), neuron specific enolase (NSE) in elderly patients with malignancies.

  Methods  A total of 90 elderly patients undergoing elective malignant tumor surgery were randomly divided into three groupscontrol group (group C, n=30), temperature protection group (group T, n=30) and temperature protection combined with dexmedetomidine group (group T-D, n=30). Routine thermal insulation in operation was adopted in the group C, while the group T and group T-D adopt comprehensive body temperature protection measures. In group T-D, dexmedetomidine was given at a dosage of 0.5 μg/kg 10 min before anesthesia induction. The nasopharyngeal temperature was recorded at induction of anesthesia (T₀), 0.5 h after operation (T₁), 1 h after operation (T₂), 1.5 h after operation (T₃), 2 h after operation (T₄) and completion of operation (T₅). The incidence of emergence agitation, chills and postoperative delirium were recorded. Serum S100β, NSE levels in three groups were measured at 10 min before induction of anesthesia, 24 h and 72 h after operation.

  Results  Compared with T₀, the nasopharyngeal temperatures in the group C at T₁ to T₅ time points were significantly decreased (P < 0.05), and were obviously higher in the group T and group T-D at T₂ to T₅ time points than those in the group C (P < 0.05). The incidence rates of emergence agitation, postoperative delirium and chills in the group T, group T-D were significantly lower than those in the group C (P < 0.05). Compared with the group T, the incidence rates of emergence agitation and postoperative chills were further decreased (P < 0.05). Compared with the group C and group T, serum S100β and NSE levels in the group T-D at 24 h and 72 h after operation were significantly decreased (P < 0.05).

  Conclusion  The combination of dexmedetomidine and comprehensive body temperature protection can obviously decrease the levels of serum S100β and NSE, and effectively reduce the incidence of postoperative delirium, emergence agitation and postoperative chills.