Mechanism of action of dexmedetomidine on hemodynamics, analgesic and sedative effects and postoperative delirium in elderly patients undergoing hip fracture surgery

Objective: The research in this paper was to explore the mechanism of action of dexmedetomidine on hemodynamics, analgesic and sedative effects, and postoperative delirium in elderly patients undergoing hip fracture surgery. Methods: A total of 120 elderly patients with hip fracture were retrospectively analyzed for clinical data and divided into two groups based on anesthetics: Patients in group A (n=62) were given 0.5 mu g/kg dexmedetomidine as loading dose followed by 10 min later anesthesia induction before maintenance dose of 0.4 mu g.kg(-1).h(-1). Patients in group B (n=58) were given the same amount of normal saline. The bispectral index (BIS), diastolic blood pressure (DBP), systolic blood pressure (SBP), heart rate (HR), Price-Henry pain score, Ramsay sedation score, postoperative delirium and intraoperative use of anesthetic drugs were compared between the two groups at different time points. Results: At T4 and T5, DBP in group A were lower than those in group B; the overall fluctuation of DBP in group A was smaller than that in group B. The same was true for SBP, and HR. Scores on the Price-Henry pain scale in group A were notably lower than those in group B as specified 10 min, 1 h, and 6 h after operation (P<0.05). Little difference was found in Post-operative Ramsay scores for sedation (P>0.05). The incidence of postoperative delirium in group A was 6.45% (4/62), which was lower than that of 41.37% (24/58) in group B, showing significant difference (P<0.05). Conclusion: Dexmedetomidine is conducive to lowering the incidence of post-operative delirium in elderly patients undergoing hip fracture surgery, which keeps perioperative haemodynamics and therefore ideal analgesic and sedative effects.