Abstract: AIM: To explore the effects of preoperative application of dezocine patient-controlled analgesia pump on stress response and cognitive function in elderly patients with lower extremity fractures.  METHODS: A total of 80 elderly patients with lower extremity fractures who were treated from November 2018 to June 2020 were selected and randomly divided into a control group and a study group, 40 cases in each. The control group was not given a patient-controlled analgesia pump before anesthesia, and the study group was given intravenous analgesia with a dezocine patient-controlled analgesia pump before surgery. The postoperative stress response, cognitive function and safety were compared between the two groups.RESULTS: There were no significant differences in cognitive function MMSE score, stress response index (cortisol, epinephrine) levels, and inflammatory factors (IL-6, TNF-α) levels between the two groups before intervention (P>0.05). Compared with the indexes after operation, the MMSE scores of the study group at 12 h, 24 h and 3 days after operation were higher than those in the control group (P<0.05); The levels of cortisol, epinephrine, IL-6 and TNF-α in the study group were lower than those in the control group at 12 h and 24 h after operation (P<0.05); At the same time, the incidences of respiratory depression, urinary retention and nausea and vomiting in the study group were significantly lower than those in the control group (P<0.05).CONCLUSION: Preoperative application of dezocine patient-controlled analgesia pump in elderly patients with lower extremity fracture can significantly reduce postoperative stress response, reduce inflammatory response, and improve postoperative cognitive function, which is worthy of clinical application.

Key words: self-controlled, analgesia pump, elderly lower extremity fractures, stress response, cognitive function