Objective  To investigate the effect of naloxone on awakening quality and cognitive function for aged patients undergoing dezocine and propofol anesthesia under painless colonoscopy.

  Methods  A total of 72 aged patients under painless colonoscopy were randomly divided into observation group (n=36) and control group (n=36). All patients received intravenous anesthesia with propofol (0.05 mg/kg) and dezocine(1~2 mg/kg). The observation group was intravenous injrcted 0.2 mg naloxone and the control group was intravenous injrcted normal saline in the same amount after examination. The mean arterial pressure (MAP), heart rate (HR), blood oxygen saturation (SpO₂), awaken time, recovery time of orientation, time of normally walking and Ramsay sedation score at 5 and 10 min after surgery before anesthesia, after anesthesia, before microscopic examination, after microscopic examination, before leaving the hospital were recorded. The incidence of side effects such as postoperative nausea and vomiting, and dizziness as well as abdominal pain were recorded, and cognitive function before and 30 minutes after the examination was assessed by Mini-Mental State Examination (MMSE).

  Results  Compared with the control group, recovery time of orientation and time of normally walking were significantly shortened, and Ramsay sedative scores after surgery and the incidence of postoperative dizziness were significantly reduced(P < 0.05). MMSE score of both groups decreased at 30 min after examination, but there was no significant difference between the two groups(P>0.05).

  Conclusion  Naloxone for aged patients after undergoing dezocine and propofol anesthesia provides a high recovery quality in painless colonoscopy examination, and can shorten hospital discharge time, reduce the incidence of side effects. There was no significant effect on early cognitive function in aged patients after the procedure.