Abstract: Objective To observe the effects of different doses of intranasal dexmedetomidine on stress response during extubation in the elderly patients after laparoscopic surgery. Methods A total of 80 elderly patients with selective laparoscopic renal cystectomy were randomly divided into control group and intranasal dexmedetomidine groups with different doses. Low-dose group, middle-dose group and high-dose group received 0.5 μg/kg, 1 μg/kg and 1.5 μg/kg intranasal dexmedetoidine 30 min before the end of the operation respectively, and control group was given 2 mL intranasal 0.9% sodium chloride solution. Heart rate (HR) and mean arterial pressure (MAP) were recorded at the end of operation (T1), during extubation (T2), 1 min after extubation (T3), 5 min after extubation (T4), and 10 min after extubation (T5), respectively. Postoperative recovery indicators were recorded. Results Compared with control group, the level of MAP in intranasal dexmedetomidine groups decreased significantly and the level of HR decreased significantly at T1-T5 (P<0.05). Compared with low-dose group, the level of HR in middle-dose group and high-dose group decreased significantly at T2-T5, and the level of MAP decreased significantly at T2-T3 (P<0.05). The extubation time and post anesthesia intensive care unit (PACU) observation time in control group, low-dose group and middle-dose group were significantly shorter than those in high-dose group (P<0.05). Ramsay score in intranasal dexmedetomidine groups at T5 was significantly higher than that in control group. However, the patients in high-dose group only responded to instructions (P<0.05). Conclusions The administration of 1 μg/kg intranasal dexmedetomidine 30 min before the end of laparoscopic renal cystectomy in the elderly patients can effectively inhibit the stress response during periextubation without affecting the postoperative recovery time.

Key words: intranasal dexmedetomidine, extubation period, stress response, aged