Abstract: AIM: To observe the effect of dexmedetomidine on patients with anesthesia hypertension about stress reaction between the extubation period.METHODS: 60 patients with previous history of hypertension, stable blood pressure control, gastric cancer surgery were enrolled in the research. The patients were randomly divided into dexmedetomidine 0.5 μg/kg group (group D₁), dexmedetomidine 1 μg/kg group (group D₂) and saline control group (group C), n=20. All the patients were used inhalation anesthesia. Dexmedetomidine 0.5 μg/kg,1 μg/kg, and normal saline 20 mL were given with micro-pumps intravenous inject at 60 min before the end of surgery,the infusion time was 30 min. Before anesthesia, before extubation, after extubation 1,3,5,10 min ,the hemodynamic parameters were recorded,the levels of plasma epinephrine (E), norepinephrine (NE), cortisol (COR), glucose (GLU), blood lactate (LAC)were determined, and the levels of lanesthesia time, wake time, extubation time were recorded.RESULTS: The levels of MAP, HR,plasma E, NE, COR, GLU, LAC in three groups were significantly higher than those of before anesthesia (P<0.01 or P<0.05). The levels of MAP, HR,plasma E, NE, COR, GLU, LAC in group C were higher than those of group D₁, group D₂ (P<0.01 or P<0.05). The levels of wake-up time, extubation time in group D₂ were higher than those of group C , group D₁ (P<0.05).CONCLUSION: Dexmedetomidine can inhibit the stress response which is caused by tracheal extubation,and the appropriate dose is 0.5 μg/kg.

Key words: Extubation period, Stress response, Dexmedetomidine