Effects of dexmedetomidine on stress reaction and recovery time during tracheal extubation in old patients with hypertension

Objective To explore the effects of dexmedetomidine( DEX) on stress reaction and recovery time during tracheal extubation in the elderly patients with hypertension. Methods Forty patients with primary hypertension of Ⅰto Ⅱ degree,aged 60 to 76,American Society of Anesthesiology Ⅰ and Ⅱ,scheduled for selective operation,were recruited in this study. The subjects were randomly assigned into dexmedetomidine group( Group D) and control group( Group C) with 20 cases in each group to receive intravenous plus inhalation anesthesia. At 30 minutes prior to the end of surgery, patients in the dexmedetomidine group were subject to intravenous 0. 5 μg / kg dexmedetomidine via micropumps for 15 minutes,while the control group received intravenous normal saline via micropumps. Heart rate( HR),mean artery blood pressure( MAP),SpO 2,epinephrine( E) and norepinephrine( NE) in both groups were recorded before the DEX application( T0),immediately before extubation( T1),immediately after extubation( T2),3 min( T3) and 5 min after extubation( T4),respectively. Recovery time of autonomous respiratory,wake-up time and extubation time on consciousness were also documented. Results In group C,HR were significant higher at time of T1- T4 compared to T0( P 0. 01),MAP were significant higher at time of T1- T4 compared to T0( P 0. 05 or P 0. 01); In group D,HR at time of T2 and T3, MAP at time of T2 and T3 were higher compared to T0( P 0. 05),but MAP and HR were significantly lower than group C( P 0. 01); In group C,E were significant higher at time of T1- T4 compared to T0( P 0. 05 or P 0. 01),NE were significant higher at time of T1- T4 compared to T0( P 0. 01),In group D,E were significant higher at time of T1- T4 compared to T0( P 0. 05 or P 0. 01),NE were significant higher at time of T1- T4 compared to T0( P 0. 05 or P 0. 01),but E and NE were significantly lower than group C( P 0. 01); There was no significant difference in recovery time of autonomous respiratory,wake-up time and extubation time on consciousness( P 0. 05). Conclusion Dexmedetomidine before the end of surgery can inhibit stress response and stability hemodynamic during extubation for the elderly patients with hypertension,and not prolong the breathing recovery time,wake-up time and extubation time.