Fig. 3

Overall fluctuation of mean arterial pressure (MAP) and heart rate (HR) compared to the baseline values in the 5 groups. Values are expressed as mean ± SD. △T1 = T0-T1, △T2 = T0-T2, △T21 = T0-T21, △T22 = T0-T22, △23 = T0-T23, △T3 = T0-T3, △T4 = T0-T4, △T502 = T0-T502, △501 = T0-T501, △T5 = T0-T5, △T6 = T0-T6, △T61 = T0-T61, △62 = T0-T62, △63 = T0-T63, △64 = T0-T64, △65 = T0-T65, △66 = T0-T66, △T7 = T0-T7, △T8 = T0-T8, △9 = T0-T9, △10 = T0-T10. T0: baseline, T1: start anaesthesia induction, T2: endotracheal intubation, T21, 22, 23: 5, 10, 15 min after endotracheal intubation, T3: skin incision, T4: end of operation, T502, 501: 10, 5 min before awakening, T5: awakening, T6: endotracheal extubation, T61, 62, 63, 64, 65, 66: 5, 10, 15, 20, 25, 30 min after endotracheal extubation, T7: 30 min after operation, T8, 9, 10: 1, 2, 6 h after operation. Group MD: midazolam 0.03 mg/kg for anaesthesia induction. Group NS: normal saline at the rate of 60 ml/h for 15 min before anaesthesia induction + 0.125 ml/kg/h continuous infusion until the end of operation. Group D0.25: dexmedetomidine 0.25 μg/kg for 15 min before anaesthesia induction + 0.5 μg/kg/h continuous infusion until the end of operation. Group D0.5: dexmedetomidine 0.5 μg/kg for 15 min before anaesthesia induction + 0.5 μg/kg/h continuous infusion until the end of operation. Group D0.75: dexmedetomidine 0.75 μg/kg for 15 min before anaesthesia induction + 0.5 μg/kg/h continuous infusion until the end of operation