Analysis of decreases > 20% of haemodynamic baseline
We then evaluated the percentage of patients whose MAP and HR decreased > 20% of baseline in each group (Table Percentage
of mean arterial pressure (MAP) and heart rate (HR) decrease > 20% of baseline in the 5 groups. Values
are expressed as No. (%)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 operationWe also analysed the relative risk (RR) for MAP and HR below > 20% of baseline between the MD, D0.25, D0.5 and D0.75 groups and the NS group (Table Relative risks for mean arterial pressure (MAP) and heart rate (HR) decrease > 20% of baseline compared with Group NSGroup 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*Statistically significant (