control group:After induction of anaesthesia, sufentanil 0.1ug/kg was given intravenously 10min before head-stapling.

Canceled by the investigator. The effect of frontal infiltration and intravenous dexmedetomidine on the stress factors and haemodynamic response to skull-pin placement for craniotomy

The effect of dexmedetomidine and local infiltration on the haemodynamic and stress response and to skull-pin placement for craniotomy