Using Lidocaine or Dexmedetomidine to Help Control Blood Pressure Spikes From a Tourniquet During Knee Surgery

patients received Lidocaine 2%, 1 mg/kg, IV bolus over 10 mins after the induction of anaesthesia , followed by Lidocaine infusion (2 mg/kg/h) diluted in 50 ml of normal saline with a maximum dose of 200 mg/h. The tourniquet was inflated 10 minutes after the start of the Lidocaine infusion then the Lidocaine infusion stopped at the time of tourniquet deflation

patients received a loading dose of Dexmedetomidine-Pfizer (0.8 μg·kg-1 over 10 min) followed by continuous infusion of Dexmedetomidine (0.4 μg·kg-1.h-1) diluted in 50 ml of normal saline. The tourniquet was inflated 10 mins after the start of Dexmedetomidine infusion then the Dexmedetomidine infusion stopped at the time of the tourniquet deflation.