Each study drug will be loaded in 50 ml syringes (for both bolus and infusion) & labeled as "study drug bolus" and "study drug infusion". The identity of the constituted drug in the syringe is not revealed to the anesthetist handling the patients and the observer recording the post procedure variables. Depending upon the body weight, each patient will receive a bolus of the study drug, diluted up to 50 ml with saline (direct IV)followed by infusion of the same drug in another 50 ml using a syringe pump. Each bolus will be given and the rate of drug infusion will be adjusted by the anesthesia resident not involved in the study.