Heart rate (HR), systolic blood pressure (SBP), mean arterial pressure (MAP), pulse oximetry (SpO2) , temperature and end tidal carbon dioxide (EtCO2) will be noted at the time of induction, intubation, incision, application of head pins, bone flap reflection, Dural reflection, clipping, Dural closure, skin closure and prior to cessation of anaesthesia. Patients heart rate and blood pressure will be kept as close to baseline as possible. Any sustained increase in BP more than 30% of the baseline values will be considered as intra-operative hypertension. Hypotension will be considered if MAP < 70 mmHg or SBP < 90 mmHg. The management of hypertension or hypotension will be at the discretion of the attending anesthesiologist.