 Patient will be ventilated with TV of 6-8mlkg,respiratory rate will be adjusted to maintain end-tidal CO2 value between 40 - 45 mmHg. Crystalloids will be used for hydration 4-6 mlkgh, and intraoperative volume deficits will be replaced by additional administration of a solution according to clinical needs. For TIVA group, the depth of anaesthesia will be monitored using Bispectral Index, with target BIS value between 40 and 60. For Sevoflurane group, the depth of anaesthesia will be monitored using MAC, with target MAC value between 0.8 and 1. Half hour before conclusion of surgery, all patients will receive 0.1mgkg of ondansetron as prophylaxis for PONV. At the end of surgery, muscle relaxation will be reversed by glycopyrrolate 10mcgkg and neostigmine 50mcgkg. 