Inclusion Criteria:  ASA I-II Undergo 2-4 hours of elective surgery  Exclusion Criteria:  Cardiovascular disease diabetes mellitus kidney, liver failure chronic obstructive pulmonary disease patients with opioid sensitivity morbidly obese personal or family history of malignant hyperthermia history of prolonged recovery from anesthesia alcohol addicted pregnant and breastfeeding women patients allergic to study drugs