Inclusion Criteria:  Patients 18-65 years old Patients withASA I and II Patients with body mass index (BMI) 21-29 kg/m2 Patients with admitted for elective VATS requiring OLV for about 1-1.5 h  Exclusion Criteria:  Patients with severe bronchial asthma Patients with chronic obstructive pulmonary disease Patients with severe renal insufficiency Patients with severe liver dysfunction Patients with cerebrovascular disease Patients with coagulopathy, uncontrolled diabetes mellitus Patients with uncontrolled hypertension Patients with cardiovascular disease Patients with mental disabilities Patients with hearing impairment were excluded