Inclusion Criteria:  Adult woman scheduled for gynecological surgery under general anesthesia American Society of Anesthesiology grade 1 or 2 When using a laryngeal mask airway to maintain general anesthesia  Exclusion Criteria:  Underlying diseases: liver, kidney, brain nervous system, glaucoma Patients with BMI greater than 30 and less than 18.5 Patients diagnosed with sleep apnea Alcohol or drug dependent patients Patients with severe or acute respiratory failure Lactose intolerance Dextran 40 hypersensitivity Patients in shock or coma