Nitrous Oxide Added at the End of Sevoflurane Anesthesia and Recovery

Inclusion Criteria: * Adult patients, American Society of Anesthesiologists Physical status ASA PS I-III, scheduled for laparotomic and laparoscopic surgery expected to last 2 hours or more who can understand and signed informed consent. Exclusion Criteria: * Patients who will be discharged within 72 hours after surgery * Patients on intensive care within few months before the study enrollment * Diseases that impair gastric motility (diabetes mellitus, chronic cholecystitis, gastric and intestinal disease, neuromuscular disorders, neuropathies, liver dysfunction) * Vestibular disease; history of migraine headaches, central nervous system injury * Renal impairment * Patients on antihistamines, antipsychotics, contraceptives, steroids within 72 hours before surgery * Known hypersensitivity to drugs used in the study protocol * Alcoholism, and/or opioid addiction * Conditions that can influence the incidence of PONV, postoperative pain or morbidity (e.g., significant intraoperative surgery complications), intraoperative drug allergy, severe intraoperative hypotension, perioperative hypoxia, excessive blood loss, difficult intubation