Prophylactic Effects of Ondansetron, Ramosetron, and Palonosetron on Patient-Controlled Analgesia Related Nausea and Vomiting After Urologic Laparoscopic Surgery

Inclusion Criteria: * ASA I or II * Patients aged (20-65 yr) Undergoing Laparoscopic Nephrectomy * Patients who want a patient-controlled IV analgesia (IV-PCA) Exclusion Criteria: * History of allergy or hypersensitivity to 5-HT3 antagonist * History of severe postoperative nausea/vomiting * Prolonged QT interval on preoperative EKG * Hypokalemia, Hypomagnesemia * Intestinal obstruction * Pregnant female or breast feeding mother