We designed this randomized, double- blind, single-center study to compare the efficacy of the combination of dexamethasone with ondansetron and dexamethasone with dimenhydrinate undergoing plastic surgery.

A total of 60 voman patient, ASA status I-II , aged 18-65 year and scheduled for elective rhinoplasty were enrolled in the study. Exclusion criterias hypersensitivity or contraindication for the studied medications, received an antiemetic drug or steroid within 24 hours before anesthesia, have history of diabetes history of motion sickness (MS) or PONV, or pregnant and lactating females.

Patients were informed on how to use the patient controlled analgesia device during the postoperative period. The risk criterias for PONV were recorded for each patient.Patients were randomly assigned to two study groups of 30 patients. All patients were premedicated with intravenous (iv) midazolam (1-2 mg). On arrival in the operating room, standard anesthetic monitors were applied. Anesthesia was induced with iv propofol (2-3 mg/kg) and fentanyl (1-1.5 μg/kg). Tracheal intubation was facilitated with rocuronium (0.6 mg/kg). After tracheal intubation all patient received iv 8 mg dexamethasone. Normocapnic mechanical ventilation was performed after intubation. General anesthesia was maintained with sevoflurane (1 minimum alveolar concentration) in oxygen / air mixture and remifentanil (0.1-0.3 μg/kg/min) infusion.Four mg ondansetron and for each patient 1 mg/kg dimenhydrinate in the 5 ml syringe solution were prepared by pharmacy department, and given to the blinded investigators. The patients, anesthesiologists (with the exception of the primary author), statistician, and observes were all blinded.

Dimenhydrinate was administered in group DD (1mg/kg), and ondansetron was administered in group DO (4mg), and all patients received tramadol (1.5mg/kg) and tenoksikam (20mg) half an hour before emergence.

Postoperative analgesia was provided with a patient controlled analgesia system by using iv tramadol (5mg/mL) (2 ml bolus and 10 minutes lockout interval without basal infusion).

After the surgery, muscle relaxation was reversed by administering neostigmine (0.05mg/kg) and atropine (0.015mg/kg). Patients were extubated and transferred to the recovery unit.

Criteria:

Inclusion Criteria:

18 Years to 60 Years woman

ASA (American Society of Anesthesiologist) physical status I or II

Patients undergoing laparoscopic gynecologic surgery or laparoscopic cholecystectomy

Exclusion Criteria:

Hypersensitivity or contraindication to the study medications,

Antiemetic drug or steroid use within 24 hours before anesthesia,

History of diabetes mellitus,

History of motion sickness or postoperative nausea and vomiting,

Pregnancy,

Breast feeding