To maximize the surgical visual field, Robot-assisted laparoscopic radical prostatectomy (RLRP) usually requires the patient to be positioned in a steep trendelenburg position in combination with prolonged intraperitoneal carbon dioxide (CO2) insufflation and increased intrabdominal pressure. Insufflations of CO2 during laparoscopic surgery, which causes stretch and irritation of the peritoneum, is known to play an important role in postoperative nausea and vomiting (PONV). In addition, prolonged pneumoperitoneum increases the risk for PONV. PONV can cause patient discomfort and prolong post anaesthesia care unit (PACU) stay. In addition, the patient with PONV is also predisposed to severe complications such as aspiration pneumonia, increased wound dehiscence, delayed recovery, prolonged hospital stay, and eventually increased medical cost.

To maximize the surgical visual field, Robot-assisted laparoscopic radical prostatectomy (RLRP) usually requires the patient to be positioned in a steep trendelenburg position in combination with prolonged intraperitoneal carbon dioxide (CO2) insufflation and increased intrabdominal pressure. Insufflations of CO2 during laparoscopic surgery, which causes stretch and irritation of the peritoneum, is known to play an important role in postoperative nausea and vomiting (PONV). In addition, prolonged pneumoperitoneum increases the risk for PONV. PONV can cause patient discomfort and prolong post anaesthesia care unit (PACU) stay. In addition, the patient with PONV is also predisposed to severe complications such as aspiration pneumonia, increased wound dehiscence, delayed recovery, prolonged hospital stay, and eventually increased medical cost. Therefore, as RLRP itself can be an important risk factor of PONV, the anaesthesiologist should give attention to prevent PONV in this patient group, although they usually have lower risk in terms of patient-related factors. Previously published studies have recommended antiemetic prophylaxis for the patients with moderate-to-high risk of PONV. However, despite routine use of prophylactic antiemetics, laparoscopic surgery has been associated with higher incidence of PONV.Previous clinical studies suggested that total intravenous anaesthesia (TIVA) with propofol reduced PONV significantly compared to inhaled anaesthetics. Also, several studies have recommended TIVA with propofol as the anaesthetic method in patients with high risk of PONV. However none of these studies were designed and powered to detect differences in PONV in patients undergoing laparoscopic surgery, especially RLRP.

Inclusion Criteria:

• Patients undergoing RLRP, ASA physical status I or II, age 50 to 70.

Exclusion Criteria:

• Emergency operation.
• patients with motion sickness or PONV history to control anticipated risk of PONV.
• Patients with antiemetic use within 24 hours before surgery.
• Patients with regular corticosteroid use.
• Patients with chemotherapy within 4 or radiotherapy within 8 weeks.
• Patients with allergy to any of the study drugs.
• Patients with liver dysfunction, confirmed renal impairment, or obesity (body mass index > 35 kg/m2).