A comparative study on anti-emetic effect of dexamethasone versus ondansetron in patients undergoing major gynaecological surgery-a prospective, randomized double blind study

Context: Postoperative nausea and vomiting (PONV) remains a common problem after major gynaecological surgeries and contributes to patient dissatisfaction. The type of surgery, choice of anesthetic technique and use of opioid analgesics can all influence the incidence of PONV. Additional factors influence the incidence of PONV which include previous history of motion sickness, gender, smoking status, pregnancy, phase of the menstrual cycle, preoperative hydration and perioperative hypotension.
Aim: To evaluate the antiemetic efficacy of dexamethasone and ondansetron in patients who had undergoing major gynaecological surgeries with respect to the use of rescue antiemetic agent.
Settings & Design: We conducted a prospective randomized double blind study in fifty female patients who underwent major gynaecological surgeries. Patients were randomized to receive either dexamethasone 8mg (group A) or ondansetron 4mg (group B) 30 minutes preoperatively. Patients were observed for the incidence of PONV. The severity of nausea was assessed using visual analog scale.
Statistical Analysis used: The results were entered in excel sheet. Students t test and Chi square test were used for quantitative and qualitative data respectively.
Results: The mean value of worst possible nausea score using Visual Analog Scale was found to be 2.64±1.55 and 3.30±1.47 (p value of 0.0984) of group A and group B respectively. The time to rescue antiemetic usage was prolonged in dexamethasone group.
Conclusion: From our study we conclude that 8mg of dexamethasone is more effective than 4mg of ondansetron in preventing PONV after major gynaecological surgeries. But the clinical profile of both drugs needs to be studied in detail by using large sample size.