Comparative study between dexamethasone and dexmedetomidine as an adjuvant to ondansetron for the prevention of postoperative nausea and vomiting following functional endoscopic sinus surgery operation

Background Postoperative nausea and vomiting (PONV) are the most common annoying events and complications following general anesthesia and surgery. Emetic incidents can lead to aspiration of gastric contents, wound unsealing, psychological distress, and delayed recovery from anesthesia and discharge times. Aim This study was designed to compare the effects of a single dose of dexmedetomidine or dexamethasone as an adjuvant to ondansetron for reducing PONV after functional endoscopic sinus surgery operation and to assess if there is any advantage of one drug over the other. Patients and methods This study is a prospective randomized single-blind study. The study involved 60 patients with American Society of Anesthesiologists physical status I and II, of both sexes, between 18 and 50 years of age, undergoing elective functional endoscopic sinus surgery operation. At the end of surgery, patients were randomly allocated to receive an intravenous single dose of either 0.1 mg/kg of ondansetron as a control group, or 8 mg of dexamethasone following 0.1 mg/kg of ondansetron, or dexmedetomidine 0.1 μ/kg following 0.1 mg/kg ondansetron. Postoperatively, all the incidents of nausea, retching and/or vomiting were recorded and patients were asked if vomiting had occurred or if the patients felt nauseated with only two possible answers (yes or no). Results There was no significant differences among the three groups regarding the incidence of PONV during the first 24 h postoperatively, with a slight difference in the ondansetron–dexmedetomidine (ondan–dexmed) group, which was less in frequency in relation to the other groups (P<0.211). Regarding the PONV incidence in relation to intraoperative and postoperative medications, there was a highly significant difference among the three groups regarding the severity of PONV. The PONV severity was lower in the ondan–dexmed group in relation to the other groups (P<0.001). The metoclopramide dose during the following 24 h was significantly low in ondan–dexmed group in relation to the other groups (P<0.001). The tramadol dose during the following 24 h was significantly low in ondan–dexmed group in relation to the other groups (P<0.001). The intraoperative fentanyl requirements was significantly lower in ondan–dexmed group in relation to the other groups (P<0.001). Regarding the first analgesic request, it was significantly delayed in ondan–dexmed group in relation to the other groups (P<0.021). Conclusion A single dose of dexmedetomidine combined with ondansetron is superior to ondansetron alone or ondansetron combined with dexamethazone for preventing PONV in patients undergoing functional endoscopic sinus surgery under general anesthesia.