Comparison of Intravenous Dexmedetomidine Versus Dexmedetomidine-Dexamethasone Combination for Preventing Postoperative Nausea and Vomiting in Adult Patients After Abdominal Surgeries.

Introduction:  Postoperative nausea and vomiting (PONV) is a common problem following general anesthesia and is one of the most unpleasant side effects that affects the patient after surgery and is the worst memory of the hospital stay. The present prospective randomized comparative study was designed to compare the effect of intravenous dexmedetomidine with dexmedetomidine-dexamethasone combination for preventing PONV following abdominal surgeries in adult patients and evaluating their sedative and analgesic effects.

Methodology: A total of 75 patients (aged 18-65 years) were assigned to undergo this comparative study via block randomization using a sealed envelope system. They were divided into three groups of 25 each: group A (control) received normal saline, group B received dexmedetomidine, and group C received a combination of dexmedetomidine with dexamethasone over 10 minutes after inducing general anesthesia before skin incision. The primary outcome was to assess PONV, where nausea was assessed by the numerical rating scale and vomiting by the number of gastric content expulsions. The secondary outcome, which is postoperative sedation and pain, was assessed by the Ramsay Sedation Score and Visual Analog Score, respectively, for 24 hours postoperatively.

Result:  During the first 24 hours after surgery, the incidence of PONV was similar in both dexmedetomidine and combination groups but lower than the control group. Postoperative sedation and analgesia were both statistically and clinically adequate and similar in dexmedetomidine and combination groups. No major side effects requiring pharmacological intervention were reported.

Conclusion:  Dexmedetomidine alone is as effective as its combination with dexamethasone in preventing PONV in adult patients following abdominal surgeries.