Efficacy of Gabapentin versus Combination of Dexamethasone-Ondansetron in Prevention of Postoperative Nausea and Vomiting in Middle Ear Surgery: A Randomised Clinical Study

Abstract

Introduction: Postoperative Nausea and Vomiting (PONV) is the most common and unpleasant complication with incidence of 30-80% after elective surgery. Dexamethasone and Ondansetron (DO) combination has superior efficacy and is recommended as an ideal choice for prevention of PONV in Middle Ear Surgery (MES). Oral Gabapentin, an anticonvulsant has been introduced as an antiemetic to fast-track bundles and enhanced recovery after surgery. Aim: To compare the efficacy of DO with gabapentin monotherapy in prevention of PONV in patients undergoing MES. Materials and Methods: This randomised, double-blind, parallel group clinical study was done at Department of Anaesthesiology, St John’s Medical College, Bengaluru, Karnataka, India from November 2018 to March 2020. Sixty-six of patients were randomised to Group DO (Intravenous Dexamethasone at start and Ondansetron at end of surgery, 100 μg/kg each) and Group G (Oral Gabapentin 300 mg one hour prior to surgery). Postoperatively, incidence and severity of PONV, duration of antiemesis and analgesia, total rescue antiemetics and analgesics, along with side-effects were assessed for 24 hour period. Descriptive statistics was summarised for continuous (mean and standard deviation) and categorical (number with percentages) variables. Inferential statistics were depicted using Fisher’s-exact and Student’s t-test. Results: The demographic profile was comparable between the two groups. Incidence of PONV was significantly lesser in Group DO compared to the Group G (12% versus 36%, p-value=0.0129). Duration of antiemesis was four hours in Group DO and two hours in Group G was statistically significant (p-value=0.021). Severity of PONV was significant (p-value=0.033 and 0.009, respectively) at four and six hours between the groups. Duration of analgesia (6.28±5.96 in Group DO versus 5.62±3.63 hours in Group G; p-value=0.252), rescue analgesics and side-effects were comparable between the two groups (p-value>0.05). Conclusion: In MES, DO combination reduced the incidence and severity of PONV and is better prophylactic antiemetic therapy than gabapentin alone.