Comparison of ondansetron with ondansetron and dexamethasone in prevention of PONV in diagnostic laparoscopy

Abstract

Purpose: To compare the efficacy of ondansetron-dexamethasone combination with ondansetron alone for prevention of postoperative nausea and vomiting (PONV).

Methods: This double blind, randomized study was carried out in 51 female patients, aged 20-40 yr, ASA-1 physical status undergoing gynecological diagnostic laparoscopy. Group 1 (n = 26) received 4 mg ondansetron i.v. and group 2 (n = 25) received a combination of 4 mg ondansetron and 8 mg dexamethasone i.v. soon after induction of anesthesia. Postoperatively patients were assessed hourly for four hours and then at 24 hr for nausea, vomiting, pain and post anesthetic discharge score. Vomiting occurring up to two hours was considered early vomiting and from 2-24 hr as delayed vomiting.

Results: The postoperative nausea score was lower in patients receiving a combination of ondansetron and dexamethasone (3.76) than ondansetron alone (4.38) at 0 hr (P < 0.01), 2 hr (P < 0.05) and 24 hr (P < 0.01). In group 1, 38.5% of patients had a nausea score of > or = 5 (major nausea) compared with only 12% of patients in group 2 (P < 0.025). The overall incidence of vomiting was greater in group 1 (35%) than in group 2 (8%) (P < 0.05). The combination group showed better control of delayed vomiting compared with the ondansetron group (4% vs 35%) (P < 0.01).

Conclusion: The combination of ondansetron and dexamethasone provides adequate control of PONV, with delayed PONV being better controlled than early PONV.