Effect of prophylactic ondansetron on vasopressor requirement following spinal anesthesia for elective surgeries: a randomized controlled double-blinded comparison with hydrocortisone and placebo

Background: Hypotension and nausea are frequently experienced side effects of spinal anesthesia. To counteract these complications, ondansetron has been proposed as an effective modality, but its effect on hemodynamic profile remains uncertain. Methods: This randomized controlled study included 120 patients planned to be spinally anesthetized for elective surgeries. They were allocated to receive either 100 mg hydrocortisone, 8 mg ondansetron, or placebo (40 each) 15 minutes before the spinal block. Hemodynamics, vasopressor administration, and nausea were recorded.Results: Hypotension in the ondansetron group occurred to 52.5% of the patients, compared to 25% of the hydrocortisone group and 65% of patients receiving placebo (P = 0.001). Nausea incidence was lower with ondansetron (2.5%) and hydrocortisone (2.5%) when compared to placebo (17.5%) (P = 0.01). Among patients who required ephedrine, total doses were significantly lower with ondansetron (11.4 ± 8.2 mg) and hydrocortisone (11 ± 10.5 mg) compared to placebo (23.7 ± 18.5 mg) (P = 0.004).Conclusion: Although Ondansetron didn’t demonstrate a reduction in the incidence of post-spinal hypotension when compared with hydrocortisone, it demonstrated evidenced reduction of vasopressor requirements and nausea incidence when compared with placebo. These findings support its use as a beneficial prophylactic agent during spinal anesthesia.