Prophylactic Ondansetron versus Glycopyrrolate for the Prevention of Hypotension Following Spinal Anaesthesia in Patients Undergoing Transurethral Resection of the Prostate: A Randomized Controlled Study

Background: Hypotension is a common adverse effect observed in patients undergoing spinal anaesthesia, particularly in older adults. Prophylactic administration of agents like glycopyrrolate and ondansetron has been explored to mitigate this risk. In this study, we aimed to compare the efficacy of intravenous glycopyrrolate and ondansetron in preventing spinal anaesthesia-induced hypotension in patients undergoing trans-urethral resection of prostate (TURP). The secondary objective was to determine the requirement for ephedrine across the study groups.
Methodology: A total of 135 patients in the American Society of Anaesthesiologists (ASA) physical status I or II category, scheduled for elective TURP surgery under spinal anaesthesia, were enrolled in the study. Patients were randomly assigned to three groups: Group A (n = 45) received 0.2 mg of glycopyrrolate, Group B (n = 45) received 4 mg of ondansetron, and Group C (n = 45) received 2 mL of normal saline intravenously, 5 minutes before spinal anaesthesia. Following the standard spinal anaesthesia procedure, vital signs were monitored to detect hypotension.  Ephedrine requirements across the study groups were also measured.
Results: Group A demonstrated the lowest incidence of hypotension (26.6%; CI: 14.6–41.1), followed by Group B (33.3%; CI: 20.0–48.2), compared to Group C (55.5%; CI: 40.0–70.1) (p < 0.001). Ephedrine was required in 22.2% (95% CI: 11.2–36.9), 28.8% (95% CI: 16.6–44.0), and 48.8% (95% CI: 33.3–64.5) in Groups A, B, and C, respectively (p = 0.020).
Conclusion: Both ondansetron and glycopyrrolate effectively reduced the incidence of hypotension following spinal anaesthesia in patients undergoing TURP surgery. Although the incidence of hypotension was numerically lower with glycopyrrolate than with ondansetron, this difference was not statistically significant. Their prophylactic use may enhance haemodynamic stability in this high-risk group.