Ondansetron Versus Lidocaine for Preventing Pain on Propofol Injection.

This is a prospective, single-center, randomized, double-blind controlled trial involving patients scheduled for elective surgery requiring general anesthesia with propofol induction. Participants are randomly assigned to one of three groups: the ondansetron group (8 mg IV), the lidocaine group (40 mg IV), or the control group (0.9% normal saline placebo). Study medications are administered intravenously over 5 minutes, ending 1 minute before anesthetic induction. the goal: To assess the efficacy of intravenous ondansetron versus lidocaine and placebo in reducing the incidence and intensity of pain associated with propofol injection in patients undergoing general anesthesia.