Interventions and anesthesia protocol
Participants were randomly assigned to one of the three groups: ibuprofen 800mg IV (Ibuprofen800, 800mg/8ml, Caspian, Rasht, Iran), meperidine 30 mg (Pethidine 100, 100mg/2ml, Caspian, Rasht, Iran) or normal saline as a placebo (8 ml). The allocation concealment was ensured using a random number generator, and the assignment results were placed into consecutively numbered sealed envelopes by a third person who was not involved in the trial. Neither the patients, the researcher responsible for data collection, nor the analyzer were aware of the assigned intervention, ensuring a triple-blind study design.The three injections (ibuprofen, meperidine, and placebo) were prepared in identical syringes with a total volume of 2 ml. The investigator responsible for controlling and recording the clinical signs remained blinded to the specific drugs administered. The injections were administered 30 minutes prior to the conclusion of surgery.Anesthesia was induced using fentanyl at 1 µg/kg, propofol at 2 mg/kg, and atracurium at 0.5 mg/kg, following a standardized protocol for all patients. Tracheal intubation was performed, and anesthesia was maintained by infusing propofol at 100 µg/kg/min. Muscular relaxation was maintained during the operation to facilitate intubation and optimize surgical conditions. Atracurium was administered as required, and patients were mechanically ventilated throughout the surgical procedure. All patients were monitored in the recovery room.