Randomization and blinding
RECRUITMENT
After written informed consent was obtained, participants were randomly assigned to the study group or the control group. Randomization was carried out using a computer-generated random number list with a 1:1 ratio. Group assignment was performed using opaque, sealed envelopes prepared by a research nurse. On the day of surgery, before entering the operating room, the nurse (GYG) not involved in patient recruitment or data collection opened the envelope and prepared the study solutions. The patients, anesthesiologists and research assistant recording postoperative data were blinded to the group allocation throughout the study period.