Effect of preoperative patient education and simulated mouth breathing training on opioid requirements in the post-anesthesia care unit after nasal surgery: a randomized controlled study.

"Declarations Ethics approval and consent to participateEthics approval for this study was provided by the Samsung Medical Center Institutional Review Board (SMC 2021-05-098-001) on 1 June 2021. The study was registered in Clinical Research Information Services (KCT0006264) on 16 June 2021. The study was also done as per the declaration of Helsinki. The benefits and purposes of the study were explained to the patients, and each participant provided written informed consent. Confidentiality was maintained at all levels of the study by avoiding identifiers and using codes to identify patients. Participants’ involvement in the study was voluntary. Participants who did not wish to participate in the study or who wished to withdraw at any time were informed that they could do so without restriction. Consent for publicationNot applicable. Competing interestsThe authors declare that they have no competing interests. Competing interests The authors declare that they have no competing interests."

"Funding None."

"Trial registration KCT0006264; 16/09/2021; Clinical Research Information Services (https://cris.nih.go.kr)."