McGRATH ™ MAC size 1 vs. 2 blades: infant intubation time.

Competing Interests: Declarations. Conflict of interest: Yuka Uchinami, Noriaki Fujita, Kazuyuki Mizunoya, and Yuji Morimoto declare that they have no financial interests relevant to this study. Isao Yokota reports grants from KAKENHI, AMED, and Health, Labour and Welfare Policy Research Grants, Nihon Medi-Physics research fund, and speaker fees from Chugai Pharmaceutical Co, AstraZeneca, and Pfizer, outside the submitted work. Ethical approval: This study was performed in line with the principles of the Declaration of Helsinki. Ethical approval was obtained from the Ethical Review Committee of Hokkaido University Hospital, Sapporo (IRB No.023–0004) on April 3, 2023. Consent to participate: Permission was obtained by the opt-out method. The opportunity to opt-out of the study was provided through the Hokkaido University Hospital website ( https://www.huhp.hokudai.ac.jp/date/rinsho-johokokai/approval/ ) for the guardians/parents of patients who did not wish to participate.