Prediction of preload dependency using phenylephrine-induced peripheral perfusion index during general anaesthesia: a prospective observational study.

"Declarations Ethics approval and consent to participateThis single-centre prospective study was approved by the Research Ethics Committee of Jichi Medical University Saitama Medical Center Saitama, Japan (Chairperson Prof. Shinichi Kako) on 4/01/2023 (approval number: S22-092). The study was registered in the University Hospital Medical Information Network (registration number: UMIN000049994 on 9/01/2023). The requirement for obtaining written informed consent was waived by the Research Ethics Committee of Jichi Medical University Saitama Medical Center owing to the non-invasive nature of the study. Consent for publicationNot applicable. Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding None."

"Trial registration University Hospital Medical Information Network (UMIN000049994 on 9/01/2023)."