Background
apnoea, hypoventilation, hypoxia, neuromuscular block, ORI
HYPOVENTILATION, HYPOXIA
Endotracheal intubation requires an anaesthetic induction process that results in loss of consciousness and neuromuscular block. This process includes hypoventilation and apnoea, resulting in a risk of hypoxia, which further exacerbates in case of difficult endotracheal intubation [The conventional preoxygenation method includes the use of a facemask, which allows patients to spontaneously breathe oxygen [In previous studies, HFNO in patients undergoing anaesthesia induction for emergency surgery resulted in similar arterial oxygen partial pressure (PaOA previous study on non-rapid sequence induction demonstrated that the post-endotracheal intubation PaOThe oxygen reserve index (ORI™, Masimo Corp., Irvine, CA) continuously monitors the amount of oxygen non-invasively, similar to what is done for SpOIn this randomised controlled study, we hypothesized that HFNO would have higher preoxygenation efficiency than facemask oxygenation in adult patients undergoing general anaesthetic induction for non-emergent surgery. The ORI was monitored during the anaesthesia induction period, and the highest ORI values obtained using HFNO and facemask oxygenation were compared.