Apnoeic oxygenation during airway management in infants for elective endotracheal intubation (OXYNEO Trial): A protocol for a randomized double-blind controlled trial

1. IntroductionHypoxemia is the leading cause of morbidity and mortality in paediatric anaesthesia. It can be major during induction for general anaesthesia at the time of intubation especially in case of difficult access to the airways or repeated attempts. Preoxygenation has been used to maximize oxygen reserves in patients and to prolong the safe apnoeic time during laryngoscopy and intubation phases. Nevertheless, safe apnoea duration remains less than 2 minutes for infants. Apnoeic oxygenation by high flow oxygen delivery from nasal cannula has already shown its effectiveness byincreasing apnoea duration in adult patients in intensive care units or in operating room for patients at risk of difficult intubation (bariatric population) and in children. We designed a clinical trial to test the hypothesis that apnoeic oxygenation reduces the incidence and severity of hypoxemia and also decrease adverse events during intubation in infants compared with standard care.2. Methods and analysisThe OXYNEO trial is a monocenter randomized controlled trial performed in paediatric center in the University Hospital of Clermont-Ferrand, France. 72 infants aged under 24 months requiring intubation for scheduled surgery will be enrolled and allocated to High Flow oxygenation (HF), Low Flow oxygenation (LF) or standard care (SC) in a 1:1:1 allocation with stratification by age (0-6, 6-12 and 12-24 months). Infants allocated to High Flow apnoeic oxygenation receive 1L/Kg bodyweight transnasal oxygen, infants allocated to Low Flow apnoeic oxygenation receive 0,2L/Kg bodyweight transnasal oxygen whereas children in the control arm will not receive any transnasal oxygen 15 insufflation during apnoea. The primary outcomes is defined as the time in seconds between the onset of apnoea and : 1) Airway management complete or 2) desaturation (SpO2<95%) Analyses will be conducted on an intention-to-treat basis. 3. Strengths and limitations of this study• This is the first study investigating the use of apnoeic oxygenation by High Flow nasal cannula during infants airway management in current practice and its effects on hypoxemia’s frequency and gravity.• High Flow oxygenation will be compared at Low Flow oxygenation, as recent study suggest Low Flow is not inferior.• Apart from the application of apnoeic oxygenation, all other aspects of the intubation process are standardized according to the actual standard of care, ensuring that bias and confounding are minimized and any observed effect can be more reliably attributed to the intervention applied.• Because knowing apnoea time duration to secure the airway is an important factor of bias for the airway management rapidity, we develop a standardized double-blinded protocol that not allow anaesthesia team to know the apnoeic oxygenation group allowed. It is the first randomized double-blinded study in this population.• In this study, apnoeic oxygenation by High Flow nasal cannula is only evaluated for infants because this population has the most important risk of hypoxemia and respiratory adverse events due to anatomical and physiological particularity (lower apnoea duration).Introduction : L’hypoxémie est une des principales causes de morbi-mortalité en anesthésie pédiatrique selon les données récentes de la littérature. La phase d’induction anesthésique est à haut risque, particulièrement chez l’enfant de <2 ans, du fait de réserves et d’une consommation en oxygène accrus proportionnellement aux patients plus âgés. La préoxygénation au masque permet d’allonger le temps d’apnée sans désaturation durant la phase d’intubation mais cette durée reste inférieure à 2 minutes chez les nourrissons. L’oxygénation apnéique par canule nasale à Haut Débit a déjà montré son efficacité sur la prolongation du temps d’apnée sans désaturation chez les adultes à risque (obèses et patients de réanimation) ainsi que chez les enfants (THRIVE), mais aucune étude ne s’est intéressée à sa capacité à diminuer la fréquence et la gravité des épisodes hypoxiques chez les nourrissons, population particulièrement à risque.Matériels et Méthodes : L’étude OXYNEO est un essai randomisé contrôlé en double aveugle réalisé au CHU de Clermont-Ferrand. 72 nourrissons (âge ≦2 ans) devant bénéficier d’une chirurgie programmée sous anesthésie générale avec intubation orotrachéale seront inclus et randomisés en 3 groupes, respectivement Oxygénation apnéique à Haut débit, à Bas débit et, Prise en charge actuelle (pas d’oxygénation apnéique). Après stratification sur l’âge, ils recevront respectivement, 1L/kg/min, 0,2L/kg/min ou 0L/kg/min d’oxygène pur via des lunettes à oxygène adaptées reliées au ventilateur au cours de la phase d’apnée pour laryngoscopie. Le reste de la prise en charge anesthésique est protocolisé selon les dernières recommandations françaises. Le critère de jugement principal est le temps, en secondes, entre le début de l’apnée et 1) la réussite de l’intubation sans hypoxie ou 2) la survenue première d’une hypoxie (SpO2