Inclusion Criteria:  child from birth until 10 years patient needing (elective or in emergency) surgery under general anesthesia requiring tracheal intubation and fulfilling all criteria for a rapid sequence induction Parents or legal guardians signed the Informed consent form Social insurance affiliation  Exclusion Criteria  - child having one or more contraindication to use high flow nasal oxygenation:  Nasal obstruction Recent trauma of aero-digestives tracts Epistaxis Known or suspected fracture of the skull base Cephalo-spinal fluid leak or all other communication between nasal space and intracranial space Tuberculosis or other nasal or lung infection Pneumothorax or pneumo-mediastin documented or suspected Complete limitation of mouth opening