This prospective observational comparative study will be conducted after obtaining approval from the Institutional Ethics Committee. A pre-anesthetic evaluation with a detailed medical history, systemic examination, and airway examination will be done and reviewed on the previous day and on the day of surgery.  Informed and written consent will be obtained from the patient and/or the patient’s guardian. Patient will be kept nil by mouth for 6 hours and premedicated according to standard institutional protocol. Once the patient is shifted to the operation theatre, standard preparations such as attaching routine monitoring devices like an electrocardiogram, pulse oximetry (SpO2), noninvasive blood pressure, and end tidal capnography will be done. Intravenous fluid will be started after securing a suitable intravenous cannula. Patients undergoing general endotracheal anesthesia with oxygenation under a face mask oxygenation will be included under group F and those with high-flow nasal oxygenation will be included under group H. The standard and common drugs for induction, muscle relaxation, and inhalational anesthesia will be followed for all the patients. In the HFNO group, oxygenation will be performed using a high-flow nasal cannula, with nasal prongs set at 30 L/min flow of heated and humidified 100% oxygen. In the FMO group, patients will breathe spontaneously with an appropriate-size standard facemask connected to a ventilation system with 100% oxygen at 8 L/min. If the patient doesn’t tolerate HFNO they will be motivated for the same and if they don’t cooperate even then will be oxygenated with regular facemask technique done as per the institutional protocol and will be excluded from the study. All of this will be after 3 minutes of oxygenation, the patient’s airway will be secured by the anesthesiologist in charge and the technique will be noted. Number of attempts, time for desaturation (SpO2 <92%), any events occurring during the process of intubation or any rescue methods if used in case of desaturation will be noted and the patient will be ventilated as per the institutional protocol. During intubation, the nasal prongs of the HFNO group will be left in place to achieve apnoeic oxygenation. In the FMO group, the facemask will be removed during intubation. The correct placement of the endotracheal tube will be confirmed by end-tidal capnography, and the nasal prongs will then be removed from the HFNO group. After intubation, maintenance of anesthesia will be done according to the standard institutional protocol.