A Comparison Of Efficacy Of Oxygenation Between High Flow Nasal Cannula And Standard Facemask For Preoxygenation And Endotracheal Intubation In Patients Undergoing General Anaesthesia

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