Comparing the effectiveness of using Optiflow Switch vs standard facemask during anaesthesia induction: a randomized controlled trial

In this study, we plan to compare two techniques of supplying oxygen to patients during general anaesthetic induction for surgery. The usual way of doing this procedure involves patient breathing about 10L/min oxygen through a standard facemask before being induced. Once the patient is asleep, the anaesthetist helps bag-mask ventilate the patient via the facemask while waiting for complete muscle relaxation for the intubation. During intubation, the facemask is removed. In this study, a computer program will randomly allocate patients to receive oxygen via one of the two devices: 1) Optiflow Switch or 2) standard facemask. The Optiflow Switch is a relatively new device, which can deliver oxygen at a very high flow rate (up to 70L/min) via two prongs in the nose. It also allows seamless transition to facemask ventilation by diverting nasal oxygen flow away from the patient when a facemask is applied on top of the nasal apparatus. Therefore, for the Optiflow Switch group, patients will receive high flow oxygen through the nasal prongs before going to sleep and during intubation, but bag-mask ventilation in between while waiting for complete muscle paralysis. The study aims to test if the Optiflow Switch provides a higher oxygen level compared to standard facemask when used during anaesthesia induction.