Effectiveness of Facial Mask NIV in Adults Under General Anesthesia: Two-Hand C-E vs V-E Techniques

This study aims to compare two different ways doctors hold a face mask to help the participant breathe during general anesthesia. The investigators are evaluating which method, the "C-E" or the "V-E" technique, works best. If the participant chooses to take part, on the day of surgery, after anesthesia has been administered and the participant is asleep, the doctor will use one of these two mask-holding techniques to assist breathing for a short period. The investigators will measure how effectively the participant is breathing, check carbon dioxide levels, and record the doctors' assessment of how easy and comfortable each technique was for them. This study will not alter any other aspect of the surgery or recovery.