The mask is just oxygen - they want your blood as saturated with O2 as it can be. The stuff that knocks you out comes in from the IV, and it knocks you out so completely that you literally don’t even breathe on your own. So, once that stuff kicks in it’s gogogo time for the anesthesiologist, cuz you’re basically holding your breath until they get you intubated, which allows the ventilator to take over.
*There are probably exceptions to that, but 99% of surgeries requiring general anesthesia will go like that.
The mask is just oxygen - they want your blood as saturated with O2 as it can be. The stuff that knocks you out comes in from the IV, and it knocks you out so completely that you literally don’t even breathe on your own. So, once that stuff kicks in it’s gogogo time for the anesthesiologist, cuz you’re basically holding your breath until they get you intubated, which allows the ventilator to take over.
*There are probably exceptions to that, but 99% of surgeries requiring general anesthesia will go like that.