I have a sneaking suspicion that would be like pumping oxygen directly into the blood and then trying to hold your breath - even though you technically don't need to breathe, millions of years of evolutionary tricks will make sure you do. Try telling your brain that it does not need to sleep after 72 hours just because you have cleared up the toxins
Actually, this would work. But O2 isn't the problem, the CO2 is. You'll need a process to filter the CO2 out of your blood, as that's what causes your body's breathing reflex to occur. If you could filter the CO2 from the blood stream, while also providing O2, you would literally not need to breath.
"like pumping oxygen directly into the blood and then trying to hold your breath - even though you technically don't need to breathe"
It's not that simple. You need to get gases in and OUT. You also need more than O2. You need to clear CO2 as well as lactic acid and other biproducts. Some CO in the mix greatly assists exchange. Simply bubbling 02 into your blood is going to kill you with a blood clot. And, RBC's actually curl up into a cylinder shape in your pulmonary capillaries to maximize gas transfer, unlike when they're flying around your circulatory system. Pick up a physio textbook, they're a fun read.
