As far as my knowledge goes, when you breathe out your breath contains about 15% oxygen as opposed to about 21% in the athmosphere, and obviously if Muamba wasn't breathing on his own I'd be surprised if you get the same intake of oxygen when you're not actually drawing breath yourself... As for heart pumping (compressions), that can only recreate about 25% of the heart's job. Incredible, incredible efforts by the medical team, but it's still nothing short of a miracle! All the best Fabrice.
