w long can you live if your brain is dead but you are still breathing. My uncle had a cardiac arrest one week ago and has been in intensive care for nearly a week, it has come to light that it took 20 minutes to recusitate him he is breathing on his own has a strong heart beat, when we touch him he opens his eyes, but there are no other responses from him we have been told he is probably brain damaged due to the lack of oxygen. How long could he live like this if he is still breathing on his own, & just on a morphing drip ONLY?!