My Brother Had A Heart Attack With No Oxygen Going

My brother had a heart attack with no oxygen going to his brain foe max of 30minutes, was in coma and awoken on reduce coma was having sezuires whilst in coma, he is awake and you can clearly see there are outlining issues chest infections, now kidneys are not working properly, flex muscles are not working in his neck so he can not eat as this is a risk of choking, had another sezuires last week what are his chances of survival ?