Critical illness. Why its happening?

Hello doc gud eve... My grandma had cardioembolic stroke  major heart attack after that she admitted in hospital cardiology after few days the support machinery ecg nd all goes down .. Doctors said that take her to home or some other centre if you want coz she cant be given pacemaker in this situation.. Then we take her to home she is taking food through ryles tube she cant able to stand or sit but she became conciouss and can speak or hear .. But from 2 days some brown and blood clots coming out of mouth and thwn we open her tube there is lot of fluid brownish along with bloody spot like thing coming out.. She is now no conciousness and no movement like before We talked to our doctor he said keep open her tube ..her body doesnt accept anything When we try to give her some liquid diet now she cough and fluid comes out.. I need to knw if u can tell what is this ...why its happening