I have no problem with providing nourishment. However, in these cases, is it reasonable to deny radical medical intervention otherwise?
IMHO yes.
The Pope didn't address that question AFAIK, but if it comes to that point I'm not going to allow my bedridden and senile 96 year old mother to suffer through something like major abdominal or cardiac surgery just to keep her breathing for a few more weeks or months. When the Lord whispers "come home child," in her ear I won't attempt to override His timing with extraordinary medical procedures.
But providing food and water through a feeding tube is not the same thing. I fed my Dad through a tube for almost a year before he died of kidney failure. I will also keep Mom on a feeding tube if it becomes necessary, because I believe that preventing death by starvation and thirst is altogether different morally and spiritually from performing a radical medical procedure just to prolong a vegetative state of life for a few more weeks or months.
These are hard questions for a Christian to answer in light of modern medical science's advances, and I agree with the Pope's pronouncement as far as it went. But I don't see anything in the article addressing the matter of attempting to keep a comatose patient alive by radical artificial means, so I intend to use my own best judgment guided by biblical principles if that situation ever arises with someone who is my responsibility, and it every well may arise in the near future given Mom's precarious physical and mental condition. I can only pray that I will make the right decision in the eyes of God if and when that time comes.