Can a Pope be Unplugged?

It doesn't sound like the Pope is doing very well. He's been read his last rights, is being given antibiotics for an infection, has a feeding tube in his nose and another tube keeping his windpipe open.

All this has me thinking... If the Pope ends up on life support, can he ever be unplugged? At his age, he probably has a Do Not Resuscitate order should he have a massive stroke or heart attack. But what if his health just slowly deteriorates to the point that a feeding tube or respirator is the only thing keeping him alive? What if he ends up in Terri Schiavo's situation? The Vatican just publicly denounced her passing as a "death sentence executed through a cruel method."

It would be a weird sort of science experiment, really. How long can a human body endure in that situation? He's 84 now and I guess there is a slight hope that he will recover and his health will grow stronger. But what about when he's 94 or 104 or even 114? And what would happen to the Papacy? Can a new Pope be named while the old one is still alive, even if he is incapacitated?

Being the heathen atheist that I am, I support euthanasia of course. But in this case, I'm perversely curious to know how the experiment would turn out.