Of course I do not say, and the Church does not say, that people should be kept alive merely because it is possible to snatch another few seconds. In fact, Church teaching, I believe, allows the use of pain-killing drugs to reduce pain even if they tend to shorten the patient's remaining hours. But that is one thing, and killing a person who could go on living and experiencing and perhaps even recover is another. My grandfather died in his own house and bed, looked after by his wife and daughters, who kept him going for months and never made him feel a burden; and from time to time he sang. (Well - it was a pretty dreadful noise - but he meant it for singing.) He was 96 when he died, too.