Are food and water 'extraordinary measures'?

There are several ethical principles relevant to assessing moral questions arising from persons said to be in the vegetative state: (1) Human bodily life, however burdened, is still a good of the person, integral to his or her being. (2) It is always gravely immoral intentionally to kill an innocent human being, i.e, to deprive him or her of the good of life itself. (3) Means chosen to preserve human life are morally obligatory if they are "morally" (not necessarily medically) "ordinary" or "proportionate." (4) Means chosen to preserve human life are not obligatory, and in fact their withholding or withdrawal may be morally indicated if they are "morally" (not necessarily medically) "extraordinary" or "disproportionate." (5) Means are extraordinary or disproportionate if the means chosen are either futile (=useless) or burdensome. Catholic.net