Wiki:
''It has been proposed that the practice of artificially prolonging the life of an individual who will not recover to be unethical. Roman Catholic moral teachings, pronounced in 1993, suggest that the employment of artificial means is not necessary to fulfill the duty to respect life; however the term "artificial means" may vary in meaning between different schools of thought within and outside Catholicism. Most Catholic theologians however, divide the issue into "ordinary" and "extraordinary" means, and believe that it is an ethical imperative to continue the ordinary means, but ethically neutral to withhold the extraordinary means. They define ordinary means as things like feeding, and extraordinary means as things like artificial breathing. This must not be confused with DNR orders or euthanasia, the withdrawal of such support from the vegetative, comatose, elderly or those who have serious injuries or illnesses that are debilitating or even terminal. All patients must be given some means of ventilation and adequate nutrition and hydration; as well as adequate palliative pain medication, such as opioid analgesics, even though it may shorten their lives.''