Youcat commented through CCC – Question n. 382.

YOUCAT Question n. 382 - Is it permissible to offer assistance in dying?

(Youcat answer) To bring about death directly is always against the commandment “You shall not kill” (Ex 20:13). In contrast, to stand by and assist a dying person is humane and even obligatory.    

A deepening through CCC (CCC 2278) Discontinuing medical procedures that are burdensome, dangerous, extraordinary, or disproportionate to the expected outcome can be legitimate; it is the refusal of "over-zealous" treatment. Here one does not will to cause death; one's inability to impede it is merely accepted. The decisions should be made by the patient if he is competent and able or, if not, by those legally entitled to act for the patient, whose reasonable will and legitimate interests must always be respected.    

Reflecting and meditating  

(Youcat comment) The terms active euthanasia and passive euthanasia often confuse the debate. What really matters iswhether a dying person is killed or allowed to die. In so-called active euthanasia, someone by direct action “helps” a person to die and thereby breaks the Fifth Commandment; in so-called passive euthanasia, someone helps another person in the dying process and thereby obeys the commandment “Love your neighbor.” Passive euthanasia means that, in view of the certain impending death of a patient, one withholds extraordinary or expensive medical procedures that are not proportionate to the expected outcome. The patient himself must make the decision to forgo “extraordinary” measures or must have stated this intention in an advance directive. If he is no longer capable of doing so, those who are legally entitled must represent the express or probable wishes of the dying person. Ordinary care of a dying person should never be discontinued; this is commanded by love of neighbor and mercy. Meanwhile it can be legitimate and in keeping with human dignity to use painkillers, even at the risk of shortening the patient’s life. The crucial thing is that the use of such medications must not aim at bringing about death, either as an end in itself or as a means of ending pain. 

(CCC Comment)

(CCC 2279) Even if death is thought imminent, the ordinary care owed to a sick person cannot be legitimately interrupted. The use of painkillers to alleviate the sufferings of the dying, even at the risk of shortening their days, can be morally in conformity with human dignity if death is not willed as either an end or a means, but only foreseen and tolerated as inevitable. Palliative care is a special form of disinterested charity. As such it should be encouraged. 

(The next question is: Why is abortion unacceptable at any phase in the development of an embryo?)