(1)Shulchan Aruch, Yoreh Deah 337:1
(2)Aruch Hashulchan, Yoreh Deah, 337:1-2
(3)Only the prohibitions of murder, idolatry, and forbidden sexual relationships take precedence over saving a life.
(4)While the Talmud does not specify how sick the patient is, it is apparent from Toras Ha’adam (Sha’ar Ha’michush, Inyan Ha’vidoi, Chavel Hebrew edition, p. 46) of the Ramban (Nachmanides) that the patient is nearing death.
(5)Birkei Yosef, s.k. 2. Professor Avraham Avraham, cogently points out "Both caregivers and visitors should therefore be extremely careful not to say anything in the presence of an unconscious patient that one would not have said in his presence were he conscious. Perhaps he is not so comatose that he will not hear, and hearing what is being said about him may bring him to despair." Prof. Avraham S. Avraham, Nishmat Avraham, Yoreh Deah (English vol. 2) (Brooklyn, NY: Mesorah Publications, 2003), p. 296.
(6)Ibid p. 294.
(7)Not only is the sick person not informed of the death of their relative, but it is incumbent on visitors to cheer up the sick person by any means possible, including telling him happy stories (Maimonides, Sefer Hanhagos Habriyos) See Sefer Assia 3, Rabbi Shlomo Aviner, "Informing A Very Sick Patient Of Their Situation," pp. 336-340.
(8)Responsa Shevus Yaakov, 2:99.
(9)Nishmat Avraham, Ibid. The mourner should preferably place earth in their shoes if it would not be recognizable to the ill person (based on Mishnah Brurah, Orach Chaim chapt. 554, s.k. 33).
(10)During the first seven days after the burial of a first degree relative (shiva) the strictest rules of mourning usually apply, such as sitting on a low chair, abstaining from bathing, and remaining at home. For the following 23 days, making a total of 30 days called shloshim, a lesser degree of mourning is observed (except regarding parents for whom mourning continues for a full year). What happens if the ill person who had not mourned recovers? Is he or she then required to mourn when it becomes safe and physically possible? As the Aruch Hashulchan (Yoreh Deah, 337:3) explains, it depends on when the mourner first found out about the death. It is important to also realize that if a major Jewish holiday occurs during the shiva or shloshim periods, the required time for mourning is reduced.
If the patient was cognizant of the death during the shiva period, even if he was unable to perform any of the usual mourning activities while he was ill, then it is considered as if he has fulfilled his obligation to begin mourning. If he recovers during the first seven days, he need only finish the remaining days of shiva and then continue to observe the shloshim. If he recovers after seven days, but before the end of the shloshim, he is bound only to observe the remaining days of shloshim. (See Responsa Tzitz Eliezer, vol. 5, Kuntrus Ramat Rachel, 26 and Sha’ar Hatzion, Orach Chaim chapt. 548, s.k. 36)
On the other hand, if the sick person was not initially informed of the death or was informed but not lucid enough to understand what he was told, then he is not considered to have begun mourning. If he recovers during the first 30 days, he must observe seven days of shiva followed by the remaining 23 days of shloshim..
If the patient is informed of the death after 30 days, then he only observes a few minutes of mourning (with the exception of being informed about the death of parents for whom the restrictions of shloshim continue for a full year after the death). This is because after 30 days, hearing about a death is considered a "report of a distant event." See Shulchan Aruch, Yoreh Deah 402 for a more complete discussion of shemuah rechokah (hearing about a death after 30 days) and shemuah kirovah (hearing about a death within 30 days).