What is prescribed for the children of the diseased to do
A:
First,
verily
Allah (Glorified and Exalted be He) afflicts people in this world and makes a trial of them with evil and good, illness and good health, distress and well-being, to test the patient and gratitude people. Then, He will reward them on the Day of Judgment. Allah (Exalted be He) says:
...and We shall make a trial of you with evil and with good. And to Us you will be returned.
(Part No. 9; Page No. 124) Allah (Exalted be He) states:
And certainly, We shall test you with something of fear, hunger, loss of wealth, lives and fruits, but give glad tidings to As-Sâbirûn (the patient).
A Muslim must be patient and wait for Allah's reward if he is afflicted with misfortune, and thank Allah if something good happened to him. The Prophet (peace be upon him) stated:
Remarkable are the affairs of the believer! Verily in every act there is good. If good befalls him then he reaches out in thanks and appreciation then that is best for him. Yet if harm or evil occurs then he shows patience and perseverance, then that is best for him. But that is not for any other except the believer.
Second,
what is permissible for you is to supplicate to Allah to restore your father's health, to forgive him, to grant him a good end, and to reward him with the best for the illness that has afflicted him. Moreover, you are permitted to pay Sadaqah (voluntary charity) for his sake and maintain his ties of kinship. You should do the same for your deceased mother. In addition, you should carry out his legal will, if he has one, be patient in nursing him, and wait for the reward of Allah (Exalted be He).
Third,
As your father is unconscious and does not recognize anything, he is not required to perform any physical `Ibadah such as Sawm, Salah (prayer) because (Part No. 9; Page No. 125) legal accountability for actions depends on the mind. If he is unconscious, he is no longer legally accountable for his actions.We hope that Allah (Glorified be He) will restore your father's health and grant you patience in waiting for His reward for nursing, which will indeed be great.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.