The first thing that is necessary is to ensure that medicines are given in time and regular contact with the treating doctor maintained.
Regarding other things it helps if you play soothing music in his environment to create a pleasant harmonious atmosphere to attract helpful forces.
Read a page of Savitri and chant the Mother’s name in his room. Keep some camphor in all the corners and pray to the Mother for Her Grace and Protection.
Rest is a question of time and individual destiny.
With Her Love and prayers
Affectionately,
Alok Da