Mother In Law 89 Heart&kidney Failure, Severe Arthriis, Cn't Walk,large

Mother in law 89 heart&kidney failure, severe arthriis, cn't walk,large hiatus hernia, pacmaker, tinitus,regularly gets water infections - on permanent catheter and bag and morphine(?) patches for arthritic pain, badly swollen lrgs, full mental capacity - recently has had large raised blood blisters on lower legs.
Concerned about the cause of these