Its very unfortunate that your dad is having a stage 4 lung cancer
with brain metastasis
. He also must be suffering from paralysis because of the same. At present there is no curative treatment for such a disease at this terminal stage. He is being appropriately managed already. Mannitol is being given to reduce the brain edema
. You can even add tablet acetazolamide
to be given through ryles tube to reduce the edema further. Though it may not improve his present condition to a lot better but may be helpful to a little amount.
Dr. Mohammed Ibrahim