Thanks for your question on Health Care Magic.
I can understand your mother's situation and problem.
By your history and description, possibility of hypercarbic
respiratory failure (high carbon dioxide level) is more.
It is common in end stage
Pulmonary fibrosis patients.
Shaking of
limbs, sleepiness, weakness etc are symptoms of high carbon dioxide level.
In such situation, patient is not conscious enough to swallow properly and hence chances of aspiration in the lungs are high.
To prevent this and for feeding also, nasogastric tube should be inserted.
It is the small tube which is introduced through nose upto stomach. And through this liquid and
soft diet is given.
So discuss about this option of feeding with her nurse and doctor.
Hope I have solved your query. Wishing good health to your mother. Thanks.