Welcome to HCM,
Your mother has small kidney that means Chronic renal failure
in which if Blood urea and Cratinine are rising and she has Uraemia.
nausea and vomiting
are common you have not mentioned about renal function if they are deteriorating she will need Hemo Dialysis
to remove waste products from blood.
Swelling all over also indicate renal failure and Lasix is treatment for it.
She also has Ischemic heart disease
other drugs she is taking may have some effects.
Other cause is stomach out let obstruction.This can be detected by Endoscpy and blood tests if this is the cause it can be treated and if need is there surgery is also possible.
you must see your Physician/Nephrologist
to detect the cause so that it can be treated.
Please take care