Hi welcome to Health care magic forum.
Thanks for calling H.C.M.Forum.
Your brother in law has a bad
bronchitis, The doctors in vietnam saved him. He became week due to not taking food.
Always make it a habbit of trusting the doctors giving treatment. They said it is difficult and he recovered 3% in ten days.
The weakness is not due to the
starvation, but due to infection. as the innfection is getting controlled the strength will be recured.
The medicines part the doctors will take care of , you can get the improvement, by food, give him npurishing food, like egg, chicken, meet, soups, green leafy vegetables etc. you can give him proteine powders with milk.
Avoid giving fruits, juices, icecream, and ice water, to avoid
allergy, and congestion.
Wishing for a quick and complete recovery.
best regards.