I have a 3 month old baby boy and he has bronchitis he is on breathing treatments after 4 days and not getting any better?

Possible pneumonia: The possibility he have pneumonia could be there and he is not sensitive to the antibiotic used. Good luck.

But is he stable?: Lower airway inflammation like you have with bronchitis is unlikely to resolve within days on any form of treatment. The breathing treatments help wet the airways and decrease the thickness of debris and mucous. Most kids with bronchitis will gradually improve over a week to 2 wks.Some may cough for a month.If the kid is wetting diapers every 6h and resting some, he is stable, if not get re-ck.