... a Nebulizer, is to open up the airways.
It does NOT, get rid of mucus.
Same for vaporizers.
Mucus, is a separate issue.
Nebulizers, are Bronchodilators.
Not mucus medicine.
At night, it is worse, because baby is lying down. Thus, the mucus accumulates and pools, in the throat or chest.
Hence, more congestion.
But the mucus is still there.
Did they check him for Pneumonia?
There are MANY kinds of chest illnesses...
all of which, cause mucus.
There is also, INFANT "Vicks."
You can try and rub this on his chest.
But, I would, take him back to the Doctor.
Babies of course, cannot spit out, mucus, nor control it.
And they can choke on it.
AND you need to look out for secondary infections.... too.
With chest illnesses/mucus, this can happen.
Even from a head cold.
Bacteria, is in the sinus mucus, it drips down the throat, and can get into the chest too.
That happened to me once, from a head cold. I then, got Pneumonia.
From the bacteria in the mucus.