My middle son went through this as well. He had his adnoids removed and tubes put in and it took almost a month for him to sleep through the night. We had his crib elevated from birth due to reflux. Here is what we have done to help him as since this surgery was done he has had sleeping issues. It always seems like he has a stuffy (not runny) nose when he is trying to sleep. During the day he has no problems with a stuffy nose.
* Take him back to the ENT and make sure the tubes are positioned properly and there is no fluid behind the tubes. It is possible for children to get ear infections even with the tubes and you might need to put him on some antibiotics. I would do this one first. I saw my ENT several times since i felt the surgery had been the catalyst in my son's problems.
* We had him tested for allergies. Once the adnoids were removed, we essentially had taken away the filtering system the body uses and if your child would be prone to allergies then it would show up after they were removed. My son has no allergies, but they did try putting him on numerous antihistamines to help with the nasal stuffiness.
* Humidifier in his room to keep the air from being too dry. We run it during the times he isn't trying to sleep since he doesn't like the sound, but a lot of people run them 24 hours.
* Gave him some Benadryl as Mucinex is only effective if there is chest congestion causing the cough, not really great for runny noses. Check with your doctor on the dosing as my son was 14 months when he started taking Benadryl at night and naptime to help him sleep. He still takes it and it has been almost 2 years.
We still struggle with this to a much lesser degree. The above suggestions have helped my son get some sleep at night and make him comfortable. We have the allergy filters in our home even though he has no allergies. Our ENT has advised that this may of just helped bring to light the fact that his sinus cavities are not as developed as they should be. He should grow out of the problem by the time he is 5. I hope that these things give you some relief. My son had to take Tylenol with Codeine in it for almost two weeks after the surgery at night because he was so miserable. I don't know what was worse the constant ear infections or how he was after the surgery. My other two sons have both gotten tubes and have no issues, it seemed to only be the adnoid removal that was the worst. Please feel free to contact me if you have any other questions.