My 2 yo was laying in bed drinking from a sippy cup watching tv. He coughed and almost spit up but swallowed it. Could this cause aspiration pneumonia?

Upright > 30 angle. This could lead to aspiration pneumonia or inflammation of the airway. Drinking while supine increases the chance for an ear infection also. I would suggest having him sit up while drinking. If he shows any signs of respiratory problems or fever, a follow up visit should be done.
Aspiration pneumonia. If he aspirated a goodly amount he could conceiveably develop aspiration pnemonia.

Related Questions

2 yo was drinking in bed. He cough, spit up & swallow. He coughed a few times today & has cold. If gets fever how do if know from cold or aspiration?

Fever from cold. It is unlikely that a normal 2 year old child aspirates and develops pneumonia with fever, if he has cold, it is more likely that he coughs due to cold and fever is due to cold. Read more...

Possibility of aspiration pneumonia if toddler drinking, coughed, started to spit up & swallowed back down. All while laying. Would symptoms be immediate?

Yes. Sounds like he has a normal gag reflex (to help get stuff out or airways that shouldn't be there). It's not uncommon to spit up and cough if goes down wrong tube. Symptoms such as breathing issues or becoming agitated would be somewhat immediate. Read more...