the couple times i've had pneumonia i was hospitalized. one time i was feeling absolutely terrible, low O2 sats, fever, bad pain, etc. and the other time i had similar symptoms as your son. both times i was admitted for at least 1 weeks to get IVs started and make sure everything was ok and i was responding to the meds, then i went home and finished the last 1.5 weeks of IVs at home.