Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services for blue or gray lips or face, pauses in breathing, severe chest pulling, gasping, unresponsiveness, or a major equipment failure when the child cannot breathe safely without the equipment.
Contact the child's healthcare team promptly for a new cough, wheezing, reduced feeding, fewer wet diapers, unusual tiredness, fever, or a mild increase in breathing effort.
Follow the child's written illness or oxygen plan when one has been provided.
Seek urgent medical care if the child is breathing much harder or faster than usual, repeatedly vomiting feeds, becoming difficult to wake, or cannot maintain the oxygen level set by the care team despite following the plan.
Follow-up often involves a primary care clinician and a neonatal or pulmonary clinic.
Some children also see cardiology, nutrition, feeding, developmental, or ear, nose, and throat specialists.
Routine visits may review:
The article also says
A clinician may gradually reduce oxygen after reviewing the child's growth, breathing, and measured oxygen levels.
Families should not test longer periods without oxygen unless the care team has provided a plan.
Every sign above is quoted from the sofidex article on Bronchopulmonary dysplasia. If you are not sure, err upward — it is always reasonable to be checked.