The client is awake and alert, interacting with parents at the bedside. She has thin, copious mucus from her nose and mouth and a cough. She took her bottle in 20 minutes, with no issues. The client’s monitor alarmed, oxygen saturation is 59%. She is cyanotic. The client was placed in a knee-to-chest position, and the rapid response team was called. What could be the potential cause of the client’s condition?