title: In reply.
authors.affiliation: *Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. litmanr@email.chop.edu.
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Litman
authors.forename: Lynne G
authors.initials: LG
authors.lastname: Maxwell
mesh_terms: D006801:Humans; D007234:Infant, Premature / Q000502:physiology*; D001239:Inhalation / Q000502:physiology*; D007442:Intubation, Intratracheal / Q000009:adverse effects*; D012135:Respiratory Sounds / Q000175:diagnosis* / Q000503:physiopathology*