Mucosal metaplasia and chronic inflammation in the middle ear of infants receiving intensive care in the neonatal period.

The histological findings in the middle ear cavity of 72 infants of varying gestations, birthweights, and ages are presented. All infants died after receiving ventilatory support and oxygen for longer than 14 days. In 5 infants there was no detectable histological abnormality. In the remainder, a wide range of lesions was seen including glandular metaplasia, retained squamous debris, squamous polyps, otitis media, and destruction of ossicles. None of the cases of otitis media was diagnosed before necropsy; all were associated with pneumonia. No single specific infectious agent predominated. Several factors could contribute to the spectrum of lesions, and these include persistent amniotic squamous debris, infection, and the effects of oxygen and a nasal airway. The possible implications of these findings are discussed, and it is argued that similar changes of lesser severity could be present in survivors in whom otitis media and conduction hearing defects could be expected.