Middle Ear Function and Pathophysiology in Andean Children Living at High Altitudes

The extent of altitude-related middle ear disorders in children native to high altitudes is unclear. This study examined middle ear pathophysiology in two groups of children living in high-altitude Ecuadorian Andean communities by investigating middle ear pressure (MEP), tympanic membrane compliance (TMC), and ear canal volume (ECV) using tympanometry, and by otological examination. Altitude I Group lived at 2850 m, and Altitude II Group resided at around 4000 m. The two high-altitude groups were compared with a reference group of children residing at sea level. Mean MEP was -3.6 daPa (SD: 39.2), 3.5 daPa (SD: 28.7), and 1.3 daPa (SD: 13.6) for Altitude I Group, Altitude II Group, and the Sea Level Group, respectively. The MEP was not significantly different among the three groups. Mean TMC was 0.63 cm³ (SD: 0.51), 0.60 cm³ (SD: 0.43), and 0.60 cm³ (SD: 0.24) for Altitude I Group, Altitude II Group, and the Sea Level Group, respectively. The TMC was not significantly different among the three groups. Mean ECV was 1.1 (SD: 0.26), 1.2 (SD: 0.26), and 1.0 (SD: 0.23) for Altitude I Group, Altitude II Group, and the Sea Level Group, respectively. The difference in ECV between Altitude I Group and Altitude II Group was significant (p = 0.043), as was the difference between Altitude II Group and the Sea Level Group (p = 0.001). ECV did not differ significantly between Altitude I Group and the Sea Level Group. Otological examination revealed a low incidence of ear canal and middle ear pathology. In conclusion, tympanometric and otological findings did not reveal a high incidence of middle ear pathophysiology in children living at altitudes as high as around 4000 m.