TY - CHAP M1 - Book, Section TI - Middle Ear Squeeze A1 - Zafren, Ken A1 - Thurman, R. Jason A1 - Jones, Ian D. A2 - Knoop, Kevin J. A2 - Stack, Lawrence B. A2 - Storrow, Alan B. A2 - Thurman, R. Jason Y1 - 2021 N1 - T2 - The Atlas of Emergency Medicine, 5e AB - Middle ear squeeze (barotitis media) results from a decrease in pressure within the middle ear as an individual descends through water or is exposed to an increase in atmospheric pressure that can be seen in descending aircraft or while driving in mountainous terrain. According to Boyle’s law, as pressure increases, volume decreases proportionately. At a depth of approximately 1.2 m (4 ft), the pressure difference is great enough to collapse the eustachian tube and cause obstruction. If attempts to equalize the pressure such as a Valsalva or Frenzel maneuver fail, ascent is necessary or injury may ensue. If a diver continues to descend, hemorrhage and edema occur within the middle ear and rupture of the TM may occur. The influx of water into the middle ear may cause extreme vertigo and lead to a diving disaster. SN - PB - McGraw-Hill CY - New York, NY Y2 - 2024/04/20 UR - accessemergencymedicine.mhmedical.com/content.aspx?aid=1181051045 ER -