Acute Otitic Barotrauma–Clinical Findings, Mechanism and Relationship to the Pathological Changes Produced Experimentally in the Middle Ears of Cats by Variations of Pressure

Barotrauma during air travel: predictions of a mathematical model

“…The functional anatomy of the ET has been described in many publications (2,5,17,52). Briefly, the posterior portion of the ET is a mucosa-lined, bony tube continuous with the anterior tympanum, whereas the anterior portion is cartilaginous medially and membranous laterally (Fig.…”

“…2). The cartilaginous portion is usually closed by a tissue pressure, ET pressure (P ET ), that equals the sum of the Pam (a consequence of the incompressibility of body fluids) and a vascular pressure (P vas ) (17,27). A muscle, the tensor veli palatini (mTVP), takes origin from the membranous wall of the ET and terminates on the hamular process and within the palatine aponeurosis (5).…”

“…Passive, pressure-driven ET opening occurs when the force, F(P), associated with either P ME or P NP exceeds that of P ET . Active, pressuredriven ET opening occurs when P NP is increased by Valsalva or other maneuvers so that the applied F(P NP ) exceeds F(P ET ), or, for some individuals, when F(P ET ) is reduced by yawning or mandibular repositioning (5,13,17,36). Active, muscleassisted ET opening occurs when the mTVP contracts with sufficient force (F TVP ) to overcome the F(P ET ) (5,27,28).…”

“…Consequently, during descent, the passenger must periodically open the ET actively by swallowing to induce mTVP activity or by other maneuvers that cause F(P NP ) to transiently exceed the extant F(P ET ) or cause F(P ET ) to decrease to less than F(P NP ). Of the latter, Valsalva is the most commonly used wherein air is forcibly expelled from the lungs while keeping the mouth closed and pinching the nose (6,17,33,36,45). This greatly increases the P NP and can passively open the ET to allow for NP gas transfer to the ME.…”

Irreparable Vesico-vaginal Fistula in Iraq

“…The subject of otitic barotrauma has received much attention in the R.A.F. (Dickson et al, 1943), but sudden change of pressure has no other physiological effects, and, provided the Eustachian tubes are patent, a fall of pressure of half an atmosphere in about half a second can be tolerated by man without any discomfort. Studies on this explosive decompression were first carried out by Armstrong and Heim, and later extended by the R.A.F.…”