![]() ![]() Sound waves travel via the EAC producing TM vibration, which is then carried through, and amplified by, the bony ossicular chain. However, this transmucosal gas exchange is less important during rapid and large changes in ambient pressure occurring during diving, flying, or when being treated in a hyperbaric chamber. Another less described air exchange takes place via the middle ear mucosa and mixed venous circulation. It is important to note that while equalization of the middle ear via the ET on ascent is passive, it requires an active maneuver on descent. This is known as the equalization of the middle ear pressure. It is also responsible for the exchange of air between the nasopharynx and the middle ear space, maintaining equal pressure between the middle ear and the EAC. The ET opens just beyond the nasal openings in the posterior nasopharynx, allowing the drainage of fluid produced in the middle ear space. The middle ear space is covered by mucosa and is connected to the throat via the eustachian tube (ET), also referred to as the auditory tube. The vestibular system, which is continuous with the cochlea, is responsible for spatial orientation and balance. The cochlea is responsible for sound transmission and is composed of three fluid-filled compartments: the scala vestibuli and scala tympani containing perilymph and the scale media containing endolymph. The inner ear space, containing the auditory (cochlea) and vestibular (semi-circular canals, utricle, and saccule) systems, is separated from the middle ear by the oval and round (labyrinthine) windows. The third ossicle, the stapes, abuts the oval window, leading into the inner ear space. The other ossicles are visible when favorable anatomical conditions are present, such as a transparent TM. It is an expected anatomical finding on otoscopy and easily visualized. The umbo is the distal portion of the malleus and connects the bony ossicles to the TM. The external auditory meatus, or the opening to the external auditory canal (EAC), extends toward and ends at the tympanic membrane (TM). Posterior to the TM is the air-filled middle ear space containing three bony ossicles: the malleus, incus, and stapes. The outside portion of the ear, the pinna, is composed primarily of ridged cartilage covered by skin. Eustachian tube dysfunction (ETD) and middle ear barotrauma (MEBT) remain the most common complication of diving and clinical hyperbaric oxygen treatment (HBO). The results of the ETF test can also be used in the usual work of an otorhinolaryngologist to evaluate Eustachian function in cases of unilateral disease of middle ear.Otic Barotrauma (OBT) or ear barotrauma is a tissue injury to the ear secondary to inadequate pressure equalization between gas-filled body spaces and the external environment. Values of 20 DaPa and less are not a definite predictor of the BFT results. 7 of the last group displayed difficulties with the BFT in the ear with poor ETF result.Ĭonclusions: We consider that the ETF test can be used to assess diving fitness as a screening method before performing a BFT, as values above 20 DaPa guarantee Eustachian tube function sufficient for diving activities. 8 divers have ETF values lower than 20 DaPa in one ear and higher than 20 DaPa in the other. 3 divers have ETF test values lower than 20 DaPa in both ears, but none of them displayed difficulties in the BFT. ![]() Results: In the current study 24 divers have ETF test results higher than 20 DaPa. Based on results from previous studies we are using a 20 DaPa cutoff point on the ETF test to predict Eustachian tube passability and a successful barofunction test. It consists of divers compressing and decompressing in a hyperbaric chamber to a pressure of 2.2 ATA for 1 minute. Then a barofunction test (BFT) was performed to assess the diving fitness and the passability of the Eustachian tubes. ![]() For all subjects is measured first intratympanal pressure at rest, then after the maneuver of Valsalva with impedancemeter. Material and methods: The study included 35 professional divers undergoing annual medical examination. The aim of our study is to compare the results of tympanometry and Valsalva part of Eustachian Tube Function test (ЕТF-test) with the ability of divers to compensate for the change in ambient pressure in a hyperbaric chamber. ![]() Background: Most of the cases of middle ear barotrauma in divers are due to the impassability of the Eustachian tube. ![]()
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