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Patients undergoing hyperbaric oxygen therapy must equalize their ears to avoid barotrauma. In this case the pressure difference causes a resultant tension in the surrounding tissues which exceeds their tensile strength.

BAROTRAUMA WIKI FREE

īarotraumas of ascent are also caused when the free change of volume of the gas in a closed space in contact with the diver is prevented. īarotraumas of descent are caused by preventing the free change of volume of the gas in a closed space in contact with the diver, resulting in a pressure difference between the tissues and the gas space, and the unbalanced force due to this pressure difference causes deformation of the tissues resulting in cell rupture. Boyle's law describes the relationship between the volume of the gas space and the pressure in the gas. This pressure change will reduce the volume of a flexible gas-filled space by half. So, a descent from the surface to 10 metres (33 feet) underwater results in a doubling of the pressure on the diver. A descent of 10 metres (33 feet) in water increases the ambient pressure by an amount approximately equal to the pressure of the atmosphere at sea level. There are two components to the surrounding pressure acting on the diver: the atmospheric pressure and the water pressure. When diving, the pressure differences which cause the barotrauma are changes in hydrostatic pressure: Several commonly recognised examples are listed below. Īny cause of sufficiently large and rapid environmental pressure change can potentially cause barotrauma.

Infections of the external, middle or inner ear.

Temporary or permanent hearing deficit, vertigo, or balance problems.

Over-vigorous attempts to equalise using the Valsalva maneuver can lead to inner ear barotrauma.

Ingress of contaminated water through a perforated eardrum can cause infections of the middle ear.

Cold water ingress through a perforated eardrum can cause caloric vertigo, usually a short term effect.

Unequal pressures in the middle ears can cause alternobaric vertigo, disorientation and nausea.

Localised pain in one or both ears while the eardrums are stretched, which may be partly relieved if the eardrum ruptures, followed by longer term dull pain in the injured ears,and possible hearing loss. Middle ear barotrauma can also be caused by shock waves and blows to the external ear, particularly in water, and large or fast changes in altitude.ĭeformation stress trauma caused by externally applied (environmental) pressure differences on the middle ear. This may cause nausea and vomiting underwater, which has a high risk of aspiration of vomit or water, with possible fatal consequences.

Tympanic rupture during a dive can allow water into the middle ear, which can cause severe vertigo from caloric stimulation. This damage causes local pain and hearing loss.

During ascent internal over-pressure is normally passively released through the eustachian tube, but if this does not happen the volume expansion of middle ear gas will cause outward bulging, stretching and eventual rupture of the eardrum known to divers as reverse ear squeeze. Unequalised ambient pressure increase during descent causes a pressure imbalance between the middle ear air space and the external auiditory canal over the eardrum, referred to by divers as ear squeeze, causing inward stretching, serous effusion and haemorrhage, and eventual rupture. Failure to equalise may be due to inexperience or eustachian tube dysfunction, which can have many possible causes. It is common in underwater divers and usually occurs when the diver does not equalise sufficiently during descent or, less commonly, on ascent. Middle ear barotrauma (MEBT), also known to underwater divers as ear squeeze and reverse ear squeeze, is an injury caused by a difference in pressure between the external ear canal and the middle ear. Pressure difference between the external environment and the gas filled space of the middle ear Inner ear barotrauma, deafness, vertigo, nausea

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