Barotrauma | |
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Synonyms | Squeeze, Decompression illness, Lung overpressure injury |
Mild barotrauma to a diver caused by mask squeeze | |
Classification and external resources | |
Specialty | emergency medicine |
ICD-10 | T70.0, T70.1 |
ICD-9-CM | 993.0, 993.1 |
DiseasesDB | 3491 |
eMedicine | emerg/53 |
MeSH | D001469 |
Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or in contact with the body, and the surrounding gas or fluid. The initial damage is usually due to over-stretching the tissues in tension or shear, either directly by expansion of the gas in the closed space, or by pressure difference hydrostatically transmitted through the tissue. Tissue rupture may be complicated by the introduction of gas into the local tissue or circulation through the initial trauma site, which can cause blockage of circulation at distant sites, or interfere with normal function of an organ by its presence.
Barotrauma generally manifests as sinus or middle ear effects, decompression sickness (DCS), lung overpressure injuries, and injuries resulting from external squeezes.
Barotrauma typically occurs when the organism is exposed to a significant change in ambient pressure, such as when a scuba diver, a free-diver or an airplane passenger ascends or descends, or during uncontrolled decompression of a pressure vessel such as a diving chamber or pressurised aircraft, but can also be caused by a shock wave. Ventilator induced lung injury (VILI) is a condition caused by over-expansion of the lungs by mechanical ventilation used when the body is unable to breathe for itself, and is associated with relatively large tidal volumes and relatively high peak pressures. Barotrauma due to over-expansion of an internal gas filled space may also be termed volutrauma. Bats can be killed by lung barotrauma when flying in low pressure regions close to operating wind turbine blades.
Examples of organs or tissues easily damaged by barotrauma are:
When diving, the pressure differences which cause the barotrauma are changes in hydrostatic pressure: There are two components to the surrounding pressure acting on the diver: the atmospheric pressure and the water pressure. 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. So, a descent from the surface to 10 metres (33 feet) underwater results in a doubling of the pressure on the diver. This pressure change will reduce the volume of a gas filled space by half. Boyle's law describes the relationship between the volume of the gas space and the pressure in the gas.