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, lung overpressure injuries and injuries resulting from external squeezes. Decompression sickness is indirectly caused by ambient pressure reduction, and the tissue damage is caused directly and indirectly by gas bubbles, but these bubbles form out of supersaturated solution from dissolved gases, and are not generally considered barotrauma. Decompression illness is a term which includes decompression sickness and arterial gas embolism caused by lung overexpansion barotrauma. It is also classified under the broader term of Dysbarism, which covers all medical conditions resulting from changes of ambient pressure.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.
TBI results about once every 20,000 times someone is intubated through the mouth, but when intubation is performed emergently, the incidence may be as high as 15%.The mortality rate for people who reach a hospital alive was estimated at 30% in 1966; more recent estimates place this number at 9%. The number of people reaching a hospital alive has increased, perhaps due to improved prehospital care or specialized treatment centers. Of those who reach the hospital alive but then die, most do so within the first two hours of arrival. The sooner a TBI is diagnosed, the higher the mortality rate; this is likely due to other accompanying injuries that prove fatal.Accompanying injuries often play a key role in the outcome. Injuries that may accompany TBI include pulmonary contusion and laceration; and fractures of the sternum, ribs and clavicles. Spinal cord injury, facial trauma, traumatic aortic rupture, injuries to the abdomen, lung, and head are present in 40–100%. The most common accompanying injury is esophageal perforation or rupture (known as Boerhaave syndrome), which occurs in as many as 43% of the penetrating injuries to the neck that cause tracheal injury. History
Throughout most of history, the mortality rate of TBI was thought to be 100%. However, in 1871 a healed TBI was noted in a duck that had been killed by a hunter, thus demonstrating that the injury could be survived, at least in the general sense. This report, made by Winslow, was the first record in the medical literature of a bronchus injury.