Pressure Changes and Barotrauma Resulting From Decompression and Recompression in the Middle Ear of Monkeys

THERE are three situations in modern life under which persons are exposed to the danger of receiving barotrauma from sudden change in atmospheric pressure: flight at high altitude, working in the caisson or escaping from a submarine and exposure to bomb blast. It is generally agreed that the outstanding pathologic effect of sudden barometric changes is on those organs which contain air. Among those organs the middle ear is evidently a vulnerable one. Although the otic symptoms incidental to sudden pressure changes have long been described clinically and interpreted in various ways, the hemorrhages in the middle ear cavity and the mastoid cells and, especially, the mechanism involved in the production of these pathologic changes have never been adequately investigated. Alt¹was probably the first who described the apoplectiform lesions in the ear of caisson workers and correctly interpreted the tympanic hemorrhage as being due to the inequality of pressures