Compressed-air Bath

Compressed-air Bath, a strong chamber of riveted iron plates in which two or more persons can sit, and into which air is driven by a steam-engine to any required pressure, as notified by the attached barometers. The inflow of fresh air and the escape of the foul air are regulated by valves. Patients remain in the bath from one to three hours, and the pressure is generally increased to an atmosphere and a half. Another appliance for using either compressed or rarefied air consists of a mask tightly covering mouth and nose, and connected by a tube and suitable valves with some form of air-cistern in which the pressure can be varied as desired. By this appliance patients can either inspire compressed or rarefied air, or can breathe out into either of these. Practically only the first and fourth of these possible methods are used. Treatment by Aerotherapeutics has long been a favourite study, but the results have varied much, and have lacked exactness. The general effects of compressed air are to lessen the frequency of the movements of the chest, and of the heart or pulse beats, while allowing the absorption of more oxygen, and increasing the blood-tension. Rarefied air produces the opposite effects. Many diseased conditions therefore should benefit by this treatment, especially asthma, chronic bronchitis, and catarrh under compressed air, and emphysema by rarefied air; while in the treatment generally we have a useful system of lung gymnastics, which increase the power of the respiratory muscles and the vital capacity of the lungs.