or decompression chamber or recompression chamber Sealed chamber supplying a high-pressure atmosphere. Breathing air at high pressure increases the oxygen level in tissues. This is used to inhibit growth of anaerobic bacteria (as in tetanus or gas gangrene); to increase the chance that babies with certain heart malformations will survive heart surgery; or to cause air bubbles (as in air embolism or decompression sickness) to be redissolved, carried to the lungs, and exhaled as pressure is gradually returned to normal