Ebullism

Under Ebullismus (from Latin ebullire = gushing ) refers to the rapid pressure drop caused by the release of dissolved gases in the body fluids (especially nitrogen) in blood and tissues. Ebullismus is the cause of decompression sickness (also known as the bends or caisson disease ).

Armstrong - border

Under the atmospheric pressure at sea level ( 101.325 kPa), water boils at a temperature of 100 ° C. At an altitude of 18,900 m, it boils at only 37 ° C, the normal body temperature of humans. In the aerospace industry is the limit, when the air pressure is so low ( 6.3 kPa or 0.0618 atm), that the blood in the human body would boil at body temperature without a pressure suit, as Armstrong Limit (after the aerospace medical Harry George Armstrong (1899-1983)) respectively. In practice, the boiling of body fluids occurs not yet on exactly this amount, since the skin and tissues maintain the pressure inside the body to the external pressure, the formation of bubbles in the blood still represents a serious medical problem

Symptoms

Symptoms of Ebullismus include bubbles in the membranes of the skin and air bubbles in the blood mouth and eyes, swelling. The evaporation also creates a strong cooling effect at these locations. Circulation and respiration are severely impaired or stopped. By the air bubbles in the arteries the brain tissue can not be sufficiently supplied with oxygen. Are the lungs filled with air, they swell and occurs due to the pressure difference to bleeding. Are the lungs is not filled with air, this collapse by swelling of the rest of the body tissue. The main problem here is mainly the nitrogen content of the air dar.

To prevent Ebullismus, a pure oxygen (O2 ) atmosphere was used in the early space travel, which, however, an increased risk of fire due. After the fire accident in the Apollo 1 capsule within the atmosphere of spacecraft during all work before the start and the start-up phase by a nitrogen -oxygen mixture was replaced and exchanged only in orbit again against a pure oxygen atmosphere.