Biomaterial Database

Decompression sickness and intravenous bubble formation using a 7.8 psia simulated pressure-suit environment. 1986

G A Dixon, and J D Adams, and W T Harvey

The purpose of this study was to determine the minimum spacesuit pressure required to prevent decompression sickness (DCS) during operational conditions in a 50% oxygen/50% nitrogen environment. In this study, 30 male volunteer subjects were exposed in groups of three, to three consecutive daily extravehicular activity (EVA) simulations at 7.8 psia (5,031 m altitude equivalent) for a continuous period of 6 h. During each altitude exposure, the subjects participated in similar exercise workloads expected to be experienced by astronauts during a typical EVA scenario. Precordial Doppler monitoring revealed that 73.3% of the subjects had intravenous bubbling during at least 1 d of the 3 d of exposure, with 26.7% remaining bubble-free during the entire study. No correlation was found between either body fat or age and incidence of bubble formation. One case of DCS occurred during the study indicating that 7.8 psia is not sufficient pressure to totally preclude DCS in a 50% oxygen/50% nitrogen environment. The necessary pressure awaits further study.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D011312	Pressure	A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Pressures
D001783	Blood Flow Velocity	A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.	Blood Flow Velocities,Flow Velocities, Blood,Flow Velocity, Blood,Velocities, Blood Flow,Velocity, Blood Flow
D003665	Decompression Sickness	A condition occurring as a result of exposure to a rapid fall in ambient pressure. Gases, nitrogen in particular, come out of solution and form bubbles in body fluid and blood. These gas bubbles accumulate in joint spaces and the peripheral circulation impairing tissue oxygenation causing disorientation, severe pain, and potentially death.	Bends,Caisson Disease,Caisson Diseases,Disease, Caisson,Diseases, Caisson,Sickness, Decompression
D005118	Extraterrestrial Environment	The environment outside the earth or its atmosphere. The environment may refer to a closed cabin (such as a space shuttle or space station) or to space itself, the moon, or other planets.	Space (Astronomy),Environment, Extraterrestrial,Environments, Extraterrestrial,Extraterrestrial Environments,Spaces (Astronomy)
D005676	Gravity Suits	Double-layered inflatable suits which, when inflated, exert pressure on the lower part of the wearer's body. The suits are used to improve or stabilize the circulatory state, i.e., to prevent hypotension, control hemorrhage, and regulate blood pressure. The suits are also used by pilots under positive acceleration.	Anti-Shock Trousers,Antigravity Suits,MAST Suit,Medical Anti-Shock Trousers,Military Anti-Shock Trousers,Pneumatic Suits,Pressure Suits,Antishock Trousers,Military Antishock Trousers,Anti Shock Trousers,Anti-Shock Trouser, Medical,Anti-Shock Trousers, Medical,Anti-Shock Trousers, Military,Antishock Trousers, Military,Gravity Suit,MAST Suits,Medical Anti Shock Trousers,Medical Anti-Shock Trouser,Military Anti Shock Trousers,Pneumatic Suit,Pressure Suit,Suit, Antigravity,Suit, Gravity,Suit, MAST,Suit, Pneumatic,Suit, Pressure,Suits, Antigravity,Trouser, Medical Anti-Shock,Trousers, Anti-Shock,Trousers, Antishock,Trousers, Medical Anti-Shock,Trousers, Military Anti-Shock,Trousers, Military Antishock
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D013026	Space Flight	Travel beyond the earth's atmosphere.	Space Exploration,Space Travel,Spaceflight,Exploration, Space,Explorations, Space,Flight, Space,Flights, Space,Space Explorations,Space Flights,Space Travels,Spaceflights,Travel, Space,Travels, Space