Hyperbaric: Pertaining to gas pressures greater than 1 atmosphere* of pressure. Also pertaining to solutions that are more dense than the medium to which they are added. The term "hyperbaric" is derived from Greek roots: "hyper-" meaning high, beyond, excessive, above normal + "baros" meaning weight.
Hyperbaric oxygenation is an increased amount of oxygen in organs and tissues resulting from the administration of oxygen in a compression chamber at an ambient pressure greater than 1 atmosphere* of pressure.
Hyperbaric oxygen is used to treat gas gangrene, some soft tissue infections, and other conditions in which high concentrations of oxygen are beneficial.
Hyperbaric solutions in spinal anesthesia are solutions that have a density greater than that of spinal fluid.
*An atmosphere is a unit of pressure taken to be the standard pressure of the earth's atmosphere at sea level. An atmosphere is equal to the pressure of a column of mercury 760 mm high and expressed as 101.325 kilopascals (1.01325 × 105 newtons per square meter), or about 14.7 pounds per square inch.