Oxygen Window

The oxygen window (literally ' oxygen window '), partial pressure vacancy ( PPV ) or inherent unsaturation is the name given to the partial pressure difference of oxygen between arterial and central venous vessels or body tissues in diving physiology . This difference increases up to a certain maximum - which depends on the oxygen consumption of the tissue - by increasing the oxygen supply and pressure. This clearly means that all body tissues - with the exception of the arteries - always contain less oxygen and is physically dissolved than in the atmospheric air itself, since the tissues consume the oxygen through cellular respiration . But because the total pressure of a gas is made up of the partial pressures of the gases it contains (oxygen, nitrogen and carbon dioxide), the nitrogen partial pressure in body tissues is also lower than in the alveoli . At the same time, increasing the pressure increases the solubility of gases in liquids such as tissue fluid and blood according to Henry's law . This fact causes technical divers in particular to carry out the last stage of decompression at a depth of 6 meters with 100 percent oxygen , as this also accelerates the release of nitrogen and carbon dioxide from the body tissue.

The Oxygen Window and Henry's Law are the basis for oxygen therapy as hyperbaric oxygenation in decompression sickness .

At standard pressure the oxygen window is about 72 mbar (54 mmHg / Torr ); the gas pressure in body tissues and veins is 941 mbar (706 mmHg / Torr).

history

The term oxygen window was coined in 1967 by Albert R. Behnke , while a working group led by Van Liew carried out studies on this topic as early as 1965, but referred to the difference as partial pressure vacancy ( PPV ). The clinical importance of the Oxygen Windows was later demonstrated by Sass.

Individual evidence

↑ Davis JR, Johnson R., Stepanek J.: Fundamentals of Aerospace Medicine. 4th edition, Lippincott Williams & Wilkins, 2008, ISBN 9780781774666 , p. 69
^ Daniel Mathieu: Handbook on Hyperbaric Medicine. Springer, 2006, ISBN 9781402043765 , p. 37
^ AR Behnke: The New Thrust Seaward. . In: Marine Tech. Soc. (Ed.): Trans. Third Marine Tech. Soc. Conf. . 1967. Retrieved March 16, 2008.
^ HD Van Liew, Bishop, B .; Walder, P .; Rahn, H .: Effects of compression on composition and absorption of tissue gas pockets. . In: J. Appl. Physiol. . 20, No. 5, 1965, ISSN 0021-8987 , pp. 927-33. OCLC 11603017 . PMID 5837620 . Retrieved March 16, 2008.
↑ DJ Sass: Minimum <delta> P for bubble formation in pulmonary vasculature. . In: Undersea Biomed. Res. . 3, No. Supplement, 1976, ISSN 0093-5387 . OCLC 2068005 . Retrieved March 16, 2008.

[1] Davis JR, Johnson R., Stepanek J.: Fundamentals of Aerospace Medicine. 4th edition, Lippincott Williams & Wilkins, 2008, ISBN 9780781774666 , p. 69

[2] Daniel Mathieu: Handbook on Hyperbaric Medicine. Springer, 2006, ISBN 9781402043765 , p. 37

[two-3] AR Behnke: The New Thrust Seaward. . In: Marine Tech. Soc. (Ed.): Trans. Third Marine Tech. Soc. Conf. . 1967. Retrieved March 16, 2008.

[nine-4] HD Van Liew, Bishop, B .; Walder, P .; Rahn, H .: Effects of compression on composition and absorption of tissue gas pockets. . In: J. Appl. Physiol. . 20, No. 5, 1965, ISSN 0021-8987 , pp. 927-33. OCLC 11603017 . PMID 5837620 . Retrieved March 16, 2008.

[ten-5] DJ Sass: Minimum <delta> P for bubble formation in pulmonary vasculature. . In: Undersea Biomed. Res. . 3, No. Supplement, 1976, ISSN 0093-5387 . OCLC 2068005 . Retrieved March 16, 2008.