Oxygen Toxicity

oxygen toxicity

n.

A condition resulting from breathing high partial pressures of oxygen, characterized by visual and hearing abnormalities, unusual fatigue, muscular twitching, anxiety, confusion, incoordination, and convulsions.

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oxygen toxicity,

a condition of oxygen overdosage that can result in pathologic tissue changes, such as retinopathy of prematurity or bronchopulmonary dysplasia. It can also decrease CO₂ drive to breathe.

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Oxygen Toxicity

Microbiology The toxic effects of atmospheric O2 on strict anaerobic bacteria are not fully understood and may be related to the lack of enzymes—e.g., superoxide dismutase, catalases, and peroxidase—capable of metabolizing free radicals, and are incapable of growth in greater than 0.5% ambient O2; to reduce the oxidation-reduction or ‘redox’ potential of a medium, reducing agents such as thioglycolate and l-cysteine may be added to the anaerobic transport medium
Pulmonary medicine Tissue and molecular damage due to the effects of O2 free radicals in cellular and extracellular micro-environments; OT occurs in infants—retinopathy of prematurity—and in the elderly—shock and inflammation

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oxygen

a chemical element, atomic number 8, atomic weight 15.999, symbol O. See Table 6. It is a colorless and odorless gas that makes up about 20% of the atmosphere. In combination with hydrogen, it forms water; by weight, 90% of water is oxygen. It is the most abundant of all the elements of nature. Large quantities of it are distributed throughout the solid matter of the earth, because the gas combines readily with many other elements. With carbon and hydrogen, oxygen forms the chemical basis of much organic material. Oxygen is essential in sustaining all kinds of life.

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oxygen analyzer

an instrument that measures the concentration of oxygen in a gas mixture.

oxygen deficiency

significant cause of losses in cultivated finfish in enclosed dams, but also in rivers and estuaries, caused by lack of natural aeration of the water or to heavy algal blooms, bushfire ash deposits and overcast conditions leading to respiration rather than photosynthesis or a high concentration of organic matter and leading to the development of a bacterial bloom; a high temperature exacerbates the development.

oxygen flux equation

a calculation that determines the rate at which oxygen is made available to tissues, based on cardiac output and arterial oxygen content.

oxygen-hemoglobin dissociation curve

a graphic explanation of the release and acquisition of oxygen from and to the hemoglobin in the blood in varying circumstances of oxygen partial pressure in the environment.

oxygen regulator

see reducing valve.

oxygen saturation

the amount of oxygen bound to hemoglobin in the blood expressed as a percentage of the maximal binding capacity.

oxygen saturation curve

graphical representation describing the relationship (usually curvilinear) between fraction of oxygen-binding sites (of a protein) that have oxygen bound to them and the partial pressure (concentration) of free oxygen.

oxygen tank

the heavy metal cylinder in which medical gases are compressed at high pressure. Called also oxygen cylinder.

oxygen tension

see tension (2).

oxygen tent

an enclosed space or plastic canopy used for oxygen therapy, humidity therapy or aerosol therapy.

oxygen therapy

supplemental oxygen administered for the purpose of relieving hypoxemia and preventing damage to the tissue cells as a result of oxygen lack (hypoxia). Companion animals are usually placed in a special cage with oxygen piped to it. A mask is used for short-term administration. Large animals can be supplied by a nasal tube taped in place to deliver oxygen into the pharynx.

oxygen toxicity

tissue damage may occur with exposure to high concentrations of oxygen for long periods. See also retrolental fibroplasia.

oxygen-transfer chain

a functional chain describing the transfer of oxygen from the external environment to the metabolizing tissue; includes uptake in the respiratory system, binding to hemoglobin, transport through the circulatory system, diffusion and dissociation in tissues and utilization in mitochondria, i.e. oxidatable substrates and enzymes.

oxygen transport

process of transfer of oxygen around the body either attached to hemoglobin or myoglobin.

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oxygen toxicity

Tissue and molecular damage due to the effects of O₂ free radicals in cellular and extracellular micro-environments; OT occurs in older subjects, shock and inflammation. See Oxygen radical.