- - oxygen t. 1. a body disturbance resulting from breathing high partial pressures of oxygen; characterized by visual and hearing abnormalities, unusual fatigue while breathing, muscular twitching, anxiety, confusion, incoordination, and convulsions; can occur when excessive quantities of oxygen are administered in patients (such as adult respiratory distress syndrome), resulting in worsening of pulmonary infiltrates and clinical deterioration; although the mechanism for development of the condition is obscure, a disruption of enzymatic activity is likely, perhaps as a result of free radical formation. Cf.:retrolental fibroplasia. 2. exposure of the lungs to greater than 60% oxygen for periods exceeding 24–48 hours can lead to severe, irreversible pulmonary fibrosis. SYN: oxygen poisoning.
* * *tox·ic·i·ty täk-'sis-ət-ē n, pl -ties the quality, state, or relative degree of being toxic or poisonous
* * *n.the degree to which a substance is poisonous. See also LD50.
* * *tox·ic·i·ty (tok-sisґĭ-te) 1. the quality of being poisonous. 2. the degree of virulence of a toxic microbe or of a poison.
Medical dictionary. 2011.