alveolar air equation

al·ve·o·lar air e·qua·tion

(al-vē'ŏ-lăr ār ĕ-kwā'zhŭn)
An equation that calculates an approximation of alveolar oxygen tension if the fractional concentration of inspired oxygen, arterial carbon dioxide tension, and respiratory exchange ratio (i.e., carbon dioxide production divided by oxygen consumption) are known.
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References in periodicals archive ?
The alveolar air equation is needed to calculate the [CcO.sub.2] and a pulmonary artery catheter is required to determine the [CvO.sub.2].
The alveolar air equation is needed to calculate the C[CO.sub.2] and a pulmonary artery catheter is required to determine the Cv[O.sub2].
Considering Henry's law, if the FIO2 was increased from 0.21 to 0.40, a significant amount of nitrogen molecules would wash out of the lungs, and the PAO2 would increase to about 225 mm Hg, based on the alveolar air equation. Assuming complete equilibration across the alveolar-capillary membrane, the PaO2 would become 225 mm Hg.