ALVEOLAR-ARTERIAL OXYGEN QUOTIENT - STANDARD NORMS, CLINICAL FINDINGS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 28  (11) , 533-539
Abstract
From the practical standpoint of view the A-aDO2 [alveolar-arterial O2 diffusion] is a good parameter for evaluation of global gas exchange. The end-expiratory O2 pressure, recorded by mass spectrometry, is set equal to the alveolar O2 pressure. It is possible for clinical use to have an on line monitoring of PETO2-PaO2 [end-tidal-arterial O2 pressure difference]. It is necessary to specify the pressure difference in dependence of the inspiratory O2 pressure since the alveolo-arterial O2 pressure difference [PAO2-PaO2] increases with increasing inspiratory O2 pressure concentration. For practical clinical purposes the relative ratio of the difference adjusted to the alveolar O2 pressure [PAO2] was developed. The alveolar-arterial O2 quotient is a clinical suitable figure. There are no standard norms reported in the literature for this quotient. The quotient was evaluated in 9 healthy human volunteers. The standard norms can be used for practical clinical purposes. This quotient is practical in intensive care medicine (obstructive pulmonary disease, acute pulmonary failure, positive pressure ventilation).