Alveolar-Arterial (A-a) Oxygen Gradient
Pulmonology specialty tool
Bedside Tool Interface Configuration
Differentiates intrapulmonary vs extrapulmonary causes of hypoxemia by calculating Alveolar to arterial oxygen tension delta.
Algorithm Checklist Parameters:
- Patient Age (years)
- PaOâ‚‚ (Arterial POâ‚‚) (mmHg)
- PaCOâ‚‚ (Arterial PCOâ‚‚) (mmHg)
- Inspired Oxygen Fraction (FiOâ‚‚) (%)
- Respiratory Quotient (RQ)
- Atmospheric Pressure (mmHg) (760 at sea level)
Primary Clinical Application:
Delineates ventilation-perfusion compliance errors, anatomical shunts, diffusion barriers or simple hypoventilation.