Lung Efficiency: Oxygen Extraction Capabilities

Assessing Pulmonary Oxygen Uptake

Healthy lungs extract 30–35% of inhaled oxygen. Key efficiency parameters:

1. Oxygen saturation (SpO₂): 95–100% normal.
2. Arterial partial pressure of O₂ (PaO₂): Higher = better extraction.
3. Alveolar-arterial O₂ gradient (AaDO₂): Lower = more efficient gas exchange.
4. Ventilation-perfusion matching: High coordination maximizes O₂ uptake.
5. Respiratory quotient (RQ): Near 1 indicates efficient O₂ utilization.
6. Tidal volume & respiratory rate: Adequate values meet demand without excessive work.

Respiratory diseases compromise efficiency, leading to complications.