What does elevated oxygen partial pressure in the upper lobes of the lungs indicate?

From the Research

Elevated Oxygen Partial Pressure in the Upper Lobes of the Lungs

Elevated oxygen partial pressure in the upper lobes of the lungs can be an indicator of several conditions, including:

• Ventilation-perfusion mismatching, which can occur in patients with chronic obstructive pulmonary disease (COPD) 1, 2
• Increased ventilation in the upper lobes, which can lead to increased oxygen uptake and carbon dioxide output (VCO(2)) 3
• Disease progression in COPD, which can result in hypoxemia and hypercapnia 4

Relationship to COPD

In patients with COPD, elevated oxygen partial pressure in the upper lobes of the lungs can be related to:

• The severity of airflow limitation, as measured by forced expiratory volume in 1 s (FEV(1)) 1
• The presence of ventilation-perfusion mismatching, which can lead to hypoxemia and hypercapnia 1, 2
• The development of adverse sequelae, such as pulmonary hypertension, secondary polycythemia, and systemic inflammation 4

Gas Exchange Abnormalities

Gas exchange abnormalities, including ventilation-perfusion mismatching, can occur in various lung diseases, including:

• Asthma, which can result in low VA/Q units and hypoxemia 2
• COPD, which can result in complex patterns of VA/Q inequality and deteriorating hypoxemia during exacerbations 2
• Cystic fibrosis, which can result in impaired oxygen diffusion across the alveolar-capillary barrier 2
• Interstitial lung diseases, which can result in impaired oxygen diffusion and VA/Q inequality 2