How is hypoventilation characterized on an arterial blood gas (ABG) analysis?

Hypoventilation on an arterial blood gas (ABG) analysis is characterized by elevated carbon dioxide levels and decreased pH. This occurs because hypoventilation leads to inadequate ventilation and a subsequent buildup of carbon dioxide (CO2) in the bloodstream. As CO2 levels rise, they cause respiratory acidosis, which is reflected in a decreased pH on the ABG results.

In a state of hypoventilation, the respiratory rate is insufficient to meet the body's metabolic demands, causing the body to retain CO2. The accumulation of CO2 produces carbonic acid when it combines with water, which in turn decreases the pH level, indicating acidosis. Therefore, elevated CO2 levels signal that ventilation is ineffective, leading to the characteristic findings of respiratory acidosis on ABG analysis.