ABG

Arterial blood gas

An arterial blood gas (ABG) is a diagnostic test that measures the levels of oxygen (O₂), carbon dioxide (CO₂), and the pH (acid-base balance) in arterial blood. It provides critical information about lung function, gas exchange efficiency, and acid-base status, making it essential in the evaluation of respiratory and metabolic conditions.

Key parameters measured in an ABG include:

• PaO₂: Partial pressure of oxygen, indicating oxygenation status.
• PaCO₂: Partial pressure of carbon dioxide, reflecting respiratory function and ventilation.
• pH: The blood’s acidity or alkalinity, helping to identify acid-base imbalances.
• HCO₃⁻: Bicarbonate level, indicating the metabolic component of acid-base balance.
• O₂ saturation: The percentage of hemoglobin saturated with oxygen.

ABGs are often used in critical care settings to monitor patients with respiratory distress, metabolic imbalances, or in situations requiring ventilation management.

SEE ALSO: base excess (BE).