What is the main purpose of an arterial blood gas (ABG) analysis?

The primary purpose of an arterial blood gas (ABG) analysis is to evaluate oxygenation, ventilation, and acid-base balance in the body. This test provides critical information about how well the lungs are transferring oxygen into the blood and removing carbon dioxide out of it, which are essential functions for maintaining proper physiological function.

ABG results show levels of oxygen and carbon dioxide in the arterial blood, alongside the blood's pH level, which indicates the overall acid-base status. This is vital for diagnosing respiratory disorders, metabolic imbalances, and monitoring critically ill patients or those undergoing respiratory therapy.

While measuring lung capacity is important for understanding pulmonary function, it does not specifically assess the gas exchange and acid-base status that an ABG does. Determining the presence of an infection requires different testing, such as cultures or imaging studies, as the ABG does not provide direct information about infections. Analyzing blood glucose levels focuses on metabolic function, particularly concerning diabetes and not the respiratory or acid-base status. Therefore, the evaluation of oxygenation, ventilation, and acid-base balance correctly identifies the main purpose of the ABG analysis.