In blood gas analysis, which gas is primarily measured?

In blood gas analysis, the primary focus is on measuring carbon dioxide (CO2). This is due to its critical role in the body's respiratory and metabolic processes. CO2 levels provide important information regarding a patient's respiratory function, particularly how well carbon dioxide is being eliminated from the body through the lungs.

Measuring CO2 levels helps assess the acid-base status of the blood, as an increase in CO2 can indicate respiratory acidosis, while a decrease can suggest respiratory alkalosis. These insights are crucial for diagnosing and managing various respiratory and metabolic disorders.

In contrast, while oxygen levels are also important in blood gas analysis, the primary evaluation often hinges on CO2, as it is a direct indicator of how well the body is regulating acid-base balance. Nitrogen and hydrogen are not typically measured in blood gas analysis because they do not play significant roles in respiratory function or acid-base balance in the same way that carbon dioxide does.