What is Exhaled Carbon Monoxide (FEco) testing primarily used for?

Exhaled Carbon Monoxide (FEco) testing is primarily used to monitor a patient's abstinence from smoking. This diagnostic tool measures the level of carbon monoxide gas that is expelled during exhalation, which is a byproduct of combustion, including that from cigarette smoke. When a patient smokes, their carbon monoxide levels rise significantly. Conversely, when they stop smoking, the levels of exhaled carbon monoxide decrease over time. Therefore, healthcare providers use this non-invasive test to assess an individual's smoking status and verify whether they have successfully abstained from smoking, providing a valuable metric for both treatment plans and patient counseling.

Other options, such as measuring carbon dioxide levels, assessing lung function, or evaluating respiratory infections, do not fall under the primary use of FEco testing. Carbon dioxide levels would typically be assessed through different methods, and lung function tests usually involve spirometry or gas exchange measurements, not carbon monoxide levels. Similarly, while exhaled carbon monoxide could indirectly suggest changes related to respiratory infections, it is not a primary tool for diagnosing those conditions.