What is the best indicator of moving air in an asthma patient?

What is the best indicator of moving air in an asthma patient?

• A. Peak expiratory flow rate
• B. Pulse oximetry
• C. ABG
• D. Chest x-ray

Answer: (A)

Airflow through the airways is what truly changes during an asthma attack, so the best indicator of moving air is how fast a person can exhale. The peak expiratory flow rate directly measures maximal speed of exhaled air, reflecting the degree of airway narrowing from bronchoconstriction and inflammation. It’s practical to monitor daily, can track response to bronchodilators, and helps categorize severity and detect early exacerbations. Pulse oximetry shows oxygen saturation and may appear normal even when airflow is reduced, especially in mild to moderate cases. Arterial blood gas assesses ventilation and gas exchange but is invasive and not needed for routine monitoring. A chest x-ray reveals structure and potential complications but does not measure current airflow.

Airflow through the airways is what truly changes during an asthma attack, so the best indicator of moving air is how fast a person can exhale. The peak expiratory flow rate directly measures maximal speed of exhaled air, reflecting the degree of airway narrowing from bronchoconstriction and inflammation. It’s practical to monitor daily, can track response to bronchodilators, and helps categorize severity and detect early exacerbations.

Pulse oximetry shows oxygen saturation and may appear normal even when airflow is reduced, especially in mild to moderate cases. Arterial blood gas assesses ventilation and gas exchange but is invasive and not needed for routine monitoring. A chest x-ray reveals structure and potential complications but does not measure current airflow.