When obtaining a MEP measurement, what is the respiratory therapist observing?

• A. Strength and ability to cough
• B. Inspiratory muscle strength
• C. RSBI
• D. Presence of fixed upper airway obstruction

Answer: (A)

When obtaining a MEP (maximum expiratory pressure) measurement, the focus is on assessing the patient's ability to generate maximum expiratory pressure against a resistance. This primarily evaluates the strength and effectiveness of the muscles involved in expiration, which directly relates to coughing strength and ability. A strong cough is essential for clearing airways, and a higher MEP indicates better respiratory muscle function.

In contrast, inspiratory muscle strength refers to the measurement of pressures generated during inhalation, which is not the focus of MEP. RSBI (Rapid Shallow Breathing Index) assesses the relationship between frequency and tidal volume to understand breathing efficiency, but it does not measure expiratory capacity or cough strength. Lastly, the presence of fixed upper airway obstruction would suggest structural problems affecting airflow, which is not what MEP measurements are evaluating. Thus, the primary observation during MEP measurement directly correlates with the strength and ability to cough effectively.