A spirometer measures air in liters with the results given in percentages. It compares the patient’s airflow to an average person with the same physical characteristics. The following are some of the measurements taken by a spirometer, (Figure 5). 1. FEV 1 (Forced Expiratory Volume). This measures the amount of air a patient can blow out within one second. 2. FEF 25-75 (Forced Expiratory Flow). This measures the airflow in the middle of a forced exhalation. 3. FVC (Forced Vital Capacity). This measures the total amount of air a patient blows out in one breath. 4. FEV1/FVC- This is a ratio of the amount of air that is forcefully exhaled in the first second divided by the total amount of air forcefully exhaled. This measurement is very useful when determining the severity of the lung disease. After reading the measurements taken by the spirometer, a physician or trained respiratory technician can determine if a patient’s airway has been narrowed. A spirometer can also
help
assess
if
a
treatment
has
been
successful in opening up a patient’s airways. We conclude that spirometry is a justifiable part of all hospital visits for patients with cystic fibrosis, assuming that one would want to detect and treat declines in pulmonary status before they become advanced.