Certified Pulmonary Function Technologist (CPFT) Practice Exam

What must be reported for plethysmography testing?

1. The highest measurement from any test

2. The average of three acceptable tests that agree within 5%

3. Only the result of the first test

4. The lowest measurement across all tests

The correct answer is: The average of three acceptable tests that agree within 5%

In plethysmography testing, it is essential to report the average of three acceptable tests that agree within 5%. This approach is fundamental for ensuring accuracy and reliability in the results. By averaging the measurements from multiple tests, it accounts for any variability or incongruence that may occur during the testing process. The stipulation that these tests must agree within a 5% margin ensures that the results are consistent, thereby providing a more accurate depiction of the patient’s lung function. The use of the average also minimizes the impact of outlier values that may arise due to factors such as patient effort or technical issues during the test. Therefore, by reporting this average, healthcare professionals can make informed decisions regarding diagnosis and treatment plans based on robust data. In contrast, reporting the highest measurement or the lowest measurement from any test does not provide a comprehensive or accurate view of lung function, as these values may not represent the patient's typical performance. Also, only reporting the result of the first test would overlook the potential variability in measurements that can give a misleading impression of the patient's lung capacity and function.