Adult-Gerontology Clinical Nurse Specialist (CNS) Practice Exam

Peak expiratory flow rate (PEFR) does not consider which of the following factors?

1. Height

2. Age

3. Gender

4. Weight

The correct answer is: Weight

Peak expiratory flow rate (PEFR) is a measure of how fast a person can exhale air from their lungs. It is an important parameter in assessing respiratory function, particularly in conditions like asthma or chronic obstructive pulmonary disease. The primary factors that influence PEFR are height, age, and gender, as these variables relate to lung capacity and physiological differences. Height is particularly significant because taller individuals generally have larger lung volumes, which can result in higher PEFR values. Age is also a crucial factor since lung function tends to decline with advancing age, affecting PEFR measurements. Furthermore, gender plays a role in PEFR, with males typically recording higher peak flow rates than females, likely due to differences in lung size and capacity. Weight, while it can influence overall health and may impact lung function indirectly, does not have a direct correlation with PEFR measurements. Unlike the other three factors, which are intrinsic characteristics of lung physiology, weight does not reflect respiratory capacity in the same way. Therefore, when assessing PEFR, weight is not factored into the standard calculations or reference values. This is why the answer indicating weight is the correct choice in relation to what PEFR does not consider.