North Carolina EMT State Practice Exam

Among elderly patients, which factor can significantly affect lung capacity?

1. Decreased tidal volume

2. Increased lung elasticity

3. Improved oxygen exchange

4. Heightened respiratory rate

The correct answer is: Decreased tidal volume

Decreased tidal volume is a significant factor that can affect lung capacity in elderly patients. As individuals age, various physiological changes occur that can lead to a reduction in the amount of air that is inhaled with each breath. Tidal volume is the volume of air moved in and out of the lungs during normal respiration. In older adults, conditions such as decreased lung elasticity, diminished strength of respiratory muscles, and possible skeletal changes (like kyphosis) can all contribute to a lower tidal volume. When tidal volume decreases, the total amount of air that can be exchanged in the lungs diminishes, ultimately affecting overall lung capacity. This reduction can lead to decreased oxygen availability and can make elderly individuals more susceptible to respiratory ailments. In contrast, increased lung elasticity (which usually allows for better expansion and contraction of the lungs) and improved oxygen exchange are typically not characteristics associated with aging, as lung elasticity tends to decrease. Heightened respiratory rate, while it may occur in some elderly patients, does not directly correlate to an increase in lung capacity and may instead be a compensatory response to decreased tidal volume and oxygenation.