Final answer:
Age-related changes in the respiratory system often result in an increased susceptibility to respiratory infections due to a decline in immune system efficacy and changes in lung function affecting breathing and gas exchange.
Step-by-step explanation:
The home health nurse assesses an older adult's respiratory function carefully because age-related changes in the respiratory system could result in increased susceptibility to respiratory infections. As individuals age, their immune system efficacy can decline, thereby elevating the risk of infections. Additionally, changes in lung compliance and resistance can affect breathing efficiency and gas exchange, making it more difficult for the body to clear pathogens. Conditions such as fibrosis can decrease lung compliance, whereas asthma or emphysema increase airway resistance, both potentially leading to compromised respiratory function.
Therefore, the correct answer to the inquiry is 2) susceptibility to respiratory infections. This recognizes the natural decline in the effectiveness of the respiratory system and immune response with age, as well as the potential increase in breathing-related challenges that heighten infection risks.