An elderly guy in his 80s has been taking part in a longitudinal study of aging. He doesn't have any serious medical issues. In order to track long-term changes in pulmonary gas exchange, arterial blood gas samples are taken once every ten years on room air at sea level. Which of the following outcomes is most consistent with normal aging as compared to 30 years ago?

Question

Quizplus · Accepted Answer

Eductional Objective: During typical aging, the human respiratory system experiences major alterations. A series of progressive alterations result in a subtle impairment in pulmonary gas exchange: The partial pressure of carbon dioxide in arterial blood (PaCO₂), which represents total alveolar ventilation, does not vary much in comparison to decreasing PaO₂. Even when dead space expands and peak diaphragm strength declines, these changes alone cannot result in alveolar hypoventilation; resting hypoventilation (elevated PaCO₂) is always pathogenic, regardless of age. As a result, when they are critically unwell, elderly people are more likely to develop hypercapnia because they are less able to compensate for high minute breathing loads (such as sepsis or thyrotoxicosis).

An Elderly Guy in His 80s Has Been Taking Part