The nurse is assessing the vital signs of an older adult. Which finding(s) should the nurse anticipate as age-related physiological changes? Select all that apply.

A. An SpO₂ of 90% is below normal and indicates hypoxemia, not an expected age-related change. Normal oxygen saturation for older adults is generally 95–100% on room air. A reading of 90% requires assessment and possible intervention. B. Older adults are more likely to develop age-related changes in cardiac conduction, including atrial fibrillation, premature beats, or other arrhythmias. These changes are often due to fibrosis of the conduction system, loss of pacemaker cells, and decreased myocardial elasticity, and may be anticipated as part of normal aging, though they may also require monitoring. C. Older adults often have a lower baseline body temperature compared with younger adults due to reduced metabolic rate and decreased thermoregulatory responses. A temperature around 97°F is an expected age-related change and may mask fever in older adults. D. Age-related changes in the respiratory system include decreased lung elasticity, weakened respiratory muscles, and reduced alveolar surface area, which may result in shallow breathing and slightly increased respiratory rates at rest. These are considered typical physiological changes with aging. E. With aging, systolic blood pressure tends to increase, not decrease, due to stiffening of the arteries and decreased vascular compliance. Isolated systolic hypertension is common in older adults, whereas a decreased systolic BP is not expected as an age-related change.