The nurse needs to closely monitor the oxygen status of an older-adult patient undergoing anesthesia because of which age-related change?

A) Thinner heart valves cause lipid accumulation and fibrosis.
B) Diminished respiratory muscle strength may cause poor chest expansion.
C) Alterations in mental status prevent patients' awareness of ineffective breathing.
D) An increased number of pacemaker cells make proper anesthesia induction more difficult.

Age-related changes in the thorax that occur from ossification of costal cartilage, decreased space between vertebrae, and diminished respiratory muscle strength lead to problems with chest expansion and oxygenation,whereby the patient will have difficulty excreting anesthesia gas. The nurse needs to monitor the patient's oxygen status carefully to make sure the patient does not retain too much of the drug. Older adults experience alterations in cardiac function as a result of calcification of the conduction pathways, thicker and stiffer heart valves caused by lipid accumulation and fibrosis, and a decrease in the number of pacemaker cells in the SA node. Altered mental status is not a normal age-related change; it indicates possible cardiac and/or respiratory problems.