Final answer:
A nurse's close monitoring of an older adult in a manic phase of bipolar disorder is crucial due to the high risk of engaging in irresponsible and physically risky behaviors during this period.
Step-by-step explanation:
The nurse closely monitoring an older adult with bipolar disorder who is in a manic phase for risks to safety is especially appropriate because mania can result in irresponsible and physically risky behaviors.
During a manic episode, individuals with bipolar disorder may exhibit elevated energy levels, impulsive behavior, and diminished capacity for judgment, which can lead to engaging in activities that could potentially harm themselves or others.
For older adults, these risks can be compounded by physical vulnerabilities related to aging, making them more prone to injuries. Consequently, close monitoring is crucial to ensure the patient's safety and well-being.