Final answer:
A 78-year-old client with pneumonia and a temperature of 100.8 F would likely exhibit mental confusion, which is an atypical symptom of pneumonia in elderly patients.
Step-by-step explanation:
The client who is 78 years old and admitted with a diagnosis of pneumonia, with inspiratory crackles in the right lower lobe and an oral temperature of 100.8 F (38.2 C), would likely exhibit mental confusion. This is because in elderly patients, pneumonia can present with atypical symptoms such as altered mental status, which may include confusion or delirium, rather than the typical symptoms seen in younger adults. Additionally, pneumonia can lead to hypoxemia, which refers to a lower-than-normal level of oxygen in the blood, and can further contribute to mental confusion.