In an elderly patient with an acute onset of altered mental status, which statement is most accurate?

• A. dementia typically presents as an acute onset of deterioration of cognitive function.
• B. because of her age and medical history, you should suspect Alzheimer disease.
• C. the patient is experiencing delirious behavior, which suggests a new health problem.
• D. her mental status is likely the result of hypoglycemia and you should give her sugar.

Answer: (C)

An acute change in mental status in an older adult almost always points to delirium—a sudden, fluctuating disturbance of attention and cognition caused by an underlying medical problem. Delirium signals something new happening in the body, such as infection, medication effects, dehydration, metabolic issues, or hypoxia, and it requires urgent evaluation and treatment of the root cause. Dementia or Alzheimer disease, by contrast, develop gradually over time and do not explain a sudden onset, so attributing the change to a chronic neurodegenerative process isn’t as accurate. While hypoglycemia can cause confusion, assuming that is the cause and treating with sugar without first recognizing delirium and identifying the underlying issue isn’t the best approach; the priority is to assess for delirium and its potential triggers and address them.