Diagnosis and management of geriatric patients exhibiting symptoms and signs of impaired cognitive functioning can make a critical difference to their overall health and the ability to function independently. Impaired cognitive function can be acute in onset, or it can be manifest by slowly progressive cognitive impairment. The major causes of impaired cognition in the geriatric population are delirium and dementia. As more people live into the tenth decade of life, the chance that they will develop some form of dementia increases substantially. Community-based studies report a prevalence of dementia as high as 47% among those 85 years of age and older. Prevalence rates are, however, highly dependent on the criteria used to define dementia (Mayeux, 2010). Between 25% and 50% of older patients admitted to acute care medical and surgical services are delirious on admission or develop delirium during their hospital stay. In nursing homes, 50% to 80% of those older than age 65 years have some degree of cognitive impairment. Delirium is often superimposed on dementia in both hospital and community settings, can persist for days to weeks after discharge from an acute hospital, and is a risk factor for functional decline and mortality. Both dementia and delirium are associated with high health-care costs (Okie, 2011).
Misdiagnosis and inappropriate management of conditions leading to confusion in geriatric patients can cause substantial morbidity among the patients, hardship for their families, and excess health-care expenditures. This chapter provides a practical framework for diagnosing and managing geriatric patients who demonstrate “confusion” or signs of cognitive impairment. We focus on the most common causes of confusion in the geriatric population—delirium and dementia—although a variety of other disorders can cause the same or similar signs.
Imprecise definition of the abnormalities of cognitive function in older patients labeled as “confused” has led to problems in diagnosis and management. Descriptions such as impairment of cognitive function or cognitive impairment coupled with careful documentation of the timing and nature of specific abnormalities provide more precise and clinically useful information. Such documentation is best accomplished by screening and a thorough mental status examination, if indicated.
Screening for delirium can be accomplished with the confusion assessment method (CAM). The Mini-Cog is useful in screening for cognitive impairment and dementia. Both of these screening tests are discussed later in the chapter.
A thorough mental status examination has several basic components that are essential in diagnosing dementia, delirium, or other syndromes (Table 6–1). The examiner should focus on each of these components in a systematic manner. Recording observations in each area facilitates recognizing and evaluating changes over time. Standardized and validated measures of cognitive function (see Appendix) should be used in diagnosis and subsequent monitoring. Several factors may, however, influence performance and interpretation of standard mental status tests, such as prior educational level, primary language other than English, severely impaired hearing, or poor baseline intellectual function. Thus, scores ...