Acute Altered Mental Status in Elderly Patients

Delirium may indicate a life threat.

This CE activity is approved by EMS World Magazine, an organization accredited by the Continuing Education Coordinating Board for Emergency Medical Services (CECBEMS), for 1.5 CEUs. There are two ways to take the CE test that accompanies this article and receive 1.5 hours of CE credit accredited by CECBEMS: 1. Click here to download a PDF of the test. The PDF has instructions for completing the test. 2. Or go to to take the test and immediately receive your CE credit. Questions? E-mail

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  • Discuss epidemiology of elderly patient population
  • Review sepsis as cause of altered mental status
  • Review subacute subdural hematoma as cause of altered mental status
  • Discuss prehospital assessment and management of these patient groups

Delirium is a serious symptom and is commonly seen in emergency departments.1 One of the most challenging problems with altered mental status can be determining its etiology. Unfortunately acute altered mental status often goes unrecognized.2 While it is easy to recognize a patient who is unresponsive or responds only to painful stimuli, it can be extremely difficult to distinguish subtle mental status changes in patients a provider hasn’t met before.

Delirium is one cause of acute altered mental status that is particularly difficult to identify. Even emergency department physicians struggle to recognize delirium, and only identify it in 35% of patients with acute changes.2 While diagnostic checklists for identifying delirium are being developed, they are far from perfect. One study just demonstrated that a prehospital delirium checklist may identify 63% of patients with delirium, but is really no more accurate than recognition of a GCS less than 15.3 This month’s CE article discusses causes of delirium and acute altered mental status in geriatric patients.


The elderly population is defined as those 65 and older.2 In the 2000 U.S. Census, the elderly made up 10% of the population, with 34.6 million individuals; this is expected to rise to 82 million (20% of the population) by 2050. Altered mental status is present in 10% of all elderly patients who present to emergency departments, yet it is only recognized 20% of the time.4 Many of these patients will present via EMS.

In one study, the average age of patients with AMS presenting to the ED was 66.5 years. One in nine (11%) of these ultimately died during their hospital stay, signifying the serious morbidity associated with AMS.1 Among these patients the most common etiologies of AMS were neurologic (34.4%), infectious (18.3%) and metabolic (12%).

There are many causes of mental status changes. AMS caused by delirium is particularly important to recognize because it represents a serious underlying condition and is marked by an acute change in the patient’s cognition. Delirium is defined by the American Psychiatric Association as a disturbance of consciousness and change in cognition that develops over a short period of time.2 It is not natural and not associated with diseases such as dementia and Alzheimer’s. Rather, delirium is a hyper- or hypoactive alteration in brain function, and thus affects behavior, memory, actions and attitude. While patients with delirium are often described, based on the word’s Latin root, as “going crazy” or “deranged,” this description only addresses the hyperactive form of delirium. A patient with delirium can also have a hypoactive brain and present with lethargy and decreased motor function. Table 1 identifies several causes of delirium, which can be remembered using the mnemonic I watch death.5 In many cases delirium may be the only symptom of a serious underlying medical condition.2

Delirium and dementia are not the same. Delirium is also not the same as a gradual mental status change. The prehospital screening assessment for dementia mentioned in the introduction asks paramedics to look for:

1) An acute onset of the condition;

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