1. 
   

   When is agitation due to delirium versus dementia?

   
   
2. 
   

   What are the most common causes of agitation in hospitalized older patients?

   
   
3. 
   

   What are the best non-pharmacologic techniques to manage agitation in older patients?

   
   
4. 
   

   Which medications are best for treating agitation in older patients?

   
   
5. 
   

   What are the potential complications of agitation?

   
   
6. 
   

   How can agitation due to delirium or dementia be prevented?

It is horrible to see an agitated patient in the hospital, even worse to try to care for one, and probably worst of all to be an agitated patient. There is often significant internal and external pressure on hospital staff to “control the patient” and this can lead to thoughtless action. But the best (and often the only) way to address the agitation is to think carefully about the problem before acting. This chapter will attempt to present a thoughtful approach to agitation in hospitalized older adults.

Agitation in an older patient can take multiple forms: aggression, psychomotor agitation, and psychosis. Aggression refers to verbal or physical aggression often involving resistance to care. Psychomotor agitation includes restless motor activity such as pacing, rocking, or other purposeless movement, as well as sleep disturbances, repetitive vocalizations, and restlessness. Psychosis includes delusions, hallucinations, and misidentifications. Patients can experience any combination of these symptoms.

Epidemiology of Agitation in Older Hospitalized Patients

Agitation is a common symptom in older hospitalized adults; it may be present on admission or develop during the hospital stay. Reports of the incidence of agitation in this population vary widely, but may be as high as 52% in older ICU patients. The risk of behavioral disturbance is highest for patients who have cognitive impairment on hospital admission.

Impact of Agitation in Hospitalized Patients

Agitation causes significant distress for patients, caregivers, and hospital staff. Hallucinations and delusions have been associated with the highest levels of distress for patients, but agitation and aggression were most distressing for hospital staff.

In addition to psychological distress, agitation in hospitalized patients is associated with increased length of hospital stay and increased health care costs. It increases the risk of injury to patients and staff, as well as the risk of complications such as falls, restraint-related injuries, and unintended removal of indwelling catheters and tubes.

Agitation can have multiple causes in an older hospitalized patient. The most common causes are delirium, dementia, and psychiatric disorders.

Delirium

Delirium is present in 14–24% of patients admitted to the hospital, and arises in 6–56% of patients during hospitalization. The prevalence of delirium increases with age. Among older adults, it can be the sole presenting symptom for medical illness such as infection or cardiac ischemia. The diagnosis of delirium is made from bedside observation, and although the diagnostic criteria are still evolving, most agree that it consists of an acute change in cognition that results in inattention, altered level of consciousness, and disorganized thinking, usually with a fluctuating course. There is significant heterogeneity in the clinical presentation of delirium: many patients develop the hypoactive form of delirium, which does not involve agitation and is often overlooked. Other patients have agitation, which can include delusions or hallucinations in 30% of delirious patients.

Delirium tends to occur in people with predisposing factors, such as advanced age, dementia, functional impairment, and multiple coexisting medical conditions. It usually is triggered by one or multiple precipitating factors, including medications, medical illness, neurologic disease, surgery, or environmental stressors.

Dementia

Dementia affects approximately 13.9% of the U.S. population over age 70. Prevalence increases with age, and in the population of adults age 90 and older prevalence approaches 40%. It is estimated that by 2050, over 9 million people in the U.S. will have dementia. Sixty percent to ninety-eight percent of patients with dementia may have agitation at some point during the course of their disease. It typically occurs in the moderate and severe stages of the disease, and symptoms are often transient. When these patients are admitted to the hospital with acute medical illness, it is common for these symptoms to persist or worsen.

Alzheimer disease is the most common type of dementia, followed by cerebrovascular dementia, and then dementia with Lewy bodies (DLB). Other forms of dementia such as frontotemporal dementia, Creutzfeldt-Jakob disease, and Parkinson dementia are significantly less common. Agitation can accompany any type of dementia. Patients with DLB commonly suffer from visual hallucinations, and those with frontotemporal dementia often exhibit impulsiveness, lack of judgment, and personality changes that can result in agitated behaviors.

The diagnosis of dementia is best made when patients are medically stable in the outpatient setting. Unfortunately, dementia is commonly overlooked by primary care providers, who fail to document cognitive problems in up to two-thirds of cases. If dementia is suspected, it is prudent to defer the full diagnostic workup until the patient is truly at his or her medical and cognitive baseline, since even mild delirium will interfere with accurate diagnosis and staging. It is appropriate, however, to perform a thorough neurologic examination and to check for reversible causes of cognitive impairment such as thyroid disease, vitamin B12 deficiency, and normal pressure hydrocephalus. Laboratory tests such as TSH, vitamin B12 levels, and possibly brain imaging can be done while the patient is hospitalized to facilitate the outpatient workup. A complete discussion of the evaluation of a person with cognitive impairment is outside the scope of this chapter.

Psychiatric Disorders

Although psychiatric disorders such as depression with psychotic features, acute mania, and schizophrenia are significantly less common than delirium or dementia, they can cause agitation in older, hospitalized adults. In patients with a history of psychiatric disease, this should be entertained in the differential diagnosis of agitation. In patients without such history, new onset bipolar disorder with mania could be considered, as it does occur in older patients, although it is quite rare. Depression is common in older adults, so depression with psychotic features should also be considered.

The pathophysiology of agitation in hospitalized older adults varies based on the underlying cause of the agitation, and it is poorly understood for most dementias and delirium. In both cases, cholinergic deficiency plays a key role. For this reason, drugs with anticholinergic properties often cause increased confusion and agitation in patients with dementia and delirium. Multiple other neurotransmitters have also been implicated in the pathophysiology of delirium, including dopamine, glutamate, serotonin, and melatonin. Mediators of inflammation such as interleukins, tumor necrosis factor alpha, interferon, cytokines, and cortisol also tend to be elevated in delirium and in many types of dementia, and these may also play a role in agitation.

As discussed above, it is not always easy to distinguish between delirium and dementia. Many agitated patients suffer from both simultaneously. Yet no matter what the diagnosis, the key is the same: to identify and address the underlying trigger for the agitation. Because there is often no test to definitively determine if a particular factor is causing the patient’s agitation, the diagnosis is sometimes achieved by correcting as many factors as possible and observing for improvement in symptoms (Table 166-1).

Older patients with new onset agitation require hospitalization, usually on a general medicine ward, since medical illness is a common cause of agitation and one that must be identified and addressed in a timely manner. In addition, hospitalization is often required to control the agitated behaviors and keep the patient from harming him- or herself and others.