Delirium is an organic mental syndrome defined by a global disturbance in consciousness and cognition, which develops abruptly and often fluctuates over the course of the day. It is precipitated by medical illness, substance intoxication/withdrawal or medication effect.
Delirium is associated with significant morbidity and mortality, and is a leading presenting symptom of illness in the elderly. Elderly patients with altered mental status, including agitation, should be presumed to have delirium until proven otherwise. The clinical manifestations of delirium are highly variable. A mental status evaluation is crucial in the diagnosis of delirium.
Medical evaluation and stabilization should occur in parallel. Life-threatening etiologies including hypoxia, hypoglycemia and hypotension require immediate intervention. The differential diagnosis of etiologies of delirium is extensive. Patients with delirium need thorough evaluations to determine the underlying causes of the delirium. Pharmacological agents should be considered when agitated patient has the potential to harm themselves or others, or is impeding medical evaluation and management. Unfortunately, the evidence to guide pharmacologic management of acute agitation in the elderly is limited. Current pharmacologic options include the typical and atypical antipsychotic agents and the benzodiazepines. These therapeutic options are reviewed in detail.
THE AGITATED ELDERLY PATIENT poses a unique clinical challenge. Delirium represents a leading presenting symptomatology in acutely ill elderly patients. Agitation in the elderly should be presumed to be a manifestation of delirium until proven otherwise. When mental status changes present as agitation, the clinician is faced with a particularly difficult and complex scenario. A potentially immediately life-threatening etiology must be searched for and addressed. If agitation is severe, it requires urgent intervention to reduce potential danger to both patient and staff. Managing the agitated geriatric patient requires a coordinated approach that allows the staff to gain control of the situation while facilitating the diagnostic work-up. This article will provide a framework to use when evaluating the agitated elderly patient, including a review of available pharmacologic treatment.
The population is becoming proportionately more elderly. The number of people over the age of 65 will double in the United States in the next 30 years (1). As the population ages, the elderly comprise a higher proportion of patients overall. This is especially true in the emergency department (ED). Persons age 65 and older account for 17.5 million ED visits in the U.S. annually and 15.4% of total ED visits (2). In a multicenter study, patients over age 65 accounted for 43% of hospital admissions from the ED (3).
The emergency department and acute hospital wards have the highest rates of patients presenting with delirium. Agitation in younger patients presenting to the ED are much more likely to be the result of substance abuse or underlying psychiatric disease (psychotic or mood disorder), than in the elderly population.
Delirium or mental status change is a leading presenting symptom for acutely ill elderly persons. In ED patients over 70 years old, it has been reported that up to 40% have an alteration in mental status, with approximately 25% diagnosed as having delirium (4). Levkoff et al. found that 24% of elderly patients from the community and 64% of those presenting from nursing homes were delirious upon hospital admission (5).
Delirium is a medical emergency requiring prompt evaluation and treatment. It is generally reversible if the underlying cause is discovered and addressed, and can be fatal if overlooked and untreated. Hospital mortality rates in patients with delirium ranges from 25 – 33%. Elderly patients who develop delirium during hospitalization have a 22 – 76% chance of dying during that hospitalization. Hospital mortality is very high in patients that develop delirium—it is as high as the mortality rate associated with acute myocardial infarction or sepsis (6 – 8).
Delirium: Definition and Diagnosis
Delirium is an organic mental syndrome defined by a global disturbance in consciousness and cognition. It is characterized by a global cognitive impairment due to a medical condition, which develops abruptly and often fluctuates over the course of the day (9). The underlying mechanism of delirium is poorly understood and its pathophysiology has not been well elucidated. Delirium is common among medically compromised patients and the elderly are highly vulnerable to its development.
Hallmarks of delirium include disturbance in attention and memory impairment. Deficits in attention are characterized by ease of distractibility, with a reduced ability to focus, sustain or shift attention, resulting in difficulty in following commands. Patients may have trouble maintaining conversations, and conversations may be rambling or incoherent. Memory impairment usually involves recent memory; patients may be disoriented to time or place but only rarely to person. Perceptual disturbances that may occur include misinterpretations, illusions, or hallucinations. Often there are alterations in the patient’s sleep/wake cycle. A fluctuating course is characteristic and lucid intervals may be misleading (Table 1).