Delirium frequently heralds a medical emergency, and patients are usually managed in an acute-care hospital setting. For some patients with milder symptoms, once the etiology of delirium has been identified and general medical management has begun, psychiatric and general medical management can take place in an alternative setting (e.g., skilled nursing facility, home, hospice). The psychiatrist is commonly asked to consult when a patient develops delirium on a general medical or surgical unit in the hospital; however, delirium may also present as an emergency in either the psychiatric outpatient or inpatient setting.

The appropriate treatment of delirium involves interventions to search for and correct underlying causes, as well as relieve current symptoms. Joint and coordinated management of the patient with delirium by the psychiatrist and internist, neurologist, or other primary care or specialty physicians will frequently help ensure appropriate comprehensive evaluation and care.

An essential principle in the psychiatric management of delirium is the identification and correction of the etiologic factors. Careful review of the patient's medical history and interview of family members or others close to the patient may provide some direction. Appropriate laboratory and radiological investigations such as those listed in Table 3 may be necessary to determine the underlying cause(s) of delirium. The choice of specific tests to be undertaken will depend on the results of the clinical evaluation.

A patient with delirium may have life-threatening general medical conditions that demand therapeutic intervention even before a specific or definitive etiology is determined. In addition to ensuring that diagnostic tests essential to identifying the cause of delirium are ordered, when acting as a consultant, the psychiatrist should raise the level of awareness of the general medical staff concerning the potential morbidity and mortality associated with delirium. Increased observation and monitoring of the patient's general medical condition should include frequent monitoring of vital signs, fluid intake and output, and levels of oxygenation. A patient's medications should be carefully reviewed; nonessential medications should be discontinued, and doses of needed medications should be kept as low as possible.

The goal of diagnosis is to discover reversible causes of delirium and prevent complications through prompt treatment of these specific disorders. One must give a high priority to identifying and treating such disorders as hypoglycemia, hypoxia or anoxia, hyperthermia, hypertension, thiamine deficiency, withdrawal states, and anticholinergic-induced or other substance-induced delirium. Examples of specific reversible causes of delirium and treatments for these disorders appear in Table 4.

Behavioral disturbances, cognitive deficits, and other manifestations of delirium may endanger patients or others. Psychiatrists must assess the suicidality and violence potential of patients and implement or advocate interventions to minimize these risks (e.g., remove dangerous items, increase surveillance and supervision, and institute pharmacotherapy). Suicidal behaviors are often inadvertent in delirium and occur in the context of cognitive impairment and/or in response to hallucinations or delusions. Additional assessments of a patient's risk for falls, wandering, inadvertent self-harm, etc., should also be made with appropriate measures taken to ensure safety.

Whenever possible, means other than restraints, such as sitters, should be used to prevent the delirious patient from harming himself or herself, others, or the physical environment. Restraints themselves can increase agitation or carry risks for injuries and should be considered only when other means of control are not effective or appropriate (50). A patient who is restrained should be seen as frequently as is necessary to monitor changes in the patient's condition (51). The justification for initiating restraints and continuing use of restraints should be documented in the patient's medical record. Additional rules may apply in some jurisdictions, and the psychiatrist should become familiar with applicable regulations and institutional policies (52).

The psychiatrist must periodically assess the patient's delirium symptoms, mental status, and other psychiatric symptoms. The symptoms and behavioral manifestations of delirium can fluctuate rapidly, and regular monitoring will allow for the adjustment of treatment strategies.

Important behavioral issues that must be addressed include depression, suicidal ideation or behavior, hallucinations, delusions, aggressive behavior, agitation, anxiety, disinhibition, affective lability, cognitive deficits, and sleep disturbances. It is helpful to record serial assessments of mental status and symptoms over time, as these may indicate the effectiveness of interventions and new or worsening medical conditions. A structured or semistructured instrument, such as those described in Section II.F, may aid in the systematic completion of this task.

Knowledge of the patient's and the family's psychodynamic issues, personality variables, and sociocultural environment may aid in dealing effectively with specific anxieties and reaction patterns on the part of both the patient and the family. This understanding may be based on prior acquaintance with the patient, current interviews or interaction with the patient or family, and/or history from the family.

It is important for the psychiatrist who is treating the patient with delirium to establish and maintain a supportive therapeutic stance. Understanding the underlying affect, concerns, and premorbid personality of the patient is frequently helpful in maintaining a supportive alliance. A solid alliance with the family is also desirable, as family members are a critical source of potential support for patients and information on patients who may be unable to give reliable histories. Establishing strong alliances with the multiple clinicians and caregivers frequently involved in the care of delirious medically ill patients is also crucial.

Educating patients and families regarding delirium, its etiology, and its course is an important role for psychiatrists involved in the care of patients with delirium. Patients may vary in their ability to appreciate their condition; however, providing reassurance that delirium is usually temporary and that the symptoms are part of a medical condition may be extremely beneficial to both patients and their families. Specific educational and supportive interventions are discussed in more detail in the following paragraphs.

Nursing staff make frequent observations of patients over time, which places them in an excellent position to detect the onset and monitor the course of delirium. Education of nursing staff on each shift regarding the clinical features and course of delirium can be an important task for psychiatrists.

Because of the behavioral problems accompanying delirium, there may be a tendency for some general medical physicians to overlook underlying general medical problems contributing to a patient's delirium and to consider the problem to be entirely in the realm of the psychiatrist. In such instances, providing education to other physicians regarding the underlying physiological etiologies of delirium may be an important task for the psychiatrist.

Following recovery, patients' memory for the experience and events of the delirium is variable. Some patients gradually or abruptly lose all apparent recall of the delirious experience, while others have vivid, frightening recollections. Explanations regarding delirium, its etiology, and its course should be reiterated. Supportive interventions that are a standard part of psychiatric management following a traumatic experience should be used for those with distressing postdelirium symptoms. Following recovery, all patients who have experienced delirium should be educated about the apparent cause of their delirium (when this could be identified) so that the patient, family, and subsequent physicians can be made aware of risk factors that may lead to delirium in the future. Psychotherapy focused on working through the experience of the delirium may, at times, be necessary to resolve anxiety, guilt, anger, depression, or other emotional states. These states may be compounded by the patient's preexisting psychological, social, or cultural characteristics.