Delirium
ONDRIA C. GLEASON, M.D., University of Oklahoma College
of Medicine, Tulsa, Oklahoma
Delirium is characterized by an acute change in
cognition and a disturbance of consciousness, usually resulting from an
underlying medical condition or from medication or drug withdrawal. Delirium
affects 10 to 30 percent of hospitalized patients with medical illness; more
than 50 percent of persons in certain high-risk populations are affected. The
associated morbidity and mortality make diagnosis of this condition extremely
important. Patients with delirium can present with agitation, somnolence,
withdrawal, and psychosis. This variation in presentation can lead to
diagnostic confusion and, in some cases, incorrect attribution of symptoms to a
primary psychiatric disorder. To make the distinction, it is important to
obtain the history of the onset and course of the condition from family members
or caregivers. Primary care physicians must be able to recognize delirium so
that the underlying etiology can be ascertained and addressed. The management
of delirium involves identifying and correcting the underlying problem, and
symptomatically managing any behavioral or psychiatric symptoms. Low doses of
antipsychotic drugs can help to control agitation. The use of benzodiazepines
should be avoided except in cases of alcohol or sedative-hypnotic withdrawal.
Environmental interventions, including frequent reorientation of patients by
nursing staff and education of patients and families, should be employed in all
cases. (Am Fam Physician 2003;67:1027-34. Copyright© 2002 American Academy
of Family Physicians.) |
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Without careful
assessment, delirium can easily be confused with a number of primary
psychiatric disorders because many of the signs and symptoms of delirium are
also present in conditions such as dementia, depression, and psychosis. Some
characteristic signs and symptoms of delirium are described in this article.
All of these symptoms may not be present in every patient. The presentation of
a patient with delirium will fluctuate during the course of the condition and
even during the course of a day. The diagnostic criteria for delirium are
listed in Table 1.1
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TABLE 1 Diagnostic Criteria for
Delirium |
A. |
Disturbance of
consciousness (i.e., reduced clarity of awareness about the environment) with
reduced ability to focus, sustain, or shift attention. |
B. |
A change in cognition
(e.g., memory deficit, disorientation, language disturbance) or development of
a perceptual disturbance that is not better accounted for by a preexisting,
established, or evolving dementia. |
C. |
The disturbance develops
over a short period of time (usually hours to days) and tends to fluctuate
during the course of a day. |
D. |
Evidence from the history,
physical examination, or laboratory findings indicate that the disturbance is
caused by direct physiologic consequences of a general medical condition. |
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Reprinted with permission from Diagnostic
and statistical manual of mental disorders: DSM-IV-TR. Washington, D.C.,
American Psychiatric Association, 2000:143. Copyright 2000, American
Psychiatric Association. |
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Acute Onset/Fluctuating Levels of Consciousness
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The primary
causes of delirium are an underlying medical condition, medication, or drug
withdrawal. |
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Delirium is characterized by an acute change
(usually over hours to days) in mental status. Patients demonstrate fluctuating
levels of consciousness that they often manifest by periodically falling asleep
during an interview. This fluctuation in consciousness can result in
conflicting reports from various caregivers about the patient's mental state.
Fluctuations in cognitive skills, including memory, language, and organization,
are also common.
ATTENTION IMPAIRMENT
Patients with delirium demonstrate attention
difficulties. They may not remember instructions and may ask that directions
and questions be repeated. Useful screening methods to identify attention
problems include asking patients to spell a word backwards or perform "serial
7s" (counting backward from 100 by sevens).
MEMORY IMPAIRMENT AND DISORIENTATION
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Visual
hallucinations are more characteristic of delirium than of a primary
psychiatric disorder. |
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Memory deficits, especially where recent events are
concerned (e.g., the reason for hospitalization or for care being given by
nursing staff), are also prominent in patients with delirium. Patients may
report not being bathed or bedding not being changed when, in fact, these
events occurred earlier in the day. Disorientation to date, place, and
situation is common. However, the latter can go unrecognized if patients are
not directly asked for the information. For example, hospital staff and family
members may assume that a patient is fully oriented only to be surprised when
the patient insists that he or she is at home and that the date is 10 years
earlier.
AGITATION
Patients with delirium may become agitated as a
result of the disorientation and confusion they are experiencing. For example,
a patient who is disoriented may think he or she is at home instead of in a
hospital, and nursing staff may be mistaken for intruders in the home.
Consequently, this patient may not comply with bed or activity restrictions and
may try to climb over the bedrails to get out of bed. Likewise, intravenous
(IV) and oxygen tubing may not be recognized as such, and the patient may
remove them.
APATHY AND WITHDRAWAL
Patients with delirium may present with apathy and
withdrawal. They may appear to be depressed because of blunted affect,
decreased appetite, decreased motivation, and disrupted sleep patterns.
sleep disturbance
Sleep disturbances are common in patients with
delirium. They may periodically fall asleep during the day and then be awake
for several hours during the night. This pattern, combined with confusion,
disorientation, and decreased nighttime environmental cues, can create an
especially hazardous situation in patients who are at risk for falling and
pulling out an IV, Foley catheter, or nasogastric tubing.
EMOTIONAL LABILITY
Patients with delirium may display a wide range of
emotions, including anxiety, sadness or tearfulness, and euphoria. They may
have more than one of these emotions during the course of delirium.
PERCEPTUAL DISTURBANCES
Disturbances in reality testing manifested by
visual and auditory hallucinations and delusions may be present. Delusions
associated with delirium are likely to be related to disorientation and memory
impairment, and fluctuate with these symptoms.
NEUROLOGIC SIGNS
Several neurologic signs and symptoms may be
present in delirium regardless of cause. They include unsteady gait; tremor;
asterixis; myoclonus, paratonia (e.g., gegenhalten) of the limbs and especially
of the neck; difficulty reading and writing; and visuoconstruction problems,
such as copying designs and finding words.
Subtypes of Delirium
The three subtypes of delirium are hyperactive,
hypoactive, and mixed. Patients with the hyperactive subtype may be agitated,
disoriented, and delusional, and may experience hallucinations. This
presentation can be confused with that of schizophrenia, agitated dementia, or
a psychotic disorder. Patients with the hypoactive subtype of delirium are
subdued, quietly confused, disoriented, and apathetic. Delirium in these
patients may go unrecognized or be confused with depression or dementia. The
mixed subtype is characterized by fluctuations between the hyperactive and
hypoactive subtypes.
Screening Tools
Several screening tools are available to aid in
identifying delirium. The Folstein Mini-Mental State Examination
(MMSE)2 is familiar to most physicians. It screens for deficits in
orientation, attention, memory, language, and visuoconstruction abilities.
Administering the MMSE several times during the course of delirium can be a way
to assess improvement. Comparison with an MMSE performed before the onset of
the delirium is ideal.
Another screening tool is the Confusion Assessment
Method.3 The Delirium Rating Scale (DRS)4 and the
Memorial Delirium Assessment Scale (MDAS)5 measure the severity of
delirium.
Indications of Underlying Medical Conditions
Recognizing delirium is important because it is an
indication of an underlying medical condition that should be identified and
treated. The underlying etiology should be aggressively sought after. Delirium
can be caused by a medical emergency or a subacute, chronic medical condition
(Table 2).6 Prescription drugs, illicit drugs, and
toxic substances can also cause delirium. The underlying medical condition is
not always readily identifiable, and more than one etiology is often
responsible for delirium. In fact, in almost one half of elderly patients with
delirium, two or more underlying conditions are responsible for the
delirium.7
Differentiating Delirium from Primary Psychiatric
Disorder
Certain signs and symptoms can help physicians
distinguish between delirium and a preexisting psychiatric disorder. For
example, visual hallucinations are an indicator of an underlying metabolic
disturbance or adverse effect of medication or substance abuse. While visual
hallucinations can occur in patients with primary psychiatric illnesses such as
schizophrenia, they are much less common than auditory hallucinations. In
primary psychiatric disorders, visual hallucinations would be associated with
other, more characteristic signs and symptoms of the disorders. Visual
hallucinations that occur in patients with delirium can be formed (e.g.,
people, animals) or unformed (e.g., spots, flashes of light).
Electroencephalography (EEG) can be useful in
differentiating delirium from other conditions. In patients with delirium, the
EEG shows a diffuse slowing of the background rhythm. An exception is patients
with delirium tremens, where the EEG shows fast activity. EEGs are also useful
in detecting ictal and postictal seizure activity, as well as nonconvulsive
status epilepticus, all of which can present as delirium. Abnormal EEG readings
would not be expected in patients with psychotic disorders or depression.
However, slowing may occur in patients with dementia.
Finally, the acute onset and fluctuating nature of
delirium are key features in distinguishing it from primary psychiatric
disorders. Patients are often unable to provide an adequate history. It is
important to interview family members and caregivers to determine the time of
onset of symptoms and other pertinent medical and psychiatric information,
including a review of medications and a history of substance abuse. It is
equally important to know how patients are currently different from their
normal cognitive state. Psychiatric symptoms that arise in persons 50 years and
older without a prior psychiatric history or the development of new symptoms in
patients with preexisting psychiatric illness should prompt a thorough medical
work-up. Table 3 provides a list of indicators suggesting
delirium. Table 4 lists some distinguishing characteristics
of delirium, dementia, psychosis, and depression.
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TABLE 4 Distinguishing
Characteristics of Delirium, Dementia, Psychotic Disorders, and Depression
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Disorder |
Distinguishing
feature |
Associated
symptoms |
Course |
Delirium |
Fluctuating levels of
consciousness with decreased attention |
Disorientation, visual
hallucinations, agitation, apathy, withdrawal, impairment in memory and
attention |
Acute onset; most cases
remit with correction of underlying medical condition |
Dementia |
Memory impairment |
Disorientation,
agitation |
Chronic, slow onset,
progressive |
Psychotic disorders |
Deficits in reality
testing |
Social withdrawal,
apathy |
Usually slow onset with
prodromal syndrome; chronic with exacerbations |
Depression |
Sadness, loss of interest
and pleasure in usual activities |
Disturbances of sleep,
appetite, concentration, and energy; feelings of hopelessness and
worthlessness; thoughts of suicide |
Single episode or recurrent
episodes; may be chronic |
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Risk Factors
Delirium affects 10 to 30 percent of hospitalized
patients who are medically ill.8 The prevalence is even higher in
certain subgroups. For example, 25 percent of hospitalized patients with
cancer, 30 to 40 percent of hospitalized patients with human immunodeficiency
virus (HIV) infection, and more than 50 percent of postoperative patients
develop delirium during hospitalization.9-11 Among nursing home
residents older than 75, up to 60 percent may have delirium at any time.12
Table 5 lists the characteristics of patients who are
at increased risk for delirium and some medical conditions that increase a
patient's risk for developing delirium. Recognizing dementia as a risk factor
for delirium can help physicians avoid attributing the confusion and agitation
associated with delirium to preexisting dementia, which can lead to a failure
to search for underlying medical conditions or to discontinue medications that
may be causing the delirium.
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TABLE 5 Risk Factors for Delirium
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- Patient characteristics
- Hospitalized elderly
- Multiple medical conditions
- Multiple medications
- Terminally ill
- Children
- Sensory (hearing or visual) deprivation
- Sleep deprived
- Medical conditions
- Dementia
- Postsurgical status
- Cardiac
- Hip
- Transplant
- Burns
- Abrupt discontinuation of alcohol or drugs
- Malnourishment
- Chronic hepatic disease
- Dialysis
- Parkinson's disease
- HIV infection
- Poststroke status
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HIV = human immunodeficiency virus.
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TABLE 6 Assessment of Patients with
Delirium |
The rightsholder did not
grant rights to reproduce this item in electronic media. For the missing item,
see the original print version of this publication. |
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Management
IDENTIFYING UNDERLYING MEDICAL CONDITIONS
The definitive treatment for delirium is to correct
the underlying medical condition causing the disorder. The initial steps in
managing patients with delirium are to conduct a careful review of the medical
history, physical examination findings, laboratory evaluations, and any drugs
the patient is using, including over-the-counter agents, illicit drugs, and
alcohol. Information from patients' current and past medical history, as well
as the physical examination, should guide the initial work-up. Often the
etiology will be fairly obvious from the history and basic laboratory
tests.13 Table 66,14 outlines a plan
for assessing patients with delirium.
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Delirium can be
exacerbated by overstimulation or understimulation in the environment.
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SYMPTOMATIC TREATMENT
During the search for an underlying medical
condition, symptomatic treatment for delirium may include the use of
antipsychotic drugs to control agitation and hallucinations, and to clear the
sensorium (i.e., improve attention abilities and level of orientation).
Haloperidol (Haldol) has been studied most often in the symptomatic management
of delirium,8 but risperidone (Risperdal)15,16 and
olanzapine (Zyprexa),17 which are newer, atypical antipsychotics,
have been the subjects of a few case reports. Two small studies18,19
with olanzapine suggested that this drug might be a useful alternative in the
treatment of delirium.
In most adult patients with delirium of moderate
severity, haloperidol therapy can be initiated at 1 to 2 mg twice daily,
repeated every four hours as needed, and can be administered via IV, oral, or
intramuscular routes. The IV route has been shown to produce a lower incidence
of extrapyramidal side effects20; however, it does carry a risk for
the development of torsades de pointes.21,22 Preferably, patients
receiving IV haloperidol should be on a cardiac monitor. QTc prolongation
greater than 450 msec or more than 25 percent above baseline should prompt the
physician to consider discontinuing haloperidol therapy, or a cardiology
consultation should be obtained.8
Elderly patients should be started at lower drug
dosages. In these patients, haloperidol therapy can be started at 0.25 to 1.0
mg twice daily and repeated every four hours, as needed.8
Risperidone therapy can be initiated at a dosage of 0.5 mg twice daily and
increased gradually if necessary. In all patients, response to antipsychotics
and the amount of as-needed medication used should be monitored at least every
24 hours.
If as-needed medication is necessary on a regular
basis, the amount of scheduled antipsychotic should be increased. When
patients' cognitive states stabilize, antipsychotics should be continued over
the next few days, then tapered and discontinued. Physicians should not
automatically discontinue antipsychotics on the first day the patient's mental
status shows improvement, because the improvement may just be a normal
fluctuation in the delirium. Gradual tapering that ends in discontinuation
allows time to assess patients, to ensure that the delirium has resolved and
avoid rapid rebound of symptoms.
ENVIRONAMENTAL INTERVENTIONS
Environmental interventions that can help in
managing patients with delirium are listed in Table
7.23 Assigning patients to a room near the nursing station will
allow for closer monitoring. The presence of a family member or close friend
can also be helpful. In more severe cases, the use of 24-hour, one-on-one
supervision may be necessary to monitor the patient and assist in controlling
agitation. Frequent reorientation by nursing staff and family members is
important. Patients should be reminded of the month, year, day of the week,
time of day, and reason for hospitalization. Patients should also be reminded
of the name of the hospital, city, and state. A calendar, clock, and family
pictures displayed within patients' view can be beneficial.
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TABLE 7 Environmental Interventions
in Treating Patients with Delirium |
- Provide support and orientation
- Communicate clearly and concisely; give repeated
verbal reminders of the day, time, location, and identity of key persons, such
as members of the treatment team and relatives.
- Provide clear signposts to patient's location,
including a clock, calendar, and chart with the day's schedule.
- Place familiar objects from patient's home in the
room.
- Ensure consistency in staff (e.g., a key nurse).
- Use television or radio for relaxation and to help the
patient maintain contact with the outside world.
- Involve family members and caregivers to encourage
feelings of security and orientation.
- Provide an unambiguous environment
- Simplify care area by removing unnecessary objects;
allow adequate space between beds.
- Consider using private room to aid rest and avoid
extremes of sensory experience.
- Avoid using medical jargon in patient's presence
because it may encourage paranoia.
- Ensure that lighting is adequate; provide a 40- to
60-watt night light to reduce misperceptions.
- Control sources of excess noise (e.g., staff,
equipment, visitors); aim for fewer than 45 dB during the day and fewer than 20
dB during the night.
- Maintain room temperature between 21.1°C
(69.98°F) and 23.8°C (74.8°F)
- Maintaining competency
- Identify and correct sensory impairments; ensure
patients have their glasses, hearing aids, and dentures. Consider whether
interpreter is needed.
- Encourage self-care and participation in treatment
(e.g., ask patient for feedback on pain).
- Arrange treatments to allow maximum periods of
uninterrupted sleep.
- Maintain activity levels: ambulatory patients should
walk three times daily; nonambulatory patients should undergo full range of
movement exercise for 15 minutes three times daily.
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Adapted with permission from Meagher DJ.
Delirium: optimising management. BMJ 2001;322:146. |
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Understimulation resulting from absence of cues
about the time of day and the situation should be avoided, but overstimulation
should also be avoided. The activity, light, and noise (including that from
beepers) in and around the patients' rooms should be monitored. Frequent
checking of vital signs during the night should be avoided unless the necessity
is clearly indicated, because frequent waking can lead to sleep deprivation,
which may worsen delirium.24
The use of physical restraints should be avoided,
if possible. Physical restraint can increase agitation and the risk for injury
in patients who are cognitively impaired. However, if other measures to control
a patient's behavior are ineffective and it seems likely that the patient, if
unrestrained, may cause personal injury or injure others, restraints can be
used with caution. Patients who are restrained should be monitored closely, and
restraints should be discontinued as soon as possible. Physicians should be
aware of hospital policies and other regulations regarding the use of physical
restraints.25
Delirium can be a frightening experience for
patients and family members. Patients may fear that they are losing their
minds. Educating patients and family members about delirium and its association
with underlying medical conditions is important. Unless there is reason to
believe that a patient has experienced permanent loss of cognitive function,
the patient and family members should be reassured that the symptoms are
temporary and should resolve. Neurologic consultation can help establish a
differential diagnosis in patients with delirium. Psychiatric consultation can
aid in distinguishing delirium from a primary psychiatric disorder and in
managing the behavior disturbances associated with delirium.
COURSE AND PROGNOSIS
Considerable morbidity and mortality are associated
with delirium. Patients with delirium have longer hospital stays and more
medical complications, such as pneumonia and pressure ulcers. Mortality is also
higher in patients with delirium, probably as a result of more severe
underlying medical pathology. The mortality rate among elderly hospitalized
patients with delirium is estimated to range from 22 to 76 percent.8
The course of delirium can last from several hours
to several months. Through appropriate identification and correction of the
underlying etiology, most patients experience complete resolution of delirium,
although full recovery of mental function may lag behind corrected laboratory
values by several days. Without treatment, however, progression to stupor,
coma, or death can occur. Patients who are elderly and those who have HIV
infection are less likely to fully recover.26,27
The author indicates that she does not have any
conflicts of interest. Sources of funding: none reported.
The Author
ONDRIA C. GLEASON, M.D., is assistant professor of
psychiatry and director of psychiatry residency training at the University of
Oklahoma College of Medicine, Tulsa. She is also a staff psychiatrist at Saint
Francis Hospital, Tulsa, Okla. Dr. Gleason earned her medical degree from the
University of Nebraska College of Medicine, Omaha, and completed a residency in
psychiatry at the University of Iowa Hospitals and Clinics, Iowa City.
Address correspondence to Ondria C. Gleason, M.D.,
University of Oklahoma College of Medicine at Tulsa, Department of Psychiatry,
4502 E. 41st St., Tulsa, OK 74135-2512 (e-mail:
ondria-gleason@ouhsc.edu).
Reprints are not available from the author.
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