Does “ICU Psychosis” Really Exist?

Marcia Justic, RN, MSN, CS

About the Author

Marcia Justic, RN, MSN, CS, is a psychiatric consult-liaison clinical nurse specialist at Methodist Hospital, Health System Minnesota, St

Louis Park, Minn.

This article originally appeared in the June 2000 issue of Critical Care Nurse, Vol 20, No. 3, pp 28-37. Reprint requests: InnoVision

Communications, 101 Columbia, Aliso Viejo, CA 92656. Phone, (800) 899-1712 or (949) 362-2050 (ext 515); fax, (949) 362-2022; e-mail,

ivcReprint@aol.com.

The behaviors described by the term “ICU psychosis” are very real. Critical care nurses are familiar with patients who are disoriented and

unable to sleep at night only to be drowsy and confused during the day. The patients are often fearful because of distorted, sometimes

paranoid, ideas. These ideas are often accompanied by visual illusions (the misinterpretation of real stimuli) and/or hallucinations that

cause the patients to be agitated or even aggressive.1

However, the causes that may lead to ICU psychosis are not due to the intensive care (ICU) environment as the term implies. In fact, the

term is inaccurate and vague and suggests that the signs and symptoms described can be expected in the intensive care setting.2,3 Too often,

the expectation that a patient will be confused can result in inaccurate assessment of the patient and a lack of attention to the indications of

delirium. Failure to recognize delirium often has an adverse effect on patients’ outcomes, whereas early recognition of delirium and

treatment of the underlying causes can reduce morbidity, length of stay, and mortality.4-6

Transferring patients from the ICU does not resolve ICU psychosis. Many healthcare professionals think that factors inherent in the ICU

environment, such as constant noise, frequent interruptions, poor orientation cues, and frequent sleep interruptions, cause a patient’s

change in mental status. However, multiple studies2-4 have found that signs and symptoms associated with ICU psychosis are diagnostic of

delirium. Environmental factors are contributing factors rather than causes.2-4 It is true that the majority of patients subjected to the ICU

environment require treatment with sedatives and anxiolytic agents.

The harsh stimuli, unfamiliar people, uncomfortable procedures, and overwhelming technology cause much anxiety and restlessness.

However, differentiating anxiety and restlessness from the disorientation and disturbed states of arousal that accompany delirium is

important to effectively treat and manage delirious patients.1-3 The term ICU psychosis also implies that the signs and symptoms are

associated with a psychiatric disorder, which is the origin of a true psychosis. Rarely are the indications of delirium related to actual

psychiatric disorders.7

Clarifying the Concept of Delirium

Understanding the nature of delirium is essential to provide accurate assessments that will lead to effective treatment. In Greek, the word

de-lira means “off the track.” Delirium has 4 essential elements: disordered attention or arousal, cognitive dysfunction, acute development

of signs and symptoms (ie, from hours to a few days), and a medical, not a psychiatric, cause.1,8-10 Disordered attention or arousal and

cognitive dysfunction, the hallmarks of delirium, result in a variety of disturbances, including lack of awareness of one’s surroundings,

disorientation, distractibility, memory impairment, an inability to follow commands, and disturbances in the sleep-wake cycle that often

result in the exacerbation of signs and symptoms at night.1,3,8

The speech of a patient who is delirious may be limited to a single word or may be rambling or incoherent because of disorganized

thinking. Perceptual disturbances are common, including illusions, hallucinations (usually visual, but sometimes auditory), and

delusions.3,10,11 A patient’s mood can be unstable, with aspects of anxiety, fear, anger, depression, and euphoria all occurring at different

times.10

The fluctuating nature of delirium is often confusing to patients’ family members and can lead to different opinions among a patient’s

caregivers. The behavior of a delirious patient can change dramatically within hours or even minutes. A drowsy, lethargic patient can

become more alert and appear lucid for a time, only to become agitated and aggressive when next approached.10

Etiology of Delirium

The last essential element that defines delirium is that the causes of the disorder are medical rather than psychiatric. Although typically the

cause of an episode of delirium is multifactorial, a variety of causes are consistently detected (Table 1).14

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Anticholinergic medications are a potential cause of delirium. They deserve special discussion because they are often used and their side

effects are common. These medications block transmission of the neurotransmitter acetylcholine. Such blockade can have dramatic effects

because transmission of acetylcholine is essential for normal brain function. This transmission modulates the interactions of

neurotransmitters that control cognitive function, behavior, and mood.12,15-19 Patients with preexisting brain disease, children, and elderly

persons are at higher risk than are other patients of having side effects when treated with anticholinergic agents.

Anticholinergic agents are used in various medical settings, from surgical anesthesia to intensive care and medical units. Medications that

block central cholinergic transmission include atropine, fentanyl, and H2-blocking agents such as cimetidine.12,13,15,17,19 Other anticholinergic

agents block transmission both centrally and peripherally. These include antihistamines, benzodiazepines, opiates, and antiparkinsonian

drugs. When any of the aforementioned drugs are combined, excessive cholinergic blockade and its cognitive and behavioral sequelae can

occur.12,14-19

Subtypes of Delirium

Recent studies5,8,9 indicate that a variety of pathophysiological mechanisms result in different types of delirium. More global and

nonspecific cerebral dysfunction leads to hypoactive delirium, the most common subtype.9,16,17 Hypoactive delirium is characterized by

withdrawal, lethargy, apathy, and a total lack of responsiveness at times.9,17,18 This subtype is related to processes such as infection, hypoxia,

hypothermia, hyperglycemia, hepatic and renal insufficiencies, and thyroid dysfunction.1,8,10,12

Another subtype is hyperactive delirium. 8,17,19,20 The various causes of this subtype are more specific than are those of hypoactive delirium,

affecting only certain neurotransmitters in the brain.17,19 The affected neurotransmitters are those associated with the adverse effects of

drug intoxication, chemical withdrawal, and anticholinergic agents.9,11-13,19 Hyperactive delirium is easily recognizable because of the

characteristic extreme level of agitation and emotional lability. The disordered thinking and fear of patients with this subtype of delirium

often lead to refusal of care and disruptive behaviors such as shouting and demands to leave. Other behaviors such as pulling out catheters

and tubes, trying to get out of bed, hitting, biting, and scratching can pose serious safety risks to the patient and to staff members.1

Patients can experience both types of delirium during the course of their illness, with frequent fluctuations.9,17 In these situations, most

likely a number of cerebral mechanisms are being affected because two or more causal factors are occurring almost simultaneously. This

simultaneous occurrence results in a mixed picture of disturbed psychomotor arousal with both hypoactivity and hyperactivity.12 This

mixed clinical picture is common.1,18

Prevalence and Risk Factors

Delirium is a common phenomenon that occurs in approximately 10% to 50% of hospitalized medically ill patients.8 The rate varies

according to the subset of hospitalized medically ill patients considered. Critical care settings have the highest rate of delirium (about

38%).20 Of all medically ill patients, those at highest risk for delirium are the elderly, with prevalence rates of 14% to 56%.20-22

Risk factors have been a focus of studies to improve prevention and early detection of delirium. Two recent studies,5,21indicated that 4 risk

factors are consistently predictive of delirium (Table 2). In their study of 196 patients more than 70 years old who had no evidence of

baseline delirium, Inouye and Charpentier21 detected 5 factors that were hospital related and independent of the 4 baseline vulnerability

factors (Table 2). Such studies offer valuable information about risk factors and assessment in patients who may experience delirium.

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Dementia Versus Delirium

One risk factor that demands special attention is dementia, because delirium develops in 30% to 50% of patients who have

dementia.17 Delirium that is superimposed on preexisting dementia is difficult to recognize and differentiate from a patient’s baseline

dementia.23 In addition, the 2 disorders have similarities that can create confusion (Table 3).24

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Detection and Assessment of Delirium

Management of delirium can be optimized by early detection and accurate evaluation. Comprehensive nursing assessments (Table 4) should

be started at the time of admission. The baseline behaviors and level of cognition can be compared with later behaviors and level of

cognition to determine when changes occur. When marked differences occur, nurses can verify changes in the patient’s behavior by

checking with the patient’s family or friends. Nurses should not assume that confusion and behavioral disruptions are normal for elderly

patients.

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Although determining and treating the causes of delirium are medical responsibilities, nurses play an essential role in initiating and assisting

in the process as they care for patients and ensure patients’ safety. For example, initial nursing assessments often provide data about use of

medications and/or chemicals before admission that may have been overlooked. Without this information, withdrawal syndromes may

occur, which include symptoms of delirium. Abnormal laboratory results, fluctuations in vital signs, poor oxygenation, and changes in

medication are consistently noted by nurses. This information can be integrated to provide an accurate clinical picture of a patient, enabling

the healthcare team to determine the causes of the patient’s delirium.1,19

The nursing staff should have a written assessment tool available to monitor the patient’s status once delirium is recognized. Consistent

and timely assessments of a patient’s cognitive status are important to compare the severity of or improvement in the patient’s signs and

symptoms each shift.6

Various delirium rating scales have been developed.8,26-29 One of these is the Confusion Assessment Method.8,26This instrument has

excellent validity and is easy to administer.8,26 Delirium is rated on the basis of observations made by the person doing the assessment. No

responses from the patient are required. The areas rated correspond to the criteria used to diagnose delirium.

Although delirium rating scales are available, nurses may find that developing a system for their own unit is more useful. Simple tools can

be integrated into routine assessment formats or into assessment flow sheets and may be the most practical. In addition to providing a

means of monitoring patients’ signs and symptoms, routine cognitive assessments also assist staff in determining if current interventions

are effective.

An Algorithm for Managing Delirium

Nurses caring for a patient with delirium should develop an individualized treatment plan based on their assessments and their knowledge

of this disorder. The goals include optimizing the patient’s mental status and level of functioning while reducing safety risks. An algorithm

can provide the basis for the treatment plan, assist staff in organizing assessments, indicate consistent and clinically sound interventions,

and guide evaluation of patients’ outcomes.30

Initial Assessment

The algorithm described here (see Figure) can be useful for nurses working with patients who have indications of a confusional state. The

first step is an essential treatment consideration: differentiating delirium caused by chemical withdrawal or intoxication from delirium

related to the other causes (Table 1). This differentiation is essential because patients with chemical intoxication or withdrawal often require

physiological support and pharmacological intervention to prevent serious sequelae.31,32 Alcohol and/or drug withdrawal protocols are

often available in the hospital setting to guide treatment.31,32

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Nonpharmacological Interventions

The algorithm addresses patients’ comfort and safety by specifying interventions that apply to both hypoactive and hyperactive delirium.

Various environmental approaches are essential to optimize patients’ cognition, allow restorative sleep, provide a sense of security, and

involve patients’ family members.33

Reorientation Strategies. One nonpharmacological intervention is use of reorientation strategies, which should be implemented by both

healthcare personnel and patients’ family members. Usually an informal conversational approach is effective and is not perceived as

patronizing. Examples include discussing the time of day, normal activities in the patient’s day, weather, or other details relevant to the

patient. Repetition of explanations and information is necessary.1Although patients often do not remember events after the confusion

clears, reality orientation is remembered.34Patients’ family members often benefit from role modeling as nursing staff offer support and

reassurance to patients while avoiding arguments and the use oflogic to deal with patients who have irrational ideas or misperceptions.

Distraction. Another valuable intervention is the use of distraction. Distraction can be helpful when a patient’s perseverating on a topic is

leading to agitation or to an escalation in hyperactive behaviors. As previously discussed, the attention span of patients with delirium is

usually impaired. Therefore, introducing different topics of conversation or presenting new visual stimuli or music that a patient enjoys are

often easily accomplished.1 Comforting tactile stimulation such as receiving a back rub or holding hands with a friend or family member

may also distract patients and de-escalate their behavior.3

Therapeutic Stimulation. The algorithm continues with interventions designed to enhance patients’ reality-based stimulation, including the use

of vision, hearing, and mobility aids. Orienting cues such as a clock, a calendar, personal items, or a window with an outside view should be

available. Excessive or confusing stimuli such as lighting that creates shadows, conversations held within hearing distance of the patient,

and unnecessary noise and sleep interruptions that prevent restorative sleep should be minimized.33Having 2 delirious patients share a

room is not advised. Sharing a room is disturbing for each patient and often leads to an increase in agitation for both patients.

Monitoring. Patients with delirium must be closely monitored. Devices such as video cameras, alarms, and audio equiment are available.

However, use of these devices should not replace frequent contact with nursing staff during patients’ waking hours.

Family Care and Teaching. Involving a patient’s family members in the patient’s plan of care is crucial. Learning to respond to the patient’s

comments and questions in a way that satisfies the patient, without reinforcing irrational thoughts, can be reassuring for them. Family

members usually appreciate education on how to spend quality time with the patient. They are often relieved when they are informed that

they need not persistently correct the patient’s thinking or question the patient to determine if his or her thinking is normal.

The presence of one or two important members of a patient’s family or of significant friends often enhances the mental status and level of

comfort of a patient who is delirious. Family members also provide valuable information by noticing subtle yet important changes in the

patient’s cognition and behavior.

Education about delirium is important for family members of patients who experience this disorder. Physicians and nursing staff should

provide accurate information and should emphasize the acute nature and physiological basis of delirium. Additionally, family members

should be reassured that behaviors that are unusual for the patient, while perhaps troublesome, are temporary and not part of the patient’s

underlying personality. Teaching family members to expect fluctuations in the patient’s behavior and mood is essential so that they will not

expect the patient to remember events or conversations even if the patient appeared lucid at the time of the event or conversation.

Often a patient’s family and friends want to involve the patient in his or her care and in decision making. They may want the patient to

make choices and decisions. However, patient who are delirious often make a different decision each time they are asked. If a patient keeps

making different decisions, the patient’s family and friends should be advised that until the delirium is resolved, they should make decisions

that they think best reflect the patient’s usual desires.

In addition, family members should be cautioned not to give patients who are cognitively clear detailed descriptions of cognitive difficulties

or disruptive or aggressive behavior that occurred when the patients were delirious.

Detailed descriptions of events that occurred during an episode of delirium can be traumatizing for patients; more general descriptions are

usually more helpful for patients who are struggling with vague memories or the loss of time.21

Safety Interventions

For all patients with delirium, the safety of the patients is always foremost. The guiding principle of using the least restrictive measure to

maintain a patient’s safety must be considered, because unnecessary use of restraints or medication only precipitates or exacerbates

delirium.21 Hospital or unit-specific protocols related to patients’ safety, safety techniques, and equipment should be available for staff.

Written informational materials about patients’ safety and hospital policies are useful for patients’ families.

Freedom of Movement. For patients who are unable to walk or who cannot walk alone safely but who are not at risk for self-harm, freely

moving about in bed and sitting in a chair can reduce restlessness and confusion. In these situations, a bed exit alarm or a personal alarm

attached to the patient and the bed or chair can alert staff to movements that may present a safety risk. Daytime activity and mobility are

useful for delirious patients. These activities provide the added benefit of promoting normal sleep-wake cycles and enhancing orientation.1,9

Safety Devices. For patients who are extremely agitated and are pulling at tubes, catheters, or dressings, additional safety measures are

necessary. Clothing (eg, underwear or long-sleeved gowns), dressings, binders, and splints minimize a patient’s ability to disturb medical

devices and dressings. Any type of tubing should be removed as soon as possible, particularly nasogastric tubes, which are irritating to

agitated patients.

When these methods are not sufficient to protect a patient, protective devices may be the only alternative. Because these devices often

immobilize a patient, they can cause more confusion, fear, and agitation.26 They should be used only as necessary and for the shortest time

possible. Again, using the least-restrictive intervention is essential.

Pharmacological Interventions

Delirium endangers patients when serious cognitive disturbances cause agitation, fear, insomnia, or the inability to participate in care

activities during the day. Delirium that disrupts a patient’s comfort and care should be treated with appropriate medication.3,7,9,30,32,35,36 The

algorithm focuses on minimizing use of agents that cause or enhance delirium and on initiating treatment with the appropriate medications.

Medications are not used to sedate patients but to clear cognition.

Neuroleptic Agents. Patients with delirium related to alcohol or drug withdrawal may continue to be delirious even when their withdrawal

symptoms are being adequately treated. In these situations, neuroleptic agents should be added to the medications specified in a withdrawal

protocol.3,6,9

Neuroleptic drugs are the first-line agents for treatment of delirium due to causes other than withdrawal.1,3,9 Other agents that are often

used to sedate patients and enhance sleep (eg, benzodiazepines, antihistamines, and hypnotics) usually worsen delirium.3,9,37

Haloperidol (Haldol) is generally the neuroleptic agent of choice because it is effective and has few anticholinergic and hypotensive

effects.1,35,37,38 The intravenous formulation is recommended because this form of haloperidol is more reliably absorbed and has fewer side

effects than do oral or intramuscular formulations.38-40 Although not approved by the Food and Drug Administration, intravenous

administration of the drug has been used safely for more than 2 decades.36,38 Dosing recommendations are presented in the algorithm (see

Figure).

Another neuroleptic agent used to treat delirium is droperidol. This agent is generally more sedating than is haloperidol, a characteristic that

may be beneficial in particular patients. However, droperidol is also more likely to cause hypotension, a characteristic that may not be

advantageous.1,9,40 The onset of action of droperidol is 30 minutes or less, and the effects may persist as long as 12 hours.1

Patients with delirium may have preexisting conditions such as Parkinson disease, tardive dyskinesia, or extrapyramidal dysfunctions (eg,

dystonias, muscle rigidity, akathisia or restlessness, tremor). These patients usually require treatment with less potent neuroleptics such as

thiothixene (Navane) or the new atypical antipsychotic medications such as risperidone and olanzapine.41,42

Neuroleptic agents can cause extrapyramidal side effects. Extrapyramidal movements include dystonias, dyskinesia, and akathisia. Patients

experiencing these side effects may have rigidity, tremor, difficulty initiating movement, unusual mouth or eye movements, and feelings of

internal restlessness. Use of the agents should not be discontinued or stopped abruptly if these effects occur. Instead, low doses of

intravenous lorazepam can be given.3

Diphenhydramine hydrochloride (Benadryl) can also be used, although this agent has excessive anticholinergic properties and can

exacerbate the restlessness associated with akathisia.3

Administration of potent neuroleptic agents such as haloperidol and droperidol can result in 2 serious, yet rare conditions.1 One condition

is torsades de pointes, a cardiac arrhythmia associated with administration of high doses (100-1200 mg/d) of neuroleptic agents.1 Patients

in whom torsades de pointes develops generally have a history of arrhythmias.41 Another potentially fatal condition is neuroleptic malignant

syndrome. This syndrome is often difficult to differentiate from other medical conditions.

Characteristics of neuroleptic malignant syndrome include fever, muscle rigidity, altered consciousness, and elevated concentrations of

creatinine phosphokinase.8,36 This condition is a medical emergency and requires immediate attention.

Because of the side effects of neuroleptic agents, patients given these drugs should be monitored for changes in vital signs, abnormal

movements, and abrupt differences in levels of consciousness. As the algorithm indicates, even as delirium begins to clear, treatment with

neuroleptic medication should be continued.

Pain Management. Adequate pain management in patients with delirium is important. Pain is difficult to assess in these patients, but

undertreatment of pain can exacerbate delirium.43 Because opiates can cause delirium, a balance must be reached to effectively treat

patients’ pain and delirium. The restlessness associated with delirium is often treated inappropriately with analgesics. Increasing narcotic

dosages in delirious patients should be done cautiously and should be based on a number of pain parameters such as vital signs, the

patient’s behavior, and the patient’s report and any history of a pain condition.

Summary

In summary, ICU psychosis does not develop in all patients. Instead, many patients are at risk for hypoactive, hyperactive, or mixed

hypoactive and hyperactive delirium. Prevention of delirium should always be foremost, including recognition of patients at high risk,

minimal use of causative medications, and treatment of physiological conditions that are often unrelated to a patient’s admitting diagnosis.

When prevention fails, early diagnosis and treatment can make a marked difference in patients’ outcomes.44-47

The potential adverse outcomes of delirium are well documented. These include increased mortality; increased length of stay; reduced level

of functioning in the elderly, which often leads to placement in a nursing home; and stress response syndrome after

hospitalization.5,22,34,44,45,48

The value of nursing in preventing delirium is evident when nurses apply their knowledge of potential causes and develop strategies to

avoid these causes in their patients. Nurses provide early detection and coordinate with other members of the healthcare team to initiate a

plan of care that includes prompt treatment of delirium to reduce the signs and symptoms, duration, and potential adverse sequelae of this

disorder.

Nursing interventions are designed to enhance patients’ cognitive status, sense of security, safety, and comfort. Nurses are instrumental in

providing appropriate choices, doses, and administration of medications and in recognizing side effects. Use of medications ordered to

treat delirium is often left to nurses’ discretion because the orders specify that the drugs should be given as needed. Finally, nurses are the

ones who recognize the need for additional assistance via psychiatric consultations or for more intensive observation and management of

patients to ensure quality care.