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ICU Psychosis

Contact Hours: 4

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Contact Hours: 4

This educational activity is credited for 4 contact hours at completion of the activity.

Course Purpose

The purpose of this course is to provide healthcare professionals with a brief overview of Intensive Care Unit (ICU) psychosis, its differential diagnoses, treatment options, preventative measures, and nursing considerations.


Intensive Care Unit (ICU) psychosis is a spectrum of severe psychiatric symptoms that manifest in an ICU environment. Often occurring in critically ill patients undergoing intensive medical interventions, these symptoms may include delirium, a significant clinical concern that is associated with higher mortality rates. This course examines ICU psychosis, detailing its mechanism of action, causes, and symptoms. It also delves into its differential diagnoses, treatment options, preventative measures, and nursing considerations necessary to address the complex interplay of factors contributing to this phenomenon within the critical care setting.

Course Objectives

Upon completion of this course, the learner will be able to:

  • Review the definition of Intensive Care Unit (ICU) psychosis and how neurobiological mechanisms impact the manifestation of the diagnosis.
  • Review diagnostic criteria for ICU psychosis and ICU psychosis classification.
  • Identify symptoms, causes and differential diagnoses of ICU psychosis.
  • Review pharmacologic and nonpharmacologic treatment measures, and preventative measures to reduce the risk of ICU psychosis in the healthcare setting.
  • Understand the nursing considerations for assessing for and managing ICU psychosis.

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AcetylcholineA compound which occurs throughout the nervous system, in which it functions as a neurotransmitter.
AnalgesicsMedications that relieve pain by reducing inflammation or changing the brain’s perception of pain.
Anticholinergic DrugsA broad group of medicines that act on the neurotransmitter, acetylcholine. They are also called antispasmodics.
AstrocytesProvide nutrients to neurons while maintaining the balance between cellular ions such as sodium chloride, potassium, and phosphate. 
Autoimmune EncephalitisA rare but serious condition where the immune system attacks the brain.
Central Nervous System (CNS)The part of the nervous system consisting primarily of the brain and spinal cord.
Confusion Assessment Method For The ICU (CAM-ICU)A delirium monitoring instrument for ICU patients.
DeliriumA temporary mental state characterized by confusion, anxiety, incoherent speech, and hallucinations.
Diagnostic And Statistical Manual Of Mental Disorders, Fifth Edition (DSM-5)Is intended to serve as a practical, functional, and flexible guide for organizing information that can aid in the accurate diagnosis and treatment of mental disorders.
Diffuse Axonal InjuryA severe type of brain injury caused by blunt force trauma.
Dopamine A type of neurotransmitter.
DysregulationAbnormality or impairment in the regulation of a metabolic, physiological, or psychological process.
Extrapyramidal Symptoms (EPS)Debilitating, interfering with social functioning and communication, motor tasks, and activities of daily living. 
Gamma-Aminobutyric Acid (GABA) NeurotransmitterThe most common inhibitory neurotransmitter in the central nervous system.
Glial CellsThe non-neuronal cells that support and protect the neurons in the nervous system.
HyperglycemiaHappens when there is too much sugar (glucose) in the blood.
HypoglycemiaA condition caused by low blood glucose levels. 
HypotensionA blood pressure reading below the specified limit (90/60 mmHG). This can cause dizziness, blurred vision and tiredness.
Infectious EncephalopathiesA condition that occurs when a virus or bacteria infects the brain.
Intensive Care Unit (ICU) PsychosisA disorder in which patients in an intensive care unit (ICU) or a similar setting experience a cluster of serious psychiatric symptoms.
Interleukin-1 (IL-1) An inflammatory cytokine.
Interleukin-6 (IL-6)An interleukin that acts as both a pro-inflammatory cytokine and an anti-inflammatory myokine. 
MicrogliaThe resident immune cells of the brain that help clean up invaders and maintain neuronal function.
NeurotransmitterChemical messengers in the body.
Paraneoplastic SyndromesA group of uncommon disorders that develop in some people who have cancer. 
Proinflammatory CytokinesA type of signaling molecule (a cytokine) that is secreted from immune cells like helper T cells (Th) and macrophages, and certain other cell types that promote inflammation. 
QT ProlongationOccurs when the heart muscle takes longer to contract and relax than usual. 
SedativesA drug taken for its calming or sleep-inducing effect.
Systemic Lupus Erythematosus (SLE)Autoimmune disease in which the immune system attacks its own tissues, causing widespread inflammation and tissue damage in the affected organs.
Torsade De PointesA rare but dangerous heart rhythm disorder that causes the lower chambers of the heart to twist and beat fast.
Traumatic Brain InjuryA serious condition that affects the brain’s function due to a sudden impact or penetration.
Tumor Necrosis Factor-Alpha (TNF-Α)A cytokine that has pleiotropic effects on various cell types.

Intensive Care Unit (ICU) psychosis is a spectrum of severe psychiatric symptoms that manifest in an ICU environment. Often occurring in critically ill patients undergoing intensive medical interventions, these symptoms may include delirium, a significant clinical concern that is associated with higher mortality rates. Studies have found that ICU patients with delirium were three times more likely to die than patients without delirium and six times more likely to have one or more complications.1,2

According to estimates, up to 80% of ICU patients may encounter delirium at some point during their hospitalization in critical care, where patients contend not only with severe medical conditions but also with an array of stressors, including invasive procedures, complex medical interventions, and the overall intensity of the critical care environment. This unique combination of physical and emotional stressors, augmented by several other factors such as patient age, overall health, and underlying conditions, contributes to the development of the severe psychiatric symptoms observed in this condition. This course examines ICU psychosis, detailing its mechanism of action, causes, and symptoms. It also delves into its differential diagnoses, treatment options, preventative measures, and nursing considerations necessary to address the complex interplay of factors contributing to this phenomenon within the critical care setting.1,2

Definition of Intensive Care Unit (ICU) Psychosis

Intensive Care Unit (ICU) psychosis is a spectrum of severe psychiatric symptoms seen specifically in ICU environments. While its pathophysiology is not completely understood, its manifestation has been linked to several neurobiological mechanisms, including the acetylcholine, dopamine, and gamma-aminobutyric acid (GABA) neurotransmitter pathways. Disturbances in these pathways result in dysregulation of these neurotransmitters, causing a chemical imbalance in the brain. This, in turn, triggers the cognitive issues and altered perceptions seen in affected patients. Acetylcholine dysregulation impairs attention and memory functions, while dopamine and GABA pathway disturbances contribute to hallucinations and mood alterations.3-5

In addition to neurotransmitter imbalances, the ICU experience itself instigates neurobiological changes. Whether it is because of the illness, injury, or invasive procedure, these factors trigger the release of proinflammatory cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) for a robust inflammatory response. If this response is not managed, it can elevate cytokines further, driving the body to a heightened and persistent state of inflammation, which has several direct and indirect effects on the central nervous system (CNS). 3-5

Elevated levels of proinflammatory cytokines may act on the blood-brain barrier, a semipermeable membrane that separates the blood from the cerebrospinal fluid. Excessive cytokines can compromise the integrity of the blood-brain barrier, leading to a breach. Immune cells and inflammatory molecules pass through and directly affect neural tissue. The infiltration of these agents into the brain initiates a localized inflammatory response, which activates glial cells, such as microglia and astrocytes in the CNS.

Microglia are the resident immune cells of the brain, and their activation results in the release of additional inflammatory mediators. This neuroinflammatory state contributes to the disruption of normal neural functioning and can lead to structural changes within the brain. 3-5

In tandem with the proinflammatory cytokine surge, oxidative stress further compounds the adverse effects on the CNS in ICU psychosis. Oxidative stress is an imbalance between the production of reactive oxygen species (ROS) and the ability of cellular antioxidant defenses to neutralize them. In the ICU setting, the increased metabolic demands and systemic inflammation contribute to an environment conducive to this condition.

Oxidative stress can damage the CNS’s cellular components, including lipids, proteins, and DNA. Neurons, particularly, are highly susceptible to damage due to their high metabolic activity and limited regenerative capacity. Therefore, under oxidative stress, structural changes within the brain may occur, amplifying the cognitive dysfunction observed in ICU psychosis. 3-5

Diagnostic Criteria for ICU Psychosis

Diagnostic criteria for ICU psychosis are crucial for accurate identification and intervention. Two widely utilized frameworks for assessing delirium in the intensive care setting are the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and the Confusion Assessment Method for the ICU (CAM-ICU). The application of these diagnostic criteria allows healthcare professionals to establish a standardized and systematic approach to the diagnosis of ICU psychosis. This, in turn, facilitates early recognition and targeted interventions to improve patient outcomes in the critical care environment.2,6

The DSM-5 criteria offer a comprehensive framework for diagnosing delirium. According to DSM-5, delirium is characterized by a disturbance in attention and awareness that develops over a short period, accompanied by additional cognitive changes. The diagnostic criteria include four key measures: 2,6

  1. Disturbance in attention, such that there is evidence of the patient’s reduced ability to direct, focus, sustain, and shift attention.
  2. Additional cognitive changes, which include the presence of other cognitive disturbances such as memory impairment, disorientation, language disturbance, or perceptual disturbances.
  3. Rapid onset such that disturbances in criteria 1 and 2 developed over a short period and tend to fluctuate during the course of the day.
  4. Etiology that suggests the disturbances in attention and cognition cannot be better explained by a pre-existing, established, or evolving neurocognitive disorder and do not occur exclusively during the course of delirium due to another medical condition.

The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is a tool used to assess delirium among patients in the intensive care unit. The tool assesses four features:

  1. The acute onset of mental status changes, or a fluctuating course
  2. Inattention
  3. Altered levels of consciousness
  4. Disorganized thinking

Confusion Assessment Method for the Intensive Care Unit

Feature 1: Acute Onset or Fluctuating Course   Is the patient different than their baseline mental status, or has the patient had any changes in mental status in the past 24 hours as evidenced by fluctuations in level of consciousness?Score   Answer either question yes →Mark Box if Present   □
Feature 2: Inattention   Say to the patient, “I am going to read you a series of 10 letters. Whenever you hear the letter ‘A,’ indicate by squeezing my hand.” Read letters from the following letter list in a normal tone 3 seconds apart. S A V E A H A A R T or C A S A B L A N C A or A B A D B A D A A Y Errors are counted when patient fails to squeeze on the letter “A” and when the patient squeezes on any letter other than “A.Score   Number of Errors >2 →Mark Box if Present   □
Feature 3: Altered Level of Consciousness   Present if the Actual RASS score is anything other than alert and calm (zero).Score   RASS anything other than zero →Mark Box if Present   □
Feature 4: Disorganized Thinking   Ask the following Yes/No Questions: Will a stone float on water? Are there fish in the sea? Does one pound weigh more than two pounds? Can you use a hammer to pound a nail? Errors are counted when the patient incorrectly answers a question. Command Say to patient: “Hold up this many fingers” (Hold 2 fingers in front of patient) “Now do the same thing with the other hand” (Do not repeat number of fingers) If the patient is unable to move both arms, for 2nd part of command ask patient to “Add one more finger” An error is counted if patient is unable to complete the entire command.Score   Combined number of errors >1→Mark Box if Present   □
Overall CAM-ICU   Feature 1 plus 2 and either 3 or 4 present = CAM-ICU positiveCriteria Met →AM-ICU Positive (Delirium Present) □  
 Criteria Not Met →CAM-ICU Negative  (No Delirium) □

ICU psychosis, particularly when classified within the spectrum of delirium, can be categorized based on psychomotor behavior. Delirium is commonly classified into subtypes according to the predominant features of psychomotor activity. The three primary categories are hyperactive delirium, hypoactive delirium, and mixed delirium. Hyperactive delirium manifests with heightened psychomotor activity, displaying restlessness, agitation, and hyper-vigilance. Patients in this category may engage in purposeless movements, incessant pacing, or attempts to disengage medical apparatus, often coupled with aggressive or combative behavior. Hypoactive delirium, in contrast, is characterized by a reduction in psychomotor activity. Patients appear lethargic, exhibiting slowed movements, and often display withdrawal from their immediate environment. Speech may be limited, and there is a notable difficulty in initiating or sustaining attention. The third category, mixed delirium, combines elements of both hyperactive and hypoactive delirium, reflecting fluctuating patterns of psychomotor behavior. This entails episodes of restlessness followed by periods of reduced activity, presenting challenges in consistent motor responses and alertness.2,6,7


The frequency of ICU psychosis occurrence, compared to total ICU admissions, is a significant clinical concern. Studies suggest that a substantial proportion of ICU patients experience delirium during their hospitalization, emphasizing the need for targeted interventions to address factors that cause ICU psychosis. Research shows that ICU psychosis develops in the presence of both environmental and medical factors inherent to the ICU setting. Understanding the multifaceted causes of ICU psychosis is crucial for healthcare professionals to implement effective preventive measures and targeted interventions. 2,7,8

Environmental Factors

The ICU experience induces profound stress on patients. The critical nature of their illness, coupled with the uncertainty of the treatment course and the loss of control over their circumstances, leads to significant psychological stress. The ICU environment itself further exacerbates this mental and emotional burden. Patients in this unit must bear the disorienting environment, often in isolation. Separation from familiar surroundings, family, and friends contributes to a sense of disconnection, amplifying stress. The ICU is also inherently disruptive to normal sleep patterns. The alarms, beeps, and persistent noise generated by continuous monitoring devices can overwhelm patients’ sensory perception, leading to sensory overload and contributing to the development of delirium. 2,7,8

In addition,  frequent medical interventions, and the need for vital sign checks around the clock all heighten the atmosphere of perpetual commotion. Patients experience fragmented sleep, resulting in severe sleep deprivation, a known precursor to delirium.

The ICU design also contributes to the development of ICU psychosis. These units are often constructed as windowless rooms with continuous lighting. In the absence of natural light, there is no clear distinction between day and night, and without such external cues, patients lose their sense of time and date. Natural circadian rhythm is disrupted, not only affecting a patient’s sleep-wake cycle but also interfering with the regulation of hormonal and physiological processes. This lack of orientation further fuels the cognitive disturbances associated with ICU psychosis. 2,7,8

Medical Causes

The underlying pathophysiology of critical illness, whether stemming from a severe disease, trauma, or surgical intervention, imposes substantial stress on the body. Combined with other underlying conditions, infections, or complications such as cardiac failure can result in further systemic issues and trigger the release of inflammatory mediators known for their role in manifesting ICU psychosis. Even the medication given while a patient is admitted to the ICU can also be a causing factor, particularly those the patient has not taken before, as it introduces the risk of adverse reactions and side effects. These medications can directly contribute to cognitive impairment. 2,7,8 The administration of analgesic medications is another concern, particularly when the patient is unable to communicate pain adequately, leading to cumulative analgesia. This state, where pain is not felt despite consciousness, may mask important physiological indicators, and contribute to the overall complexity of the patient’s condition. To prevent this, medication may be restricted. However, this may lead to inadequacies in pain control, which in turn causes distress and can contribute to the development of delirium. Critically ill patients in the ICU may also suffer from other complications from the illness itself or side effects of medical interventions, such as inadequate fluid balance, electrolyte imbalances, hypoxia (low blood oxygen levels), and elevated liver enzymes. The dehydration and metabolic disturbances, whether independently or in combination, contribute to the physiological derangements associated with delirium. 2,7,8


ICU psychosis encompasses a range of severe psychiatric symptoms that profoundly impact a patient’s cognitive and perceptual functions within the intensive care unit (ICU) setting. Among the most prominent symptoms is a fluctuating level of consciousness, where patients may oscillate between aggressive or hyper-alert behavior and passive or lethargic behavior. This abnormal behavior often comes with confusion and disorientation, with patients often unaware of their surroundings, the current date, or the identities of those around them. Attention and concentration are typically impaired, leading to a patient’s marked inability to maintain focus and increased distractibility.2,9,10

Visual, auditory, or tactile hallucinations may manifest. Patients may perceive non-existent objects, hear imaginary voices, or feel sensations that are not present. Patients may also develop false beliefs, delusions, paranoid or persecutory feelings, or nightmares. These delusions can contribute to heightened anxiety, fear, and stress. Mood swings may also occur. Patients may also exhibit rapid and unpredictable changes in mood, suddenly shifting between euphoria, sadness, anxiety, or irritability for no apparent reason. Speech may become disorganized and incoherent, making communication challenging. Patients may struggle to express themselves coherently or may speak in a manner that does not make sense. Short-term memory deficits are common in ICU psychosis. Patients may struggle to recall recent events or conversations. 2,9,10

Common physical symptoms of ICU psychosis typically relate to its psychomotor aspect, characterized by either an increase or decrease in activity. Patients can become agitated, restless, experience extreme excitement, and become fidgety. They may attempt to remove medical devices or leave the bed. In the case of decreased activity, patients will appear lethargic, sluggish, and less responsive to stimuli. With this, disruptions in the normal sleep-wake cycle are common. Patients may have trouble falling asleep, frequent awakenings, or excessive daytime sleepiness. 2,9,10  

Onset and Duration of Symptoms

The onset and duration of symptoms associated with ICU psychosis are influenced by the critical care environment and the individual patient’s clinical condition. ICU psychosis typically manifests acutely, often emerging within the first 24- 48 hours of the patient’s admission to the intensive care unit (ICU). The abrupt onset is frequently linked to increased environmental stressors, medical interventions, and the physiological response to critical illness. However, this trajectory can vary widely, and in some cases, ICU psychosis may develop gradually, particularly in instances of prolonged ICU stays. 2,9,10 The duration of ICU psychosis varies equally, ranging from brief episodes to more prolonged and persistent states, mirroring the fluctuating nature of ICU psychosis itself. The reversible nature of some contributing factors, such as medication side effects or electrolyte imbalances, may result in shorter-lived episodes, while underlying medical conditions and the cumulative impact of stressors can lead to a more protracted course. Importantly, the duration of symptoms is closely tied to the resolution of the underlying causes, with effective management strategies and targeted interventions playing a critical role in mitigating the impact of ICU psychosis on the patient’s overall well-being. 2,9,10

Differential Diagnoses

Differential diagnoses for ICU psychosis involve considering alternative explanations for the observed psychiatric symptoms. Several other conditions may mimic aspects of ICU psychosis but differ in underlying etiologies. A comprehensive evaluation, including medical history, laboratory tests, imaging studies, and specialized consultations, is crucial to identify the underlying cause of psychiatric symptoms and distinguish ICU psychosis from other potential diagnoses. Collaborative efforts among healthcare professionals from various specialties are often necessary to ensure a thorough and accurate differential diagnosis. Potential differential diagnoses are given below.2

·      Primary Psychiatric Disorders

  • Primary psychiatric disorders, such as schizophrenia, bipolar disorder, and major depressive disorder, are chronic and enduring conditions that can share certain clinical features with ICU psychosis. For example, patients with schizophrenia may experience hallucinations, delusions, and disorganized thinking, which can overlap with the psychotic symptoms observed in ICU psychosis. However, schizophrenia is chronic, with symptoms persisting over an extended period outside a critical care facility, unlike ICU psychosis, which has a sudden onset. The manic or depressive episodes in bipolar disorder can include symptoms such as altered consciousness, psychomotor agitation or retardation, and impaired cognitive function, like ICU psychosis. It is also characterized by recurrent episodes that typically last for days to weeks over an extended period, often across a person’s lifetime. Patients with bipolar disorder also follow distinct mood episodes, while patients with ICU psychosis fluctuate more unpredictably. Severe episodes of major depression can lead to psychotic features, including hallucinations or delusions, but also come with persistent depressive symptoms that last for at least two weeks, unlike ICU psychosis.2,10,11

·      Substance-Induced Psychotic Disorders

  • Substance-induced psychotic disorders refer to the development of psychotic symptoms resulting from the use, withdrawal, or intoxication of certain substances, including alcohol, hallucinogens, stimulants, and other psychoactive substances. The hallmark feature of such a disorder is the presence of psychotic symptoms, such as hallucinations, delusions, disorganized thinking, or grossly disorganized or abnormal motor behavior. However, these symptoms are a direct result of the psychoactive properties of substances or the neurochemical changes during withdrawal and typically resolve with the clearance of the substance from the body. In contrast, ICU psychosis is a response to the stressors specific to the intensive care unit setting rather than a direct result of substance use. 2,10,12

·      Neurological Disorders

  • Neurological disorders are conditions that specifically affect the CNS, such as seizures, encephalitis, or brain tumors, potentially leading to altered consciousness, hallucinations, and cognitive disturbances like ICU psychosis. However, neurological disorders often present with a more gradual onset that may persist or progress over time. Symptoms will likely be stable and progressive rather than fluctuating, unlike ICU psychosis. Also, these disorders are directly attributable to structural or functional abnormalities in the brain. Specific diagnostic tests such as neurological examinations, imaging studies (MRI or CT scans), and electroencephalogram (EEG) evaluations can identify these abnormalities and be used to rule out brain lesions. 2,10,13

·      Metabolic Disorders

  • Metabolic disorders such as electrolyte imbalances, hypoglycemia, or hyperglycemia can contribute to neuropsychiatric symptoms, including confusion and altered mental status. While the onset of symptoms may be acute and occur in critical care settings, metabolic disorders are identified via laboratory tests that assess metabolic parameters, such as electrolyte levels, blood glucose, and other relevant markers. Imaging studies can also be used to identify structural causes if applicable. The cognitive disturbance from metabolic disorder resolves once the metabolic imbalance is corrected through appropriate interventions, including fluid resuscitation, electrolyte replacement, or glucose administration. 2,10,14

·      Endocrine Disorders

  • Hormonal imbalances from disorders in endocrine organs, such as the thyroid, adrenal glands, or pituitary gland can lead to disturbances, including confusion, altered mental status, or cognitive impairment. For example, hypothyroidism may lead to cognitive slowing and memory deficits. While symptoms may develop gradually or acutely depending on the specific endocrine disorder, they are not necessarily tied to critical care settings. Laboratory tests can assess hormone levels or other relevant markers, while imaging studies may be used to identify structural causes if applicable. Unlike ICU psychosis, treatment focused on correcting the hormonal imbalance through targeted interventions such as hormone replacement therapy, can resolve the symptoms. 2,10,15

·      Infectious Encephalopathies

  • Infectious encephalopathies are conditions that affect the CNS, such as meningitis or encephalitis. These infections cause inflammation in the brain and the gradual appearance of cognitive dysfunction, which progressively increases as opposed to the fluctuations seen in ICU psychosis. Diagnostic evaluation for infectious encephalopathies involves cerebrospinal fluid analysis, neuroimaging studies, and serological tests to identify the infectious agent. Unlike ICU psychosis, which may improve as the underlying medical condition stabilizes, infectious encephalopathies require targeted antimicrobial or antiviral therapies to address the specific pathogen responsible for the neurological symptoms. 2,10,16

·      Autoimmune Disorders

  • Certain autoimmune conditions, such as autoimmune encephalitis or systemic lupus erythematosus (SLE), can cause abnormal immune responses, leading to inflammation and damage to various tissues, including the CNS, resulting in neuropsychiatric symptoms. However, unlike the variations seen in ICU psychosis, cognitive symptoms of autoimmune disorders often have a more gradual onset and may have a chronic or relapsing-remitting course. Diagnostic evaluation, such as cerebrospinal fluid analysis, can identify specific autoimmune markers, and immunosuppressive therapies can modulate the immune response to resolve cognitive disturbances, thus differentiating autoimmune disorders from ICU psychosis. 2,10,17

·      Traumatic Brain Injury (TBI)

  • Traumatic brain injury TBI involves physical trauma to the head, resulting in structural damage to the brain. Patients with a history of recent trauma may exhibit psychiatric symptoms resembling ICU psychosis, however TBI symptoms are typically progressive and may lead to permanent cognitive impairments if brain tissue is significantly damaged. Neuroimaging studies, such as CT scans or MRIs, can reveal any of these structural abnormalities, including contusions, hemorrhages, or diffuse axonal injury not seen in ICU psychosis. Also, TBI is typically characterized by a more predictable temporal relationship, with symptoms emerging directly after the traumatic event as opposed to the ICU environment. 2,10,18

·      Paraneoplastic Syndromes

  • Paraneoplastic syndromes are a group of rare disorders triggered by an immune response to an underlying malignancy, leading to systemic effects and neurological manifestations. If associated with the CNS, these disorders may present with cognitive disturbances resembling aspects of ICU psychosis. However, paraneoplastic syndromes typically have a more insidious onset and are often characterized by a subacute or chronic course. Identifying specific autoantibodies in serum or cerebrospinal fluid is crucial in confirming the presence of a paraneoplastic process. Diagnostic evaluation for paraneoplastic syndromes involves a combination of imaging studies, such as CT or PET scans, and serological tests to detect tumor markers and specific autoantibodies. Treatment focuses on addressing the underlying malignancy and, in some cases, immunosuppressive therapies to modulate the aberrant immune response. 2,10,19

·      Medication Side Effects or Toxicity

Certain medications, particularly those administered in the ICU setting can contribute to cognitive disturbances, altered consciousness, and perceptual abnormalities. These effects may be dose-dependent or related to patient factors such as age, renal or hepatic function, or drug interactions. Common culprits include sedatives, analgesics, anticholinergic drugs, and certain antimicrobial agents. Diagnostic evaluation involves a careful review of the patient’s medication history, consideration of potential drug interactions, and monitoring for signs of toxicity. Laboratory tests may be employed to assess drug levels, and specific antidotes or interventions may be administered to reverse toxic effects. Unlike ICU psychosis, which is associated with the ICU environment, medication-induced neuropsychiatric symptoms may persist or worsen until the offending drug is identified and discontinued.2,5-8

Treatment Options

Treating ICU psychosis requires a multidimensional approach, considering both pharmacological and non-pharmacological interventions. While there is no definitive therapy proven to decrease the duration or severity of symptoms, it is imperative to manage the underlying physiological issues and factors contributing to psychosis for favorable clinical outcomes. Due to the range of cognitive disturbances a patient may present with, healthcare professionals must conduct a thorough examination to assess for symptoms. 7-10,20

Pharmacological treatments may use antipsychotic medications, such as haloperidol, or atypical antipsychotics, like quetiapine or olanzapine, to manage acute psychotic symptoms. These medications act on neurotransmitter systems to alleviate delirium and improve cognitive functioning. However, these medications may pose risks such as cardiotoxicity (QT prolongation, torsade de pointes), hypotension, and extrapyramidal symptoms (EPS). Careful dosage considerations are crucial to mitigate these risks, especially with other QT-prolonging medications. Administering sedatives and analgesics may also be necessary in cases of ICU psychosis to manage agitation, anxiety, and pain, which can contribute to or exacerbate delirium. These medications, such as short-acting benzodiazepines (midazolam and lorazepam) or opioids, are used cautiously to achieve a balance between sedation and maintaining patient comfort without exacerbating cognitive impairment. 7-10,20

Non-pharmacological interventions focus on patient-centered strategies to create a supportive care environment and alleviate symptoms. These interventions are particularly important considering the limitations and potential risks associated with pharmacological treatments. Behavioral strategies are pivotal and involve creating structured routines to aid in a patient’s reorientation within the ICU environment. Proper sleep/wake cycles need to be established to enhance sleep hygiene. This may involve minimizing noise and light disruptions during the night, using earplugs and eye masks, and promoting relaxation techniques. Adequate sleep contributes to cognitive function and overall well-being in critical care. Occupational therapy can also be used to promote cognitive stimulation and physical mobility. Techniques such as reality orientation may also help address distorted perceptions and thoughts. 7-10,20

Early mobilization therapy has also emerged as a critical non-pharmacological intervention in cases of ICU psychosis. Engaging affected patients in physical activities and mobility exercises under the guidance of physical therapists can contribute to improved outcomes. While the option to use restraints exists, it should be approached cautiously and only after other pharmacological and non-pharmacological interventions have been employed. Restraint use aims to deter specific behaviors that impede care delivery or harm the patient and should only be applied when necessary. Restraints, when used, should remain on for the shortest duration possible, and their need should be continually reassessed. 7-10,20

Preventative Measures

Preventing the onset or minimizing the impact of ICU psychosis involves a multifaceted approach that integrates a combination of strategies. These measures encompass collaboration among various medical specialties, careful pharmacological interventions, and non-pharmacological approaches to create an environment conducive to patient well-being. The cornerstone of prevention lies in a combined and comprehensive approach within the ICU team. Close monitoring by nurses, physicians, and other healthcare professionals is essential to identify early signs of ICU psychosis. Regular assessments, particularly in high-risk patients, contribute to timely intervention. Psychiatry and neurology specialists should also be brought on board to enhance the ability of the medical team to address the complex nature of ICU psychosis. Psychiatric and neurological consultations can provide insights into the underlying causes, facilitate early diagnosis, and guide tailored interventions. This joint effort ensures a tailored approach that addresses the patient’s specific needs in critical care. 7-10,20

Pharmacological Interventions

The use of antipsychotic medications as a prophylactic measure, especially in patients deemed at high risk for developing ICU psychosis, has been a topic of considerable discussion within the medical community. The rationale behind this approach stems from the desire to pre-emptively address the neurobiological and psychological factors that contribute to delirium in the ICU. The decision to administer antipsychotics necessitates a careful evaluation of potential benefits and risks, considering the acute psychotic symptoms in relation to the individual characteristics of each patient, such as age, underlying medical conditions, and the presence of other medications. 7-10,20

Sedation Management

A targeted sedation management strategy is a critical aspect of preventing delirium within intensive care. By adopting a systematic approach to sedation, healthcare providers aim to strike a delicate balance between ensuring patient comfort and minimizing the risk of cognitive disturbances. Avoiding over-sedation is key as it can have detrimental effects on patients, potentially leading to extended periods of mechanical ventilation, prolonged ICU stays, and an increased vulnerability to delirium. Recognizing the importance of maintaining the patient’s cognitive function, healthcare teams should prioritize sedative use to avoid unnecessary and excessive sedation. 7-10,20

Light sedation, whenever feasible, can help prevent ICU psychosis. In this approach, patients remain more alert and responsive, reducing the likelihood of cognitive impairment associated with deeper levels of sedation. This contributes to improved short-term outcomes and aligns with long-term goals, seeing patients experience fewer cognitive and rehabilitation challenges as they recover. For effective management, sedation levels must be continuously assessed to ensure they factor in the ever-changing nature of a patient’s clinical condition in the ICU. Sedation medications should be adjusted to respond promptly to any changes, whether it be variations in pain levels, evolving illness severity, or the need for procedural interventions. This adaptability is crucial for achieving the delicate balance between ensuring patient comfort and preventing delirium. 7-10,20

Non-pharmacological Interventions

Non-pharmacological interventions focus on addressing the environmental factors that have been shown to contribute to ICU psychosis. These interventions include environmental modifications such as establishing regular day-night cycles by providing adequate lighting during the day and dimming lights at night. Patients can also be given earplugs and eye masks during resting periods to minimize disturbances. Calendars and familiar objects can also be placed in the patient’s line of sight, providing visual cues for orientation. This helps patients connect with the familiar, reducing confusion and disorientation. 7-10,20

Early mobility and rehabilitation can also be employed as initiative-taking measures. These interventions not only prevent muscle atrophy and enhance circulation but also keep the patient alert and oriented. Early mobilization programs involve engaging patients in physical activities as soon as feasible through exercises, range-of-motion activities, and ambulation when appropriate. Beyond physical activity, early rehabilitation programs can incorporate cognitive stimulation exercises such as memory exercises, puzzles, and interactive games designed to engage the patient’s cognitive function. Cognitive stimulation prevents the cognitive decline often associated with prolonged ICU stays. 7-10,20

Nursing Considerations

When managing a patient with ICU psychosis or managing one who is at risk of developing the condition, several nursing considerations should be considered to ensure prompt and comprehensive intervention. These responsibilities encompass observation, documentation, patient safety measures, and collaborative efforts for the multidisciplinary team. 7-10,20

Patients should be regularly monitored for signs of delirium, changes in behavior, and responses to interventions. All observations must be documented accurately and in a timely manner to ensure the healthcare team has a comprehensive understanding of the patient’s condition, aiding in developing targeted interventions. Patient education is another aspect of ICU psychosis management, as patients who are more informed about the critical care environment feel less overwhelmed.

Nurses should take the time to make sure their patients understand their condition, care plans, and ICU routine. Similarly, families should be kept up to date on the patient’s well-being and be given information about ICU psychosis. This collaborative approach helps build trust and encourages active participation in the patient’s care. Family members may be able to perceive early signs of cognitive disturbances, thereby aiding teams in intervening more effectively. 7-10,20

Fall prevention strategies also should be developed and implemented as patients with delirium may be at an increased risk. This involves assessing and mitigating environmental hazards, using appropriate assistive devices, and ensuring that patients receive assistance with mobility. The judicious use of restraints is a consideration in patient safety. While healthcare teams should first focus on alternatives such as environmental modifications, restraint use may be necessary to protect the patient. If employed, restraint use must be under careful observation, adhering to established guidelines and regularly reassessing its appropriateness. 7-10,20 If cognitive disturbances are observed, nurses should collaborate with other healthcare professionals to implement targeted interventions that address the underlying causes of these disturbances. Conducting a thorough assessment to identify potential contributors to cognitive issues is essential. Once the root causes are identified, the healthcare team can work together to develop and implement a tailored care plan. In cases where medications are part of the treatment strategy, nurses must ensure that medications are administered on time and following the prescribed dosages. Adherence to medication schedules is crucial for maintaining therapeutic levels and optimizing the effectiveness of the treatment plan. Nurses should carefully monitor patients for adverse reactions or side effects and promptly communicate concerns to the healthcare team. 7-10,20


ICU psychosis in critically ill patients stems from a complex interplay of neurobiological mechanisms and environmental stressors within the ICU environment. These factors contribute to structural changes in the brain, underlining the cognitive dysfunction observed. Given its profound implications for patient outcomes, the importance of heightened awareness, early detection, and individualized interventions cannot be overstated. Managing ICU psychosis involves careful consideration of potential diagnoses, especially given the diverse range of conditions that mimic ICU psychosis. Through in-depth evaluation and observation, ICU psychosis can be accurately identified, allowing for the development of effective treatments that utilize pharmacological and non-pharmacological interventions as needed. The initiative-taking involvement of nurses is essential for preventing and managing ICU psychosis observation, documentation, patient safety measures, and patient and family education. Also, their collaboration with the healthcare team ensures a comprehensive, patient-centered strategy for optimizing outcomes in ICU psychosis.

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