Delirium

Predisposing Factor: Cognitive Status

-Dementia -Cognitive Impairment - related to a 2.82 times increased risk for dementia -History of delirium -Depression

Inattention

-Difficulty focusing, sustaining, and shifting attention -Difficulty maintaining conversation or following commands

Delirium

-A common, life-threatening and potentially preventable clinical syndrome induced by a variety of physical causes -Defined as an acute decline in the cognitive processes of the brain - namely attention and cognition -Strongly associated with hospitalized patients who are 65 years of age or older -Patients with delirium may exhibit periods of inattention, disorganized thinking, changes in level of consciousness, disorientation, delusions, perceptual disturbances, as well as impaired memory, speech, sleep and psychomotor activity -Can fluctuate in severity throughout the day and as such, delirium is often under recognized and underrated -Some clinicians use "confusional state" or "encephalopathy" when diagnosing delirium further complicating the proper identification, management and treatment of this life-threatening syndrome -As mentioned earlier, delirium frequently accompanies acute illness -Was accepted as harmless process but studies prove that this is actually linked to poor clinical syndromes -Delirium complicates the hospital stays of approximately 20% of patients 65 years of age and older

Hypoactive delirium

-A slowing or lack of movement, a paucity of speech with or without prompting, and unresponsiveness characterize hypoactive delirium -Apathy and decreased alertness are also typical in patients with the hypoactive subtype of delirium -It is this subtype that is most often mistaken for depression -This hypoactive subtype of delirium is more common in elderly, with more than 50% of elderly hospitalized patients presenting with the hypoactive form of the syndrome -Due to its almost silent nature, this form of dementia is the most difficult for clinicians to identify - especially if the patient's baseline, or normal, behaviour was never established

Multifactorial Model of Delirium

-A wide variety of factors, or noxious insults, can precipitate delirium -A wide variety of factors can influence a patients' vulnerability to developing delirium in response to a noxious stimulus -In elderly patients, age is a predisposing factor -For young to middle aged patients, age is a protective factor -Poor cognitive function, even full blown dementia is a predisposing factor for delirium, whereas cognitive function reduces a patient's risk for delirium by exerting a protective effect -Good vision and hearing are protective factors against delirium, while hearing or visual impairments increase a patient's risk for developing delirium especially in a hospital setting -Overall health influences the risk of developing delirium

Acute Onset

-Acute onset is a hallmark feature of delirium -If the patient's mental status has deteriorated over time and the changes are more chronic in nature, the possibility of dementia should be explored

Precipitating Factor: Environmental

-Admission to an intensive care unit -Use of physical restraint - related to a 4.4 times increased risk for delirium -Use of bladder cathetr related to a 2.4 times increased risk for delirium -Use of multiple procedures -Pain -Emotional stress

Predisposing Factor: Demographic Characteristic

-Age of 65 years or older -Male sex

Review Medications

-All readmission and current medications should be reviewed -Even long-term medications can contribute to delirium and should be reevaluated

Prevention of Delirium: Early-Mobilization Protocol

-Ambulation or active range-of-motion exercises three times daily: minimal use of immobilizing equipment (e.g. bladder catheter or physical restraints)

Pharmacological Management of Delirium

-Antipsychotics are the drug class of choice for the treatment of delirium -Both low dose haloperidol treatment and atypical antipsychotic therapy are effective in managing the symptoms of delirium -HIgh dose haloperidol therapy should be avoided due to the increased risk of extrapyramidal side effects -Mortality was most commonly associated with the cardiovascular effects of atypical antipsychotic drugs and the risk of aspiration pneumonia due to over-sedation -Clinicians need to sue careful judgement when prescribing for delirium, as the majority of patients in their care are elderly and medically compromised -The dose and duration of neuroleptic therapy should always be minimized for this patient population

Altered Sleep-Wake Cycle

-Characteristics sleep-cycle disturbances -Typically daytime drowsiness, nighttime insomnia, fragmented sleep, anxiety, depression, irritability, apathy, anger or euphoria

Mixed delirium

-Characterized by alternating hyperactive or hypoactive states

Altered Level of Consciousness

-Clouding of consciousness, with reduced clarity of awareness of the environment

Emotional Disturbances

-Common -Manifested by intermittent and liable symptoms of fear, paranoia, anxiety, depression, irritability, apathy, anger, or euphoria

Prevention of Delirium

-Coordinating schedules for drug administration, obtaining vital signs, and performing procedures during the night will provide patients with an uninterrupted period of sleep -Operating blinds and promoting wakefulness and mobility during the daytime can also encourage normal sleep-wake cycles

Delirium and its outcomes

-Current studies investigating delirium and its outcomes suggests that the development of delirium in the hospitalized elderly initiates a cascade of events that culminate in the loss of the patient's independence, an increased risk of morbidity and morality, and an increase in healthcare costs due to longer hospital stays, rehabilitation, the need for formal home health care, and long-term institutionalized care -Only 40% of clinicians routinely screen for delirium in hospitalized elderly patients

Predisposing Factor: Decreased Oral Intake

-Dehydration - related to a 2.02 times increased risk for delirium -Malnutrition

Prevention of Delirium: Dehydration Protocol

-Dehydration Protocol: Early recognition of dehydration and volume repletion (i.e. encouragement of oral intake of fluids)

Types of Delirium

-Delirium exists in 3 different subtypes: hyperactive, hypoactive and mixed subtypes -Of the three subtypes, those with severe hypoactive delirium have the lowest 60month survival rate -This may be because those with hyperactive delirium are more likely to be referred to psychiatrists and receive appropriate therapy or interventions due to the more disruptive and potentially self-harming nature of the subtype -In contrast, hypoactive delirium may be mistaken for compliance, fatigue or simply behaviours incorrectly ascribed to old age

Prevention and Management of Delirium

-Formal cognitive testing with the confusion assessment method instrument should be performed to establish baseline cognitive performance in all elderly patients and identify any subtle cases of hypoactive delirium -When a patient is admitted with confusion, the severity of change in mental status should be determined -If no history is available, delirium should be assumed -Failure to do so is the leading cause for missing a diagnosis or delirium -All patients should be woken during rounds and evaluated daily for delirium

Predisposing Factor: Functional Status

-Functional dependance -Immobility -Low level of activity -History of falls

Prevention of Delirium: Hearing Impairment

-Hearing Protocol: Portable amplifying devices, earwax disimpactation, and special communication techniques, with daily reinforcement of these adaptations

Perceptual Disturbances

-Illusions or hallucinations in about 30% of patients

Cholinergic Hypothesis of Delirium

-In addition to the effects on cerebral blood flow, neuroinflammation has been shown to induce a cholinergic deficit in the brain -Acetylcholine plays an important role in memory and cognition -Consequently, a decrease in acetylcholine levels within the brain would be somewhat expected in patients presenting with delirium -The finding that anticholinergic drugs cause delirium in healthy adults, and are even more likely to cause delirium in the elderly population support this hypothesis -Most drug-induced episodes of delirium are associated with a medication that possess anticholinergic activity -Isoflurance anesthesia decreases acetylcholine release in most brain regions, providing a rationale as to why many elderly patients experience delirium while in post-operative recovery -Opiate administration induces an increase in dopamine levels, which then leads to a corresponding decrease in AcH levels within the brain -This finding is commonly observed with dopaminergic drugs because dopamine has an inhibitory effect on AcH release -Dopamine antagonists have been shown to effectively treat some of the symptoms associated with delirium -Studies have shown that medical conditions that precipitate delirium, such as hypoxemia and hypoglycaemia decrease AcH synthesis in the central nervous system -Clinical investigations have shown the thgiehr levels of serum anticholinergic activity are associated with an increased risk of delirium in both medical and surgical inpatients -Other studies have also implicated a role for serotonin, GABA, glutamate and melatonin as neuromodulators of the cholinergic and dopaminergic neurotransmitter systems -Other studies have also implicated a role for serotonin, GABA, glutamate, and melatonin as neuromodulators of the cholinergic and dopaminergic neurotransmitter systems -While both the neuroinflmmatory and cholinergic hypothesis of delirium provide insight into the biological mechanisms that underlie delirium, it is evident that neither hypothesis can fully explain all of the characteristic features of delirium -This is likely due to the fact that delirium is associated with multiple, interacting heterogenous risk factors -It is unlikely that a single neurobiological pathway is responsible for the syndrome

Predisposing Factors

-Include any baseline characteristic present at the time of admission that is patient dependent -Make the patient vulnerable to delirium, and can thus be considered predictive of those at risk for developing the syndrome -Leading factors include the presence of dementia or cognitive impairment, functional impairment, visual impairment, history of alcohol abuse, advanced age (particularly those 75) and comorbidity burden or presence of specific comoboridites

Precipitating Factor: Intercurrent Illnesses

-Infections -Iatrogenic complications -Severe acute illness -Hypoxia -Shock -Fever or hypothermia -Anemia -Dehydration -Poor nutritional status -Low serum albumin level - related to a 4 times increased risk for delirium -Metabolic derangements (e.g. electrolyte, glucose, acid-base)

Causes of Delirium: Predisposing and Precipitating Factors

-It is the interrelationship between predisposing and precipitating factors that puts a patient at risk for developing delirium -While reach factor has its own interdependent effect, the synergy between the vulnerable patient and their exposure to noxious stimuli represents a strong predictive model of which hospitalized patients are most at risk for delirium -Patients who are highly vulnerable to delirium, such as those with dementia, will develop delirium after exposure to a minor insult, such as a single dose of a sedative drug -In constrast, in patients who are not vulnerable or predisposed to delirium, the condition will only manifest after exposure to a number of noxious insults, such as general anesthesia, major surgery, and multiple psychoactive medications -Taken together, this information can be used to predict which patients are at either a high or low risk for developing delirium during the first 9 days of their hospital stay

Neuroinflammatory Hypothesis of Delirium

-It is widely accepted that cells within the brain - neutrons, glia and astrocytes react to the presence of peripheral immune cells in the systemic circulation -Activation of the brain by peripheral immune cells leads to the production of cytokines, neuronal cell proliferation and activation of the hypothalamus-pituitary-adrenal axis -These changes allow the central nervous system to help combat acute infections in the body -These changes may also contribute to the pathogenesis of delirium -Peripheral immune cells are able to gain access to the brain by altering the expression of tight-junction proteins that help form the blood-brain-barrier -These changes lead to an increase in permeability of the BBB and allow for the recruitment and infiltration of blood-derived leukocytes and other inflammatory agents into brain tissue -Once outside the brain, these pro-inflammatory agents activate endothelial cells, microglia and astrocytes -Activation of the microglia induces morphological changes and initiates the production of pro-inflammatory cytokines such as interleukin-1, interleukin-2 and tutor necrosis factor - alpha -Changes within the microglia in turn modulate the activatity of adjacent endothelial cells, astrocytes and neurones, impacting cerebral blood flow, signal propagation and neuronal excitability It is hypothesized that these changes in neurotransmission and cerebral blood flow contribute to the pathogenesis of delirium -This hypothesis is supported by recent neuroimaging studies that show a 42% reduction in overall cerebral blood flow in patients with delirium -The symptoms of inattention and decreased cognitive functioning observed in patients with delirium may be associated with decreased cerebral blood flow -Reduced blood supply to the brain impairs the supply of oxygen and glucose - both of which are essential to proper cognitive functioning -Cannot fully account for all of the clinical features associated wit this syndrome, it does provide an explanation as to how peripheral changes in the body such as surgery, infection and medical illness can affect brain function and increase a patient's risk for developing delirium -This hypothesis offers insight as to why elderly patients are more vulnerable to delirium, since neuroanatomical studies have shown the presence of enlarged and damaged microglia in the brains of elderly non-delirious patients -The finding that microglial cells undergo age-related structural and functional changes suggest that the elderly brain may exist in a pro-inflammatory state that is "primed" and thus more vulnerable to noxious insults resulting in decreased cerebral blood flow, and neurotransmitter dysfunction associated with delirium

Metabolic derangements

-Lactic acidosis -Hyper/hypoglycemia -IGF1 (neurotrophic peptide; decreased levels) -Hypercapnia

Disorganized Thinking

-Manifested by disorganized or incoherent speech -Rambling or irrelevant conversation or an unclear or illogical flow of notes

Delirium, Depression or Dementia

-Many of the symptoms observed in patients with delirium are also observed in patients with other neuropsychiatric diseases or medical illnesses -This is why it's difficult to identify delirium in patients -It is critical that health care team perform both a careful and detailed history and physical examination of the patient to distinguish between delirium and other types of mental illness or dementia -In cases of delirium, the onset of altered consciousness, cognitive disturbance or hallucinations is typically acute and presents in the context of medical illness, surgery or medication change -To the untrained eye, these features can be sometimes mistaken for a psychotic disorder -Schizophrenia tends to have a gradual onset, and appears in late adolescence/early adulthood -It is also preceded by a phase of social isolation that lasts weeks to months -Disorientation and fluctuations in level of consciousness are rare in schizophrenia but are a hallmark of delirium -In patients with dementia, the client's level of consciousness is typically intact, and inattention is either absent or mild when compared to other cognitive deficits -Patients with dementia rarely exhibit fluctuations in their cognitive function - another distinguishing feature between dementia and delirium -Delirium may also be mistaken for depression especially when the patient's symptoms are hypoactive in nature -Unlike delirium, depression has a more gradual onset of psychomotor slowing, and the cognitive deficits tend to reflect disinterest as opposed to the disorientation commonly seen in patients with delirium

Nonpharmacological Treatment Strategies

-Non-pharmacological appraoches to managing symptoms should always be instituted -Creating a calm, comfortable environment with the use of renting influences such as calendars, clocks and familiar objects from home are important -Regular reorienting communication with staff, involving the family and supportive care and limiting room and staff changes can also make a difference

Prevention of Delirium: Sleep Deprivation

-Nonpharmacoligical: at bedtime, warm drink (milk or herbal tea), relaxation tapes or music and back massage -Sleep-enhancement Protocol: Unit-wide noise-reduction strategies (e.g. silent pill crushes, vibrating beepers, and quiet hallways) and schedule adjustments to allow sleep (e.g. rescheduling of medications and procedures)

Acute Onset (clinical feature)

-Occurs abruptly, usually over a period of hours or days -Reliable information often needed to ascertain the time course of onset

Hyperactive delirium

-Often characterized by symptoms of restlessness, constant movement and agitation -Insomnia, hypervigilance, irritability, distractibility, rapid speech, uncooperativeness and wandering behaviour are also observed -These features may be often be mistaken for schizophrenia, bipolar disorder or agitated dementia

Prevention of Delirium: Cognitive Impairment

-Orientation Protocol: Board with names of care-team members and day's schedule; communication to reorient and surroundings -Cognitively stimulating activities three times daily (e.g. discussion of current events, structured reminiscence or wot games)

Precipitating Factor: Surgery

-Orthopaedic surgery -Cardiac Surgery -Prolonged cardiopulmonary bypass -Noncardiac surgery

Pharmacological Management

-Pharmacological therapy should be reversed for patients whose symptoms threaten their own safety or the safety of other persons or would result in the interruption of essential therapy such as technical ventilation and central venous catheters

Psychomotor Disturbances

-Psychomotor variants of delirium -Hyperactive: marked by agitation and vigilance -Hypoactive: marked by lethargy, with a markedly decrease level of motor activity -Mixed

Causes of Delirium

-Rarely caused by a single factor -Multifactorial and involves a complex interaction between the vulnerable patient and their exposure to precipitating factors -Showed that effects of baseline and precipitating factors on the risk for developing delirium are cumulative -The presence of 3 or more delirium risk factors increases the odds that an individual will develop delirium by 60% -In light of the evidence, it is unlikely that addressing only one risk factor would resolve delirium in an elderly hospitalized patient -All factors - predisposing and precipitating should be addressed

Precipitating Factors

-Refer to any noxious insults or factors that are related to hospitalization that contribute to a patient's risk of developing delirium -Leading precipitating factors include polypharmacy,use of psychoactive drugs, use of physical restraints, and abnormal lab findings

Precipitating Factor: Drugs

-Sedative hypnotics -Narcotics -Anticholinergic drugs -Treatment with multiple drugs - related to a 2.9 times increased risk for delirium -Alcohol or drug withdrawal

Predisposing Factor: Coexisting Medical Conditions

-Severe illness - related to a 3.49 times increased risk for delirium -Multiple coexisting conditions -Chronic renal or hepatic disease -History of stroke -Neurological disease -Metabolic derangements -Fracture or trauma -Terminal illness -Infection with human immunodeficiency virus

Screening fro Delirium

-Since the vast majority of elderly patients fall into hypoactive delirium subtype, the risk of not identifying a patient with delirium is high -Given that unmanaged delirium is associated with a significant risk of mortality in the first year, the use of effective screening tools for the diagnosis of delirium is critical -The Confusion Assessment Method Instrument or CAM has been widely accepted as the most useful scale for diagnosing delirium -This screening tool diagnoses the delirious state by a yes or a no answer to a four-point algorithm based on the DSM criteria -Proper use of this instrument has the potential to enhance the detection of delirium in hospital settings, and reduce the number of delirious patients who go undiagnosed and untreated -For those patients that are intubated/ventilated, this scale has been adapted so that direct communication is not required -However it is not able to rate symptom severity -The Delirium Rating Scale is often used to rate symptom severity, follow the course of the syndrome, and assess whether a patient's symptoms are improving with treatment interventions

Precipitating Factor: Primary Neurological Disease

-Stroke, particularly non dominant hemispheric -Intracranial bleeding -Meningitis or encephalitis

Fluctuating Course

-Symptoms tend to come and go or increase and decrease in severity over a 24-hour period -Characteristics lucid intervals

Systemic Inflammation

-Systemic inflammation is a predominant feature of many surgical and medical conditions associated with delirium, especially when tissue destruction and/or infection is involved -Delirium is a presenting clinical feature of sepsis, urinary tract infections, pneumonia, myocardial infarctions, fractures, hepatitis, burns, and also commonly appears with complications following major surgical procedures -All of these medical or surgical conditions share a common thread; the release and production of pro-inflammatory mediators into the systemic circulation -As such, there appears to be a strong link between delirium and inflammation -The suggestion is supported by the clinical evidence that patients with post-operative delirium have higher circulating blood levels of inflammatory cytokines than patients without delirium

Diagnostic Criteria for Delirium

-The DSM defines delirium by the presence of disturbed consciousness and a chance in cognition or the development of a perceptual disturbance that is not better accounted for by a preexisting, established or evolving dementia -The distburance in consciousness must develop over a short period of time and should fluctuate during the course of the day -There must be evidence from clinical history, physical examination and/or laboratory findings that the disturbance is caused by the physiological consequences of a medical condition

Delirium PRevention

-The most common preventable adverse event amongst the hospitalized elderly population -30-40% of cases of delirium are preventable -Some experts suggest that delirium rates should be used as an indicator of an institution's overall quality of health care -Many elements of hospital care contribute to the development of delirium; adverse effects to medication, complications of invasive procedures, immobilization, dehydration, the uses of bladder catheter and sleep deprivation -Most of these risk factors are modifiable and amenable to intervention -Targeted interventions are better -Such interventions were also shown o reduce delirium duration, and should also therefore be used to manage a delirious patient once the syndrome has manifested -The following risk factors were targeted: cognitive impairment, seep deprivation, immobility, vision impairment, hearing impairment and dehydration -The goal of the Hospital Elder Life Program is to provide proactive, comprehensive care for older hospitalized patients in an acute care setting to help prevent delirium and functional decline

Pathophysiology of Delirium

-The pathophysiology remains poorly understood -First, the core features of delirium - inattention and impaired cognition are difficult to define -Second, the fluctuating course of the syndrome and its diverse clinical symptoms make delirium difficult to recognize -Third, delirium can be caused by a multitude of risk factors, reflecting a complex interaction between environmental and individual factors -Finally the overall inaccessibility of the central nervous system limits scientific investigation into the possible neurobiological correlates into delirium -However it is evident from the clinical features of delirium that this syndrome manifests from a strong link between the brain and the body -Delirium occurs when physical stressors affect a vulnerable patient -As such there must be a link between physiological changes in the body and the cognitive changes that constitute delirium -The leading hypothesis for the pathogenesis of delirium focuses on the roles of inflammation and neurotransmitter dysregulation on brain function -Other mechanisms thought to contribute to delirium include physiological stressors, metabolic derangements, electrolyte disorders, and genetic factors -IN general, these mechanisms are thought to interfere directly with neurotransmission or cellular metabolism, leading to acute cognitive dysfunction

Predisposing Factor: Drugs

-Treatment with multiple psychoactive drugs -Treatment with many drugs -Alcohol abuse

Cognitive Deficits

-Typically global or multiple deficits in cognition, including disorientation, memory deficits or language impairment

Prevention of Delirium: Vision Impairment

-Vision Protocol: Visual aids (e.g. glasses or magnifying lenses) and adaptive equipment (e.g. large illuminated telephone key pads, large-print books, and fluorescent tape on call bel) with daily reinforcement of their use

Predisposing Factor: Sensory impairment

-Visual impairment - related to a 3.51 times increased risk for delirium -Hearing Impairment

Identify and Address Predisposing and Precipitating Factors

-When investing the underlying cause of delirium the healthcare team should be aware of atypical presentations of many diseases in the elderly including MI, infection, and respiratory failure -Delirium is often the sole manifestation of a serious underlying disease in the population

Delirium & Dementia

-While delirium and dementia are two distinct conditions, there is significant evidence to suggest that delirium and dementia are highly interrelated -Dementia is the leading risk factor for delirium -Two-thirds of delirium cases occur in patients with dementia - this finding suggests that dementia is a significant predisposing factor for delirium and is also highly vulnerable to minor insults -Second, both conditions are associated with decreased cerebral blood flow, acetylcholine deficiency and inflammation, suggesting overlapping neurobiological mechanisms -In some patients delirium can last for months to years, blurring the boundaries between delirium and dementia -50% of delirium cases persist after discharge -Persistent delirium is associated with worse long-term cognitive and functional outcomes and is 2.3 times more likely to occur in patients with underlying dementia -The most sigifnciant risk factor for persistent derlium is the use of physical restraints -The use of restrains leads to increased agitation, immobility, functional decline, inconteintence, pressure ulcers, asphyxiation and in some cases, cardiac arrest -Therefore physical restraints should not be used for older person with delirium, especially those with agitated dementia -In those with dementia, delirium worsens functional status, accelerates the patients' loss of independence and is associated with poorer outcomes -Patitnets with dementia never return to their baseline mental sate after an episode of delirium and are more likely to experience delirium in the future -Taken together, this evidence suggest that delirium may serve as an important means by which to identify patients in the early stages of dementia or mild cognitive decline

List all the clinical features of delirium

1) Acute Onset 2) Fluctuating Course 3) Inattention 4) Disorganized Thinking 5) Altered level of consciousness 6) Cognitive deficits 7) Perceptual disturbances 8) Psychomotor disturbances 9) Altered sleep0wake cycles 10) Emotional disturbances

CAM: Inattention

2a) Did the client have difficulty focusing attention, for example, being easily distractible, or having difficulty keeping track of what was being said? 2b) Did this behaviour fluctuate during the interview, that is, tend to come and go or increase and decrease in severity? 2c) Please describe this behaviour.

Physiological stressors

Cortisol, hypoxia

CAM: Acute Onset

Is there evidence of an acute change in mental status from the client's baseline?