Delirium

Raymone Shenouda, MD

No Disclosures

No conflict of interest

The word “delirium” is Latin for “a going off the furrow”, symbolic of madness or a train going off the tracks.

This term is thought to have been coined by Aulus Cornelius Celsus (ca 25 BC—ca 50). in De Medicina. Celsus also described delirium.

Hippocrates called it phrenitis.

History

Delirium is a global dysfunction in cerebral metabolism

• Acute onset

• Reversible (may be persistent)

• Associated with significant morbidity mortality and health care cost

Definition

Prevalence of delirium

• 15-25% among patient’s in the general hospital

• 30-80% among patient’s in the ICU (Fong et al 2009)

• Prevalence and incidence are highest in complex care setting (Fong et al. 2009; Franco et al. 2001; Robinson et al. 2009)

Epidemiology

Mortality

• Mortality in Delirium patients is estimated to be 15-30% in the hospital and up to 40% over 1 year in elderly patients with delirium (Inouye2006; Tennen and Rundell 2008)

• Relative risk for mortality in elderly patient’s with delirium and age matched control subjects without delirium is 3.44. This effects is sustained over 12 months. (McCusker et al.2002).

Epidemiology (cont’d)

Morbidity

•The more severe the Delirium is the poorer the outcome for the patient (Marcantonio et al. 2002)

•Agitation or lethargy associated with delirium can produce significant medical complications (decrease oral intake, pulmonary emoboli, aspiration, and decubitus ulcer) (Fong et. al 2009)

Epidemiology (cont’d)

Common Risk Factors (Inouye2006, Robinson et al. 2009):1. Age, over 65

2. Dementia (2/3 of delirium patients have underlying dementia)

3. Visual or hearing impairment

4. Dehydration or malnutrition

5. Multiple medications

6. Multiple medical problems

7. Impaired functional status

Predisposing Factors

Delirium in higher vulnerability patient’s is often the result of mild precipitants, such as UTI and dehydration which is treatable.

Delirium in lower vulnerability patient’s is more likely to be the result of serious insults

Assertive management of remediable etiologies in vulnerable patients (e.g. elderly with dementia) can result in robustly positive responses

Relationship of Predisposing Factors and Delirium Etiology

1) Toxic Etiologies

2) Metabolic Etiologies

3) Central Nervous System Conditions and Events

4) Hypoxic Etiologies

5) Inflammatory Etiologies

Precipitating Factors

Medications *

Substance of Abuse(e.g. sedatives, hypnotics, Hallucinogens).

Withdrawal Syndromes (life threatening)

Poisons (pesticides, solvents, lead and Mercury)

1) Toxic Etiologies

Acid Base Balance Abnormalities

Electrolyte disturbance

Organ Failure (hepatic, renal, CHF etc)

Burns

Vitamin Deficiencies

Endocrinopathies (thyroid, adrenal, hypo/hyperglycemia)

2) Metabolic Etiologies

CNS Trauma (closed head injury, heatstroke etc

Structural Lesions (stroke, tumor, hydrocephalus, abscess, hemorrhage)

Vasculitis

Limbic Encephalitis

Seizure Disorder

Hypertensive Encephalopathy

3) CNS Conditions and Events

Anemia

Carbon Monoxide

Hypotension

Pulmonary failure

Cardiac failure (CHF, MI, Arrhythmia and Shock)

4) Hypoxic Etiologies

CNS infections-meningitis,encephalitis

CNS effects of inflammatory infections-HIV, Syphilis, Sepsis

5) Inflammatory Etiologies

Minutes Hours Days

hypoxia CHF/edema Infection

stroke/MI infection Metabolic

Head trauma Metabolic Thyroid

Seizure hyperglycemia Vit. B12

Hypoglycemia Electrolyte Tumor

Embolism Uremia Hematoma

Intoxication Withdrawal Meningitis

Etiology (temporal)

Clinical Characteristics

•Core Features

•Prodromal and subsyndromal states

•Psychomotor Variations

•Temporal course

•Characteristic Neuropsychiatric Impairments on Mental Status Exam

Delirium has a core set of clinical features that are virtually always present, and other signs and symptoms that are occasionally present APA 2000, Cole et al 2007.

Core features

Frequency (%) of symptoms in an elderlymedical inpatient population diagnosed with delirium

Clinical Characteristics

Confusion assessment method (CAM) item*

Percentage identified

Acute onset* 100%

Inattention*’ 100%

Disorientation*’ 100%

Fluctuation* 100%

Memory impairment* 99%

Psychomotor change (agitation or retardation)

87%

Altered level of consciousness* 59%

Altered sleep wake cycle 59%

Perceptual Disturbances* 25%

*indicates DSM-IV-TR Criteria item 3 DSM-IV-TR Criteria are associated with recovery, disorientation to self, hyperactivity and inattention are associated with recovery.

Hyperkinetic (Psychomotor agitation) 15%-45%

Hypokinetic (Psychomotor retardation) 20%-30%

Mixed 25%-50%

Prognosis• Hypokinetic delirium has the worse prognosis in terms of

• Illness severity length of stay morbiditymortality

• More likely than hyperkinetic delirium to be unrecognized and undertreated

Complications

Hypokinetic delirium is associated with higher frequency of medical and surgical complications

• More severely ill to begin with.

• High risk of nosocomial infections, sores, venous thrombosis, aspiration

Psychomotor Variations

Initial phase of delirium

Three features of the temporal course of acute delirium are characteristic and assist in the differential diagnosis:

1. Abrupt acute or subacute onset of symptoms

2. Fluctuation of symptom severity during an episode- relatively lucid intervals alternating with more severe symptoms.

3. Subsyndromal or prodromal signs

Persistence of cognitive dysfunction

Jackson et al. (2004) reviewed 7 prospective studies of patients who developed delirium as inpatient and were compared over time (median 2 yrs) with control patients without delirium• Four studies showed that patients with delirium had lower scores

overtime on cognitive measures.

• Three studies found a higher incidence of dementia in patients with history of delirium

Temporal course

1. Impaired attention (distractible or unable to focus)

2. Impaired short term memory (secon. to impaired attention and registration)

3. Disorientation

4. Change in level of consciousness

5. Impaired visuospacial skillsa) nondominant parietal overall spatial properties

b) dominant parietal numbers and hands

c) prefronatal understanding the concept of time

6. Disturbed executive function (abstraction, sequential thinking, 3 step comm)

7. Disorganized thought process (circumstantiality-loose association)

8. Impaired language and speech

9. Perceptual disturbance (visual illusions and hallucinations)

Characteristic Neuropsychiatric Impairments on Mental Status Exam

1. Components of Diagnostic assessment

2. Differential diagnosis

3. Diagnostic instruments

Diagnosis

• History

• establishing a timeline of temporal association

• While temporality does not equate causality, it raises index of suspicion and help prioritize evaluation and management.

• Physical and neurological exam including vital signs

• Medication review (correlate dose initiation or change with behavioral change)

• Mental status exam (also standardized tests like MMSE or clock drawing that could be repeated over time

• Labs: CBC, electrolyte, LFT, liver functions including ammonia, renal functions, calcium, magnesium, medication levels, urine drugs screen, ABG and O2 Sat.

• Chest X-ray and lumbar puncture, (if indicated)

• EEG:

• Diffuse slowing (delta waves)

• While other EEG patterns are suggestive of particular delirium etiologies none pathognomonic

Components of diagnostic assessment

•Extensive

•Can have multiple etiologies•55% of elderly patients with delirium had one single definitive or probable cause.

•45% remaining had an average of 2.8 etiologies per patient Francis et al. (1990)

•Differentiating delirium from Depression and dementia is particularly important Trzepacz et al. (2011)

Differential Diagnosis

Delirium Dementia Depression

Onset Acute or subacute

Chronic Subacute/variable

Course Fluctuating Progressive Variable

Reversibility

Common Rare Remission

Orientation Impaired Impaired late Clear

Attention Impaired Impaired late Impaired

Memory Impaired Impaired Intact

Hallucinations

Usually visual Visual or auditory

Auditory

Delusions Fleeted/Fragmented

More fixed Mood congruent

The three Ds: delirium, dementia and depression trzepacz et al. 2011

• Confusion Assessment Method: (Inouye et al.1990)

• Algorithm of 4 cardinal symptoms of Delirium

• Intended for use in high risk settings by nonpsychiatric clinicians

• Delirium Rating Scale DRS (Trzepacz et al. 1988) and the more extensively revised DRS-R-98 (Trzepacz et al. 2001)

• Can help distinguish Delirium from other disorders as dementia, schizophrenia and depression

• Available in several languages

• Memorial Delirium Assessment Scale MDAS Breitbartet al. (1996)

• 10 item severity rating scale

• Used in serial examinations after a patient has been diagnosed with Delirium

Diagnostic Tools

• Most Effective Delirium management principle.

• Attention to the following six factors by nursing staff reduces delirium frequency, number of delirium episodes and delirium duration (Inouye et al.1999)

1. Frequent orientation2. Noise reduction protocol3. Early mobilization4. Visual aids5. Hearing aids 6. Hydration

Prevention of Delirium

Identification and Reversal of Remediable Etiologies

Reduction of Symptoms

• Environmental Management of Delirium Signs and Symptoms

• Pharmacological Management of Delirium Signs and Symptoms

Management and symptomatic treatment

1. Monitor vital signs fluid I&O and oxygenation

2. Avoid sleep interruption

3. Place close to the nursing station

4. Arrange for a sitter if safety is potential issue

5. Maintain the bed in a low position, exercise caution with the use of side rails

6. Avoid placing delirious patients in a room together

7. Encourage presence of family members; educate patients and families about delirium

8. Provide familiar objects and visual cues, such as family photos, clocks and calendars

9. Provide adequate lighting

10. Minimize transfers, perform procedure in the patient’s room if possible

11. Maximize staff continuity and familiarity

12. Reduce excessive environmental stimuli

13. Repeatedly orient the patient

14. Make sure visual and hearing aids are used

15. Use restraints as a last resort.

Environmental Management of Delirium Signs and Symptoms

• When an etiology of delirium is not immediately remediable

• When hyperactive signs and symptoms produce clinical or safety complications

• There is scant evidence to support the use of psychotropic medications in managing hypoactive delirium

• Antipsychotics are the most commonly used

• The most frequently used nonantipsychotic medication is lorazepam (used in addition to antipsychotic, first line in Alcohol withdrawal delirium

• No clinical benefit has been demonstrated for one antipsychotic medication over another in terms of target symptoms, although medications have different side effect profile (Fong et al. 2009)

Pharmacological Management of Delirium Signs and Symptoms

• Delirium is common and frequently undiagnosed

• Incidence and prevalence highest in complex care settings

• Associated with high morbidity and mortality

• The more severe the delirium the higher the higher the morbidity and mortality

• Predisposing Factors (age, dementia, multiple medical, multiple medication, sensory impairment, functional impairment)

• Delirium in highly vulnerable patient’s is due to milder etiologies that are easier to treat

• Precipitating factors (Toxic, metabolic, hypoxic, inflammatory, CNS)

• Delirium can be hypo- or Hyper- kinetic or mixed.

• Hypokinetic delirium has worse prognosis (sicker patient, medical comp., difficult to recognise

Summary

Diagnosis (history, Physical and neuro exam, med review, labs, MSE, X-ray, EEG).

Differential Diagnosis: Vast, can be multifactorial, remember the 3 Ds (delirium, dementia and Depression)

Prevention is better than treatment

Treatment: TREAT THE CAUSE+ reduce symptoms (environmentally and or Pharmacologically)

Summary cont’d

Thank you