Table of Contents

1. Diagnosis

  • disturbance in attention (focus, redirection, sustain, shift) and awareness (orientation)
  • short time (hours to few days), change from baseline, fluctuate during the day
  • +1 cognitive disturbance (memory, orientation, language, visuospatial ability, perception)
  • not neurocognitive, not coma
  • direct physiological consequence of medical condition, substance, toxin, multiple etiologies
  • specifiers
    • etiology
      • substance intoxication
      • substance withdrawal
      • medication-induced
      • due to another medical condition
      • due to multiple etiologies
    • timeline
      • acute - hours or days
      • persistent - weeks or months
    • type
      • hyperactive - mood lability, agitation, refusal to cooperate
      • hypoactive - slggishness and lethargy
      • mixed - normal psychomotor activity with disturbed attention and awareness; also if rapidly fluctuates

2. Clinical features

  • cardinal feature: reduced alertness
    • inattention and distractable
    • higher integrative functions are also affected
    • frequently impaired memory
  • sleep typically becomes fragmented
  • cannot be predicted

3. Rating Scales

  • MDRS (memorial delirium rating scale)
    • based on current interaction
    • 6 items, rated 0-3
  • DRS (delirium rating scale)
    • 3 items, rated 0-3

4. Etiology

  • substance intoxication and withdrawal
  • post-op - CABG and hip/joint replacement

5. Pathophysiology

  • poorly understood
  • neurotransmitters
    • dopamine, glutamate, GABA

6. Epidemiology

  • prevalence
    • 1-2% overall in the community
    • 14% >85 in the community
    • 10-30% older ER patients
    • 14-24% of admissions
    • 15-53% of older post-op
    • 70-87% of ICU
    • 60% of nursing home
    • 83% of end of life
  • course
    • most recover in full
    • may progress to stupor, coma, seizure, death (if cause untreated)

7. Risk

  • predisposing
    • Demographis
      • Age 65 and Older
      • Male sex
    • Cognitive status
      • Dementia
      • Cognitive impairment
      • History of delirium
    • Functional status
      • Functional dependence
      • Immobility
      • History of falls
      • Low level of activity
    • Sensory impairment
      • Hearing
      • Vision
    • Decreased oral intake
      • Dehydration
      • Malnutrition
    • Drugs
      • Treatment with psychotropic drugs
      • Treatment with drugs with anticholinergic properties
      • Alcohol abuse
    • Coexisting medical conditions
      • Severe medical diseases
      • Chronic renal or hepatic disease
      • Stroke
      • Neurological disease
      • Metabolic abnormalities
      • Infection with human immunodeficiency virus
      • Fractures or trauma
  • precipitating
    • Drugs
      • Sedative hypnotics
      • Narcotics
      • Anticholinergic drugs
      • Polypharmacy
      • Alcohol or drug withdrawal
    • Primary neurologic diseases
      • Stroke, nondominant hemispheric
      • Intracranial bleeding
      • Meningitis or encephalitis
    • Intercurrent illnesses
      • Infections
      • Iatrogenic complications
      • Severe acute illness
      • Hypoxia
      • Hyponatremia
      • Shock
      • Anemia
      • Fever or hypothermia
      • Dehydration
      • Poor nutritional status
      • Low serum albumin levels
      • Metabolic derangements
    • Surgery
      • Orthopedic surgery
      • Cardiac surgery
      • Prolonged cardiopulmonary bypass
      • Noncardiac surgery
    • Environmental
      • Admission to intensive care unit
      • Use of physical restraints
      • Use of bladder catheter
      • Use of multiple procedures
      • Pain
      • Emotional stress
      • Prolonged sleep deprivation

8. Course and prognosis

  • usually last 7 days
  • lots of variability: slow resolution contributes to longevity of symptoms
  • ~15% remain symptomatic of delirium at 6 months
  • early recognition contributes to improved outcome
  • mortality outcome post-d/c at 6 months was similar for delirious treated vs non-delirious treated patients
  • prognostic factors
    • time to delirium resolution
    • increase in independence in ADL
    • decreased length of stay
    • increased rate of discharge to the community rather than institutional settings
  • prevention is the most effective strategy

9. Consequences

  • functional decline
  • risk of placement (3x risk of nursing home placement)

10. DDx

  • if vivid hallucinations: psychotic d/o and mood+psychosis
  • if with fear, anxiety, dissociation, depersonalization: acute stress disorder
  • if atypical and no cause: factitious d/o
  • NCD

11. Other Dx

  • Other specified delirium
    • does not meet full criteria
    • attenuated delirium syndrome - severity of impairment falls short of that required for diagnosis or if some (not all) criteria are met
  • unspecified delirium
    • does not meet full criteria

12. Treatment

12.1. Non-pharm

  • first line
  • moderate stimulation
    • safety and calmness to provide reassurance and decrease fear and agitation
    • room with a window
    • hearing aids and glasses
    • avoiding extremes of sensory input
    • near a nursing station for close observation
    • orienting cues: windows, clocks, frequent reorientation
  • comfort
    • pain: balance medication pros and cons
    • physical activity should be initiated as soon as possible
    • normal sleep-wake cycle: promote with environmental cues and activities
      • reduce interruption of sleep
    • adequate nutrition
    • psychosocial support for staff and family

12.2. Pharm

  • no strong evidence
  • should be reserved for management of behaviours that pose a safety risk or for drug withdrawal
  • antipsychotics and benzos most frequently used
  • antipsychotics
    • low dose haloperidol (weak evidence and lack of FDA approval)
      • fewer antichol and hypotensive properties
      • more EPS - monitor closely
      • QTc prolongation if IV
      • agitated, perceptual disturbances, sleep-wake disturbance, behaviour dyscontrol
    • low dose risperidone, olanzapine, quetiapine for aggression
      • aggression
      • higher incidence of all-cause mortality in dementia patients
  • benzos
    • historical use
    • can increase risk and duration of delirium
    • reserved for management of agitation in sedative-hypnotic withdrawal (alcohol, benzo, barbiturate)
  • ECT
    • if all else fails (even high dose haloperidol)
    • severe agitation
    • can cause delirium on its own
  • sedating agents
    • brief, careful
    • to reset sleep-wake cycle, also caffeine in the morning

13. Notes

  • cognitive domains
    • complex attention - sustained, divided, selective, processing speed
    • executive function - planning, decision, working memory, responding, error correction, inhibition
    • learning and memory - immediate and recent memory (free and cued recall), very long term memory (semantic, autobiographical)
    • language - expressive (fluency, syntax, grammar, naming) and receptive
    • perceptual-motor - visual perception, visuo-spatial, visuo-constructional
    • social cognition - recognition of emotions, theory of mind

Author: Armin

Created: 2022-07-10 Sun 14:04

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