Delirium

WBA - Delirium

# Case

Delirium

  • Causes
    • Drugs (polypharmacy/side-effects/withdrawal/intoxication)
      • Any centrally acting substances
      • Anticholinergics in particular
    • Infections
    • Surgery
    • Constipation
    • Urinary retention
    • Sleep deprivation
  • Risk factors
    • Brain vulnerabilities: age, dementia and mild-cognitive impairment, long-term alcohol usage
    • Poor inputs ie. vision and hearing
  • Clinical manifestations
    • Onset: acute, fluctuating course
    • Hyperactive: agitated, increased sympathetic activity, psychosis
    • Hypoactive: increased sleeping, decreased arousal. Poorer prognosis (possibly due to underdetection)
    • Mixed: fluctuating between above
    • Other: worse at night, disturbed sleep-wake cycle
  • DSM-5 criteria
    • Disturbance in attention (focus) and awareness (reduced environmental stimuli)
    • Acute onset, different to baseline
    • Additional disturbed cognition (memory, disorientation, language, visuospatial ability or perception)
    • Cause: must be evidence of a physical cause
    • Exclusions: not explained by coma or other known neurocognitive disorder
  • Tests
    • CAM
    • 4AT
  • Management
    • Treat the underlying cause
      • ADEs: review medications for cessation (anything centrally acting, anticholinergics)
      • Constipation: bowel chart, laxatives
      • Urinary retention: in/out catheters
      • Avoid lines where possible
      • Withdrawal: CIWA, COWS
      • Manage pain adequately with analgesia
    • Non-pharmacological and prevention
      • Optimise sleep (nil evidence for melatonin, avoid BZDs)
      • Provide orientation eg. windows, family members
      • Manage sensory inputs eg. hearing aids, vision
      • Reduce lines and catheters
      • 1:1 nursing special
      • Early mobilisation
      • Lower the bed to reduce falls risk
    • If hyperactive and at risk of aggression, can use antipsychotics. WHO CONSENTS?
      • Haloperidol 0.5-1mg PO do these doses actually do anything??????
      • Olanzapine 1.25-5mg PO (beware sedation)
      • Risperidone 0.5-1mg PO (beware EPSE and hypotension)
      • Quetiapine 25mg PO (particularly in PD or DLB, beware sedation and hypotension)
      • Escalate to haloperidol 0.5-1mg IM or olanzapine 2.5-5mg IM
      • eTG says: wait for 30-60 mins for onset. Aim single dose only. Regular courses for 2-3 days max. Cease in case antipsychotics are causing the delirium. Avoid PRN.
      • Maudsley says: use one drug at a time, small doses regularly compared to large doses less regularly. Maintain at effective dose for 7-10 days after symptoms resolve.
        • Risperidone and olanzapine have poorer response rates in the elderly
        • Risperidone 0.5mg BD with PRN (max 4mg/day)
        • Quetiapine 12.5-50mg BD (max 200mg/day)
        • Olanzapine 2.5-5mg once daily ()
      • Avoid BZDs due to sedation, respiratory depression and paradoxical excitement unless treating withdrawal. Typically prolongs and worsens delirium.
      • Pharmacological prophylaxis is contentious
  • Differentials
    • Dementia
    • Psychosis
  • Complications
    • Increases mortality and length of stay
    • Increases risk of long-term institutional placement
  • Prognosis
    • Fatal in 37% if untreated. Also progresses to dementia if not treated.
    • 60% have persistent cognitive impairment
    • 50% do not recover prior to discharge
    • 1 year mortality rate in elderly: 35-40%
    • 3x more likely to develop dementia

Delirium vs Acute Encephalopathy

  • Delirium is technically the syndrome, encephalopathy the pathology
  • Acute encephalopathy
    • Rapidly developing pathobiological process in the brain (within 4 weeks)
    • Manifests clinically as subsyndromal delirium (ie. does not meet DSM-5 criteria), DSM-5 delirium or coma
    • However, acute encephalopathy should not be diagnosed by bedside assessment. Note that delirium as per DSM-5 also states that an underlying physiological cause should be present.
    • Can also have seizures or EPS
  • Terms such as altered mental status, acute brain failure, acute confusional state should not be used
  • Ref: https://doi.org/10.1007%2Fs00134-019-05907-4

Last modified: Wed Aug 14 21:29:04 2024