Frequently Asked Questions

What is Delirium?

  • Behavioral and cognitive manifestations of BRAIN FAILURE
  • A syndrome, a spectrum of clinical diseases
  • Not a single entity
  • Not a dichotomous disorder but a continuous one
  • An abnormal vital sign: the SIXTH vital sign

What is Pathophysiology Delirium?

  • Cholinergic Deficiency Hypothesis
  • Dopaminergic Excess Hypothesis
  • Contribution of other neuro transmitter function perturbations:
    • Norepinephrine
    • Serotonin
    • γ-aminobutyric acid
    • Glutamate
    • Melatonin
    • Cytokines

If Delirium Indicates Brain Failure, What Physiological Processes Can Be Affected?

  • Consciousness
  • Interpreting sensory input
  • Higher cognitive functions: i.e. memory, attention
  • Respiration
  • Blood Pressure
  • Heart rate
  • Speech
  • Swallowing

Delirium is Different from Dementia

The most commonly used system for subtyping delirium is based on motoric behavior

  • Hyperactive Delirium
    • Patients are agitated and combative
  • Hypoactive delirium
    • Patients are quiet and withdrawn
  • Mixed delirium 
    • Combination of hyper- and hypoactive

Delirium vs Dementia graphicNotes to Remember

  • Not all delirious patients are combative and agitated
  • Majority of delirious patients have mixed or hypoactive delirium
  • Hypoactive and mixed delirium patients must be treated as aggressively as patients with hyperactive & agitated delirium

Negative Consequences of Delirium during Hospitalization

  • Mortality rates 25% to 33% during hospitalization
  • Increased hospital length of stay
  • Increased incidence of falls
  • Increased incidence of aspiration
  • Poor recovery from acute medical conditions or surgery
  • Behavioral concerns leading to need for increased surveillance
  • Frequently getting out of bed unassisted, calls for attention, and agitation
  • Potential self-harm
  • Removing catheters, etc.

Negative Consequences of Delirium after Hospital Discharge

  • Readmissions and mortality rates increase
  • Six-fold probability of discharge to skilled nursing facility
  • Greater risk of long-term cognitive impairment
  • Also applies to patients cognitively intact prior to admission
    • Fold increase in rate of dementia post discharge
  • A single episode of delirium produces permanent structural and functional brain changes in otherwise neurologically healthy patients
  • These brain changes are associated with long term cognitive impairment
  • The greater the duration and/or severity of the delirium episode – the greater the magnitude of these brain changes