Definition
A.Delirium includes five key characteristics as described in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Publishing; needed for diagnosis).
1.Lack of attention and awareness.
2.Developed over hours to days with a change in baseline functioning. May fluctuate with the time of day.
3.Changes in cognition.
4.Not influenced by an existing neurocognitive disorder or state of arousal (e.g., coma).
5.Reasonable suspicion the change is caused by a medical condition, substance addiction or withdrawal, or medication side effect.
B.Additional features.
1.Hyper- or hypoactivity with alterations in sleep.
2.Emotional disturbance, some seeming psychotic, such as fear, euphoria, confusion, or depression.
3.Extremes of mood including agitation.
4.Sensory disturbances such as hallucinations.
5.Motor alterations including tremors.
C.The terms acute confusional state, delirium, and encephalopathy are often used interchangeably.
Incidence
A.Age: More common in the aged, but can occur with any illness.
B.Incidence.
1.Up to 50% of older surgical patients can experience delirium.
2.Highest rates found among ICU patients, followed by ED and hospice.
C.Frequency: While once considered only a temporary condition common in ill patients, delirium is now associated with increased length of stay, rate of complications, and cost of hospitalization and, more importantly, in hospital mortality rates.
Pathogenesis
A.Multifactorial.
1.Difficult to study in already ill patients.
2.Affects arousal and attention.
a.Arousal and attention are affected by the reticular activation system (RAS).
b.The nondominant parietal and frontal lobes govern attention.
c.Cortical functions are needed for insight and judgment.
3.May be related to drug toxicity, inflammation from trauma, sepsis, surgery, neuronal injury, and environmental factors.
Predisposing Factors
A.Increase baseline vulnerability.
1.Underlying brain disease.
2.Advanced age.
3.Sensory impairment.
4.Use of restraints.
B.Precipitate the disturbance.
1.Polypharmacy.
2.Infection.
3.Dehydration.
4.Immobility.
5.Malnutrition.
6.Bladder catheters.
Subjective Data
A.Common complaints/symptoms.
1.Feeling confused.
2.Hallucinations.
3.Difficulty maintaining attention.
B.Common/typical scenario.
1.Patient with delirium is not able to give information or accurate details.
2.Family or caregivers will often seek medical attention for the patient or the patient is brought in through emergency services.
C.Family and social history.
1.Inquire if the patient uses drugs or drinks alcohol.
2.Inquire about medications and recent travel.
D.Review of systems.
1.Inquire about disturbances of consciousness.
a.Change in level of awareness.
b.Inability to focus.
c.Loss of mental clarity.
d.Family member may report not acting like herself
or not acting right.
e.Distractible, usually noted in conversation.
f.May have decreased level of consciousness (typical) or be hypervigilant (some situations like withdrawal).
g.Day/night reversal.
2.Inquire about altered cognition.
a.Memory loss.
b.Disorientation.
c.Difficulty with language and speech.
d.Perceptual disturbances.
i.Delusions.
ii.Hallucinations: Visual, auditory, or somatosensory.
iii.Lack of insight.
3.Medications.
a.Changes in medications, particularly any new medications, dose changes, or brand changes.
4.Changes in health status.
5.Note time of acute onset, fluctuation of symptoms, changes in consciousness, and decline.
6.Identify modifiable risk factors.
a.Sensory impairment.
b.Immobilization.
c.Concurrent disease or illness.
d.Metabolic derangements.
e.Environment.
f.Pain.
g.Sleep deprivation.
7.Identify nonmodifiable risk factors.
a.Dementia.
b.Age older than 65.
c.Multiple comorbidities.
d.Renal or hepatic disease.
Physical Examination
A.Sometimes difficult with the delusional patient.
B.Be alert for signs that may point to a cause of the delirium.
1.Diaphoresis may be postfebrile, indicating some type of infection.
2.Jaundice indicating hepatic failure.
3.Stigmata of drug use.
4.Smell of alcohol.
5.Indication of postictal state.
6.Indication of sepsis.
C.Neurological examination is typically very difficult and can be misleading. Should assess:
1.Attention.
2.Arousal.
3.Motor function.
4.Senses.
5.Deep tendon reflexes.
6.Higher cognitive functioning.
7.Thought cohesiveness.
Diagnostic Tests
A.Confusion Assessment Method (CAM; see Exhibit 16.1).
1.Standard screen for delirium.
2.Takes 5 minutes.
3.Has a method especially for ICU patients, including vented patients, called the CAM-ICU.
B.Intensive care delirium screening checklist (ICDSC) is also used in the ICU setting (see Exhibit 16.2).
C.Mini Mental is not useful for this population.
D.Use the history and physical examination to guide additional diagnostic testing.
1.Labs for fluid/electrolyte disturbances, infections, toxicities, metabolic disorders, shock states, and postoperative status.
2.Arterial blood gas (ABGs).
3.Liver function test (LFT), thyroid, and B12 as with dementia.
4.EKG.
E.Medication review is very important as toxicities are culprits in 30% of all cases of delirium.
F.If no cause is found, further diagnostics are necessary.
1.CT/MRI head.
2.EEG.
3.Lumbar puncture.
Differential Diagnosis
A.Medical issues; determine if patient has a masked baseline dementia.
B.Treat sundowning as delirium until all medical issues are ruled out.
C.Wernicke’s aphasia, bitemporal dysfunction, Anton’s syndrome, tumors, or trauma in the frontal region.
D.Subacute brain lesions, stroke, or inflammation. Head injuries.
E.Nonconvulsive status epilepticus.
F.Dementia or primary psychiatric illness.
Evaluation and Management Plan
A.General plan.
1.Treat the underlying cause.
2.Supportive care.
B.Patient/family teaching points.
1.Treat pain issues.
2.Encourage movement.
3.Avoid overstimulation.
4.Manage behaviors.
5.Family might need a sitter to assist with care.
C.Pharmacotherapy.
1.Pharmacological treatment of delirium depends on cause.
a.Removing medications may be the treatment.
b.All medications should be evaluated for polypharmacy interactions.
2.Use BEERS criteria for prescribing medications for the elderly.
a.Behavioral control.
i.Haloperidol.
ii.Risperidol.
iii.Quetiapine.
b.Agitation.
i.Haloperidol (first line).
ii.Olanzapine (oral only).
iii.Risperidone.
c.Anxiolytics-benzodiazepine, such as lorazepam.
d.Cholinesterase inhibitor, such as donepezil.