​Delirium ​ 



A neuropsychiatric syndrome also called acute confusional state or acute brain failure


It is common among the medically ill and often is misdiagnosed as a psychiatric illness which can result in delay of appropriate medical intervention.


There is significantly mortality associated

with delirium so identifying it is crucial.


The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)
1. Disturbed Attention and awareness

Disturbance in attention (ie, reduced ability to direct, focus, sustain, and shift attention) and awareness
2. Change in cognition

eg, memory deficit, disorientation, language disturbance, perceptual disturbance, that is not better accounted for by a preexisting, established, or evolving dementia
3. Develops Acutely

The disturbance develops over a short period (usually hours to days) and tends to fluctuate during the course of the day.
4. Physiological consequence of medical condition

There is evidence from the history, physical examination, or laboratory findings that the disturbance is caused by a direct physiologic consequence of a general medical condition, an intoxicating substance, medication use, or more than one cause.
Clinical Presentation
1. Develops acutely (hours to days)

2. Characterized by fluctuating level of consciousness

3. Reduced ability to maintain attention

4. Agitation or hypersomnolence (sleepiness)

5. Extreme emotional lability

6. Cognitive deficits can occur…


Cognitive Defects

• Language difficulties: word finding difficulties, dysgraphia

• Speech disturbances: slurred, mumbling, incoherent or disorganized

• Memory dysfunction: marked short-term memory impairment, disorientation to person, place, time.

• Perceptions: misinterpretations, illusions, delusions and/or visual (more common) or auditory hallucinations

• Constructional ability: can’t copy a pentagon

Types of delirium


Hyperactive (50%)

• the patient is hyperactive, combative and uncooperative.

• May appear to be responding to internal stimuli

• Frequently these patients come to our attention because they are difficult to care for.


Mixed (25%)

• A combination of the two





Hypo active of hypoalert (25%)

• Patient appears to be napping on and off throughout the day

• Unable to sustain attention when awakened, quickly falling back asleep

• Misses meals, medications, appointments

• Does not ask for care or attention

• This type is easy to miss because caring for these patients is not problematic to staff



Etiology – usually multifactorial




Anticholinergics (furosemide, digoxin, theophylline, cimetidine, prednisolone, TCA’s, captopril)

Analgesics (morphine, codeine..)


Antiparkinson (anticholinergic and dopaminergic)

Sedatives (benzodiazepines, barbiturates)



Antiarrhythmics (digitalis)



Antimicrobials (penicillin, cephalosporins, quinolones)







Systemic illness;


Electrolyte abnormalities

Endocrine dysfunctions (hypo or hyper)

Liver failure- hepatic encephalopathy

Renal failure- uremic encephalopathy

Pulmonary disease with hypoxemia

Cardiovascular disease/events: CHF, arrhythmias, MI

CNS pathology: tumors, strokes, seizures

Deficiency states: Thiamine, nicotinic or folic acid, B12

Risk Factors




• >60 years of age

• Male

• Visual impairment

• Underlying brain pathology such as stroke, tumor, vasculitis, trauma, dementia

• Major medical illness

• Recent major surgery

• Depression

• Functional dependence

• Dehydration

• Substance abuse/dependence

• NOF#

• Metabolic abnormalities

• Polypharmacy

• Medications (above)

• Severe acute illness


• Hyponatremia

• Hypoxemia

• Shock

• Anemia

• Pain

• Orthopedic surgery

• Cardiac surgery

• ICU admission

• High number of hospital procedures




Approach to Assessment



Must Rule Out:

• Wernicke’s

• Hypoxia

• Hypoglycemia

• Hypertensive encephalopathy

• Meningitis/encephalitis

• Poisoning

• Anticholinergic psychosis

• Subdural hematoma

• Septicemia

• Subacute bacterial endocarditis

• Hepatic or renal failure

• Thyrotoxicosis/myx-edema

• Delirium tremens

• Complex partial seizures





Pointers for differentiating between a true psychiatric disorder and delirium

In delirium: 

• There is clouded consciousness or decreased level of alertness

• Disorientation

• Acuity of onset and course- serial mental status exams can help demonstrate an acute onset and fluctuating symptomatology

• Age >40 without prior psychiatric history

• Presence of risk factors for delirium (see above), recent medical illness or treatment



Dementia vs Delirium

• Dementia has insidious onset, chronic memory/cognitive disturbance not usually fluctuating. In delirium it’s acute and tends to fluctuate

• Alertness and attention initially intact in dementia with impoverished speech/thinking. In delirium speech can be confused/disorientated and alertness fluctuates.


Schizophrenia vs Delirium

• Onset of schizophrenia is rarely after 50.

• In schizophrenia, auditory hallucinations are more common than visual hallucinations

• Memory is grossly intact and disorientation is rare

• Speech is not dysarthric

• No wide fluctuations over the course of a day



Mood disorder vs Delirium

• Mood disorders manifest persistent rather than labile mood with more gradual onset

• In mania, patient can be very agitated but cognitive performance is not usually as impaired

• Flight of ideas usually have some thread of coherence unlike simple distractibility

• Disorientation is unusual in mania





• From the notes: Whats the level of consciousness/behavior/cooperativeness?

• What’s the time course?

• Could drugs be cause? What’s new / discontinued / polypharmacy

• Evaluate for recent medical illness and interventions

• Any history of substance dependence could they be withdrawing?

• Review recent bloods, imaging, vital signs







• Interview the patient paying close attention to concentration, level of somnolence, mood lability, cognitive function, short term memory deficits, kinetics. Use AMTS.

• Gather collateral information from family/friends regarding baseline function, personality, psych history





• Treat the underlying cause

• Environmental interventions: cues for orientation

• calendar, clock, family pictures, windows,

• frequently reorient the patient,

• have family or friends visit frequently making sure they introduce themselves,

• minimize staff switching.

• Minimize psychoactive medications


Medications if necessary

• Antipsychotics decrease psychotic symptoms, confusion, agitation

• Antipsychotics- IV Haldol is first line because of significantly reduced risk of Extrapyramidal side effects. Onset of action within 5-20 minutes. After IV dose established transition to BD or qds oral dose and taper.

• Some data now supports use of atypical antipsychotics: Risperdal 0.5-2mg, Quetiapine 12.5-50mg, Olanzapine 2.5-10mg.



• Let the family know what is going on including that delirium waxes and wanes and can last for several weeks

• Once the patient starts to improve explain to them what delirium is, how common it is and the usual course. It is very frightening for them and may fear they have a psychiatric illness.



• Prodromal symptoms may occur a few days prior to full development of symptoms

• The symptoms will continue to progress/fluctuate until underlying cause treated

• Most of the symptoms of delirium will resolve within a week of correction/improvement of the underlying etiology however, the symptoms may wax and wane. In some patients it can take weeks for the symptoms to resolve.

• Some patients, particularly older patients, may never return to baseline