DELIRIUM

2. Predisposing Factors
Four factors independently predispose to delirium:
• vision impairments (<20/70 binocular),
• severity of illness,
• cognitive impairment, and
• dehydration (high ratio of blood urea to creatinine)
Inouye, 2006

3. Predisposing Factors
• Elderly, especially 80 years or older
• Dementia, cognitive impairment, or other brain disorder
• Fluid and electrolyte disturbances and dehydration
• Other metabolic disturbance, especially elevated BUN level or hepatic
insufficiency
• Number and severity of medical illnesses including cancer

4. Predisposing Factors
• Infections, especially urinary tract, pulmonary, and AIDS
• Malnutrition, low serum albumin level
• Cardiorespiratory failure or hypoxemia
• Prior stroke or other nondementia brain disorder
• Polypharmacy and use of analgesics, psychoactive drugs, or
anticholinergics
• Drug abuse, alcohol or sedative dependency

5. Predisposing Factors
• Sensory impairment, especially visual
• Sensory overstimulation and “ICU psychosis”
• Sensory deprivation
• Sleep disturbance
• Functional impairment
• Fever, hypothermia
• Physical trauma or severe burns
• Fractures
• Male gender

6. Predisposing Factors
• Specific surgeries:
• Cardiac, especially open heart surgery
• Orthopaedic, especially femoral neck and hip fractures, bilateral knee
replacements
• Ophthalmological, especially cataract surgery
• Noncardiac thoracic surgery and aortic aneurysmal repairs
• Transurethral resection of the prostate.

7. Predisposing Factors
• Elderly patients with dementia are five times more likely to develop
delirium.
• Advanced age, especially older than 80 years,
• Neuroimaging: Many of these elderly patients predisposed to
delirium have cerebral atrophy or white matter and basal ganglia
ischemic changes.

8. Predisposing Factors
• The predisposing factors for delirium are ADDITIVE,
• As each new factor increases the risk considerably increases.
• The cause of delirium is multifactorial,
• resulting from the interaction between patient-specific predisposing
factors and multiple precipitating factors.
Inouye et al., 2014; Inouye and Charpentier, 1996; Laurila et al., 2008

9. Five specific factors that can independently precipitate delirium
Use of physical restraints.
malnutrition or weight loss (albumin levels less than 30 g/L)
use of indwelling bladder catheters
adding more than three medications within a 24-hour period
Iatrogenic medical complication
Inouye and Charpentier, 1996

12. Genes and Delirium
Genes associated with possible pathophysiological vulnerabilities for
delirium are
• Apolipoprotein E (APOE),
• Dopamine receptor genes DRD2 and DRD3,
• Dopamine transporter gene, SLC6A3
• APOE ε4 carriers associated with longer duration of delirium.
van Munster et al., 2009, 2010

13. Diagnostic Scales and Criteria
• Diagnosis: (DSM-V; APA, 2013), criteria for delirium.
• The confusion assessment method (CAM): Screening and diagnosing
delirium.
• The Delirium Rating Scale-Revised-98 (DRS-R-98): Distinguish
delirium from dementia, depression, and schizophrenia.
• Both the CAM and the DRS-R-98 are best used in combination with a
cognitive test.

14. DSM-V; APA, 2013
DSM-5 = Diagnostic and Statistical Manual of Mental Disorders, 5th ed,2013.
APA - American Psychiatric Association.
The presence of delirium requires all the criteria to be met:
Disturbance in attention and awareness
Disturbance develops acutely and tends to fluctuate in severity
At least one additional disturbance in cognition
Disturbances are not better explained by a preexisting dementia
Disturbances do not occur in the context of a severely reduced level of
arousal or coma
Evidence of an underlying organic cause or causes

15. Confusion Assessment Method (CAM)
The criteria are adapted from Inouye et al.
The presence of delirium requires features 1 and 2 and either 3 or
4:
 Acute change in mental status with a fluctuating course (feature 1)
 Inattention (feature 2)
 Disorganized thinking (feature 3)
 Altered level of consciousness (feature 4)

16. 3-Minute Diagnostic Interview for Delirium Using the
Confusion Assessment Method (3D-CAM).

17. Feature 1: Acute Change in Mental
Status with a Fluctuating Course†
Type of Assessment
Patient responses: any
positive symptom report,
incorrect response, lack
of response, or nonsense
response indicates that
the feature is present.
Interviewer
observations: any “yes”
indicates that the feature
is present
Ask whether patient has experienced the
following in the past day:
Being confused
Thinking that he or she is not in the hospital
Seeing things that are not really there
Were there fluctuations in the level of
consciousness?
Fluctuations in attention?
Fluctuations in speech or thinking?
Feature 2: Inattention
Ask patient to do the following:
Digit span (3 digits) backward
Digit span (4 digits) backward
Days of the week backward
Months of the year backward
Did the patient have trouble keeping
track of the interview?
Was the patient easily distractible?
Feature 3: Disorganized Thinking
Ask patient to state the following:
The current year
The day of the week
The type of place (hospital)
Was the patient’s flow of ideas unclear
or illogical?
Conversation rambling or tangential?
Speech unusually limited or sparse?
Feature 4: Altered Level of
Consciousness
None
Was the patient sleepy?
Stuporous or comatose?
Hypervigilant?
The CAM algorithm requires the presence of
features 1 and 2 and either 3 or 4 to
diagnose delirium.

19. Confusion assessment method (CAM) for the diagnosis of delirium
The diagnosis
of delirium
requires the
presence of
features 1
AND 2 plus
either 3 OR 4.

20. • The Memorial Delirium Assessment Scale (MDAS): Quantify the
severity of delirium in medically ill patients.
• It may also be useful as a diagnostic tool, generally used after the
initial delirium diagnosis is made.
• The Neelon and Champagne (NEECHAM) Confusion Scale: used in
the nursing community
• It combines behavioral and physiological signs of delirium
• NEECHAM measures acute confusion rather than delirium.

21. • Critical care assessment tools:
• The confusion assessment method for ICU (CAM-ICU)
• Intensive care delirium screening checklist (ICDSC)
• Quick screening for delirium in the ICU.

22. Thank You