Delirium

Abbas Johar

Definition

• Transient, usually reversible, mental dysfunction and manifests clinically with a wide range of neuropsychiatric abnormalities

Pathophysiology

• Fundamental mechanism(s) remain(s) unclear• The characteristic EEG findings demonstrate

global functional derangements • focal dysfunction localized to nondominant

cortex.• NTs ↓Ach, ↑D, ↑/↓ HT• Inflammation microglial neurotoxicity

Epidemiology• the most common behavioral disorder in a medical-surgical

setting• The prevalence in:• General hospital patients is 10–30%.• 50% of surgical patients in the postoperative period.• in 25–40% of cancer pt. and in up to 85% of with advanced

cancer.• Close to 80% of terminal patients before they die• potentially poor prognosis; hospital mortality rates is 22% to

76%, as high as mortality rates associated MI and sepsis !

Etiology

• Multifactorial• interrelationship between patient vulnerability

(ie, predisposing factors) and the occurrence of noxious insults (ie, precipitating factors).

• Dementia half of delirious pt. have background Hx of dementia + 2-5X risk of developing delirium.

• Nearly any chronic medical condition can predispose to delirium

• Decreased mobility is strongly associated with delirium and concomitant functional decline

Eg. Restraints, indwelling bladder catheter.• Iatrogenic events increase 3-5X in >65 yrs (eg.

Procedures, bleeding, allergic reactions)• Organ dysfunction (Renal/Hepatic).• Occult diseases (Resp. F, CHF, infection).

Presentation

Other features:- disorientation (TP>P), - cognitive impairments - psychomotor agitation or

retardation, - perceptual disturbances- paranoid delusions- emotional lability,- sleep-wake cycle disruption

Cardinal features:- Acute onset (hours, days)Inattention- fluctuating course (lucid intervals).- Poor concentration- Incoherent speech

Classification of Delirium

Hypoactive:- Lethargy- Depressed psychomotor activity- Common in older pt.-Often under-recognized- Poorer prognosis

Hyperactive: 15%Agitationincreased vigilance, concomitant hallucinations

BOTH 50%

Evaluation

• most widely used is the CAM (Confusion assessment method)

• The algorithm has a sensitivity of 94-100%, specificity of 90-95%

3D-CAM Algorithm

DDx (ALTERED MENTAL STATUS)CHARACTERISTIC DELIRIUM DEMENTIA DEPRESSION ACUTE PSYCHOSIS

Onset Acute (hours to days) Progressive, insidious (weeks to months)

Either acute or insidious

Acute

Course over time Waxing and waning Unrelenting Variable EpisodicAttention Impaired, a hallmark

of deliriumUsually intact, until end-stage disease

Decreased concentration and attention to detail

Variable

Level of consciousness

Altered, from lethargic to hyperalert

Normal, until end-stage disease

Normal Normal

Memory Impaired commonly Prominent short- and/or long-term memory impairment

Normal, some short-term forgetfulness

Usually normal

Orientation Disoriented Normal, until end-stage disease

Usually normal Usually normal

Speech Disorganized, incoherent, illogical

Notable for parsimony, aphasia, anomia

Normal, but often slowing of speech (psychomotor retardation)

Variable, often disorganized

Delusions Common Common Uncommon Common, often complex

Hallucinations Usually visual Sometimes Rare Usually auditory and more complex

Organic etiology Yes Yes No No

PreventionRISK FACTOR INTERVENTION PROTOCOL

Cognitive impairment

•Orienting communication, including orientation board•Therapeutic activities program

Immobilization •Early mobilization (eg, ambulation or bedside exercises)•Minimizing immobilizing equipment (eg, restraints, bladder catheters)

Psychoactive medications

•Restricted use of PRN sleep and psychoactive medications (eg, sedative-hypnotics, narcotics, anticholinergic drugs)•Nonpharmacologic protocols for management of sleep and anxiety

Sleep deprivation •Noise-reduction strategies•Scheduling of nighttime medications, procedures, and nursing activities to allow uninterrupted period of sleep

Vision impairment •Provision of vision aids (eg, magnifiers, special lighting)•Provision of adaptive equipment (eg, illuminated phone dials, large-print books)

Hearing impairment •Provision of amplifying devices; repair hearing aids•Instruct staff in communication methods

Dehydration •Early recognition and volume repletion

THANKS

References

• 1- Bradley’s neurology in clinical practice, 5th edition, Delirium, Ch. 4, p. 27-37.

• 2- Hazzard's Geriatric Medicine and Gerontology, 7e, Ch. 47, Delirium

• 3- CAM Form http://www.viha.ca/NR/rdonlyres/6121360B-B90F-4EF3-88F6-D50CC4825EE7/0/camshortform.pdf