Delirium
Definition (DSM V)
A. Disturbance of attention (reduced ability to focus, sustain, or shift attention)
B. Develops over a short time (hours or a few days) – a change from baseline attention and awareness, fluctuates in severity in the course of a day.
C. An additional disturbance in cognition (such as memory deficit, disorientation, language disturbance).
Types of delirium:
1. Hyperactive (hyperaroused, hyperalert, or agitated)
2. Hypoactive (hypoaroused, hypoalert, or lethargic)
3. Mixed (alternating features of hyperactive and hypoactive types)
Risk Factors
Aetiology
I nfectious (encephalitis, meningitis, UTI, pneumonia)
W ithdrawal (alcohol, barbiturates, benzodiazepines)
A cute metabolic disorder (electrolyte imbalance, hepatic or renal failure)
T rauma (head injury, postoperative)
C NS pathology (stroke, hemorrhage, tumour, seizure disorder, Parkinson's)
H ypoxia (anemia, cardiac failure, pulmonary embolus)
D eficiencies (vitamin B12, folic acid, thiamine)
E ndocrinopathies (thyroid, glucose, parathyroid, adrenal)
A cute vascular (shock, vasculitis, hypertensive encephalopathy)
T oxins (drugs)
H eavy metals (arsenic, lead, mercury)
or
W ithdrawal (EtOH/ drugs)
H ypo/hyper (Temp, electrolytes, metabolites, O2)
I nfections
M eningitis/ Encephalitis
P ain/ poisoning
S eizure/ stroke/ systemic (cardioresp, liver, renal, endocrine)
NOTE: Most patients have more than 1 aetiology
Clinical Features
Symptoms
D isordered thinking
E uphoric/ fearful/ angry/ depressed
L anguage impairment
I llusion/ delusion/ hallucinations (tactile, visual usually)
R eversal of sleep-wake cycle
I nattention
U naware/ disoriented to time place person
M emory deficits
Investigations
Management
Intrinsic
Biological
NOTE: Avoid benzos due risk of worsening matters
Prognosis
Source
Toronto Notes 2012
Prof S Pridmore
DETECT manual 2009
A. Disturbance of attention (reduced ability to focus, sustain, or shift attention)
B. Develops over a short time (hours or a few days) – a change from baseline attention and awareness, fluctuates in severity in the course of a day.
C. An additional disturbance in cognition (such as memory deficit, disorientation, language disturbance).
- Generally: Inattention + acute cognitive dysfunction
Types of delirium:
1. Hyperactive (hyperaroused, hyperalert, or agitated)
2. Hypoactive (hypoaroused, hypoalert, or lethargic)
3. Mixed (alternating features of hyperactive and hypoactive types)
Risk Factors
- Hospitalization (incidence 10-40%)
- Nursing home residents (incidence 60%)
- Childhood (e.g. febrile illness, anticholinergic use)
- Old age (especially males)
- Severe illness (e.g. cancer, AIDS)
- Pre-existing cognitive impairment or brain pathology
- Recent anaesthesia
- Substance abuse
Aetiology
I nfectious (encephalitis, meningitis, UTI, pneumonia)
W ithdrawal (alcohol, barbiturates, benzodiazepines)
A cute metabolic disorder (electrolyte imbalance, hepatic or renal failure)
T rauma (head injury, postoperative)
C NS pathology (stroke, hemorrhage, tumour, seizure disorder, Parkinson's)
H ypoxia (anemia, cardiac failure, pulmonary embolus)
D eficiencies (vitamin B12, folic acid, thiamine)
E ndocrinopathies (thyroid, glucose, parathyroid, adrenal)
A cute vascular (shock, vasculitis, hypertensive encephalopathy)
T oxins (drugs)
H eavy metals (arsenic, lead, mercury)
or
W ithdrawal (EtOH/ drugs)
H ypo/hyper (Temp, electrolytes, metabolites, O2)
I nfections
M eningitis/ Encephalitis
P ain/ poisoning
S eizure/ stroke/ systemic (cardioresp, liver, renal, endocrine)
NOTE: Most patients have more than 1 aetiology
Clinical Features
Symptoms
D isordered thinking
E uphoric/ fearful/ angry/ depressed
L anguage impairment
I llusion/ delusion/ hallucinations (tactile, visual usually)
R eversal of sleep-wake cycle
I nattention
U naware/ disoriented to time place person
M emory deficits
Investigations
- Confusion Assessment Method (CAM)
- Standard: FBC, UEC, CMP, glucose, ESR, LFTs, TFT, vitamin B12, folate, urine C&S
- As indicated: ECG, CXR, CT head, toxicology/heavy metal screen, HIV, LP, EEG (typically abnormal: generalized slowing or fast activity), blood cultures
- Indications for CT head: focal neurological deficit, acute change in status, anticoagulant use, acute incontinence, gait abnormality, history of cancer
Management
Intrinsic
- Identify and treat underlying cause immediately
- Stop all non-essential medications
- Maintain nutrition, hydration, electrolyte balance and monitor vitals
- Environment should be quiet and well lit
- Optimize hearing and vision
- Room near nursing station for closer observation; constant care if patient jumping out of bed, pulling out lines
- Family member present for reassurance and re-orientation
- Calendar, clock for orientation cues
Biological
- Haloperidol or risperidone (low dose)
- Physical restraints if patient becomes violent
NOTE: Avoid benzos due risk of worsening matters
Prognosis
- Up to 50% 1 yr mortality rate after episode of delirium
Source
Toronto Notes 2012
Prof S Pridmore
DETECT manual 2009