Delirium

Delirium

·        Global and transient disturbances of consciousness, attention, perception, thinking, memory, psychomotor behaviour, emotion and sleep-wake cycle

·        = Acute Confusional State

·        Epidemiology:

o   Rare in the community

o   Common in hospital, especially in elderly, 10 – 25% of > 65 years olds admitted to medical wards

o   Significant mortality: approx 25% of elderly patient acquiring delirium in hospital die

·        Will get poor history from the patient.  Need informant

Symptoms

·        Rapid onset (potentially related to new illness/drug).  Rarely lasts more than several weeks

·        Fluctuating consciousness (cf psychiatric illness, which does not present with impaired consciousness)

·        Marked abnormalities of attention and concentration

o   Attention unfocused

o   Thinking: disorganised, delusions, rambling incoherent speech

o   Memory impairment

·        Perception: illusions and hallucinations (especially visual)

·        Psychomotor behaviour: over/under active, purposeless

·        Mood: labile, agitation, fear, anxiety

·        Sleep-wake cycle: disrupted or even reversed

Aetiology

·        Common causes: Often multi-factorial – a little bit of a number of things

o   Infection: UTI, pneumonia

o   Drug reactions

o   Hypoglycaemia 

o   ¯O2 or ­CO2

·        Comprehensive list: 

o   Drugs: antiarrhythmics, antibiotics, anti-virals, anti-fungals, b-blockers, etc. etc

o  Drugs of abuse

o  Withdrawal: alcohol, amphetamines, barbiturates, benzos, cocaine 

o  Neurologic: stroke, epilepsy, Parkinson‟s, Huntington‟s, MS, Tumour, normal pressure hydrocephalus (confusion, incontinence, gait disturbance) 

o  Endocrine: Hyper/hypothyroidism, hyper/hypoPTH, Hyper/hypoadrenocorticolism, diabetes mellitus, phaeochromocytoma, etc 

o  Metabolic: hyponatraemia, hypokalaemia, hyper/hypocalcaemia, acidosis, hypoxia, uraemia, porphyria

o  Vitamin deficiencies: thiamine, folate, B12 

o  Infection: Especially chest and urinary tract, also sepsis, meningitis, encephalitis, AIDS, Hepatitis, etc 

o  Other: lung/pancreatic cancer, paraneoplastic syndromes, SLE, etc

·        Differential of acute confusion:

o  Psych illness: delirium, psychosis, dementia, depression 

o  Drugs, illness, metabolic, trauma, hypoxia, poisoning/overdose, post-ictal, ¯thiamine

Risk factors

·        Multiple, severe or unstable medical problems

·        Dementia or cognitive impairment

·        Polypharmacy

·        Metabolic disturbances

·        Advanced age (especially > 80 years)

·        Infection (especially UTI)

·        Fractures

·        Visual impairment

·        Fever or hypothermia

·        Psychoactive drug use

Treatment

·        First, recognise the delirium (it often isn‟t). Careful and repeated assessment. Watch for confused/disorientated behaviour or inattention, especially at night

·        Examination:

o  Mini-mental

o  Temperature, hydration, ketosis, foetor

o  Signs of injury, including scalp

o  Infection screen

o  Neuro exam

o  Signs of drug abuse

·        Investigations:

o  Bloods: FBC, ESR, U&E, Glucose, Ca, Renal, Liver, Thyroid, Thiamine

o  Urine, ECG, CXR

o  Consider: blood alcohol, cardiac enzymes, blood culture, ABG, B12/folate, CT

·        Treatment of underlying cause: may require history from care giver

·        Management of delirium:

o  Supportive:

§  Reorientation (a smoke and a cup of tea works wonders!)

§  Reassurance

§  Attention to noise and light levels (not too much nor too little)

§  Stimulate during the day: get up and dressed, put on glasses and hearing aid

§  Continuity of staffing

§  Family member (or even an orderly) to sit with patient

§  Familiar objects (eg family photos) in the room

§  Stimulate during the day: get them dressed, false teeth in, glasses on, hearing aid in

o  Attention to nutrition and hydration 

o  Target risk factors of cognitive impairment, sleep deprivation, immobility, visual and hearing impairment

o  Drugs: only in addition to the above, and usually to treat those caring for the patient!

·        Haloperidol 0.5 mg bd (iv if possible): low dose (eg 0.5 – 1.5 mg), especially in elderly, absolute max 2 – 5 mg prn 1 – 2 hourly. Doesn‟t have anticholinergic side effects, but may cause restlessness. Maori and Pacific Islanders may be more sensitive so lower dose initially

·        Lorazepam (short acting benzo) 0.5 – 2 mg q 15 – 20 min iv/im/sublingual/po