Delirium is a syndrome characterised by a rapid onset of altered consciousness and cognition. Delirium is the presenting feature in 52% of postoperative patients, 10-24% of elderly admitted to hospital, and 56% of hospitalised elderly at some stage during their admission.
Features of a delirium:
- typically fluctuates
- can be a frightening or devastating experience for the patient
- is an independent predictor of adverse outcome
- may be more persistent than first thought (e.g. 15% after 4 weeks)
- symptoms of memory impairment together with disorientation are especially prolonged
Assessment of the patient in an acute confusional state:
- acute onset and fluctuation
- has there been an acute change in mental status from baseline?
- do symptoms fluctuate during the day?
- inattention
- easily distracted
- perseverate
- check ability to: phrase repetition, digit spans, count backwards from 20, follow 3-stage command
- disorganised thinking – rambling, unpredictable changes of subject
- altered level of consciousness
- alert
- vigilant (hyperalert)
- lethargic
- stupor
- coma
Predisposing factors:
- dementia
- multiple medications
- visual and hearing impairment
- severe, multiple chronic medical conditions
- dehydration
- chronic renal impairment
- neurological damage
- functional disability
- advanced age
Precipitating factors:
- severe acute illness
- medications
- addition of more than three (> 3) new medications
- infection
- electrolyte or acid-base disturbance
- hypoxia or hypercapnia
- hepatic or renal failure
- hypoglycaemia
- stroke
- restraint use
- immobilisation
- indwelling catheter
- ethanol / benzodiazepine withdrawal
Investigations:
- FBC
- EUC
- Calcium
- LFT
- Urinalysis (MSU)
- CXR
- others
- ECG
- CKs / Troponin
- Blood cultures
- TFTs
- ABGs
- B12 & folate
- Brain CT scan
- ± LP + CSF
- ± EEG
Management:
- consider hospitalisation (admit)
- treat underlying medical condition
- stop medications (as appropriate)
- correct dehydration: 1-3 L/day sci fluids
- correct sensory deficits: glasses, hearing aids
- good quality communications using simple instructions: avoid use of jargon
- orientation – calendar, clocks, schedules
- quiet environment, low level light (to reduce misperceptions and avoid sensory overload)
- decrease number of room and staff changes
- decrease noise (especially at night)
- adjust medication to avoid sleep disruption
- minimise immobilising devices, e.g. catheters, drips
- encourage mobility and self-care
- avoid restraints and bed rails – use companions
- involve family where possible to help reorient and reassure
- avoid grouping delirious patients together
Acute Pharmacological management:
Mild-moderate delirium
- haloperidol 0.5 mg bd: can double dose daily until maximum of 10 mg / day, or, if prolonged treatment necessary:
- risperidone 0.5 mg bd: can double dose daily until maximum 4 mg / day, or
- olanzapine 2.5 mg nocte: can double dose daily until maximum of 10 mg per day
Moderate delirium
- haloperidol 0.25 mg IMI q4h until response, or
- risperidone 1 mg bd, can double dose daily until maximum 4 mg / day, or
- olanzapine 5 mg nocte: can double dose daily until maximum of 10 mg per day
Severe delirium
- haloperidol 0.25 mg IMI escalating every 30 minutes, 0.5 mg, 1.0 mg, 2.5 mg, and 5.0 mg till maximum 10 mg
and / or
- midazolam 1.25 mg IMI, then 2.5 mg IMI after 30 minutes (avoid prolonged sedation)