Why do geriatric patients have atypical presentations?
- ageing process
- cumulative pathology
- masked and/or late presentation
- multiple medications
- impaired homeostasis
What is delirium?
- acute confusional state w/ impaired consciousness
- not a disease itself but a clinical syndrome
- result from underlying disease or new problem w/ mentation
- presents commonly in elderly who may have chronic problems
- 20% of elderly pts on wards have some form of delirium
- look for organic causes (UTI, pneumonia, MI)
What is the aetiology of delirium?
- Infection - viral, bacterial, chest, urine, cellulitis, endocarditis, biliary, diverticulitis, pancreatitis, abdo perforation
- Withdrawal - from alcohol or drugs
- Acute Metabolic - dehydration, uraemia, hyper/hyponatraemia, hypercalcaemia
- Traumatic injury - head injury, SOL, inc pressure, cerebrovascular disease
- CNS Lesion - epilepsy, TIA
- Deficiency of Vitamins
- Acute Vascular
- Toxins (incl meds) - anticholinergics, anxiolytics, antipsychs, antidepressants, anticonvulsants, antihistamines, opiates
- Heavy metals
These factors may be accentuated on admission to hosp by env disorientation, a lack of info, impersonal setting, poorly understood investigations + tx, being away from a familiar home/carers.
What are the 3 core features of delirium?
- disturbance of consciousness
- change in cognition
- acute onset + fluctuates
What are the 8 features of delirium?
- Disordered thinking - slow, irrational, rambling, incoherent, jumbled
- Emotional disturbances - euphoric, fearful, depressed, angry, scream/moan
- Language impairment - reduced speech, repetitive, disruptive
- Illusions/delusions/hallucinations - persecutory, transient, tactile/visual
- Reversal of sleep-wake cycle - drowsy in day, hypervigilant at night
- Inattention - focusing/sustaining attention poor, no real dialogue
- Unaware/disorientated - time, place or person
- Memory deficits - often marked
Poor insight is also typical + disturbed psychomotor behaviour which may be up (oversensitive to stimuli, restless, wandering, aggressive, psychotic, noisy) or down (quiet, slow, immobile, few psychotic syndromes)
How do you distinguish delirium from psychosis?
- distinguishing feature = fluctuating levels of consciousness w/ decreased attention
- whereas, psychosis presents w/ deficits in reality testing
acute onset of delirium is also a key feature in distinguishing it from primary psychiatric disorders
- presence of visual hallucinations also suggests delirium
auditory hallucinations are more common in psychosis
- finally, in pts w/ delirium, the EEG shows diffuse slowing of background rhythm (not the case with psychosis)
Delirium is a variable syndrome which fluctuates over time and in nature. It manifests distinctly in different patients or in the same patient at diff times.
Diagnosis is difficult - delirium may be diagnosed when it is not present in patients who are deaf, blind or those who are dysphasic.
More commonly, diagnosis it not made when delirium is present. AMTS is an effective screening tool. Usually there is evidence of the medical condition that has lead to delirium.
What are the possible investigations for delirium?
One contributing factor may be obvious (eg UTI) but do not assume that this is the sole, most important factor until the others have been excluded.
- FBC, ESR -> infection, anaemia
- urea, creatinine, electrolytes -> hyper/hyponatraemia, dehydration, renal impairment
- glucose -> hyper/hypoglycaemia (re-check)
- LFTs + amylase
- CRP -> may be normal early in course of infection
- Ca + PO4
- ECG -> silent infarction/ischaemia
- urinanalysis +/- urine MC+S -> asymptomatic bacteriuria common, a positive dipstick may not therefore explain pt's delirium
- blood culture -> always send before starting abx, occult bacteraemia is common
- blood gases -> hypoxaemia or hypercapnia may contribute to delirium
If cause remains unclear, consider less common causes + advanced tests such as CT/MRI brain or CSF examination.
Delirium is a medical emergency so treatment should be initiated early.
Patients with delirium are not usually competent to direct treatment, common law allows assessment + treatment in their best interests, this may include:
- holding within a ward or hospital if pt attempts to leave
- temp physical restraint (eg. whilst drugs are administered)
- covert administration of essential drugs
What is the non-pharmacological treatment of delirium?
- provide a quiet environment, free from worrying sounds, appropriate clothes, quality lighting appropriate for time of day, a clock or view outside to aid with orientation
reassure pt repeatedly + calmly
- optimise visual + auditory acuity w/ appropriate specs + aids
expl who you are + what you wish to do
- use non-verbal comms, sit down, smile, appear friendly
- don't argue or correct delusions + avoid aggrevation
visitors w/ heightened emotions should leave
- use minimal physical force when restraining
- enlist help of relatives in supervising, feeding + bringing in items familiar to pt
When should pharmacological therapy be used for delirium?
Drugs should complement, not replace non-pharm approaches.
Drugs are needed only when the agitation accompanying delirium is:
- causing pt distress
- threatening pts safety or that of others
- interfering w/ medical treatment (eg. pulling out IV, aggression preventing examination)
What is the pharmacological treatment of delirium?
- antipsychotics (haloperidol)
- short acting benzo (lorazepam)
- long acting benzo (chlordiazepoxide)
- atypical antispychotics (risperidone, olanzapine)
- combo treatment - benzos + antipsychotics
Once behaviour has improved, consider step-wise dose reduction aiming to stop the drug ASAP without prompting relapse
Also remember the correct dose is the minimum effective dose - response and prescription must be reviewed regularly
What is hypoactive delirium?
Patients with hyperactive delirium demonstrate features of restlessness, agitation and hyper vigilance and often experience hallucinations and delusions.
By contrast, patients with hypoactive delirium present with lethargy and sedation, respond slowly to questioning, and show little spontaneous movement.
4AT is a test used to detect delirium. What does the 4AT involve?