see also:

• psychiatry and mental health
• Mental state - delirium vs dementia vs psychosis
• the acutely confused patient
• toxicology
• ethanol intoxication/poisoning
• neurology

• the ED has an important role in ensuring patients are appropriately and safely admitted into mental health units.
• routine diagnostic screening and application of medical technology for the mental health patient in ED who meets the low medical risk criteria is of very low yield and therefore not recommended.¹⁾
• it is a waste of resources and illogical to routinely investigate potential admissions for the multitude of causes of delirium if indeed the patient does not clinically have a delirium.
• patients being considered for admission to a mental health facility from the ED generally need “medical clearance” with regard to:
  • have any injuries been definitively managed?
  • have any drug overdoses been assessed and deemed safe for ongoing care in an essentially non-clinical environment?
  • is the cognitive disorder an acute confusional state (delirium) rather than a psychiatric state in which case admission to a medical ward would be more appropriate?
    • it is important to distinguish between an organic medical condition which is best managed in a medical ward (perhaps with a psych special) from a functional psychiatric condition which can be managed in a mental health facility with limited medical supervision.
    • the cardinal feature of delirium is an acute onset with fluctuating course characterised by inattention and this can be tested by asking the patient to name months of year in reverse order or serial subtraction tasks. See also CAM confusion assessment test for diagnosis of delirium.
    • if the confusional state is clearly drug related, the ED staff may still feel this can be safely managed in a mental health facility assuming that there is a psychiatric condition that makes this appropriate.
    • elderly patients with delirium are usually admitted to an aged care unit for a delirium workup which usually includes:
      • CT brain
      • FBE, U&E, glucose, Ca, P, TSH
      • septic workup even if not febrile - urinalysis, CXR
  • is the patient pregnant?
  • has the patient's medical conditions and medications been documented and adequately managed?

• the patient may not clearly have a delirium nor a pyschosis but is acutely disturbed
  • the thought disorganisation and agitation of some patients with acute psychosis can make it hard to distinguish from a delirium
  • delirium patients may have auditory hallucinations instead of the more common visual hallucinations
  • psychosis patients may have visual hallucinations instead of the more common auditory hallucinations
  • up to 40% of patients with dementia have psychotic symptoms (delusions and hallucinations)
  • most of the causes of delirium can also cause an acute “toxic” psychosis
• delirium is commonly caused by anti-psychotic medications or drug overdoses
• patients are often uncooperative if not plain violent and aggressive compromising history-taking and careful examination
• many patients with mental health issues also abuse substances which add to the complexity of the assessment
• a history of a drug overdose may not be forthcoming
  • have they been taking too much lithium and developed acute on chronic lithium toxicity?
  • have they taken a potentially lethal paracetamol overdose and not disclosed it?

• documentation and definitive management of any injuries
• documentation to exclude acute medical illnesses and delirium:
  • vital signs, glucose and pregnancy status if appropriate
  • cognition assessment
  • targeted neurologic assessment - headache, photophobia, neck stiffness, seizures, focal neurology, nystagmus, cerebellar signs
  • drug history - could an overdose have been taken and if so has there been an adequate period of observation and Ix?
  • alcohol history - if alcohol dependent, could this be an alcohol-related event such as subdural, sepsis, intoxication, withdrawal or Wernicke's encephalopathy?
  • important past medical history
• clearance should indicate within reasonable medical certainty that:
  • there is no known contributory medical cause for the patient's presenting psychiatric complaints that requires acute intervention in a medical setting
  • there is no medical emergency
  • the patient is medically stable enough for the transfer to the intended dispositional setting (e.g. a general hospital, a psychiatric hospital, an out patient treatment setting or no follow-up treatment).
• Medical clearance does not indicate the absence of ongoing medical issues. Neither does it guarantee that there are no as yet undiagnosed medical conditions.

• all of the following must be present to be regarded low risk:
  • age > 15 and < 55 years
  • alert, orientated, clinically well
  • normal vital signs
  • normal gait
  • fluent speech (although cognition may be disorganised, delusional or displaying flight of ideas)
  • no history of significant injury or overdose
  • no acute medical illness
• this may include those with acute functional psychoses if known past psychotic illness.

• first presentation of a psychiatric illness
• those with suspicion for an acute medical illness:
  • abnormal vital signs
  • history of febrile illness
  • new onset headaches
  • meningism
  • focal neurology
  • evidence of head injury
  • exacerbation of a chronic medical illness (eg. unstable diabetes)
• those whose mental disturbance is possibly organic acute confusional state rather than a functional psychosis:
  • disorientation
  • decreased attention
  • impaired cognition rather than systematic delusional state
  • visual or tactile hallucinations
• drug and alcohol affected

• this is generally guided by the above indications
• first presentation of an acute psychiatric illness usually warrants:
  • FBE, U&E, glucose, Ca, P, TSH, HCG if appropriate
  • +/- CT brain
    • psychosis secondary to a brain tumour is rare but becomes more common in the elderly²⁾
• the patient with risk of having drug abuse or overdose may be considered for:
  • FBE, U&E, glucose, ethanol level, LFTs, se paracetamol, se lithium (if on lithium Rx)
• those with neurologic findings or possible head injury should be considered for a CT brain
• those with possible febrile illness without clear cause should be considered for a septic workup such as:
  • FBE, U&E, glucose, urinalysis, CXR +/- Ct brain and LP if suspicion of meningitis