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Mental Health Nursing · Chapter 4

The Mimic Desk

The most consequential error in psychiatric assessment is calling a medical presentation a mental illness. Seven people have arrived on the unit. For each, run the bedside checks you would actually run, watch the results come back, then commit a verdict — and see which single clue was the one that cracked it. One of the seven is genuinely psychiatric; a normal workup is a finding you document, not an assumption you make.

The presentation

Case 1

Bedside checksEach one returns a real result. You do not have to run them all — but you do have to run the right one.

Commit a verdict

Results, as they come back

Nothing run yetVital signs and a capillary glucose come first in almost every acute behavioural presentation. Agitation is a symptom of hypoglycaemia and hypoxia long before it is a symptom of anything psychiatric.

Verdict and discriminator

Run some checks, then commitYou will be scored on the verdict, on whether you found the clue that cracks the case, and on whether you reached for glucose and vital signs before you reached for a psychiatric explanation.
0 of 7 cases decided

The delirium screen you carry in your head

The Confusion Assessment Method (CAM) is positive when both of the first two are present, plus either of the last two:
  1. Acute onset or fluctuating course — required
  2. Inattention — required
  3. Disorganised thinking
  4. Altered level of consciousness
Delirium arrives over hours to days, fluctuates through the day and hits attention early. Dementia arrives over months to years with attention relatively preserved until late. The quiet, withdrawn, slowed-down hypoactive form of delirium is the one most often missed — and it is most often mislabelled as depression.
Interpret every cognitive screen in context. Put the person’s glasses and hearing aids on first. Note pain, sedation, sleep deprivation, language and education, and the fact that you tested at 4 a.m. And never use a screening score alone to draw a conclusion about capacity — capacity is decision-specific and time-specific, and turns on whether the person can understand, retain, weigh and communicate a choice, not on whether their answer is the one you would have picked.