CAM
Delirium Diagnosis (Confusion Assessment Method)
(1 AND 2) AND (3 OR 4) → delirium.
For the FNP boards, distinguishing delirium from dementia in a hospitalized or post-op older adult is a recurring vignette and CAM is the bedside tool that does it. The diagnostic algorithm requires (1) acute onset and fluctuating course AND (2) inattention, plus either (3) disorganized thinking OR (4) altered level of consciousness. Both of the first two features are mandatory; one of the last two completes the diagnosis. AANP exam questions hinge on recognizing inattention as the cardinal sign — not memory loss — and on knowing CAM is for diagnosis, not screening severity. Treat the underlying cause; antipsychotics are last-line.
- 1Acute onset AND fluctuating courseREQUIRED. Ask family or nursing: is this a change from baseline? Does it wax and wane through the day?
- 2InattentionREQUIRED. Test: digit span, serial 7s, months of the year backward, or squeeze-my-hand-on-A (letter A test).
- 3Disorganized thinkingRambling, incoherent, illogical conversation, unpredictable switching of subject.
- 4Altered level of consciousnessAnything other than alert — hyperalert, drowsy, lethargic, stuporous, comatose.
Clinical Context
Gold-standard bedside tool for delirium, ~94% sensitive and ~89% specific. Delirium ≠ dementia: delirium is acute, fluctuating, and reversible; dementia is chronic, progressive, and stable day-to-day. They commonly coexist — delirium superimposed on dementia is easy to miss without baseline input from family.
Work up every new delirium: UA/culture (UTI is the classic trigger in elderly), BMP, CBC, medication review (anticholinergics, benzos, opioids), look for hypoxia, constipation/urinary retention, pain, and sleep disruption. Treat the cause — antipsychotics are a last resort for severe agitation and carry mortality risk in dementia.
AANP geriatric stem: 82-year-old "more confused than usual" with acute onset and attention deficit on digit span — that's delirium, not progression of dementia. Work up the cause.
Practice Questions
You are reviewing the chart of an 82-year-old woman discharged from the hospital three days ago after treatment for a urinary tract infection. The home health nurse calls because the patient's daughter reports she has been "in and out of it" since coming home — appearing alert and oriented in the morning but agitated and unable to track conversation by evening. On bedside assessment, the patient cannot recite the months backward and is easily distracted mid-sentence. Her speech wanders off topic. She has no prior diagnosis of cognitive impairment. Applying the Confusion Assessment Method (CAM), what is the most likely diagnosis?
Related Mnemonics
- ABCD² — TIA Stroke Risk (ABCD² Score)
- AEIOU-TIPS — Causes of Altered Mental Status
- BE FAST — Stroke Recognition (Extended)
- FAST — Stroke Recognition
- Mini-Cog — Brief Cognitive Screen (Geriatric)
Sources
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