neurology anaesthesia-icu

Confusion Assessment Method for the ICU (CAM-ICU)

Validated ICU-specific delirium assessment tool. Based on the DSM criteria for delirium adapted for use in non-verbal, intubated ICU patients. Requires RASS (Richmond Agitation-Sedation Scale) score above -3 for valid assessment. CAM-ICU positive indicates delirium. Validated by Ely et al. 2001 in 96 ICU patients. Sensitivity 95-100%, specificity 89-93%. NICE and SCCM guidelines recommend routine delirium screening in all ICU patients.

Used in: Delirium & Cognitive Impairment

RASS Score (Richmond Agitation-Sedation Scale) at time of assessment*

Feature 1 -- Acute onset of mental status change OR Fluctuating course (based on RASS changes or GCS over past 24 hours)*

Feature 2 -- Inattention: Ask patient to squeeze your hand only when you say the letter A in the sequence S-A-V-E-A-H-A-A-R-T. Errors = squeezing on non-A letters or NOT squeezing on A. 3 or more errors = positive*

Feature 3 -- Altered level of consciousness: any RASS score other than 0 (alert and calm) during this assessment*

Feature 4 -- Disorganised thinking: Ask 4 Yes/No questions (e.g. Does a stone float on water? Do fish live in the sea? Does 1 pound weigh more than 2 pounds? Can you use a hammer to pound a nail?) Plus command (hold up this many fingers, now do the same with the other hand). More than 1 error = positive*

Score interpretation

Unable to Assess (RASS −4 or −5) -1

Too sedated for CAM-ICU — comatose, not assessable.

→ Reassess when RASS is −3 or above.

CAM-ICU Negative — No Delirium 0

Delirium criteria not met.

→ Continue to screen each shift.

CAM-ICU Positive — Delirium Present 1

Features 1 and 2 plus 3 or 4.

→ Look for causes; non-drug measures; review sedation and drugs.

Interpretation bands for the CAM-ICU. Apply clinical judgement and local guidance.

References

Ely EW et al. Evaluation of delirium in critically ill patients: validation of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Crit Care Med. 2001;29(7):1370-1379.
NICE CG103. Delirium: prevention, diagnosis and management in hospital and long-term care. NICE. 2010 (updated 2023).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Pathways

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.

Score interpretation

References

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