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

CAM-ICU Negative -- No Delirium Detected 0

CAM-ICU negative -- delirium NOT present at this assessment

→ Continue routine CAM-ICU monitoring every 8-12 hours (or per ICU protocol); implement ABCDEF bundle prevention: A (assess/treat pain), B (breathing trials -- SAT/SBT), C (choice of sedation -- prefer lighter, dexmedetomidine if appropriate), D (delirium monitoring), E (early exercise/mobility), F (family engagement); optimise sleep hygiene (eye masks, ear plugs, cluster care); maintain day/night light cycles; reorientation; avoid deliriogenic medications where possible (benzodiazepines, anticholinergics, steroids); document CAM-ICU result every shift.

CAM-ICU Positive -- DELIRIUM PRESENT 1–4

CAM-ICU positive -- delirium identified; immediate management required

→ NON-PHARMACOLOGICAL FIRST: Reorientation (clock, calendar, familiar voices, family presence if allowed); optimise sleep; reduce unnecessary noise; ensure glasses/hearing aids; early mobilisation; consistent nursing staff; treat underlying cause urgently: (1) Infection -- blood cultures, antibiotics; (2) Metabolic: check Na, K, Mg, Ca, glucose, TSH, B12; (3) Drug-induced: review and stop offending medications (benzodiazepines, opioids, steroids, anticholinergics -- use the STOPP/START tool); (4) Urinary retention, constipation, pain (unrecognised pain is common cause); (5) Sepsis/hypoxia; PHARMACOLOGICAL (only if risk of harm to patient/staff): haloperidol 0.5-1 mg IV/PO BD-TDS (not for alcohol withdrawal or Parkinsonism); quetiapine 12.5-25 mg BD alternative; dexmedetomidine for ICU delirium if ventilated; AVOID benzodiazepines except in alcohol withdrawal delirium (CIWA-Ar protocol); monitor ECG for QTc prolongation; document CAM-ICU positive, cause investigation, and management plan.

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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