Analgesia, sedation and delirium

Delirium: CAM-ICU screening, prevention and management

Reviewed Nov 2026·6 references
New· views rounded down, updated weekly

Screen every shift with CAM-ICU, prevent with the ABCDEF bundle, treat causes, and use antipsychotics only for distressing agitation.

Definition
Delirium: acute fluctuating disturbance of attention and awareness. CAM-ICU positive = feature 1 (acute change or fluctuation) + feature 2 (inattention) + either feature 3 (altered level of consciousness, RASS ≠ 0) or feature 4 (disorganised thinking). Subtypes: hypoactive (commonest, often missed), hyperactive, mixed.

At the bedside

  1. 1

    Screen every shift

    CAM-ICU (or ICDSC) when RASS ≥ -3; document result.

  2. 2

    Look for causes (THINK)

    Toxic (drugs: benzodiazepines, anticholinergics, steroids; withdrawal), Hypoxaemia, Infection/sepsis, Non-pharmacological factors (immobility, sleep deprivation, no glasses/hearing aids), K+/electrolytes/glucose/urea; also urinary retention, constipation, pain, alcohol withdrawal.

  3. 3

    Prevent - ABCDEF bundle

    Minimise benzodiazepines, light sedation, SAT/SBT, early and enhanced mobilisation, sleep hygiene (lights, noise, melatonin), reorientation, family involvement.

  4. 4

    Hyperactive delirium endangering safety

    Ensure analgesia; dexmedetomidine for agitation preventing extubation; short course of haloperidol 2.5-5 mg IV or quetiapine for distressing agitation; avoid physical restraints where possible.

  5. 5

    Do not routinely use antipsychotics

    Neither haloperidol nor ziprasidone shortened delirium (MIND-USA); PADIS 2025 makes no recommendation for routine antipsychotic treatment.

  6. 6

    Follow-up

    Delirium predicts long-term cognitive impairment: inform family, ICU follow-up clinic where available.

Distressing agitation in delirium

Haloperidol

IV
Dose
2.5-5 mg every 6-8 h as needed (max ~20 mg/day)

Check QTc; lower doses in elderly.

Persistent agitated delirium

Quetiapine

Oral/NG
Dose
25-50 mg every 12 h, titrate

Agitated delirium in ventilated patients

Dexmedetomidine

IV
Dose
0.2-1.4 mcg/kg/h

Sleep promotion

Melatonin

Oral/NG
Dose
3-10 mg at night

CAM-ICU

FeatureAssessment
1. Acute change or fluctuating courseDifferent from baseline, or fluctuating RASS/GCS in last 24 h
2. InattentionSqueeze hand on letter 'A' in SAVEAHAART: > 2 errors = positive
3. Altered level of consciousnessCurrent RASS anything other than 0
4. Disorganised thinkingYes/no questions (e.g. 'Will a stone float on water?') + command; > 1 error = positive

Delirium = 1 + 2 + (3 or 4). Not assessable if RASS -4/-5.

Red flag · call your senior now
New delirium may be the first sign of sepsis, hypoxia, hypoglycaemia, stroke or alcohol withdrawal.
Pitfall
Missing hypoactive delirium in a 'quiet, good' patient.
Pitfall
Using benzodiazepines for delirium (except alcohol/benzodiazepine withdrawal).
Pearl
Family presence and familiar voices are among the most effective non-drug measures.

References

  1. 1

    Ely EW, Inouye SK, Bernard GR, et al. Delirium in mechanically ventilated patients: validity and reliability of the Confusion Assessment Method for the ICU (CAM-ICU). JAMA 2001;286:2703-10.

  2. 2

    Devlin JW, Skrobik Y, Gelinas C, et al. Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU (PADIS). Crit Care Med 2018;46:e825-73.

  3. 3

    Lewis K, Balas MC, Stollings JL, et al. A focused update to the clinical practice guidelines for the prevention and management of pain, anxiety, agitation/sedation, delirium, immobility, and sleep disruption in adult patients in the ICU. Crit Care Med 2025;53:e711-27.

  4. 4

    Girard TD, Exline MC, Carson SS, et al. Haloperidol and ziprasidone for treatment of delirium in critical illness (MIND-USA). N Engl J Med 2018;379:2506-16.

  5. 5

    Andersen-Ranberg NC, Poulsen LM, Perner A, et al. Haloperidol for the treatment of delirium in ICU patients (AID-ICU). N Engl J Med 2022;387:2425-35.

  6. 6

    Vincent JL, Shehabi Y, Walsh TS, et al. Comfort and patient-centred care without excessive sedation: the eCASH concept. Intensive Care Med 2016;42:962-71.

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