Clinical Calculators

CAM-ICU (Confusion Assessment Method for the ICU)

Delirium assessment in ICU patients (four features)

1 item left

-5 to 4

RASS is a whole number from -5 to +4. 0 is alert and calm. -4 and -5 mean no response to voice, and CAM-ICU is not performed.

Criteria

  • Feature 1 (acute change or fluctuation of mental status) is present
  • Feature 2 (inattention) is present: 3 or more errors on the attention test (more than 2)
  • Feature 3 (altered level of consciousness) is present: the current RASS is anything other than 0
  • Feature 4 (disorganized thinking) is present: 2 or more errors on the questions and command combined (more than 1)

Cautions

  • Assess the current RASS first. If the RASS is -4 or -5 (stupor or coma), CAM-ICU is not performed. RASS -3 looks like a borderline, but most patients at this level respond enough to be assessed. "Unable to assess" is used only for stupor or coma (training manual).
  • Delirium is judged present when both Feature 1 (acute change or fluctuation of mental status) and Feature 2 (inattention) are present, and in addition either Feature 3 (altered level of consciousness: the current RASS is anything other than 0) or Feature 4 (disorganized thinking) is present.
  • If Feature 1 or Feature 2 is absent, Features 3 and 4 need not be assessed. If Features 1 and 2 are present and Feature 3 is also present, Feature 4 need not be assessed (Feature 4 is assessed when Feature 3 is absent).
  • The baseline for Feature 1 is the usual mental status before admission. If the mental status has changed permanently (for example after a stroke), the status after the change is the baseline.
  • Feature 2 is present when there are 3 or more errors on the attention test (more than 2). There is also a method that uses pictures; when both are performed, the result of the pictures is used for Feature 2 (this calculator takes the number of errors of the attention test).
  • For Feature 4, an alternate set of questions may be used (see the training manual). When paralysis or visual impairment prevents the command, count the four questions only (2 or more errors in total means Feature 4 is present).
  • CAM-ICU is an assessment method for adult ICU patients and can also be used in ventilated patients who cannot speak. A separate version (pCAM-ICU) exists for children aged 5 to 17 years (training manual).
  • Copyright notice (requested by Vanderbilt University): Copyright © 2002, E. Wesley Ely, MD, MPH and Vanderbilt University, all rights reserved. The wording on this page is a shortened description based on the Vanderbilt CAM-ICU worksheet and training manual; the test scripts (letter list, questions and command) are not reproduced here. Use the training manual for the exact procedure.

References

  1. Ely EW, Inouye SK, Bernard GR, et al. Delirium in mechanically ventilated patients: validity and reliability of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). JAMA. 2001; 286(21): 2703-2710. (original not seen) PMID: 11730446, DOI: 10.1001/jama.286.21.2703[Original article]
  2. Ely EW, Vanderbilt University (translated by Inoue S, supervised by Tsuruta R). Training manual for the Confusion Assessment Method for the ICU (CAM-ICU), Japanese version, revised March 2014 (in Japanese). (Worksheet (p.10), explanation of Features 1 to 4 (pp.12-22), case studies (pp.32-39)) https://cdn.prod.website-files.com/5b0849daec50243a0a1e5e0c/6644be6fdebf765eec451cc8_CAM_ICU2014-training_Japanese_version.pdf[Guideline]
  3. Ely EW, Vanderbilt University. CAM-ICU Worksheet (English version). Vanderbilt ICU Delirium and Cognitive Impairment Study Group. (Features 1 to 4 and Overall CAM-ICU) https://cdn.prod.website-files.com/5b0849daec50243a0a1e5e0c/5bad3d007cb3f184ca3a6907_CAM-ICU-worksheet.pdf[Guideline]

Checked on: 2026-10-13

Disclaimer

This calculation is intended to support the judgment of healthcare professionals. Results are for reference only; decisions about diagnosis and treatment must be made by the responsible healthcare professional. The values you enter never leave your device.