Two scales are in common use, the Confusion Assessment Method for the ICU (CAM-ICU) and the Intensive Care Delirium Screening Checklist (ICDSC).
Scoring Systems for the Diagnosis of Delirium in Critically Ill Patients
Confusion Assessment Method for the ICU (CAM-ICU)*
Scoring is positive or negative according to the presence or absence of criteria listed
Patient must be sufficiently awake (RASS score, -3 or more) for assessment according to the following criteria:
An acute change from mental status at baseline or fluctuating mental status during the past 24 hr (must be true to be positive)
More than 2 errors on a 10 point test of attention to voice or pictures (must be true to be positive)
If the RASS is not 0 and the above two criteria are positive, the patient is delirious
If the RASS is 0 and the above two criteria are positive, test for disorganized thinking using 4 yes/no questions and a 2 step command; >1 error means the patient is delirious; </=1 error excludes delirium
Intensive Care Delirium Screening Checklist (ICDSC)
A score of >/=4 is positive for delirium (with scores of 1 to 3 termed “subsyndromal delirium”)
Patient must show at least a response to mild or moderate stimulation. Then score 1 point for each of the following features, as assessed in the manner thought appropriate by the clinician:
- Anything other than “normal wakefulness”
- Inattention
- Disorientation
- Hallucination
- Psychomotor agitation
- Inappropriate speech or mood
- Disturbance in sleep or wake cycle
- Fluctuation in symptoms
* RASS denotes Richmond Agitation–Sedation Scale.
References:
- Reade MC, Finfer S. Sedation and delirium in the intensive care unit. N Engl J Med. 2014 Jan 30;370(5):444-54. [Medline]
- Brummel NE, Girard TD. Preventing delirium in the intensive care unit. Crit Care Clin. 2013 Jan;29(1):51-65. [Medline]
- Bergeron N, Dubois MJ, Dumont M, Dial S, Skrobik Y. Intensive Care Delirium Screening Checklist: evaluation of a new screening tool. Intensive Care Med. 2001 May;27(5):859-64. [Medline]
- Ely EW, Inouye SK, Bernard GR, Gordon S, Francis J, May L, Truman B, Speroff T, Gautam S, Margolin R, Hart RP, Dittus R. Delirium in mechanically ventilated patients: validity and reliability of the confusion assessment method for the intensive care unit (CAM-ICU). JAMA. 2001 Dec 5;286(21):2703-10. [Medline]