Implementing Delirium Screening in the ICU

Secrets to Success

Nathan E. Brummel, MD, MSCI; Eduard E. Vasilevskis, MD, MPH; Jin Ho Han, MD, MSc; Leanne Boehm, MSN, RN, ACNS-BC; Brenda T. Pun, MSN, RN, ACNP; E. Wesley Ely, MD, MPH, FCCM


Crit Care Med. 2013;41(9):2196-2208. 

In This Article


The CAM-ICU is modified from the Confusion Assessment Method (CAM)[2,42,43] and assesses four features: 1) acute change or fluctuation in mental status from baseline, 2) inattention, 3) altered level of consciousness, and 4) disorganized thinking.[1,42] The CAM-ICU is positive, and the patient is considered to have delirium, if features 1 and 2 and either feature 3 or 4 are present. Each feature relies on components considered to be standard neurologic assessments and provides objective evaluation of each. Figure 1 provides an outline of how each feature is assessed. As shown in this figure, the CAM-ICU is logically ordered to allow for early stoppage, therefore increasing its efficiency in the clinical setting. For example, if the patient is at his/her mental status baseline with no fluctuation and attentive (features 1 and 2 negative), then it is not necessary to assess other CAM-ICU features because a patient must be inattentive to meet criteria for delirium. Similarly, evaluation of disorganized thinking (feature 4) is only needed when the patient is positive for features 1 and 2 (i.e., not at mental status baseline or fluctuating and inattentive), but negative for feature 3 (i.e., alert and calm). All other times, feature 4 assessment is not required. Although a more in-depth description of performing the CAM-ICU as well the CAM-ICU training manual is available at, some additional salient tips can be found in Table 1.


Table 1.

Tips for Assessing Inattention (Feature 2) Using the Confusion Assessment Method for the ICU

Figure 1.

The Confusion Assessment Method for the ICU (CAM-ICU). The CAM-ICU assesses the four features of delirium: feature 1 is an acute change in mental status or a fluctuating mental status, feature 2 is inattention, feature 3 is altered level of consciousness, and feature 4 is disorganized thinking. Only patients who are arousable to voice can be assessed for delirium (Richmond Agitation-Sedation Scale [RASS], –3; Riker Sedation-Agitation Scale [SAS], 3 or more alert). A patient screens positive for delirium if features 1 and 2 and either feature 3 or feature 4 are present. See text for additional details of how to perform the CAM-ICU.