The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is a delirium assessment that takes approximately 1 to 2 minutes to perform. If performed algorithmically using the CAM-ICU flowsheet, it can be performed in less than one minute in many patients.
The CAM-ICU uses the CAM algorithm and has four features: (1) altered mental status/fluctuating course, (2) inattention, (3) altered level of consciousness, and (4) disorganized thinking. Like the CAM, a patient must be inattentive (cardinal feature of delirium) in order to be CAM-ICU positive. The CAM-ICU uses objective testing prespecified cutoffs to determine the presence of inattention and disorganized thinking. Inattention is assessed for by asking the patient to squeeze on the letter “A” as the rater recites a series of 10 letters (“S-A-V-E-A-H-A-A-R-T”). Disorganized thinking is tested for by asking four yes/no questions and asking the patient to perform a simple command.
The CAM-ICU was originally developed for intensive care unit patients (ICU) who were both mechanically and non-mechanically ventilated. The sensitivity is 93% to 100% and specificity is 98% to 100% for delirium in ICU patients (Ely et al. JAMA. 2001). In non-critically ill patients, the CAM-ICU’s sensitivity has been reported to be as low as 18% (Neufeld et al. Psychosomatics 2011). In older emergency department patients, however, the CAM-ICU is 68% to 72% sensitive and 99% specific for delirium when used by physicians and non-physicians, respectively (Han et al. Acad Emerg Med. 2014).
Additional information about the CAM-ICU can be found at www.icudelirium.org.