Routine use of the confusion assessment method for the intensive care unit: a multicenter study.

RATIONALE: Delirium is often unrecognized in ICU patients and associated with poor outcome. Screening for ICU delirium is recommended by several medical organizations to improve early diagnosis and treatment. The Confusion Assessment Method for the ICU (CAM-ICU) has high sensitivity and specificity for delirium when administered by research nurses. However, test characteristics of the CAM-ICU as performed in routine practice are unclear. OBJECTIVES: To investigate the diagnostic value of the CAM-ICU in daily practice. METHODS: Teams of three delirium experts including psychiatrists, geriatricians, and neurologists visited 10 ICUs twice. Based on cognitive examination, inspection of medical files, and Diagnostic and Statistic Manual of Mental Disorders, 4th edition, Text Revision criteria for delirium, the expert teams classified patients as awake and not delirious, delirious, or comatose. This served as a gold standard to which the CAM-ICU as performed by the bedside ICU-nurses was compared. Assessors were unaware of each other's conclusions. MEASUREMENTS AND MAIN RESULTS: Fifteen delirium experts assessed 282 patients of whom 101 (36%) were comatose and excluded. In the remaining 181 (64%) patients, the CAM-ICU had a sensitivity of 47% (95% confidence interval [CI], 35%-58%); specificity of 98% (95% CI, 93%-100%); positive predictive value of 95% (95% CI, 80%-99%); and negative predictive value of 72% (95% CI, 64%-79%). The positive likelihood ratio was 24.7 (95% CI, 6.1-100) and the negative likelihood ratio was 0.5 (95% CI, 0.4-0.8). CONCLUSIONS: Specificity of the CAM-ICU as performed in routine practice seems to be high but sensitivity is low. This hampers early detection of delirium by the CAM-ICU.

Comparison of delirium assessment tools in a mixed intensive care unit.

OBJECTIVE: Delirium is a frequent problem in the intensive care unit (ICU) associated with poor prognosis. Delirium in the ICU is underdiagnosed by nursing and medical staff. Several detection methods have been developed for use in ICU patients. The aim of this study was to compare the value of three detection methods (the Confusion Assessment Method for the ICU [CAM-ICU], the Intensive Care Delirium Screening Checklist [ICDSC] and the impression of the ICU physician with the diagnosis of a psychiatrist, neurologist, or geriatrician). DESIGN: Prospective study. SETTING AND PATIENTS: During an 8-month period, 126 patients (mean age 62.4 years, sd 15.0; mean Acute Physiology and Chronic Health Evaluation II score 20.9, sd 7.5) admitted to a 32-bed mixed medical and surgical ICU were studied. MEASUREMENTS: The included patients were assessed independently by trained ICU nurses using either the CAM-ICU or the ICDSC. Furthermore, the ICU physician was asked whether a patient was delirious or not. A psychiatrist, geriatrician, or neurologist serving as reference rater diagnosed delirium using established criteria. MAIN RESULTS: The CAM-ICU showed superior sensitivity and negative predictive value (64% and 83%) compared with the ICDSC (43% and 75%). The ICDSC showed higher specificity and positive predictive value (95% and 82% vs. 88% and 72%). The sensitivity of the physicians view was only 29%. CONCLUSIONS: ICU physicians underdiagnose delirium in the ICU, which underlines the necessity of standard evaluation in all critically ill patients. In our mixed ICU population, the CAM-ICU had a higher sensitivity than the ICDSC.