Comparison of CAM-ICU and ICDSC for the detection of delirium in critically ill patients focusing on relevant clinical outcomes

Abstract

Purpose: Delirium is a frequent and serious problem in the intensive care unit (ICU) that is associated with increased mortality, prolonged mechanical ventilation, and prolonged hospital length of stay (LOS). The main objective of the present study was to compare and assess the agreement between the diagnosis of delirium obtained by the Confusion Assessment Method for the ICU (CAM-ICU) and Intensive Care Delirium Screening Checklist (ICDSC) in patients admitted to the ICU and their association with outcomes.

Methods: Adult patients admitted to the ICU for more than 24 hours between May and November 2008 were included. Patients with a Richmond Agitation-Sedation Scale score of -4 to -5 for more than 3 days were excluded. Delirium was evaluated twice a day by the ICDSC and CAM-ICU. Patients were followed-up until ICU discharge or for a maximum of 28 days.

Results: During the study period, 383 patients were admitted to the ICU and 162 (42%) were evaluated; delirium was identified in 26.5% of patients by CAM-ICU and in 34.6% by ICDSC. There was agreement in diagnosing delirium diagnosis between the 2 methods in 42 (27.8%) patients and in excluding delirium in 105 (64.8%) patients. The ICDSC was positive in 14 (8.6%) patients in whom CAM-ICU was negative. Delirium, diagnosed either by ICDSC or CAM-ICU assessments, was associated with both significantly increased hospital LOS (14.8 ± 8.3 vs 9.8 ± 6.4, P < .001; 15.3 ± 8.7 vs 10.5 ± 7.1, P < .001, respectively), mortality in the ICU (11.1% vs 5.8%, P < .001; 12.5% vs 2.5%, P = .022), and in the hospital (10.7% vs 5.6%, P < .001; 23.2% vs 10.9%, P = .047). In addition, patients with positive ICDSC presenting with negative CAM-ICU had similar outcomes as compared with those without delirium.

Conclusion: The findings of our study suggest that the CAM-ICU is better predictor of outcome when compared with ICDSC.