Delirium in the cardiovascular ICU: exploring modifiable risk factors.

OBJECTIVE: Delirium, an acute organ dysfunction, is common among critically ill patients leading to significant morbidity and mortality; its epidemiology in a mixed cardiology and cardiac surgery ICU is not well established. We sought to determine the prevalence and risk factors for delirium among cardiac surgery ICU patients. DESIGN: Prospective observational study. SETTING: Twenty-seven-bed medical-surgical cardiac surgery ICU. PATIENTS: Two hundred consecutive patients with an expected cardiac surgery ICU length of stay >24 hrs. INTERVENTIONS: None. MEASUREMENTS: Baseline demographic data and daily assessments for delirium using the validated and reliable Confusion Assessment Method for the ICU were recorded, and quantitative tracking of delirium risk factors were conducted. Separate analyses studied the role of admission risk factors for occurrence of delirium during the cardiac surgery ICU stay and identified daily occurring risk factors for the development of delirium on a subsequent cardiac surgery ICU day. MAIN RESULTS: Prevalence of delirium was 26%, similar among cardiology and cardiac surgical patients. Nearly all (92%) exhibited the hypoactive subtype of delirium. Benzodiazepine use at admission was independently predictive of a three-fold increased risk of delirium (odds ratio 3.1 [1, 9.4], p = 0.04) during the cardiac surgery ICU stay. Of the daily occurring risk factors, patients who received benzodiazepines (2.6 [1.2, 5.7], p = 0.02) or had restraints or devices that precluded mobilization (2.9 [1.3, 6.5], p < 0.01) were more likely to have delirium the following day. Hemodynamic status was not associated with delirium. CONCLUSIONS: Delirium occurred in one in four patients in the cardiac surgery ICU and was predominately hypoactive in subtype. Chemical restraints via use of benzodiazepines or the use of physical restraints/restraining devices predisposed patients to a greater risk of delirium, pointing to areas of quality improvement that would be new to the vast majority of cardiac surgery ICUs.

Implementation, reliability testing, and compliance monitoring of the Confusion Assessment Method for the Intensive Care Unit in trauma patients.

OBJECTIVE: To implement delirium monitoring, test reliability, and monitor compliance of performing the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) in trauma patients. DESIGN AND SETTING: Prospective, observational study in a level 1 trauma unit of a tertiary care, university-based medical center. PATIENTS: Acutely injured patients admitted to the trauma unit between 1 February 2006 and 16 April 2006. MEASUREMENTS AND RESULTS: Following web-based teaching modules and group in-services, bedside nurses evaluated patients daily for depth of sedation with the Richmond Agitation-Sedation Scale (RASS) and for the presence of delirium with the CAM-ICU. On randomly assigned days over a 10-week period, evaluations by nursing staff were followed by evaluations by an expert evaluator of the RASS and the CAM-ICU to assess compliance and reliability of the CAM-ICU in trauma patients. Following the audit period the nurses completed a postimplementation survey. The expert evaluator performed 1,011 random CAM-ICU assessments within 1h of the bedside nurse's assessments. Nurses completed the CAM-ICU assessments in 84% of evaluations. Overall agreement (kappa) between nurses and expert evaluator was 0.77 (0.721-0.822; p < 0.0001), in TBI patients 0.75 (0.667-0.829; p < 0.0001) and in mechanically ventilated patients 0.62 (0.534-0.704; p < 0.0001). The survey revealed that nurses were confident in performing the CAM-ICU, realized the importance of delirium, and were satisfied with the training that they received. It also acknowledged obstacles to implementation including nursing time and failure of physicians/surgeons to address treatment approaches for delirium. CONCLUSIONS: The CAM-ICU can be successfully implemented in a university-based trauma unit with high compliance and reliability. Quality improvement projects seeking to implement delirium monitoring would be wise to address potential pitfalls including time complaints and the negative impact of physician indifference regarding this form of organ dysfunction.