Introduction: Delirium in the intensive care unit (ICU) is associated with increased morbidity and mortality. Using an assessment tool has been shown to improve the ability of clinicians in the ICU to detect delirium. The confusion assessment method for the ICU (CAM-ICU) is a validated delirium-screening tool for critically ill intubated patients. The aim of this project was to establish the feasibility of routine delirium screening using the CAM-ICU and to identify the incidence of delirium in a UK critical care unit.
Methods: Routine CAM-ICU monitoring was implemented in a mixed critical care unit in January 2007 following a two-month educational and promotional campaign. Guidelines for the management of delirium were introduced. During a two-month prospective audit in September and October 2007, the daily CAM-ICU was recorded by the bedside nurse for consecutive level 2 and level 3 patients admitted to the mixed medical/surgical critical care ward in a district general hospital. This was repeated in January 2008. Patient outcome was recorded. The records of an additional cohort of ventilated patients were reviewed retrospectively to determine compliance with routine CAM-ICU assessments.
Results: Seventy-one patients were included in the observational cohort, with 60 patients in the retrospective cohort. In the prospective group it was not possible to assess for delirium with the CAM-ICU in nine patients due to persistent coma or inability to understand simple instructions. Excluding elective post-operative patients, the incidence of delirium was 45% in patients who could be assessed; in the 27 ventilated patients who could be assessed it was 63%. From the retrospective data compliance with the CAM-ICU assessment was 92%. The incidence of delirium in this retrospective group of ventilated patients who could be assessed was 65%.
Conclusions: We have demonstrated that delirium screening is feasible in a UK ICU population. The high incidence of delirium and the impact on outcomes in this UK cohort of patients is in line with previous reports.