Multicentre study of delirium in ICU patients using a simple screening tool

A total of 185 patients in six ICUs in Australia and New Zealand were screened for delirium using the ICDSC over two 12-hour periods per day for the duration of their ICU admission. Some 84 patients (45%) developed delirium. Development of delirium was associated with increased severity of illness (acute physiology and chronic health evaluation - APACHE II - and sequential organ failure assessment - SOFA), ICU length of stay (LOS), and use of psycho-active drugs. Delirious patients showed no statistically significant difference in ICU and hospital mortality rates, nor prolonged hospital LOS. The ICDSC was found to be user-friendly. The incidence of delirium, observed characteristics and outcomes for patients admitted to Australian and New Zealand ICUs for >36 hours without any history of altered mental state fell in the mid-range and were generally consistent with previous literature. An ICU-specific delirium assessment, such as the ICDSC, should be included in routine ICU observations to minimise under-diagnosis of this serious phenomenon.