Occurrence of delirium is severely underestimated in the ICU during daily care

OBJECTIVE: Delirium is associated with prolonged intensive care unit (ICU) stay and higher mortality. Therefore, the recognition of delirium is important. We investigated whether intensivists and ICU nurses could clinically identify the presence of delirium in ICU patients during daily care. METHODS: All ICU patients in a 3-month period who stayed for more than 48 h were screened daily for delirium by attending intensivists and ICU nurses. Patients were screened independently for delirium by a trained group of ICU nurses who were not involved in the daily care of the patients under study. The Confusion Assessment Method for the ICU (CAM-ICU) was used as a validated screening instrument for delirium. Values are expressed as median and interquartile range (IQR; P25–P75). RESULTS: During the study period, 46 patients (30 male, 16 female), median age 73 years (IQR = 64–80), with an ICU stay of 6 days (range 4–11) were evaluated. CAM-ICU scores were obtained during 425 patient days. Considering the CAM-ICU as the reference standard, delirium occurred in 50% of the patients with a duration of 3 days (range 1–9). Days with delirium were poorly recognized by doctors (sensitivity 28.0%; specificity 100%) and ICU nurses (sensitivity 34.8%; specificity 98.3%). Recognition did not differ between hypoactive or active status of the patients involved. CONCLUSION: Delirium is severely under recognized in the ICU by intensivists and ICU nurses in daily care. More attention should be paid to the implementation of a validated delirium-screening instrument during daily ICU care. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00134-009-1466-8) contains supplementary material, which is available to authorized users.