804

Introduction: Although delirium has been reported to be associated with poor outcome, such as increased mortality and increased ICU and hospital length of stay, no data were available in Japan. Hypothesis: The object was to study the prevalence and effect of delirium on outcomes of mechanically ventilated critically ill patients in Japan. Methods: We conducted a prospective cohort study enrolling 192 consecutive mechanical ventilated patients admitted to medical and surgical ICUs of 24 Japanese medical centers in a 2-month period between June and November 2011. Patients were followed up daily for development of delirium during the ICU stay after enrollments. Coma was defined with Richmond Agitation Sedation Scale (RASS) of -4 or -5. Delirium was diagnosed using the Confusion Assessment Method for the ICU (CAM-ICU). Cox Proportional Hazard regression were used to assess the effects of delirium and coma on 28-day mortality, time to extubation, and time to ICU discharge. Delirium and coma were included in Cox regression as time-varying covariates after controlling for age, Acute Physiology and Chronic Health Evaluation (APACHE) II score, ventilator associated pneumonia, and the reason for intubation with infection. Results: In total, 192 patients were enrolled, of those 12 patients were excluded because of persistent coma. Of those 180 patients, an average age was 70 ± 14 years, and average APACHE II score was 21 ± 9 with major reasons for intubation were major surgery (37%), cardiovascular disease (18%), respiratory disease (18%), infection (8%). One hundred fourteen (63%) of 180 patients developed delirium. Fifteen patients (8%) died in 28 days after ICU admission including, 7 patients (16%) who experienced in coma, 8 (9%) in both coma and delirium. There were no deaths among patients without coma including patients with only delirium, and those patients who presented normal cognition during ICU stay. Delirium was associated with shortening time to extubation [adjusted hazard ratio (HR) 1.5, 95% confidence interval (CI), 1.1–2.1, p = 0.018], while coma was associated with prolonging time to extubation (HR 0.7, 95%CI 0.5-1.0, p = 0.044). Conclusions: Delirium during the ICU stay was not associated with poor outcome.