The impact of delirium on the survival of mechanically ventilated patients

Crit Care Med. 2004 Nov;32(11):2254-9. doi: 10.1097/


Objectives: To revalidate a means of assessing delirium in intensive care unit patients and to investigate the independent effect of delirium on the mortality of mechanically ventilated patients.

Design: A prospective cohort study.

Setting: A 37-bed medical intensive care unit of a tertiary care hospital.

Patients: Subjects were 102 of 131 consecutive mechanically ventilated patients.

Measurements: All the enrolled patients were assessed for delirium using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Mortality rate were compared between patients with or without delirium, and the predictors of death were investigated.

Results: The two CAM-ICU assessors' sensitivities in diagnosing delirium compared with reference standard were 91% and 95%, whereas their specificities were both 98%. They also demonstrated high interrater reliability with kappa statistics of 0.91. Delirium was present in 22 of 102 (22%) patients in the first 5 days. The delirious patients had higher intensive care unit mortality rate than nondelirious patients (63.6% vs. 32.5%, respectively), with a hazard ratio of 2.57 (95% confidence interval, 1.56-8.15). In multivariate analysis, delirium (odds ratio, 13.0; 95% confidence interval, 2.69-62.91), shock (odds ratio, 12.91; 95% confidence interval, 2.93-56.92), and illness severity (odds ratio, 9.61; 95% confidence interval, 2.24-41.18) were independent predictors of mortality.

Conclusions: This study confirms previous work showing that delirium is an independent predictor for increased mortality among mechanically ventilated patients.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Academic Medical Centers
  • Aged
  • Analysis of Variance
  • Case-Control Studies
  • Comorbidity
  • Delirium / complications*
  • Delirium / diagnosis*
  • Delirium / epidemiology
  • Diagnostic and Statistical Manual of Mental Disorders
  • Female
  • Hospital Mortality*
  • Humans
  • Logistic Models
  • Male
  • Observer Variation
  • Predictive Value of Tests
  • Prognosis
  • Proportional Hazards Models
  • Prospective Studies
  • Psychiatric Status Rating Scales / standards*
  • Respiration, Artificial / mortality*
  • Respiratory Insufficiency / complications
  • Respiratory Insufficiency / mortality*
  • Respiratory Insufficiency / therapy
  • Risk Factors
  • Sensitivity and Specificity
  • Survival Analysis
  • Taiwan / epidemiology