Risk factors for the development of early-onset delirium and the subsequent clinical outcome in mechanically ventilated patients

Abstract

Objectives: The aim of the study was to investigate the risk factors of developing early-onset delirium in mechanically ventilated patients and determine the subsequent clinical outcomes.

Methods: Confusion assessment method for the intensive care unit (ICU) was used to assess the enrolled mechanically ventilated patients for delirium. The risk factors of developing delirium and clinical outcomes were determined in these subjects.

Results: Delirium was present in 31 (21.7%) of 143 patients in the first 5 days. In multivariable analysis, hypoalbuminemia (odds ratio, 5.94; 95% confidence interval, 1.23-28.77) and sepsis (odds ratio, 3.65; 95% confidence interval, 1.03-12.9) increased the risk of developing delirium in mechanically ventilated patients. The patients with delirium had a higher in-hospital mortality (67.7% vs 33.9%, respectively; P = .001) and longer duration of mechanical ventilation (19.5 +/- 15.8 vs 9.3 +/- 8.8 days, respectively; P = .003) than patients without delirium. The incidence of nosocomial pneumonia was increased in delirious patients (64.5% vs 38.4%, P = .01) compared with nondelirious patients, whereas the lengths of ICU or hospital stay were similar between both groups.

Conclusions: Mechanically ventilated patients with sepsis or hypoalbuminemia were more vulnerable to develop delirium in their early stay in the ICU. Early-onset delirium is associated with prolonged duration of mechanical ventilation and higher incidence of nosocomial pneumonia, leading to a higher mortality.