ICU Delirium

Introduction As the survival of critically ill patients improves, the development of delirium in the ICU has become a growing public health issue. Delirium is defined as a rapid change in consciousness (hours to days) characterized by reduced environmental awareness, decreased attention and altered cognition. These clinical features can manifest themselves as memory deficits, disorientation, hallucinations, fluctuating levels of alertness and motor abnormalities.

According to Ely et al [APA], as much as 83% of ICU patients on mechanical ventilation develop delirium. This figure is significant as ICU delirium is associated with negative patient and healthcare outcomes. These outcomes include increased time on mechanical ventilation [systematic review], longer ICU and hospital length of stay [Ely 2001, Thomason 2005], higher health care costs [mildbrant 2004], increased cognitive dysfunction [systematic review] and increased risk of death [Ely JAMA 2004].