Over 25 different terms have been used to describe the spectrum of cognitive impairment in the ICU including: ICU psychosis, ICU syndrome, acute confusional state, septic encephalopathy and acute brain failure. The Diagnostic and Statistical Manual of Mental Disorders (DSM IV) officially defines delirium as a disturbance of consciousness with inattention accompanied by a change in cognition or perceptual disturbance that develops over a short period of time (hours to days) and fluctuates over time.

The three motoric subtypes of delirium are hyperactive, hypoactive, and mixed. Medical and nursing literature often refers to patients with hyperactive delirium as having ICU psychosis. The neurology literature generally uses the term “delirium” to refer almost exclusively to hyperactive patients and “acute encephalopathy” as a synonym for hypoactive delirium. We recognize that patients in the ICU develop the spectrum of 3 delirious states (hyper, hypo, and mixed). For general purposes within this web site, we will use the term “delirium” to indicate the spectrum of these states and will make distinctions between these motoric subtypes whenever possible with regard to etiology, clinical outcome, and treatment.

Under development: descriptions of hypoactive, hyperactive, and subsyndromal delirium.

Understanding international differences in terminology for delirium and other types of acute brain dysfunction in critically ill patients

Abstract
Background: Delirium (acute brain dysfunction) is a potentially life threatening disturbance in brain function that frequently occurs in critically ill patients. While this area of brain dysfunction in critical care is rapidly advancing, striking limitations in use of terminology related to delirium internationally are hindering cross-talk and collaborative research. In the English literature, synonyms of delirium such as the Intensive Care Unit syndrome, acute brain dysfunction, acute brain failure, psychosis, confusion, and encephalopathy are widely used. This often leads to scientific ‘‘confusion’’ regarding published data and methodology within studies, which is further exacerbated by organizational, cultural and language barriers.

Objective: We undertook this multinational effort to identify conflicts in terminology and phenomenology of delirium to facilitate communication across medical disciplines and languages.

Methods: The evaluation of the terminology used for acute brain dysfunction was determined conducting communications with 24 authors from academic communities throughout countries/regions that speak the 13 variants of the Romanic languages included into this manuscript.

Results: In the 13 languages utilizing Romanic characters, included in this report, we identified the following terms used to define major types of acute brain dysfunction: coma, delirium, delirio, delirium tremens, délire, confusion mentale, delir, delier, Durchgangs-Syndrom, acute verwardheid, intensivpsykose, IVA-psykos, IVA-syndrom, akutt konfusion/ forvirring. Interestingly two terms are very consistent: 100%of the selected languages use the term coma or koma to describe patients unresponsive to verbal and/or physical stimuli, and 100% use delirium tremens to define delirium due to alcohol withdrawal. Conversely, only 54% use the term delirium to indicate the disorder as defined by the DSM-IV as an acute change in mental status, inattention, disorganized thinking and altered level of consciousness. Conclusions: Attempts towards standardization in terminology, or at least awareness of differences across languages and specialties, will help cross-talk among clinicians and researchers.

Understanding international differences in terminology for delirium and other types of acute brain dysfunction in critically ill patients

Morandi A, et al. Understanding the international differences in terminology for delirium and other types of acute brain dysfunction in critically ill patients. Intensive Care Med 2008; 34: 1907-1915.