Sleep disturbances in the critically ill patients: role of delirium and sedative agents

BACKGROUND: Impairment of sleep quality and quantity has been described in critically ill patients. Delirium, an organ dysfunction that affects outcome of the critically ill patients, is characterized by an acute onset of impaired cognitive function, visual hallucinations, delusions, and illusions. These symptoms resemble the hypnagogic hallucinations and wakeful dreams seen in patients with neurological degenerative disorders and suffering of disorders of rapid eye movement (REM) sleep. We assessed the characteristics of sleep disruption in a cohort of surgical critically ill patients examining the hypothesis that severe impairments of rapid eyes movement (REM) sleep are associated to delirium. METHODS: Surgical patients admitted to the intensive care units of the San G. Battista Hospital (University of Turin) were enrolled. Once weaning was initiated, sleep was recorded for one night utilizing standard polysomnography. Clinical status, laboratory data on admission, co-morbidities and duration of mechanical ventilation were recorded. Patients were a priori classified as having a "severe REM reduction" or "REM reduction" if REM was higher or lower than 6% of the total sleep time (TST), respectively. Occurrence of delirium during intensive care unit (ICU) stay was identified by CAM-ICU twice a day. Multivariate forward stepwise logistic regression analysis was performed with sleep ("severe REM reduction" vs. "REM reduction") as the a priori dependent factor. RESULTS: REM sleep amounted to 44 (16-72) minutes [11 (8-55) % of the TST] in 14 patients ("REM reduction") and to 2.5 (0-36) minutes [1 (0-6) % of the TST] in the remaining 15 patients ("severe REM reduction") (P = 0.0004). SAPS II on admission was higher in " severely REM deprived" then in "REM deprived" patients. Delirium was present in 11 patients (73.3%) of the patients with "severe REM reduction" and lasted for a median of 3 (0-11) days before sleep assessment, while only one patient having "REM reduction" developed delirium that lasted for 1 day. The factors independently associated with a higher risk of developing "severe REM reduction" were delirium and daily dosage of lorazepam. CONCLUSION: The present study shows that while all critically ill patients present a profound fragmentation of sleep with a high frequency of arousals and awakenings and a reduction of REM sleep, a percentage of patients present an extremely severe reduction of REM sleep. Delirium and daily dosage of lorazepam are the factors independently associated to extremely severe REM sleep reduction

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

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, d\ue9lire, confusion mentale, delir, delier, Durchgangs-Syndrom, acute verwardheid, intensiv-psykose, 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

Sleep and Circadian Rhythm in Critical Illness

Abstract This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2019. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2019. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901