Bench-to-bedside review: Delirium in ICU patients - importance of sleep deprivation

Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA.
Critical care (London, England) (Impact Factor: 4.48). 12/2009; 13(6):234. DOI: 10.1186/cc8131
Source: PubMed


Delirium occurs frequently in critically ill patients and has been associated with both short-term and long-term consequences. Efforts to decrease delirium prevalence have been directed at identifying and modifying its risk factors. One potentially modifiable risk factor is sleep deprivation. Critically ill patients are known to experience poor sleep quality with severe sleep fragmentation and disruption of sleep architecture. Poor sleep while in the intensive care unit is one of the most common complaints of patients who survive critical illness. The relationship between delirium and sleep deprivation remains controversial. However, studies have demonstrated many similarities between the clinical and physiologic profiles of patients with delirium and sleep deprivation. This article aims to review the literature, the clinical and neurobiologic consequences of sleep deprivation, and the potential relationship between sleep deprivation and delirium in intensive care unit patients. Sleep deprivation may prove to be a modifiable risk factor for the development of delirium with important implications for the acute and long-term outcome of critically ill patients.

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    • "All these functions may be important to the recovery of the patients in an intensive care unit (ICU), who are known to suffer from sleep deprivation (Kamdar et al., 2012a). Lack of sleep is also believed to be a risk factor for delirium during ICU care (Weinhouse et al., 2009). Inability to sleep has been ranked among the two most distressing factors in the ICU by two groups of patients undergoing abdominal surgery (Biancofiore et al., 2005). "
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    ABSTRACT: Background: Inability to sleep is one of the most distressing factors for patients in the intensive care unit (ICU). Sleep is perceived as light and awakenings are numerous. Nurses' documentations of sleep are narrow, mainly concentrating on the quantity and general quality. Nurses should diversely evaluate, document and promote sleep to provide patient centered care. Aim: To investigate the content of nurses' documentation about the sleep of ICU patients, patients' own perceptions of sleep, and the correspondence of the two. Design and methods: Nurses' documentations (n=90) were analysed retrospectively with quantitative content analysis. A cross-sectional survey of patients' (n=114) perspectives was collected with the five-item Richards-Campbell Sleep Questionnaire (RCSQ), on a visual analogue scale from 0 (the poorest quality sleep) to 100 (optimum sleep). The data was analysed statistically. Correspondence was tested with cross-tabulation. Results: Nurses documented sleep quantity for 71% and quality for 27% of patients, along with the needs assessment, used interventions and their effect on sleep. Patients' perspectives varied widely. Sleep depth was rated the lowest and falling asleep highest of the RCSQ sleep domains. Age of the patients correlated positively with general quality of sleep, sleep depth and falling asleep. Nurses' documentations and patients' perceptions correlated in over half of the cases. Conclusions: Nurses' documentation of ICU patients' sleep is not systematic or comprehensive and corresponds only partially with patients' own perception. The sleep of non-intubated patients is light and awakenings are frequent. Documentation of ICU patients' sleep should include the whole nursing process, i.e. needs assessment, interventions used, and evaluation of sleep and the effects of the interventions, along with patients' own perspective to promote patient-centered care.
    No preview · Article · Sep 2014 · Nursing in Critical Care
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    • "Sleep deprivation can result in delirium-like symptoms, such as inattention and fluctuations in mental capacity; however, it is still unclear whether sleep disruption in the ICU is a cause, consequence, or comorbidity of delirium. That said, sleep disturbance appears to be a potential risk factor by interacting with various neurobiological systems that are involved in delirium.86,87 "
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    ABSTRACT: Maintaining a stable and adequate sleeping pattern is associated with good health and disease prevention. As a restorative process, sleep is important for supporting immune function and aiding the body in healing and recovery. Aging is associated with characteristic changes to sleep quantity and quality, which make it more difficult to adjust sleep–wake rhythms to changing environmental conditions. Sleep disturbance and abnormal sleep–wake cycles are commonly reported in seriously ill older patients in the intensive care unit (ICU). A combination of intrinsic and extrinsic factors appears to contribute to these disruptions. Little is known regarding the effect that sleep disturbance has on health status in the oldest of old (80+), a group, who with diminishing physiological reserve and increasing prevalence of frailty, is at a greater risk of adverse health outcomes, such as cognitive decline and mortality. Here we review how sleep is altered in the ICU, with particular attention to older patients, especially those aged 80 years. Further work is required to understand what impact sleep disturbance has on frailty levels and poor outcomes in older critically ill patients.
    Full-text · Article · Jun 2014 · Clinical Interventions in Aging
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    • "Sleep is a dynamic, complex and vital state of human physiology [1]. Sleep is essential to life, and is thought to be restorative, conservative, adaptive, thermoregulatory and have memory consolidative functions [2]. "
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    ABSTRACT: Intensive care unit (ICU) patients are known to experience severely disturbed sleep, with possible detrimental effects on short- and long- term outcomes. Investigation into the exact causes and effects of disturbed sleep has been hampered by cumbersome and time consuming methods of measuring and staging sleep. We introduce a novel method for ICU depth of sleep analysis, the ICU depth of sleep index (IDOS index), using single channel electroencephalography (EEG) and apply it to outpatient recordings. A proof of concept is shown in non-sedated ICU patients. Polysomnographic (PSG) recordings of five ICU patients and 15 healthy outpatients were analysed using the ICU depth of sleep (IDOS) index, based on the ratio between gamma and delta band power. Manual selection of thresholds was used to classify data as either wake, sleep or slow wave sleep (SWS). This classification was compared to visual sleep scoring by Rechtschaffen & Kales criteria in normal outpatient recordings and ICU recordings to illustrate face validity of the IDOS index. When reduced to 2 or 3 classes, the scoring of sleep by IDOS index and manual scoring show high agreement for normal sleep recordings. The obtained overall agreements, as quantified by the kappa coefficient, were 0.84 for sleep/wake classification and 0.82 for classification into 3 classes (wake, non-SWS and SWS). Sensitivity and specificity were highest for the wake state (93% and 93%, respectively) and lowest for SWS (82% and 76%, respectively). For ICU recordings, agreement was similar to agreement between visual scorers previously reported in literature. Besides the most satisfying visual resemblance with manually scored normal PSG recordings, the established face-validity of the IDOS index as an estimator of depth of sleep was excellent. This technique enables real-time, automated, single channel visualization of depth of sleep, facilitating the monitoring of sleep in the ICU.
    Full-text · Article · Apr 2014 · Critical care (London, England)
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