Sleep disturbances in critically ill patients in ICU: how much do we know?

The reliability of the German version of the Richards Campbell Sleep Questionnaire

BACKGROUND

The assessment of sleep quality in critically ill patients is a relevant factor of high-quality care. Despite the fact that sleep disturbances and insufficient sleep management contain an increased risk of severe morbidity for these patients, a translated and applicable instrument to evaluate sleep is not available for German-speaking intensive care settings.

AIM

This study aimed to translate the Richards Campbell Sleep Questionnaire (RCSQ), a simple and validated instrument eligible for measuring sleep quality in critically ill patients, and subsequently to evaluate the internal consistency of the German version of the RCSQ. Furthermore, it also aimed to inquire into the perception of sleep in a sample of critically ill patients.

METHODS

The RCSQ was translated following established methodological standards. Data were collected cross-sectionally in a sample of 51 patients at 3 intensive care units at a university hospital in Germany.

RESULTS

The German version of the RCSQ showed an overall internal consistency (Cronbach's alpha) of 0·88. The mean of the RSCQ in the sample was 47·00 (SD ± 27·57). Depth of sleep was rated the lowest and falling asleep again the highest of the RCSQ sleep items.

CONCLUSION

The study demonstrated very good internal consistency of the German version of the RCSQ, allowing for its application in practice and research in German-speaking countries. Quality of sleep perception was generally low in this sample, emphasizing the need for enhanced care concepts regarding the sleep management of critically ill patients. Relevance to clinical practice Assessment of self-perception of sleep is crucial in order to plan an individually tailored care process.

Low-dose Dexmedetomidine Improves Sleep Quality Pattern in Elderly Patients after Noncardiac Surgery in the Intensive Care Unit

Background

Patients admitted to the intensive care unit (ICU) after surgery often develop sleep disturbances. The authors tested the hypothesis that low-dose dexmedetomidine infusion could improve sleep architecture in nonmechanically ventilated elderly patients in the ICU after surgery.

Methods

This was a pilot, randomized controlled trial. Seventy-six patients age 65 yr or older who were admitted to the ICU after noncardiac surgery and did not require mechanical ventilation were randomized to receive dexmedetomidine (continuous infusion at a rate of 0.1 μg kg−1 h−1; n = 38) or placebo (n = 38) for 15 h, i.e., from 5:00 pm on the day of surgery until 8:00 am on the first day after surgery. Polysomnogram was monitored during the period of study-drug infusion. The primary endpoint was the percentage of stage 2 non–rapid eye movement (stage N2) sleep.

Results

Complete polysomnogram recordings were obtained in 61 patients (30 in the placebo group and 31 in the dexmedetomidine group). Dexmedetomidine infusion increased the percentage of stage N2 sleep from median 15.8% (interquartile range, 1.3 to 62.8) with placebo to 43.5% (16.6 to 80.2) with dexmedetomidine (difference, 14.7%; 95% CI, 0.0 to 31.9; P = 0.048); it also prolonged the total sleep time, decreased the percentage of stage N1 sleep, increased the sleep efficiency, and improved the subjective sleep quality. Dexmedetomidine increased the incidence of hypotension without significant intervention.

Conclusions

In nonmechanically ventilated elderly patients who were admitted to the ICU after noncardiac surgery, the prophylactic low-dose dexmedetomidine infusion may improve overall sleep quality.

Sleep Disturbances and Critical Illness

Sleep disturbances are common in the intensive care unit setting. This article describes the causal factors associated with alterations in sleep in the intensive care setting, effects of sleep disturbances for patients, and strategies to mitigate sleep disturbances. A review of normal sleep architecture is provided, as is a discussion of the methods of measuring sleep in the critical care setting.

Examining the evidence to guide practice: challenging practice habits

Nurses are the largest segment of the nation's health care workforce, which makes nurses vital to the translation of evidence-based practice as a practice norm. Critical care nurses are in a position to critically appraise and apply best evidence in daily practice to improve patients' outcomes. It is important for critical care nurses to continually evaluate their current practice to ensure that they are applying the current best evidence rather than practicing on the basis of tradition. This article is based on a presentation at the 2013 National Teaching Institute of the American Association of Critical-Care Nurses. Four practice interventions that are within the realm of nursing are critiqued on the basis of current best evidence: (1) turning critically ill patients, (2) sleep promotion in the intensive care unit, (3) feeding tube management in infants and children, and (4) prevention of venothromboembolism…again. The related beliefs, current evidence, and implications for practice associated with each topic are described.

Effect of oral melatonin and wearing earplugs and eye masks on nocturnal sleep in healthy subjects in a simulated intensive care unit environment: which might be a more promising strategy for ICU sleep deprivation?

Introduction

Sleep deprivation is common in critically ill patients in the intensive care unit (ICU). Noise and light in the ICU and the reduction in plasma melatonin play the essential roles. The aim of this study was to determine the effect of simulated ICU noise and light on nocturnal sleep quality, and compare the effectiveness of melatonin and earplugs and eye masks on sleep quality in these conditions in healthy subjects.

Methods

This study was conducted in two parts. In part one, 40 healthy subjects slept under baseline night and simulated ICU noise and light (NL) by a cross-over design. In part two, 40 subjects were randomly assigned to four groups: NL, NL plus placebo (NLP), NL plus use of earplugs and eye masks (NLEE) and NL plus melatonin (NLM). 1 mg of oral melatonin or placebo was administered at 21:00 on four consecutive days in NLM and NLP. Earplugs and eye masks were made available in NLEE. The objective sleep quality was measured by polysomnography. Serum was analyzed for melatonin levels. Subjects rated their perceived sleep quality and anxiety levels.

Results

Subjects had shorter total sleep time (TST) and rapid eye movement (REM) sleep, longer sleep onset latency, more light sleep and awakening, poorer subjective sleep quality, higher anxiety level and lower serum melatonin level in NL night (P <0.05). NLEE had less awakenings and shorter sleep onset latency (P <0.05). NLM had longer TST and REM and shorter sleep onset latency (P <0.05). Compared with NLEE, NLM had fewer awakenings (P = 0.004). Both NLM and NLEE improved perceived sleep quality and anxiety level (P = 0.000), and NLM showed better than NLEE in perceived sleep quality (P = 0.01). Compared to baseline night, the serum melatonin levels were lower in NL night at every time point, and the average maximal serum melatonin concentration in NLM group was significantly greater than other groups (P <0.001).

Conclusions

Compared with earplugs and eye masks, melatonin improves sleep quality and serum melatonin levels better in healthy subjects exposed to simulated ICU noise and light.

Trial registration

Chinese Clinical Trial Registry ChiCTR-IPR-14005458. Registered 10 November 2014.

Sleep and nursing care activities in an intensive care unit

This study aimed to describe the quality of sleep of non-intubated patients and the night-time nursing care activities in an intensive care unit. The study also aimed to evaluate the effect of nursing care activities on the quality of sleep. An overnight polysomnography was performed in 21 alert, non-intubated, non-sedated adult patients, and all nursing care activities that involved touching the patient were documented by the bedside nurse. The median (interquartile range) amount of sleep was 387 (170, 486) minutes. The portion of deep non-rapid-eye-movement (non-REM) sleep varied from 0% to 42% and REM sleep from 0% to 65%. The frequency of arousals and awakenings varied from two to 73 per hour. The median amount of nursing care activities was 0.6/h. Every tenth activity presumably awakened the patient. Patients who had more care activities had more light N1 sleep, less light N2 sleep, and less deep sleep. Nursing care was often performed while patients were awake. However, only 31% of the intervals between nursing care activities were over 90 min. More attention should be paid to better clustering of care activities.

Protecting the melatonin rhythm through circadian healthy light exposure

Currently, in developed countries, nights are excessively illuminated (light at night), whereas daytime is mainly spent indoors, and thus people are exposed to much lower light intensities than under natural conditions. In spite of the positive impact of artificial light, we pay a price for the easy access to light during the night: disorganization of our circadian system or chronodisruption (CD), including perturbations in melatonin rhythm. Epidemiological studies show that CD is associated with an increased incidence of diabetes, obesity, heart disease, cognitive and affective impairment, premature aging and some types of cancer. Knowledge of retinal photoreceptors and the discovery of melanopsin in some ganglion cells demonstrate that light intensity, timing and spectrum must be considered to keep the biological clock properly entrained. Importantly, not all wavelengths of light are equally chronodisrupting. Blue light, which is particularly beneficial during the daytime, seems to be more disruptive at night, and induces the strongest melatonin inhibition. Nocturnal blue light exposure is currently increasing, due to the proliferation of energy-efficient lighting (LEDs) and electronic devices. Thus, the development of lighting systems that preserve the melatonin rhythm could reduce the health risks induced by chronodisruption. This review addresses the state of the art regarding the crosstalk between light and the circadian system.

Impact of oral melatonin on critically ill adult patients with ICU sleep deprivation: study protocol for a randomized controlled trial

Background

Sleep deprivation is common in critically ill patients in intensive care units (ICU). It can result in delirium, difficulty weaning, repeated nosocomial infections, prolonged ICU length of stay and increased ICU mortality. Melatonin, a physiological sleep regulator, is well known to benefit sleep quality in certain people, but evidence for the effectiveness in ICU sleep disturbance is limited.

Methods/Design

This study has a prospective, randomized, double-blind, controlled, parallel-group design. Eligible patients are randomly assigned to one of the two treatment study groups, labelled the ‘melatonin group’ or the ‘placebo group’. A dose of 3 mg of oral melatonin or placebo is administered at 9:00 pm on four consecutive days. Earplugs and eye masks are made available to every participant. We plan to enrol 198 patients. The primary outcome is the objective sleep quality measured by the 24-hour polysomnography. The secondary outcomes are the subjective sleep quality assessed by the Richards Campbell Sleep Questionnaire, the anxiety level evaluated by the Visual Analogue Scale-Anxiety, the number of delirium-free days in 8 and 28 days, the number of ventilation-free days in 28 days, the number of antibiotic-free days, ICU length of stay, the overall ICU mortality in 28 days and the incidence and severity of the side effects of melatonin in ICU patients. Additionally, the body stress levels, oxidative stress levels and inflammation levels are obtained via measuring the plasma melatonin, cortisone, norepinephrine, malonaldehyde(MDA), superoxide dismutase(SOD), interleukin-6 (IL-6) and interleukin-8 (IL-8)concentrations.

Discussion

The proposed study will be the first randomized controlled study to use the polysomnography, which is the gold standard of assessing sleep quality, to evaluate the effect of melatonin on the sleep quality and circadian rhythms of ICU patients. The results may recommend a new treatment for ICU patients with sleep deprivation that is safe, effective and easily implementable in daily practice.

Trial registration

This study was registered with ClinicalTrials (NCT; registration number: ChiCTR-TRC-14004319) on 4 March 2013.

Sleep disturbance in older ICU patients

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.

Propofol versus flunitrazepam for inducing and maintaining sleep in postoperative ICU patients

Context:

Sleep deprivation is a common problem on intensive care units (ICUs) influencing not only cognition, but also cellular functions. An appropriate sleep-wake cycle should therefore be maintained to improve patients’ outcome. Multiple disruptive factors on ICUs necessitate the administration of sedating and sleep-promoting drugs for patients who are not analgo-sedated.

Aims:

The objective of the present study was to evaluate sleep quantity and sleep quality in ICU patients receiving either propofol or flunitrazepam.

Settings and Design:

Monocentric, randomized, double-blinded trial.

Materials and Methods:

A total of 66 ICU patients were enrolled in the study (flunitrazepam n = 32, propofol n = 34). Propofol was injected continuously (2 mg/kg/h), flunitrazepam as a bolus dose (0.015 mg/kg). Differences between groups were evaluated using a standardized sleep diary and the bispectral index (BIS).

Statistical Analysis Used:

Group comparisons were performed by Mann-Whitney U-Test. P < 0.05 was considered to be statistically significant.

Results:

Sleep quality and the frequency of awakenings were significantly better in the propofol group (Pg). In the same group lower BIS values were recorded (median BIS propofol 74.05, flunitrazepam 78.7 [P = 0.016]). BIS values had to be classified predominantly to slow-wave sleep under propofol and light sleep after administration of flunitrazepam. Sleep quality improved in the Pg with decreasing frequency of awakenings and in the flunitrazepam group with increasing sleep duration.

Conclusions:

Continuous low-dose injection of propofol for promoting and maintaining night sleep in ICU patients who are not analgo-sedated was superior to flunitrazepam regarding sleep quality and sleep structure.

Intensive care unit depth of sleep: proof of concept of a simple electroencephalography index in the non-sedated

INTRODUCTION

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.

METHODS

Polysomnographic (PSG) recordings of five ICU patients and 15 healthy outpatients were analyzed using the 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.

RESULTS

When reduced to two or three 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 three 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.

CONCLUSIONS

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.

Improvement of intensive care unit sound environment and analyses of consequences on sleep: an experimental study

OBJECTIVE

Uninterrupted sleep is of vital importance for restoration and regaining health. In intensive care units (ICUs) where recovering and healing is crucial, patients' sleep often is fragmented and disturbed due to noise from activities from oneself, other patients, and alarms. The aim of our study was to explore if sleep could be improved by modifying the sound environment in a way that is practically feasible in ICUs.

METHODS

We studied the effects of originally recorded ICU noise and peak reduced ICU noise on sleep in healthy male participants. Sleep was registered with polysomnography (PSG) during four nights: one adaptation night, one reference (REF) night, and the two exposed nights with similar equivalent sound levels (47dB LAeq) but different maximum sound levels (56- vs 64-dB LAFmax). The participants answered questionnaires and saliva cortisol was sampled in the morning.

RESULTS

During ICU exposure nights, sleep was more fragmented with less slow-wave sleep (SWS), more arousals, and more time awake. The effects of reduced maximum sound level were minor. The subjective data supported the polysomnographic findings, though cortisol levels were not significantly affected by the exposure conditions.

CONCLUSIONS

Noise in ICUs impairs sleep and the reduction of maximal A-weighted levels from 64 to 56dB is not enough to have a clear improved effect on sleep quality.

An investigation of sound levels on intensive care units with reference to the WHO guidelines

Introduction

Patients in intensive care units (ICUs) suffer from sleep deprivation arising from nursing interventions and ambient noise. This may exacerbate confusion and ICU-related delirium. The World Health Organization (WHO) suggests that average hospital sound levels should not exceed 35 dB with a maximum of 40 dB overnight. We monitored five ICUs to check compliance with these guidelines.

Methods

Sound levels were recorded in five adult ICUs in the UK. Two sound level monitors recorded concurrently for 24 hours at the ICU central stations and adjacent to patients. Sample values to determine levels generated by equipment and external noise were also recorded in an empty ICU side room.

Results

Average sound levels always exceeded 45 dBA and for 50% of the time exceeded between 52 and 59 dBA in individual ICUs. There was diurnal variation with values decreasing after evening handovers to an overnight average minimum of 51 dBA at 4 AM. Peaks above 85 dBA occurred at all sites, up to 16 times per hour overnight and more frequently during the day. WHO guidelines on sound levels could be only achieved in a side room by switching all equipment off.

Conclusion

All ICUs had sound levels greater than WHO recommendations, but the WHO recommended levels are so low they are not achievable in an ICU. Levels adjacent to patients are higher than those recorded at central stations. Unit-wide noise reduction programmes or mechanical means of isolating patients from ambient noise, such as earplugs, should be considered.

Neuropeptides in sepsis: from brain pathology to systemic inflammation

Septic encephalopathy is frequently diagnosed in critically ill patients and in up to 70% of patients with severe systemic infection [19]. The syndrome is defined by diffuse cerebral dysfunction or structural abnormalities attributed to the effects of systemic infection, rather than a direct central nervous system cause. The clinical characteristics can range from mild delirium to deep coma, but patients are often medically sedated making the diagnosis difficult. Any manifestation, however, is specific and markers of disease are lacking [43]. Sepsis survivors present long term cognitive impairment, including alterations of memory, attention and concentration [10,54]. Here, we propose that neuropeptides may play a key role in septic encephalopathy, leading to a vicious circle characterized by brain disease and systemic inflammation.