Sleep in the intensive care unit

Quality of Sleep Among Intensive Care Unit Patients: A Literature Review

Investigating sleep disturbances among intensive care unit (ICU) patients and its serious consequences is considered a crucial issue for nurses. The need of sleep increases during hospitalization time to preserve energy for the healing process. Previous studies have demonstrated that sleep disturbance is one of the most common complaints of patients in the ICUs, with a prevalence of more than 50%. Although the total sleep time might be normal, the patients' sleep is fragmented and light in the intensive care settings. The main purpose of this review is to generate a clear view of what is known about sleep disturbances among ICU patients as well as to identify the gap in knowledge regarding this issue. This was done by describing, summarizing, clarifying, and evaluating well-selected previous studies about this topic. In addition, this concise review has focused on the prevalence of sleep disturbances in the ICU, factors contributing to poor quality of sleep among ICU patients, and the physiological effects of poor sleep on the patients' prognosis.

The effects of mechanical ventilation on the quality of sleep of hospitalised patients in the Intensive Care Unit

Aim

To examine the effects of mechanical ventilation on the quality of sleep in patients in the intensive care unit (ICU) using recent and relevant literature.

Methods

To verify the examined objective, the results of the analysis of available original scientific works have been used including defined inclusion/exclusion criteria and search strategy. Appropriate works found were analysed further. The applied methodology was in line with the general principles of Evidence-Based Medicine. The following literary databases were used: CINAHL, Medline and gray literature: Google Scholar.

Results

A total of 91 trials were found. Eleven of these relevant to the follow-up analysis were selected: all trials were carried out under real ICU conditions and the total of 192 patients were included in the review. There is an agreement within all trials that sleep in patients requiring mechanical ventilation is disturbed. Most reviewed trials have shown that mechanical ventilation is probably not the main factor causing sleep disturbances, but an appropriate ventilation strategy can significantly help to improve its quality by reducing the frequency of the patient-ventilator asynchrony.

Conclusion

Based on the analysis, it appears that an appropriate ventilation mode setting can have a beneficial effect on the quality of sleep in ICU patients.

Melatonin for the promotion of sleep in adults in the intensive care unit

BACKGROUND

Patients in the intensive care unit (ICU) experience sleep deprivation caused by environmental disruption, such as high noise levels and 24-hour lighting, as well as increased patient care activities and invasive monitoring as part of their care. Sleep deprivation affects physical and psychological health, and patients perceive the quality of their sleep to be poor whilst in the ICU. Artificial lighting during night-time hours in the ICU may contribute to reduced production of melatonin in critically ill patients. Melatonin is known to have a direct effect on the circadian rhythm, and it appears to reset a natural rhythm, thus promoting sleep.

OBJECTIVES

To assess whether the quantity and quality of sleep may be improved by administration of melatonin to adults in the intensive care unit. To assess whether melatonin given for sleep promotion improves both physical and psychological patient outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 8), MEDLINE (1946 to September 2017), Embase (1974 to September 2017), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1937 to September 2017), and PsycINFO (1806 to September 2017). We searched clinical trials registers for ongoing studies, and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials with adult participants (over the age of 16) admitted to the ICU with any diagnoses given melatonin versus a comparator to promote overnight sleep. We included participants who were mechanically ventilated and those who were not mechanically ventilated. We planned to include studies that compared the use of melatonin, given at an appropriate clinical dose with the intention of promoting night-time sleep, against no agent; or against another agent administered specifically to promote sleep.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, assessed risk of bias, and synthesized findings. We assessed the quality of evidence with GRADE.

MAIN RESULTS

We included four studies with 151 randomized participants. Two studies included participants who were mechanically ventilated, one study included a mix of ventilated and non-ventilated participants and in one study participants were being weaned from mechanical ventilation. Three studies reported admission diagnoses, which varied: these included sepsis, pneumonia and cardiac or cardiorespiratory arrest. All studies compared melatonin against no agent; three were placebo-controlled trials; and one compared melatonin with usual care. All studies administered melatonin in the evening.All studies reported adequate methods for randomization and placebo-controlled trials were blinded at the participant and personnel level. We noted high risk of attrition bias in one study and were unclear about potential bias introduced in two studies with differences between participants at baseline.It was not appropriate to combine data owing to differences in measurement tools, or methods used to report data.The effects of melatonin on subjectively rated quantity and quality of sleep are uncertain (very low certainty evidence). Three studies (139 participants) reported quantity and quality of sleep as measured through reports of participants or family members or by personnel assessments. Study authors in one study reported no difference in sleep efficiency index scores between groups for participant assessment (using Richards-Campbell Sleep Questionnaire) and nurse assessment. Two studies reported no difference in duration of sleep observed by nurses.The effects of melatonin on objectively measured quantity and quality of sleep are uncertain (very low certainty evidence). Two studies (37 participants) reported quantity and quality of sleep as measured by polysomnography (PSG), actigraphy, bispectral index (BIS) or electroencephalogram (EEG). Study authors in one study reported no difference in sleep efficiency index scores between groups using BIS and actigraphy. These authors also reported longer sleep in participants given melatonin which was not statistically significant, and improved sleep (described as "better sleep") in participants given melatonin from analysis of area under the curve (AUC) of BIS data. One study used PSG but authors were unable to report data because of a large loss of participant data.One study (82 participants) reported no evidence of a difference in anxiety scores (very low certainty evidence). Two studies (94 participants) reported data for mortality: one study reported that overall one-third of participants died; and one study reported no evidence of difference between groups in hospital mortality (very low certainty). One study (82 participants) reported no evidence of a difference in length of ICU stay (very low certainty evidence). Effects of melatonin on adverse events were reported in two studies (107 participants), and are uncertain (very low certainty evidence): one study reported headache in one participant given melatonin, and one study reported excessive sleepiness in one participant given melatonin and two events in the control group (skin reaction in one participant, and excessive sleepiness in another participant).The certainty of the evidence for each outcome was limited by sparse data with few participants. We noted study limitations in some studies due to high attrition and differences between groups in baseline data; and doses of melatonin varied between studies. Methods used to measure data were not consistent for outcomes, and use of some measurement tools may not be effective for use on the ICU patient. All studies included participants in the ICU but we noted differences in ICU protocols, and one included study used a non-standard sedation protocol with participants which introduced indirectness to the evidence.

AUTHORS' CONCLUSIONS

We found insufficient evidence to determine whether administration of melatonin would improve the quality and quantity of sleep in ICU patients. We identified sparse data, and noted differences in study methodology, in ICU sedation protocols, and in methods used to measure and report sleep. We identified five ongoing studies from database and clinical trial register searches. Inclusion of data from these studies in future review updates would provide more certainty for the review outcomes.

Propofol for the promotion of sleep in adults in the intensive care unit

BACKGROUND

People in the intensive care unit (ICU) experience sleep deprivation caused by environmental disruption, such as high noise levels and 24-hour lighting, as well as increased patient care activities and invasive monitoring as part of their care. Sleep deprivation affects physical and psychological health, and people perceive the quality of their sleep to be poor whilst in the ICU. Propofol is an anaesthetic agent which can be used in the ICU to maintain patient sedation and some studies suggest it may be a suitable agent to replicate normal sleep.

OBJECTIVES

To assess whether the quantity and quality of sleep may be improved by administration of propofol to adults in the ICU and to assess whether propofol given for sleep promotion improves both physical and psychological patient outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 10), MEDLINE (1946 to October 2017), Embase (1974 to October 2017), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1937 to October 2017) and PsycINFO (1806 to October 2017). We searched clinical trials registers for ongoing studies, and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials with adults, over the age of 16 years, admitted to the ICU with any diagnoses, given propofol versus a comparator to promote overnight sleep. We included participants who were and were not mechanically ventilated. We included studies that compared the use of propofol, given at an appropriate clinical dose with the intention of promoting night-time sleep, against: no agent; propofol at a different rate or dose; or another agent, administered specifically to promote sleep. We included only studies in which propofol was given during 'normal' sleeping hours (i.e. between 10 pm and 7 am) to promote a sleep-like state with a diurnal rhythm.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, assessed risk of bias and synthesized findings.

MAIN RESULTS

We included four studies with 149 randomized participants. We identified two studies awaiting classification for which we were unable to assess eligibility and one ongoing study.Participants differed in severity of illness as assessed by APACHE II scores in three studies and further differences existed between comparisons and methods. One study compared propofol versus no agent, one study compared different doses of propofol and two studies compared propofol versus a benzodiazepine (flunitrazepam, one study; midazolam, one study). All studies reported randomization and allocation concealment inadequately. We judged all studies to have high risk of performance bias from personnel who were unblinded. We noted that some study authors had blinded study outcome assessors and participants for relevant outcomes.It was not appropriate to combine data owing to high levels of methodological heterogeneity.One study comparing propofol with no agent (13 participants) measured quantity and quality of sleep using polysomnography; study authors reported no evidence of a difference in duration of sleep or sleep efficiency, and reported disruption to usual REM (rapid eye movement sleep) with propofol.One study comparing different doses of propofol (30 participants) measured quantity and quality of sleep by personnel using the Ramsay Sedation Scale; study authors reported that more participants who were given a higher dose of propofol had a successful diurnal rhythm, and achieved a greater sedation rhythmicity.Two studies comparing propofol with a different agent (106 participants) measured quantity and quality of sleep using the Pittsburgh Sleep Diary and the Hospital Anxiety and Depression Scale; one study reported fewer awakenings of reduced duration with propofol, and similar total sleep time between groups, and one study reported no evidence of a difference in sleep quality. One study comparing propofol with another agent (66 participants) measured quantity and quality of sleep with the Bispectral Index and reported longer time in deep sleep, with fewer arousals. One study comparing propofol with another agent (40 participants) reported higher levels of anxiety and depression in both groups, and no evidence of a difference when participants were given propofol.No studies reported adverse events.We used the GRADE approach to downgrade the certainty of the evidence for each outcome to very low. We identified sparse data with few participants, and methodological differences in study designs and comparative agents introduced inconsistency, and we noted that measurement tools were imprecise or not valid for purpose.

AUTHORS' CONCLUSIONS

We found insufficient evidence to determine whether administration of propofol would improve the quality and quantity of sleep in adults in the ICU. We noted differences in study designs, methodology, comparative agents and illness severity amongst study participants. We did not pool data and we used the GRADE approach to downgrade the certainty of our evidence to very low.

Evaluation of stressors in intensive care units

Objective

Physical and psychological stressors adversely affect the treatment and length of stay of patients in intensive care units. In this study, we aimed to describe environmental and psychological stressors affecting intensive care unit patients and to determine their priorities.

Material and Methods

In this study, the 40-item Intensive Care Unit Environmental Stressor Scale was administered to patients in the General Surgery Intensive Care Unit and the Anesthesiology and Reanimation Intensive Care Unit. The patients' age, gender, marital status, educational status, cause of hospitalization, and intensive care unit length of stay were questioned and recorded. Acute Physiology And Chronic Health Evaluation II scores were determined for intensive care unit patients.

Results

A total of 98 patients, 80 in the General Surgery Intensive Care Unit and 18 in the Anesthesiology and Reanimation Intensive Care Unit, were included in the study between May 1, 2015 and October 31, 2015. Fifty-six of the patients were male (57.1%) and 42 were female (42.9%). The mean age of the patients was 55.1±15.1 years. The mean intensive care unit length of stay was 3.4±1.6 days. The median Acute Physiology And Chronic Health Evaluation II score of the patients was 6 (0 to 17). The patients were most affected by thirst (mean 2.44). The second most stressful stress factor was the presence of tubes in the mouth and nose (mean 2.25). The least stressful factor for the patients was the presence of nurses constantly performing activities around the bed. Although 51% of the patients were postoperative, pain was ranked 5th among stress factors.

Conclusion

The environmental and psychological factors affecting intensive care unit patients varied according to age, sex, and educational and surgical status. These factors had adverse effects on the patients. The elimination or modification of these factors would contribute positively to the treatment of intensive care unit patients and shorten their length of stay in the intensive care unit.

Sleep Quality and Quantity in Intensive Care Unit Patients: A Cross-sectional Study

Introduction:

Lack of restorative sleep and altered sleep-wake cycle is a frequent problem among patients admitted to the Intensive Care Unit (ICU). This study was conducted to estimate the prevalence of poor sleep and patient's perspective of factors governing poor sleep in the ICU.

Materials and Methods:

A cross-sectional study was performed in medical ICU of a tertiary care hospital. A total of 32 patients admitted to the ICU for at least 24 h were recruited. A 72-h actigraphy was done followed by a subjective assessment of sleep quality by the Richards-Campbell Sleep Questionnaire (RCSQ). Patient's perspective of sleep quality and quantity and possible risk factors for poor sleep were recorded.

Results:

Poor sleep (defined as RCSQ <50, sensitivity 88% and specificity 87%) was found in 15 out of the 32 patients (47%). The prevalence of poor sleep was higher among patients on mechanical ventilation (n = 15) (66.7% vs. 33.3%, P < 0.05). Patients with poor sleep had higher age (median age [in years] 42.8 vs. 31.4, P = 0.008), acute physiology, and chronic health evaluation II score (mean 14 ± 5.15 vs. 9.3 ± 5.64, P = 0.02), SAPS 3 score (62.7 ± 8.9 vs. 45.6 ± 10.5, P ≤ 0.0001), and worse actigraphy parameters. Only 55.63% of total sleep time was in the night (2200–0600). All patients had discomfort from indwelling catheters and suctioning of endotracheal tubes. All patients suggested that there be a minimum interruption in the sleep for interventions or medications.

Conclusion:

There is a high prevalence of poor sleep among patients admitted to the ICU. There is a dire need to minimize untimely interventions and design nonpharmacological techniques to allow patients to sleep comfortably.

EEG dynamical correlates of focal and diffuse causes of coma

BACKGROUND

Rapidly determining the causes of a depressed level of consciousness (DLOC) including coma is a common clinical challenge. Quantitative analysis of the electroencephalogram (EEG) has the potential to improve DLOC assessment by providing readily deployable, temporally detailed characterization of brain activity in such patients. While used commonly for seizure detection, EEG-based assessment of DLOC etiology is less well-established. As a first step towards etiological diagnosis, we sought to distinguish focal and diffuse causes of DLOC through assessment of temporal dynamics within EEG signals.

METHODS

We retrospectively analyzed EEG recordings from 40 patients with DLOC with consensus focal or diffuse culprit pathology. For each recording, we performed a suite of time-series analyses, then used a statistical framework to identify which analyses (features) could be used to distinguish between focal and diffuse cases.

RESULTS

Using cross-validation approaches, we identified several spectral and non-spectral EEG features that were significantly different between DLOC patients with focal vs. diffuse etiologies, enabling EEG-based classification with an accuracy of 76%.

CONCLUSIONS

Our findings suggest that DLOC due to focal vs. diffuse injuries differ along several electrophysiological parameters. These results may form the basis of future classification strategies for DLOC and coma that are more etiologically-specific and therefore therapeutically-relevant.

Factors Affecting Acoustics and Speech Intelligibility in the Operating Room: Size Matters

Supplemental Digital Content is available in the text.

INTRODUCTION:

Noise in health care settings has increased since 1960 and represents a significant source of dissatisfaction among staff and patients and risk to patient safety. Operating rooms (ORs) in which effective communication is crucial are particularly noisy. Speech intelligibility is impacted by noise, room architecture, and acoustics. For example, sound reverberation time (RT₆₀) increases with room size, which can negatively impact intelligibility, while room objects are hypothesized to have the opposite effect. We explored these relationships by investigating room construction and acoustics of the surgical suites at our institution.

METHODS:

We studied our ORs during times of nonuse. Room dimensions were measured to calculate room volumes (V_R). Room content was assessed by estimating size and assigning items into 5 volume categories to arrive at an adjusted room content volume (V_C) metric. Psychoacoustic analyses were performed by playing sweep tones from a speaker and recording the impulse responses (ie, resulting sound fields) from 3 locations in each room. The recordings were used to calculate 6 psychoacoustic indices of intelligibility. Multiple linear regression was performed using V_R and V_C as predictor variables and each intelligibility index as an outcome variable.

RESULTS:

A total of 40 ORs were studied. The surgical suites were characterized by a large degree of construction and surface finish heterogeneity and varied in size from 71.2 to 196.4 m³ (average V_R = 131.1 [34.2] m³). An insignificant correlation was observed between V_R and V_C (Pearson correlation = 0.223, P = .166). Multiple linear regression model fits and β coefficients for V_R were highly significant for each of the intelligibility indices and were best for RT₆₀ (R² = 0.666, F(2, 37) = 39.9, P < .0001). For D_max (maximum distance where there is <15% loss of consonant articulation), both V_R and V_C β coefficients were significant. For RT₆₀ and D_max, after controlling for V_C, partial correlations were 0.825 (P < .0001) and 0.718 (P < .0001), respectively, while after controlling for V_R, partial correlations were −0.322 (P = .169) and 0.381 (P < .05), respectively.

CONCLUSIONS:

Our results suggest that the size and contents of an OR can predict a range of psychoacoustic indices of speech intelligibility. Specifically, increasing OR size correlated with worse speech intelligibility, while increasing amounts of OR contents correlated with improved speech intelligibility. This study provides valuable descriptive data and a predictive method for identifying existing ORs that may benefit from acoustic modifiers (eg, sound absorption panels). Additionally, it suggests that room dimensions and projected clinical use should be considered during the design phase of OR suites to optimize acoustic performance.

The nocturnal acoustical intensity of the intensive care environment: an observational study

BACKGROUND

The intensive care unit (ICU) environment exposes patients to noise levels that may result in substantial sleep disruption. There is a need to accurately describe the intensity pattern and source of noise in the ICU in order to develop effective sound abatement strategies. The objectives of this study were to determine nocturnal noise levels and their variability and the related sources of noise within an Australian tertiary ICU.

METHODS

An observational cross-sectional study was conducted in a 24-bed open-plan ICU. Sound levels were recorded overnight during three nights at 5-s epochs using Extech (SDL 600) sound monitors. Noise sources were concurrently logged by two research assistants.

RESULTS

The mean recorded ambient noise level in the ICU was 52.85 decibels (dB) (standard deviation (SD) 5.89), with a maximum noise recording at 98.3 dB (A). All recorded measurements exceeded the WHO recommendations. Noise variability per minute ranged from 9.9 to 44 dB (A), with peak noise levels >70 dB (A) occurring 10 times/hour (SD 11.4). Staff were identified as the most common source accounting for 35% of all noise. Mean noise levels in single-patient rooms compared with open-bed areas were 53.5 vs 53 dB (p = 0.37), respectively.

CONCLUSION

Mean noise levels exceeded those recommended by the WHO resulting in an acoustical intensity of 193 times greater than the recommended and demonstrated a high degree of unpredictable variability, with the primary noise sources coming from staff conversations. The lack of protective effects of single rooms and the contributing effects that staffs have on noise levels are important factors when considering sound abatement strategies.

Effects of dexmedetomidine on sleep quality of patients after surgery without mechanical ventilation in ICU

Sleep quality of patients in intensive care unit (ICU) has been recently recognized as an important aspect of the intensive care. Dexmedetomidine is one of the most recently introduced for sedation in the ICU. This study was designed to evaluate the effect of dexmedetomidine on sleep quality of patients without mechanical ventilation in ICU.The patients who were included in this study were divided into two groups. In the sedation group, dexmedetomidine was given by a continuous infusion targeting a sedation level -1 to -2 on the score of RASS (Richmond Agitation-Sedation Scale). In the no sedation group, the patients slept by themselves. No other sedatives were given. Bispectral Index (BIS) was performed on these hemodynamically stable critically ill patients for 12 consecutive hours. Sleep time and sleep depth were recorded.Twenty patients were studied. Compared to no sedation group, sleep efficiency and sleep time of patients in the sedation group was significantly higher during the night. Moreover, there was no significantly difference between the changes of blood pressure, heart rate, and respiratory rate.Dexmedetomidine is a clinically effective and safe sedative for the highly selected critically ill patients without endotracheal tube and mechanical ventilation in the ICU to increases total sleep time and improve sleep efficiency.

Factors influencing quality of sleep among non-mechanically ventilated patients in the Intensive Care Unit

AIM

To investigate the self-reported quality of sleep of non-mechanically ventilated patients admitted to an ICU, and to identify barriers to sleep in this setting.

METHOD

Patients admitted to the ICU of Frankston Hospital over a two month period who had spent at least one night in the ICU, and had not received mechanical ventilation were surveyed as they were discharged from the ICU. This survey required patients to rate the quality of their sleep in the ICU and at home immediately prior to hospitalisation on a 10cm visual analogue scale; and to identify perceived barriers to sleep in the ICU and at home prior to hospitalisation.

RESULTS

56 respondents were surveyed during the study period. Median age was 74 years (range=18-92 years); median ICU length of stay was 1 day (range=1-7 days). Overall, respondents rated their quality of sleep in ICU (median=4.9/10) as significantly worse than at home immediately prior to ICU admission (median=7.15/10; Z=-3.02, p<0.002); however 44% of respondents rated their quality of sleep in ICU as better, or no worse, than at home immediately prior to hospitalisation. Sub-group analysis revealed that among patients with reduced quality of sleep (<5/10) prior to hospitalisation, 71.4% rated their quality of sleep in ICU as better, or no worse, than at home prior to hospitalisation, with no significant difference between sleep quality ratings in ICU and at home (p=0.341). Respondents identified the following as barriers to sleep in the ICU: noise levels overnight (53.6%); discomfort (33.9%); pain (32.1%); being awoken for procedures (32%); being attached to medical devices (28.6%); stress/anxiety (26.8%); and light levels (23.2%).

CONCLUSION

Pre-hospitalisation sleep quality appears to be an important influence on sleep in ICU. Many barriers to sleep in the ICU identified by respondents are potentially modifiable.

Quality of sleep in patients undergoing cardiac surgery during the postoperative period in intensive care

OBJECTIVES

To describe the quality of sleep of patients undergoing cardiac surgery during the first two nights following surgery and identify some of the factors conditioning the nightly rest of these patients in the Intensive Care Unit.

METHOD

Observational descriptive study based on applying the Richards-Campbell Sleep Questionnaire through a consecutive sample of patients undergoing cardiac surgery with Intensive Care Unit admission. Simultaneously, a questionnaire assessing different environmental factors existing in the unit as possible conditioning of the night's rest was applied. The association between consumption of opioid and sleep quality was studied.

RESULTS

Sample of 66 patients with a mean age of 65±11.57 years, of which 73% were men (N=48). The Richards-Campbell sleep questionnaire garnered average scores of 50.33mm (1.st night) and 53.30mm (2.nd night). The main sleep disturbing factors were discomfort with the different devices, 30.91mm and pain, 30.18mm. The problems caused by environmental noise, 27.5mm or through the voices of the professionals, 26.53mm were also elements of nocturnal discomfort. No statistical association was found between sleep and the distance of the patient with respect to the nursing control area or related to opioid analgesics.

CONCLUSIONS

The quality of sleep during the first two nights of Intensive Care Unit admission was "regular". The environmental factors that conditioned the night-time rest of patients were discomfort, pain and ambient noise.

Effects of Handling and Environment on Preterm Newborns Sleeping in Incubators

OBJECTIVE

To describe the total sleep time, stages of sleep, and wakefulness of preterm newborns and correlate them to levels of sound pressure, light, temperature, relative air humidity, and handling inside incubators.

DESIGN

Observational, correlational study.

SETTING

A neonatal intermediate care unit.

PARTICIPANTS

Twelve preterm newborns, who were 32.2 ± 4.2 weeks gestational age and weighed 1,606 ± 317 g.

METHODS

Sleep records were assessed by polysomnograph. Environmental variables were measured with a noise dosimeter, light meter, and thermohygrometer. To record time and frequency of handling, a video camera was used. All recordings were made for an uninterrupted 24-hour period.

RESULTS

Mean total sleep time in 24 hours was 899 ± 71.8 minutes (daytime = 446 ± 45.3 and nighttime = 448 ± 60.2). Mean wakefulness was 552 ± 94.0 minutes. The predominant stage was quiet sleep. A significant correlation was identified only between the levels of light and wakefulness (r = 0.65 and p = .041).

CONCLUSION

The environmental conditions and care provided to hospitalized preterm newborns did not influence sleep except for high light levels, which increased wakefulness. Nurses in clinical practice should implement strategies to promote and protect sleep by decreasing newborns' exposure to excessive light.

Reducing false alarms in the ICU by quantifying self-similarity of multimodal biosignals

False arrhythmia alarms pose a major threat to the quality of care in today's ICU. Thus, the PhysioNet/Computing in Cardiology Challenge 2015 aimed at reducing false alarms by exploiting multimodal cardiac signals recorded by a patient monitor. False alarms for asystole, extreme bradycardia, extreme tachycardia, ventricular flutter/fibrillation as well as ventricular tachycardia were to be reduced using two electrocardiogram channels, up to two cardiac signals of mechanical origin as well as a respiratory signal. In this paper, an approach combining multimodal rhythmicity estimation and machine learning is presented. Using standard short-time autocorrelation and robust beat-to-beat interval estimation, the signal's self-similarity is analyzed. In particular, beat intervals as well as quality measures are derived which are further quantified using basic mathematical operations (min, mean, max, etc). Moreover, methods from the realm of image processing, 2D Fourier transformation combined with principal component analysis, are employed for dimensionality reduction. Several machine learning approaches are evaluated including linear discriminant analysis and random forest. Using an alarm-independent reduction strategy, an overall false alarm reduction with a score of 65.52 in terms of the real-time scoring system of the challenge is achieved on a hidden dataset. Employing an alarm-specific strategy, an overall real-time score of 78.20 at a true positive rate of 95% and a true negative rate of 78% is achieved. While the results for some categories still need improvement, false alarms for extreme tachycardia are suppressed with 100% sensitivity and specificity.

Taming of the monitors: reducing false alarms in intensive care units

False alarms in intensive care units represent a serious threat to patients. We propose a method for detection of five live-threatening arrhythmias. It is designed to work with multimodal data containing electrocardiograph and arterial blood pressure or photoplethysmograph signals. The presented method is based on descriptive statistics and Fourier and Hilbert transforms. It was trained using 750 records. The method was validated during the follow-up phase of the CinC/Physionet Challenge 2015 on a hidden dataset with 500 records, achieving a sensitivity of 93% (95%) and a specificity of 87% (88%) for real-time (retrospective) files. The given sensitivity and specificity resulted in score of 81.62 (84.96) for real-time (retrospective) records. The presented method is an improved version of the original algorithm awarded the first and the second prize in CinC/Physionet Challenge 2015.

False alarm reduction in critical care

High false alarm rates in the ICU decrease quality of care by slowing staff response times while increasing patient delirium through noise pollution. The 2015 PhysioNet/Computing in Cardiology Challenge provides a set of 1250 multi-parameter ICU data segments associated with critical arrhythmia alarms, and challenges the general research community to address the issue of false alarm suppression using all available signals. Each data segment was 5 minutes long (for real time analysis), ending at the time of the alarm. For retrospective analysis, we provided a further 30 seconds of data after the alarm was triggered. A total of 750 data segments were made available for training and 500 were held back for testing. Each alarm was reviewed by expert annotators, at least two of whom agreed that the alarm was either true or false. Challenge participants were invited to submit a complete, working algorithm to distinguish true from false alarms, and received a score based on their program's performance on the hidden test set. This score was based on the percentage of alarms correct, but with a penalty that weights the suppression of true alarms five times more heavily than acceptance of false alarms. We provided three example entries based on well-known, open source signal processing algorithms, to serve as a basis for comparison and as a starting point for participants to develop their own code. A total of 38 teams submitted a total of 215 entries in this year's Challenge. This editorial reviews the background issues for this challenge, the design of the challenge itself, the key achievements, and the follow-up research generated as a result of the Challenge, published in the concurrent special issue of Physiological Measurement. Additionally we make some recommendations for future changes in the field of patient monitoring as a result of the Challenge.

Real-time arrhythmia detection with supplementary ECG quality and pulse wave monitoring for the reduction of false alarms in ICUs

False intensive care unit (ICU) alarms induce stress in both patients and clinical staff and decrease the quality of care, thus significantly increasing both the hospital recovery time and rehospitalization rates. In the PhysioNet/CinC Challenge 2015 for reducing false arrhythmia alarms in ICU bedside monitor data, this paper validates the application of a real-time arrhythmia detection library (ADLib, Schiller AG) for the robust detection of five types of life-threatening arrhythmia alarms. The strength of the application is to give immediate feedback on the arrhythmia event within a scan interval of 3 s-7.5 s, and to increase the noise immunity of electrocardiogram (ECG) arrhythmia analysis by fusing its decision with supplementary ECG quality interpretation and real-time pulse wave monitoring (quality and hemodynamics) using arterial blood pressure or photoplethysmographic signals. We achieved the third-ranked real-time score (79.41) in the challenge (Event 1), however, the rank was not officially recognized due to the 'closed-source' entry. This study shows the optimization of the alarm decision module, using tunable parameters such as the scan interval, lead quality threshold, and pulse wave features, with a follow-up improvement of the real-time score (80.07). The performance (true positive rate, true negative rate) is reported in the blinded challenge test set for different arrhythmias: asystole (83%, 96%), extreme bradycardia (100%, 90%), extreme tachycardia (98%, 80%), ventricular tachycardia (84%, 82%), and ventricular fibrillation (78%, 84%). Another part of this study considers the validation of ADLib with four reference ECG databases (AHA, EDB, SVDB, MIT-BIH) according to the international recommendations for performance reports in ECG monitors (ANSI/AAMI EC57). The sensitivity (Se) and positive predictivity (+P) are: QRS detector QRS (Se, +P)  >  99.7%, ventricular ectopic beat (VEB) classifier VEB (Se, +P)  =  95%, and ventricular fibrillation detector VFIB (P  +  = 94.8%)  >  VFIB (Se  =  86.4%), adjusted to the clinical setting requirements, giving preference to low false positive alarms.

Cardiac arrhythmia classification using multi-modal signal analysis

In this paper, as a contribution to the Physionet/Computing in Cardiology 2015 Challenge, we present individual algorithms to accurately classify five different life threatening arrhythmias with the goal of suppressing false alarm generation in intensive care units. Information obtained by analysing electrocardiogram, photoplethysmogram and arterial blood pressure signals was utilized to develop the classification models. Prior to classification, the signals were subject to a signal pre-processing stage for quality analysis. Classification was performed using a combination of support vector machine based machine learning approach and logical analysis techniques. The predicted result for a certain arrhythmia classification model was verified by logical analysis to aid in reduction of false alarms. Separate feature vectors were formed for predicting the presence or absence of each arrhythmia, using both spectral and time-domain information. The training and test data were obtained from the Physionet/CinC Challenge 2015 database. Classification algorithms were written for two different categories of data, namely real-time and retrospective, whose data lengths were 10 s and an additional 30 s, respectively. For the real-time test dataset, sensitivity of 94% and specificity of 82% were obtained. Similarly, for the retrospective test dataset, sensitivity of 94% and specificity of 86% were obtained.

Sleep Neurobiology and Critical Care Illness

The intensive care unit (ICU) environment is not propitious for restoring sleep and many studies have reported that critically ill patients have severe sleep disruptions. However, sleep alterations in critically ill patients are specific and differ significantly from those in ambulatory patients. Polysomnographic patterns of normal sleep are frequently lacking in critically ill patients and the neurobiology of sleep is important to consider regarding alternative methods to quantify sleep in the ICU. This article discusses elements of sleep neurobiology affecting the specificity of sleep patterns and sleep alterations in patients admitted to the ICU.

Noise Pollution: Do We Need a Solution? An Analysis of Noise in a Cardiac Care Unit

Introduction

Hospitals are meant to be places for respite and healing; however, technological advances and reliance on monitoring alarms has led to the environment becoming increasingly noisy. The coronary care unit (CCU), like the emergency department, provides care to ill patients while being vulnerable to noise pollution. The World Health Organization (WHO; Geneva, Switzerland) recommends that for optimum rest and healing, sound levels should average approximately 30 decibels (dB) with maximum readings less than 40 dB.

Problem

The purpose of this study was to measure and analyze sound levels in three different locations in the CCU, and to review alarm reports in relation to sound levels.

Methods

Over a one-month period, sound recorders (Extech SDL600; Extech Instruments; Nashua, New Hampshire USA) were placed in three separate locations in the CCU at the West Roxbury Veterans’ Administration (VA) Hospital (Roxbury, Massachusetts USA). Sound samples were recorded once per second, stored in Comma Separated Values format for Excel (Microsoft Corporation; Redmond, Washington USA), and then exported to Microsoft Excel. Averages were determined, plotted per hour, and alarm histories were reviewed to determine alarm noise effect on total noise for each location, as well as common alarm occurrences.

Results

Patient Room 1 consistently had the lowest average recordings, though all averages were >40 dB, despite decreases between 10:00pmand 7:00am. During daytime hours, recordings maintained levels >50 dB. Overnight noise remained above recommended levels 55.25% of the period in Patient Room 1 and 99.61% of the same time period in Patient Room 7. The nurses’ station remained the loudest location of all three. Alarms per hour ranged from 20-26 during the day. Alarms per day averaged: Patient Room 1-57.17, Patient Room 7-122.03, and the nurses’ station - 562.26. Oxygen saturation alarms accounted for 33.59% of activity, and heart-related (including ST segment and pacemaker) accounted for 49.24% of alarms.

Conclusion

The CCU cares for ill patients requiring constant monitoring. Despite advances in technology, measured noise levels for the hospital studied exceeded WHO standards of 40 dB and peaks of 45 dB, even during night hours when patients require rest. Further work is required to reduce noise levels and examine effects on patient satisfaction, clinical outcomes, and length of stay.

RyanKM,GagnonM,HannaT,MelloB,FofanaM,CiottoneG,MolloyM.Noise pollution: do we need a solution? An analysis of noise in a cardiac care unit.Prehosp Disaster Med.2016;31(4):432–435.

Role of a service corridor in ICU noise control, staff stress, and staff satisfaction: environmental research of an academic medical center

OBJECTIVE

To investigate the role of a dedicated service corridor in intensive care unit (ICU) noise control and staff stress and satisfaction.

BACKGROUND

Shared corridors immediately adjacent to patient rooms are generally noisy due to a variety of activities, including service deliveries and pickups. The strategy of providing a dedicated service corridor is thought to reduce noise for patient care, but the extent to which it actually contributes to noise reduction in the patient care environment and in turn improves staff performance has not been previously documented.

METHODS

A before-and-after comparison was conducted in an adult cardiac ICU. The ICU was relocated from a traditional hospital environment to a new addition with a dedicated service corridor. A total of 118 nursing staff participated in the surveys regarding pre-move and post-move environmental comfort, stress, and satisfaction in the previous and new units. Acoustical measures of noise within the new ICU and a control environment of the previous unit were collected during four work days, along with on-site observations of corridor traffic.

RESULTS

Independent and paired sample t-tests of survey data showed that the perceived noise level was lower and staff reported less stress and more satisfaction in the new ICU (p < 0.01). Analyses of acoustical data confirmed that the new ICU was significantly quieter (p < 0.02). Observations revealed how the service corridor impacted patient care services and traffic.

CONCLUSIONS

The addition of a dedicated service corridor works in the new unit for improving noise control and staff stress and satisfaction.

KEYWORDS

Critical care/intensive care, noise, satisfaction, staff, work environment.

Sleep and Mechanical Ventilation in Critical Care

Sleep disturbances in critically ill mechanically ventilated patients are common. Although many factors may potentially contribute to sleep loss in critical care, issues around mechanical ventilation are among the more complex. Sleep deprivation has systemic effects that may prolong the need for mechanical ventilation and length of stay in critical care and result in worse outcomes. This article provides a brief review of the physiology of sleep, physiologic changes in breathing associated with sleep, and the impact of mechanical ventilation on sleep. A summary of the issues regarding research studies to date is also included. Recommendations for the critical care nurse are provided.

Sleep neurobiology and critical care illness

The intensive care unit (ICU) environment is not propitious for restoring sleep and many studies have reported that critically ill patients have severe sleep disruptions. However, sleep alterations in critically ill patients are specific and differ significantly from those in ambulatory patients. Polysomnographic patterns of normal sleep are frequently lacking in critically ill patients and the neurobiology of sleep is important to consider regarding alternative methods to quantify sleep in the ICU. This article discusses elements of sleep neurobiology affecting the specificity of sleep patterns and sleep alterations in patients admitted to the ICU.

Sleep in the intensive care unit

Poor sleep quality is a consistently reported by patients in the ICU. In such a potentially hostile environment, sleep is extremely fragmented and sleep architecture is unconventional, with a predominance of superficial sleep stages and a limited amount of time spent in the restorative stages. Among the causes of sleep disruption in the ICU are factors intrinsic to the patients and the acute nature of their condition, as well as factors related to the ICU environment and the treatments administered, such as mechanical ventilation and drug therapy. Although the consequences of poor sleep quality for the recovery of ICU patients remain unknown, it seems to influence the immune, metabolic, cardiovascular, respiratory, and neurological systems. There is evidence that multifaceted interventions focused on minimizing nocturnal sleep disruptions improve sleep quality in ICU patients. In this article, we review the literature regarding normal sleep and sleep in the ICU. We also analyze sleep assessment methods; the causes of poor sleep quality and its potential implications for the recovery process of critically ill patients; and strategies for sleep promotion.

Non-pharmacological interventions for sleep promotion in the intensive care unit

BACKGROUND

Adults in intensive care units (ICUs) often suffer from a lack of sleep or frequent sleep disruptions. Non-pharmacological interventions can improve the duration and quality of sleep and decrease the risk of sleep disturbance, delirium, post-traumatic stress disorder (PTSD), and the length of stay in the ICU. However, there is no clear evidence of the effectiveness and harms of different non-pharmacological interventions for sleep promotion in adults admitted to the ICU.

OBJECTIVES

To assess the efficacy of non-pharmacological interventions for sleep promotion in critically ill adults in the ICU.To establish whether non-pharmacological interventions are safe and clinically effective in improving sleep quality and reducing length of ICU stay in critically ill adults.To establish whether non-pharmacological interventions are cost effective.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2014, Issue 6), MEDLINE (OVID, 1950 to June 2014), EMBASE (1966 to June 2014), CINAHL (Cumulative Index to Nursing and Allied Health Literature, 1982 to June 2014), Institute for Scientific Information (ISI) Web of Science (1956 to June 2014), CAM on PubMed (1966 to June 2014), Alt HealthWatch (1997 to June 2014), PsycINFO (1967 to June 2014), the China Biological Medicine Database (CBM-disc, 1979 to June 2014), and China National Knowledge Infrastructure (CNKI Database, 1999 to June 2014). We also searched the following repositories and registries to June 2014: ProQuest Dissertations & Theses Global, the US National Institutes of Health Ongoing Trials Register (www.clinicaltrials.gov), the metaRegister of Controlled Trials (ISRCTN Register) (www.controlled-trials.com), the Chinese Clinical Trial Registry (www.chictr.org.cn), the Clinical Trials Registry-India (www.ctri.nic.in), the Grey Literature Report from the New York Academy of Medicine Library (www.greylit.org), OpenGrey (www.opengrey.eu), and the World Health Organization International Clinical Trials Registry platform (www.who.int/trialsearch). We handsearched critical care journals and reference lists and contacted relevant experts to identify relevant unpublished data.

SELECTION CRITERIA

We included all randomized controlled trials (RCT) and quasi-RCTs that evaluated the effects of non-pharmacological interventions for sleep promotion in critically ill adults (aged 18 years and older) during admission to critical care units or ICUs.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the search results and assessed the risk of bias in selected trials. One author extracted the data and a second checked the data for accuracy and completeness. Where possible, we combined results in meta-analyses using mean differences and standardized mean differences for continuous outcomes and risk ratios for dichotomous outcomes. We used post-test scores in this review.

MAIN RESULTS

We included 30 trials, with a total of 1569 participants, in this review. We included trials of ventilator mode or type, earplugs or eye masks or both, massage, relaxation interventions, foot baths, music interventions, nursing interventions, valerian acupressure, aromatherapy, and sound masking. Outcomes included objective sleep outcomes, subjective sleep quality and quantity, risk of delirium, participant satisfaction, length of ICU stay, and adverse events. Clinical heterogeneity (e.g., participant population, outcomes measured) and research design limited quantitative synthesis, and only a small number of studies were available for most interventions. The quality of the evidence for an effect of non-pharmacological interventions on any of the outcomes examined was generally low or very low. Only three trials, all of earplugs or eye masks or both, provided data suitable for two separate meta-analyses. These meta-analyses, each of two studies, showed a lower incidence of delirium during ICU stay (risk ratio 0.55, 95% confidence interval (CI) 0.38 to 0.80, P value = 0.002, two studies, 177 participants) and a positive effect of earplugs or eye masks or both on total sleep time (mean difference 2.19 hours, 95% CI 0.41 to 3.96, P value = 0.02, two studies, 116 participants); we rated the quality of the evidence for both of these results as low.There was also some low quality evidence that music (350 participants; four studies) may improve subjective sleep quality and quantity, but we could not pool the data. Similarly, there was some evidence that relaxation techniques, foot massage, acupressure, nursing or social intervention, and sound masking can provide small improvements in various subjective measures of sleep quality and quantity, but the quality of the evidence was low. The effects of non-pharmacological interventions on objective sleep outcomes were inconsistent across 16 studies (we rated the quality of the evidence as very low): the majority of studies relating to the use of earplugs and eye masks found no benefit; results from six trials of ventilator modes suggested that certain ventilator settings might offer benefits over others, although the results of the individual trials did not always agree with each other. Only one study measured length of stay in the ICU and found no significant effect of earplugs plus eye masks. No studies examined the effect of any non-pharmacological intervention on mortality, risk of post-traumatic stress disorder, or cost-effectiveness; the included studies did not clearly report adverse effects, although there was very low quality evidence that ventilator mode influenced the incidence of central apnoeas and patient-ventilator asynchronies.

AUTHORS' CONCLUSIONS

The quality of existing evidence relating to the use of non-pharmacological interventions for promoting sleep in adults in the ICU was low or very low. We found some evidence that the use of earplugs or eye masks or both may have beneficial effects on sleep and the incidence of delirium in this population, although the quality of the evidence was low. Further high-quality research is needed to strengthen the evidence base.

A meta-analysis of sleep-promoting interventions during critical illness

BACKGROUND

Sleep quality and quantity are severely reduced in critically ill patients receiving mechanical ventilation with a potential for adverse consequences. Our objective was to synthesize the randomized controlled trials (RCTs) that measured the efficacy of sleep-promoting interventions on sleep quality and quantity in critically ill patients.

METHODS

We included RCTs that objectively measured sleep with electroencephalography or its derivatives and excluded observational studies and those that measured sleep by subjective reports. The research was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Of 6022 studies identified, 13 met eligibility criteria involving 296 critically ill patients. Eight trials looked at different modes of mechanical ventilation as sleep interventions, and the remaining 5 involved pharmacologic, nonpharmacologic, or environmental interventions. Meta-analysis of the studies revealed that sleep-promoting interventions improved sleep quantity (pooled standardized mean difference [SMD], 0.37; 95% confidence interval [CI], 0.05-0.69; P = .02) and sleep quality through reduction in sleep fragmentation (SMD, -0.31; 95% CI, -0.60 to -0.01; P = .04). Subgroup analysis revealed that timed modes of ventilation improved sleep quantity when compared with spontaneous modes of ventilation (SMD, 0.45; 95% CI, 0.10-0.81; P = .01). Nonmechanical ventilation interventions tended to improve sleep quantity (SMD, 0.65; 95% CI, -0.03 to 1.33; P = .06) and to reduce sleep fragmentation (SMD, -0.29; 95% CI, -0.61 to 0.03; P = .07).

CONCLUSIONS

The synthesized evidence suggests that both mechanical ventilation- and nonmechanical ventilation-based therapies improve sleep quantity and quality in critically ill patients, but the clinical significance is unclear. In the future, adequately powered multicenter RCTs involving pharmacologic interventions to promote sleep in critically ill patients are warranted.

Sleep in the intensive care unit

Sleep is an important physiologic process, and lack of sleep is associated with a host of adverse outcomes. Basic and clinical research has documented the important role circadian rhythm plays in biologic function. Critical illness is a time of extreme vulnerability for patients, and the important role sleep may play in recovery for intensive care unit (ICU) patients is just beginning to be explored. This concise clinical review focuses on the current state of research examining sleep in critical illness. We discuss sleep and circadian rhythm abnormalities that occur in ICU patients and the challenges to measuring alterations in circadian rhythm in critical illness and review methods to measure sleep in the ICU, including polysomnography, actigraphy, and questionnaires. We discuss data on the impact of potentially modifiable disruptors to patient sleep, such as noise, light, and patient care activities, and report on potential methods to improve sleep in the setting of critical illness. Finally, we review the latest literature on sleep disturbances that persist or develop after critical illness.

ICBEN review of research on the biological effects of noise 2011-2014

The mandate of the International Commission on Biological Effects of Noise (ICBEN) is to promote a high level of scientific research concerning all aspects of noise-induced effects on human beings and animals. In this review, ICBEN team chairs and co-chairs summarize relevant findings, publications, developments, and policies related to the biological effects of noise, with a focus on the period 2011-2014 and for the following topics: Noise-induced hearing loss; nonauditory effects of noise; effects of noise on performance and behavior; effects of noise on sleep; community response to noise; and interactions with other agents and contextual factors. Occupational settings and transport have been identified as the most prominent sources of noise that affect health. These reviews demonstrate that noise is a prevalent and often underestimated threat for both auditory and nonauditory health and that strategies for the prevention of noise and its associated negative health consequences are needed to promote public health.

Relational sustainability: environments for long-term critical care patients

Patients undergoing bone marrow transplant, using spinal cord services, and with traumatic brain injury represent a relatively new patient type, requiring both intense care and long-term care in the same facility. As medical advances allow these patients the opportunity to recover from their critical illnesses or injuries, designers and caregivers must give increased attention to the long-term critical care environment. Designing for this type of care requires an understanding of new technologies and the potential for the built environment to address the wide range of physical, sensory, and psychological issues long-term inpatients face. Recent work by SmithGroupJJR has provided valuable insights into the ways in which lighting, patient room and unit layouts, spatial volumes, and other design elements can contribute to the recovery of patients who must spend weeks or months in a critical care environment. This knowledge was gained through an approach that allows design professionals to immerse themselves in a health care institution's values, culture, and work processes. By mapping both operational flow and patients' experiences, project teams can develop design solutions that sustain the well-being of higher-acuity patients and their family members and caregivers.

Across the consciousness continuum-from unresponsive wakefulness to sleep

Advances in the development of new paradigms as well as in neuroimaging techniques nowadays enable us to make inferences about the level of consciousness patients with disorders of consciousness (DOC) retain. They, moreover, allow to predict their probable development. Today, we know that certain brain responses (e.g., event-related potentials or oscillatory changes) to stimulation, circadian rhythmicity, the presence or absence of sleep patterns as well as measures of resting state brain activity can serve the diagnostic and prognostic evaluation process. Still, the paradigms we are using nowadays do not allow to disentangle VS/UWS and minimally conscious state (MCS) patients with the desired reliability and validity. Furthermore, even rather well-established methods have, unfortunately, not found their way into clinical routine yet. We here review current literature as well as recent findings from our group and discuss how neuroimaging methods (fMRI, PET) and particularly electroencephalography (EEG) can be used to investigate cognition in DOC or even to assess the degree of residual awareness. We, moreover, propose that circadian rhythmicity and sleep in brain-injured patients are promising fields of research in this context.

Sleeping on a problem: the impact of sleep disturbance on intensive care patients - a clinical review

Sleep disturbance is commonly encountered amongst intensive care patients and has significant psychophysiological effects, which protract recovery and increases mortality. Bio-physiological monitoring of intensive care patients reveal alterations in sleep architecture, with reduced sleep quality and continuity. The etiological causes of sleep disturbance are considered to be multifactorial, although environmental stressors namely, noise, light and clinical care interactions have been frequently cited in both subjective and objective studies. As a result, interventions are targeted towards modifiable factors to ameliorate their impact. This paper reviews normal sleep physiology and the impact that sleep disturbance has on patient psychophysiological recovery, and the contribution that the clinical environment has on intensive care patients' sleep.

Health care worker attitudes and identified barriers to patient sleep in the medical intensive care unit

OBJECTIVE

To identify barriers to sleep for intensive care unit (ICU) patients.

DESIGN

A qualitative study using semi-structured interviews.

SUBJECTS

Nurses and physicians who had experience working the night shift.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Multiple environmental barriers to sleep in the ICU were identified when participants were directly asked about factors affecting sleep. Responses highlighted healthcare system-based barriers related to hospital/ICU policy and workflow. Implicit barriers to sleep were found when participants responded to open-ended questions. These included attitudinal barriers such as the uncertainty about the significance of sleep, the tension between providing protocol-driven ICU care and allowing uninterrupted patient sleep, and lack of consensus regarding interventions to promote sleep.

CONCLUSIONS

This qualitative study suggests that health care worker attitudes, methods of sleep promotion, hospital institutional policies and workflow may contribute to sleep disruption in the ICU. These barriers provide additional targets for intervention in studies designed to improve sleep in the ICU.

Sleep deprivation, pain and prematurity: a review study

The aim was to describe current reports in the scientific literature on sleep in the intensive care environment and sleep deprivation associated with painful experiences in premature infant. A systematic search was conducted for studies on sleep, pain, premature birth and care of the newborn. Web of Knowledge, MEDLINE, LILACS, Cochrane Library, PubMed, EMBASE, Scopus, VHL and SciELO databases were consulted. The association between sleep deprivation and pain generates effects that are observed in the brain and the behavioral and physiological activity of preterm infants. Polysomnography in intensive care units and pain management in neonates allow comparison with the first year of life and term infants. We have found few references and evidence that neonatal care programs can influence sleep development and reduce the negative impact of the environment. This evidence is discussed from the perspective of how hospital intervention can improve the development of premature infants.

Psychological evaluation of patients in critical care/intensive care unit and patients admitted in wards

BACKGROUND

Psychological assessment for depression, anxiety and stress among ICU patients and the patients admitted to ward in a hospital in India. This aspect did not get much attention in India so far. Such studies were common in developed countries. Therefore we decided in this study, to analyse the psychological status responses from the hospitalised patients in Mangalore using a validated questionnaire.

AIM

To assess and compare the depression, anxiety and stress Scores from the patients admitted in Intensive Care Unit (ICU) and those admitted to ward.

MATERIALS AND METHODS

Eighty patients admitted to hospital, 40 from ICU and 40 admitted to ward were recruited. They were explained the procedure and after taking an informed consent, they were administered Depression, Anxiety, Stress Scale (DASS) Questionnaire, which contains 42-item questionnaire which includes three self-report scales designed to measure the negative emotional states of depression, anxiety and stress. The responses were computed and tabulated. We analysed the responses with Student's t-test and Chi-square test, p<0.05 accepted as statistically significant.

RESULTS

The results revealed significantly elevated stress, depression and anxiety among the ICU patients when compared to those in the ward (p<0.001). Above normal anxiety and stress levels were also seen in the ward patients, compared to the scores in normal range. 50% and 25% respectively showed mild and normal depression scores in ward patients, compared to 12% and 5% in those admitted to ICU. This trend was also true for Anxiety and stress scores.

CONCLUSION

From the results we found that there were elevated depression, anxiety and stress levels among the patients and this was significantly higher in ICU patients. Various factors could influence the psychological wellbeing of the patients, including the hospital environment, care givers, presence of family members nearby apart from the seriousness of illness, apprehensions about possibility of death. Such studies were rare among Indian patients. The findings of this study could be useful in incorporating suitable psychological help to the patients in hospitals to improve their recovery and wellbeing.

Effects of Dexmedetomidine on Sleep Quality in Critically Ill Patients

Background:

Dexmedetomidine, a potent α-2-adrenergic agonist, is widely used as sedative in critically ill patients. This pilot study was designed to assess the effect of dexmedetomidine administration on sleep quality in critically ill patients.

Methods:

Polysomnography was performed on hemodynamically stable critically ill patients for 57 consecutive hours, divided into three night-time (9:00 pm to 6:00 am) and two daytime (6:00 am to 9:00 pm) periods. On the second night, dexmedetomidine was given by a continuous infusion targeting a sedation level −1 to −2 on the Richmond Agitation Sedation Scale. Other sedatives were not permitted.

Results:

Thirteen patients were studied. Dexmedetomidine was given in a dose of 0.6 μg kg−1 h−1 (0.4 to 0.7) (median [interquartile range]). Compared to first and third nights (without dexmedetomidine), sleep efficiency was significantly higher during the second night (first: 9.7% [1.6 to 45.1], second: 64.8% [51.4 to 79.9], third: 6.9% [0.0 to 17.1], P &lt; 0.002). Without dexmedetomidine, night-time sleep fragmentation index (7.6 events per hour [4.8 to 14.2]) and stage 1 of sleep (48.0% [30.1 to 66.4]) were significantly higher (P = 0.023 and P = 0.006, respectively), and stage 2 (47.0% [27.5 to 61.2]) showed values lower (P = 0.006) than the corresponding values (2.7 events per hour [1.6 to 4.9], 13.1% [6.2 to 23.6], 80.2% [68.9 to 92.8]) observed with dexmedetomidine. Without sedation, sleep was equally distributed between day and night, a pattern that was modified significantly (P = 0.032) by night-time dexmedetomidine infusion, with more than three quarters of sleep occurring during the night (79% [66 to 87]).

Conclusion:

In highly selected critically ill patients, dexmedetomidine infusion during the night to achieve light sedation improves sleep by increasing sleep efficiency and stage 2 and modifies the 24-h sleep pattern by shifting sleep mainly to the night.

Feasibility study of unattended polysomnography in medical intensive care unit patients

OBJECTIVES

To evaluate the feasibility of using unattended, portable polysomnography (PSG) to measure sleep among patients in the medical intensive care unit (MICU).

BACKGROUND

Accurate measurement of sleep is critical to studies of MICU sleep deprivation. Although PSG is the gold standard, there is limited data regarding the feasibility of utilizing unattended, portable PSG modalities in the MICU.

METHODS

MICU based observational pilot study. We conducted unattended, 24-h PSG studies in 29 patients. Indicators of feasibility included attainment of electroencephalography data sufficient to determine sleep stage, sleep efficiency, and arousal indices.

RESULTS

Electroencephalography data were not affected by electrical interference and were of interpretable quality in 27/29 (93%) of patients. Overnight sleep efficiency was 48% reflecting a mean overnight sleep duration of 3.7 h.

CONCLUSIONS

Unattended, portable PSG produces high quality sleep data in the MICU and can facilitate investigation of sleep deprivation among critically ill patients. Patient sleep was short and highly fragmented.

Auditory and non-auditory effects of noise on health

Noise is pervasive in everyday life and can cause both auditory and non-auditory health effects. Noise-induced hearing loss remains highly prevalent in occupational settings, and is increasingly caused by social noise exposure (eg, through personal music players). Our understanding of molecular mechanisms involved in noise-induced hair-cell and nerve damage has substantially increased, and preventive and therapeutic drugs will probably become available within 10 years. Evidence of the non-auditory effects of environmental noise exposure on public health is growing. Observational and experimental studies have shown that noise exposure leads to annoyance, disturbs sleep and causes daytime sleepiness, affects patient outcomes and staff performance in hospitals, increases the occurrence of hypertension and cardiovascular disease, and impairs cognitive performance in schoolchildren. In this Review, we stress the importance of adequate noise prevention and mitigation strategies for public health.

Sleep of critically ill children in the pediatric intensive care unit: a systematic review

Critically ill children in the pediatric intensive care unit (PICU) are exposed to multiple physical, environmental and pharmacologic factors which increase the propensity for sleep disruption and loss and may, in turn, play a role in short-term recovery from critical illness and long-term neurocognitive outcomes. Mechanically ventilated children receive sedative and analgesic medications, often at high doses and for long durations, to improve comfort and synchrony with mechanical ventilation. Sedatives and analgesics can decrease slow wave sleep and rapid eye movement sleep. Paradoxically, sedative medication doses are often increased in critically ill children to improve the subjective assessment of sedation and sleep, leading to further agitation and deterioration of sleep quality. The heterogeneity in age and critical illness encountered in the PICU pose several challenges to research on sleep in this setting. The present article reviews the available evidence on sleep in critically ill children admitted to the PICU, with an emphasis on subjective and objective methods of sleep assessment used and special populations studied, including mechanically ventilated children and children with severe burns.