Using Clinically Accessible Tools to Measure Sound Levels and Sleep Disruption in the ICU: A Prospective Multicenter Observational Study

Relationship between noise levels and intensive care patients' clinical complexity: An observational simulation study

BACKGROUND

Noise pollution in intensive care units is a relevant problem, associated with psychological and physiological consequences for patients and healthcare staff. Sources of noise pollution include medical equipment, alarms, communication tools, staff activities, and conversations.

AIMS

To explore the cumulative effects of noise caused by an increasing number and type of medical devices in an intensive care setting on simulated patients with increasing clinical complexity. Secondly, to measure medical device alarms and nursing activities' sound levels, evaluating their role as potentially disruptive noises.

STUDY DESIGN

Observational simulation study (reported according to the STROBE checklist). Using an electronic sound meter, the sound levels of an intensive care room in seven simulated clinical scenarios were measured on a single day (09 March 2022), each featuring increasing numbers of devices, hypothetically corresponding to augmented patients' clinical complexity. Secondly, noise levels of medical device alarms and specific nursing activities performed at a distance of three meters from the sound meter were analysed.

RESULTS

The empty room's mean baseline noise level was 37.8 (±0.7) dBA; among the simulated scenarios, noise ranged between 45.3 (±1.0) and 53.5 (±1.5) dBA. Alarms ranged between 76.4 and 81.3 dBA, while nursing tasks (closing a drawer, opening a saline bag overwrap, or sterile packages) and speaking were all over 80 dBA. The noisiest activity was opening a sterile package (98 dBA).

CONCLUSION

An increased number of medical devices, an expression of patients' higher clinical complexity, is not a significant cause of increased noise. Some specific nursing activities and conversations produce higher noise levels than medical devices and alarms. This study's findings suggest further research to assess the relationships between these factors and to encourage adequate noise reduction strategies.

RELEVANCE TO CLINICAL PRACTICE

Excessive noise level in the intensive care unit is a clinical issue that negatively affects patients' and healthcare providers' well-being. The increase in baseline room noise from medical devices is generally limited. Typical nursing tasks and conversations produce higher noise levels than medical devices and alarms. These findings could be helpful to raise awareness among healthcare professionals to recognize noise sources. The noisiest components of the environment can be modified by staff behaviour, promoting noise reduction strategies and improving the critical care environment.

Mitigating Intensive Care Unit Noise: Design-Led Modeling Solutions, Calculated Acoustic Outcomes, and Cost Implications

OBJECTIVES, PURPOSE, OR AIM

The study aimed to decrease noise levels in the ICU, anticipated to have adverse effects on both patients and staff, by implementing enhancements in acoustic design.

BACKGROUND

Recognizing ICU noise as a significant disruptor of sleep and a potential hindrance to patient recovery, this study was conducted at a 40-bed ICU in Fiona Stanley Hospital in Perth, Australia.

METHODS

A comprehensive mixed-methods approach was employed, encompassing surveys, site analysis, and acoustic measurements. Survey data highlighted the importance of patient sleep quality, emphasizing the negative impact of noise on work performance, patient connection, and job satisfaction. Room acoustics analysis revealed noise levels ranging from 60 to 90 dB(A) in the presence of patients, surpassing sleep disruption criteria.

RESULTS

Utilizing an iterative 3D design modeling process, the study simulated significant acoustic treatment upgrades. The design integrated effective acoustic treatments within patient rooms, aiming to reduce noise levels and minimize transmission to adjacent areas. Rigorous evaluation using industry-standard acoustic software highlights the design's efficacy in reducing noise transmission in particular. Additionally, cost implications were examined, comparing standard ICU construction with acoustically treated options for new construction and refurbishment projects.

CONCLUSIONS

This study provides valuable insights into design-based solutions for addressing noise-related challenges in the ICU. While the focus is on improving the acoustic environment by reducing noise levels and minimizing transmission to adjacent areas. It is important to clarify that direct measurements of patient outcomes were not conducted. The potential impact of these solutions on health outcomes, particularly sleep quality, remains a crucial aspect for consideration.

[Sounds in intensive care units: Perspectives of patients and parents. A qualitative study]

Sounds in intensive care units: Perspectives of patients and parents. A qualitative study Abstract: Background: Sound levels in intensive care units exceed internationally recommended limits. This can have negative effects on patients, relatives, and staff. There is a lack of evidence on noise-reducing measures. Aim: The aim of the study was the implementation and evaluation of ward-specific noise management in intensive care units. In the present article, the question of the noise and stress experience of intensive care patients and parents of neonatal intensive care patients was explored. Methods: 33 semi-structured interviews with intensive care patients and parents of neonatal intensive care patients in three intensive care units were conducted and analysed. Results: Sounds in intensive care units can be stressful (especially alarms) but also be interpreted as meaningful. This is not only related to the context of the ICU, but also to individual experiences and the social aspects of the sounds. In order to avoid or reduce stress, participants apply individual noise (stress) management. In contrast, ward-related noise management had no specific effect on the participants. Conclusions: The findings offer indications for suitable measures to reduce the noise exposure of intensive care patients and parents of neonatal intensive care patients. Research about measures such as concepts for supporting the attribution and differentiation of sounds could follow.

Sleep during and following critical illness: A narrative review

Sleep is a complex process influenced by biological and environmental factors. Disturbances of sleep quantity and quality occur frequently in the critically ill and remain prevalent in survivors for at least 12 mo. Sleep disturbances are associated with adverse outcomes across multiple organ systems but are most strongly linked to delirium and cognitive impairment. This review will outline the predisposing and precipitating factors for sleep disturbance, categorised into patient, environmental and treatment-related factors. The objective and subjective methodologies used to quantify sleep during critical illness will be reviewed. While polysomnography remains the gold-standard, its use in the critical care setting still presents many barriers. Other methodologies are needed to better understand the pathophysiology, epidemiology and treatment of sleep disturbance in this population. Subjective outcome measures, including the Richards-Campbell Sleep Questionnaire, are still required for trials involving a greater number of patients and provide valuable insight into patients’ experiences of disturbed sleep. Finally, sleep optimisation strategies are reviewed, including intervention bundles, ambient noise and light reduction, quiet time, and the use of ear plugs and eye masks. While drugs to improve sleep are frequently prescribed to patients in the ICU, evidence supporting their effectiveness is lacking.

Sleep assessment in critically ill adults: A systematic review and meta-analysis

PURPOSE

To systematically review sleep evaluation, characterize sleep disruption, and explore effects of sleepdisruption on outcomes in adult ICU patients.

MATERIALS AND METHODS

We systematically searched databases from May 1969 to June 2021 (PROSPERO protocol number: CRD42020175581). Prospective and retrospective studies were included studying sleep in critically ill adults, excluding patients with sleep or psychiatric disorders. Meta-regression methods were applied when feasible.

RESULTS

132 studies (8797 patients) were included. Fifteen sleep assessment methods were identified, with only two validated. Patients had significant sleep disruption, with low sleep time, and low proportion of restorative rapid eye movement (REM). Sedation was associated with higher sleep efficiency and sleep time. Surgical versus medical patients had lower sleep quality. Patients on ventilation had a higher amount of light sleep. Meta-regression only suggested an association between total sleep time and occurrence of delirium (p < 0.001, 15 studies, 519 patients). Scarce data precluded further analyses. Sleep characterized with polysomnography (PSG) correlated well with actigraphy and Richards Campbell Sleep Questionnaire (RCSQ).

CONCLUSIONS

Sleep in critically ill patients is severely disturbed, and actigraphy and RCSQ seem reliable alternatives to PSG. Future studies should evaluate impact of sleep disruption on outcomes.

Impact of sound levels on physiological and consciousness state of cardiovascular patients

BACKGROUND

Patients treated in intensive care units (ICUs) experience life-threatening medical conditions but some external factors in ICUs do not help or even adversely affect and complicate their evolution. Among others, such factors include noise pollution due to alarms and medical clinical equipment, as well as the activities of the health care personnel themselves.

AIM

This study aimed to evaluate the influence of elevated sound levels on physiological variables and the consciousness state of patients treated in a cardiovascular area in an ICU.

DESIGN

A longitudinal study with several observations was carried out during 1 month in the cardiovascular area of an ICU of a third-level hospital in southern Spain.

METHODS

Sound levels were monitored in different work shifts and patients' physiological data and consciousness status were recorded. Generalized additive mixed models (GAMMs) were developed to detect the variability of the sound levels together with the vital parameters of the patients in the ICU.

RESULTS

Thirty-eight patients were included. The mean sound level was 54.09 dBA. The GAMM sound levels analysis showed a significant increase in sound levels from 4:30 p.m. to 8:00 p.m. (1.83 dBA; P < .001) and 8:00 p.m. to 11:30 p.m. (3.06 dBA; P < .001). An increase in heart rate (3.66 bpm; P < .001), respiratory rate (2.62 rpm; P < .001) and the Glasgow Coma Scale (0.50 units; P = .002) was detected during the 4:30 p.m.-8:30 p.m.

PERIOD

CONCLUSIONS

Elevated sound levels in cardiovascular ICUs seem to influence positively the physiological and consciousness status of patients. Given the importance of the findings for patient safety, future intervention studies are recommended.

RELEVANCE TO CLINICAL PRACTICE

The finding of this study could translate into structural changes in ICU facilities, as well as the development of clinical practice guidelines that influence the behaviour of health care professionals.

Noise Exposure and Quality of Life Among Nurses

BACKGROUND

The purpose of this study was to describe the relationship between noise exposure, selected health conditions, and well-being among nurses.

METHODS

A secondary analysis was performed on data obtained from 3,818 U.S. nurses who responded to a survey regarding noise exposure, health conditions, stress, professional quality of life, and workplace support.

FINDINGS

Those who reported high noise exposure reported more health conditions, higher stress and burnout scores, and lower supportive environments. High noise exposure was significantly associated with lower professional quality of life.

CONCLUSION/APPLICATION TO PRACTICE

Noise may impact the health and quality of professional life of nurses. Occupational health nurses should advocate for the regular monitoring of nurses' exposure to hazardous noise at work, compare it to OSHA permissible levels, and collaborate with the occupational health team to ensure safe noise levels are maintained. Occupational health nurses should advocate for expanded research on effects of noise on health.

Development and Implementation of a Multicomponent Protocol to Promote Sleep and Reduce Delirium in a Medical Intensive Care Unit

BACKGROUND

Evidence suggests that poor sleep increases risk of delirium. Because delirium is associated with poor outcomes, institutions have developed protocols to improve sleep in critically ill patients.

OBJECTIVE

To assess the impact of implementing a multicomponent sleep protocol.

METHODS

In this prospective, preimplementation and postimplementation evaluation, adult patients admitted to the medical intensive care unit (ICU) over 42 days were included. Outcomes evaluated included median delirium-free days, median Richards-Campbell Sleep Questionnaire (RCSQ) score, median optimal sleep nights, duration of mechanical ventilation (MV), ICU and hospital length of stay (LOS), and in-hospital mortality.

RESULTS

The preimplementation group included 78 patients and postimplementation group, 84 patients. There was no difference in median delirium-free days (1 day [interquartile range, IQR, = 0-2.5] vs 1 day [IQR = 0-2]; P = 0.48), median RCSQ score (59.4 [IQR = 43.2-71.6] vs 61.2 [IQR = 49.9-75.5]; P = 0.20), median optimal sleep nights (1 night [IQR = 0-2] vs 1 night [IQR = 0-2]; P = 0.95), and in-hospital mortality (16.7% vs 17.9%, P = 1.00). Duration of MV (8 days [IQR = 4-10] vs 4 days [IQR = 2-7]; P = 0.03) and hospital LOS (13 days [IQR = 7-22.3] vs 8 days [IQR = 6-17]; P = 0.05) were shorter in the postimplementation group, but both were similar between groups after adjusting for age and severity of illness.

CONCLUSIONS AND RELEVANCE

This report demonstrates that implementation of a multicomponent sleep protocol in everyday ICU care is feasible, but limitations exist when evaluating impact on measurable outcomes. Additional evaluations are needed to identify the most meaningful interventions and best practices for quantifying impact on patient outcomes.

Administration of pharmacological sleep aids prior to, during and following critical illness

BACKGROUND

Sleep in the intensive care unit (ICU) is frequently disturbed and this may have a detrimental effect on recovery.

AIMS

To determine use of pharmacological sleep aids in critically ill patients prior to, during and after ICU admission.

METHODS

We conducted a single-centre period prevalence study of all adult patients admitted to a university-associated adult medical-surgical Intensive Care Unit (ICU) for more than two nights in a three-month period ending September 2019. The major outcome of interest was the proportion of ICU patients who had a pharmacological sleep aid administered prior to, during and after ICU admission. Associations of selected patient variables with sleep aid prescription in the ICU were summarized both as unadjusted univariable comparisons, and as adjusted effect estimates returned by a multivariable logistic regression model.

RESULTS

During the study period, 370 patients met all eligibility criteria. A pharmacological sleep aid was identified prior to hospital admission in 34 patients (9%) and in 62 patients (17%) during ICU admission. Of the 340 ICU survivors, 292 remained in the same hospital. Of these, 96 (33%) received a pharmacological sleep aid at least once during their post-ICU general hospital ward stay. Pre-hospital sleep aid use, male sex, longer ICU admission and higher APACHE III scores were associated with sleep aid prescription in the ICU.

CONCLUSIONS

Pharmacological sleep aids are administered frequently in the ICU with administration increasing substantially after ICU discharge. This article is protected by copyright. All rights reserved.

A Systematic Review of Risk Factors for Sleep Disruption in Critically Ill Adults

OBJECTIVES

Numerous risk factors for sleep disruption in critically ill adults have been described. We performed a systematic review of all risk factors associated with sleep disruption in the ICU setting.

DATA SOURCES

PubMed, EMBASE, CINAHL, Web of Science, Cochrane Central Register for Controlled Trials, and Cochrane Database of Systematic Reviews.

STUDY SELECTION

English-language studies of any design published between 1990 and April 2018 that evaluated sleep in greater than or equal to 10 critically ill adults (> 18 yr old) and investigated greater than or equal to 1 potential risk factor for sleep disruption during ICU stay. We assessed study quality using Newcastle-Ottawa Scale or Cochrane Risk of Bias tool.

DATA EXTRACTION

We abstracted all data independently and in duplicate. Potential ICU sleep disruption risk factors were categorized into three categories based on how data were reported: 1) patient-reported reasons for sleep disruption, 2) patient-reported ratings of potential factors affecting sleep quality, and 3) studies reporting a statistical or temporal association between potential risk factors and disrupted sleep.

DATA SYNTHESIS

Of 5,148 citations, we included 62 studies. Pain, discomfort, anxiety/fear, noise, light, and ICU care-related activities are the most common and widely studied patient-reported factors causing sleep disruption. Patients rated noise and light as the most sleep-disruptive factors. Higher number of comorbidities, poor home sleep quality, home sleep aid use, and delirium were factors associated with sleep disruption identified in available studies.

CONCLUSIONS

This systematic review summarizes all premorbid, illness-related, and ICU-related factors associated with sleep disruption in the ICU. These findings will inform sleep promotion efforts in the ICU and guide further research in this field.

A Systematic Review of Sleep Measurement in Critically Ill Patients

Background: Clinical trialists and clinicians have used a number of sleep quality measures to determine the outcomes of interventions to improve sleep and ameliorate the neurobehavioral consequences of sleep deprivation in critically ill patients, but findings have not always been consistent. To elucidate the source of these consistencies, an important consideration is responsiveness of existing sleep measures. The purpose of an evaluative measure is to describe a construct of interest in a specific population, and to measure the extent of change in the construct over time. This systematic literature review identified measures of sleep quality in critically ill adults hospitalized in the Intensive Care Unit (ICU), and assessed their measurement properties, strengths and weaknesses, clinical usefulness, and responsiveness. We also recommended modifications, including new technology, that may improve clinical usefulness and responsiveness of the measures in research and practice.

Methods: CINAHAL, PubMed/Medline, and Cochrane Library were searched from January 1, 2000 to February 1, 2020 to identify studies that evaluated sleep quality in critically ill patients.

Results: Sixty-two studies using polysomnography (PSG) and other electroencephalogram-based methods, actigraphy, clinician observation, or patient perception using questionnaires were identified and evaluated. Key recommendations are: standard criteria are needed for scoring PSG in ICU patients who often have atypical brain waves; studies are too few, samples sizes too small, and study duration too short for recommendations on electroencephalogram-based measures and actigraphy; use the Sleep Observation Tool for clinician observation of sleep; and use the Richards Campbell Sleep Questionnaire to measure patient perception of sleep.

Conclusions: Measuring the impact of interventions to prevent sleep deprivation requires reliable and valid sleep measures, and investigators have made good progress developing, testing, and applying these measures in the ICU. We recommend future large, multi-site intervention studies that measure multiple dimensions of sleep, and provide additional evidence on instrument reliability, validity, feasibility and responsiveness. We also encourage testing new technologies to augment existing measures to improve their feasibility and accuracy.

Impact of sound levels and patient-related factors on sleep of patients in the intensive care unit: a cross-sectional cohort study

Sleep disruption is common in patients in the intensive care unit (ICU). The aim of the study was to measure sound levels during sleep-protected time in the ICU, determine sources of sound, assess the impact of sound levels and patient-related factors on duration and quality of patients' sleep. The study was performed between 2018 and 2019. A commercially available smartphone application was used to measure ambient sound levels. Sleep duration was measured using the Patient's Sleep Behaviour Observational Tool. Sleep quality was assessed using the Richards-Campbell Sleep Questionnaire (RCSQ). The study population comprised 18 (58%) men and 13 (42%) women. There were numerous sources of sound. The median duration of sleep was 5 (IQR 3.5–5.7) hours. The median score on the RCSQ was 49 (IQR 28–71) out of 100 points. Sound levels were negatively correlated with sleep duration. The cut-off peak sound level, above which sleep duration was shorter than mean sleep duration in the cohort, was 57.9 dB. Simple smartphone applications can be useful to estimate sound levels in the ICU. There are numerous sources of sound in the ICU. Individual units should identify and eliminate their own sources of sound. Sources of sound producing peak sound levels above 57.9 dB may lead to shorter sleep and should be eliminated from the ICU environment. The sound levels had no effect on sleep quality.

The effects of noise levels on pain, anxiety, and sleep in patients

BACKGROUND

Intensive care is a noisy environment for patients and one that affects pain, anxiety levels, and sleep quality.

AIMS AND OBJECTIVES

To determine the relationship between noise levels and pain, anxiety, and sleep levels in patients in intensive care units.

DESIGN

A descriptive and observational study design was used.

METHODS

This study was conducted between June and December 2018 in a public hospital and included 111 patients admitted to surgical critical care for at least 24 hours. Three Benetech Gm1351 manual sound level metres were used to measure noise. A Patient Information Form, a pain Visual Analog Scale (VAS), the Spielberger State-Trait Anxiety Inventory, and the Richards Campbell Sleep Questionnaire (RCSQ) were used for data collection.

RESULTS

The mean age of the patients was 57.29 years. The mean noise level detected in the intensive care unit was 66.52 dB (dB). Patients' mean pain VAS score was 3.79 ± 1.72, the mean State Anxiety Inventory score was 39.74 ± 2.98, and the mean total RCSQ score was 25.10 ± 13.17. Our findings show that patients in the intensive care unit are exposed to high noise levels and that, while this has no effect on pain, it significantly impacts anxiety and quality of sleep.

CONCLUSIONS

Noise levels in intensive care units significantly exceed recommended thresholds, and this adversely affects patients' anxiety levels and sleep quality. It is important for suitably restful conditions to be provided for patients, to be aware of the potential for anxiety, and for these factors to be borne in mind when planning nursing interventions.

RELEVANCE TO CLINICAL PRACTICE

Further studies on the effects of noise levels on pain, anxiety, and sleep levels in patients admitted to intensive care units are needed.

Research Outcomes of Implementing CEASE: An Innovative, Nurse-Driven, Evidence-Based, Patient-Customized Monitoring Bundle to Decrease Alarm Fatigue in the Intensive Care Unit/Step-down Unit

INTRODUCTION

The research literature is replete with evidence that alarm fatigue is a real phenomenon in the clinical practice environment and can lead to desensitization of the need to respond among nursing staff. A few studies attest to the effectiveness of incorporating parts of the American Association of Critical-Care Nurses recommended nursing practices for alarm management. No studies could be found measuring the effectiveness of the American Association of Critical-Care Nurses recommendations in their entirety or the effectiveness of a nursing-driven, evidence-based, patient-customized monitoring bundle.

PURPOSE/RESEARCH QUESTION

The purpose of this study was to describe the effect of implementing CEASE, a nurse-driven, evidence-based, patient-customized monitoring bundle on alarm fatigue. CEASE is an acronym for Communication, Electrodes (daily changes), Appropriateness (evaluation), Setup alarm parameters (patient customization), and Education (ongoing).

RESEARCH QUESTIONS

(1) In a 36-bed intensive care unit/step-down unit (ICU/SDU) with continuous hemodynamic and respiratory monitoring, does application of an evidence-based, patient-customized monitoring bundle compared with existing monitoring practice lead to less alarm fatigue as measured by the number of hemodynamic and respiratory monitoring alarms? (2) In a 36-bed ICU/SDU with continuous hemodynamic and respiratory monitoring, does application of an evidence-based, patient-customized monitoring bundle compared with existing monitoring practice lead to less alarm fatigue as measured by duration of alarms? and (3) In a 36-bed ICU/SDU with continuous hemodynamic and respiratory monitoring, does application of an evidence-based, patient-customized monitoring bundle compared with existing monitoring practice lead to less alarm fatigue as measured by nurse perception?

METHODS

This was an institutional review board approved exploratory, nonrandomized, pretest and posttest, 1-group, quasi-experimental study, without-comparators design describing difference in pretest and posttest measures following CEASE Bundle implementation. The study was conducted over a 6-month period. Convenience sample of 74 registered nurses staffing a 36-bed ICU/SDU using the CEASE Bundle participated. Preimplementation/postimplementation number of alarms and alarm duration time for a 30-day period were downloaded from the monitoring system and compared. Nurses completed an electronic 36-item Clinical Alarms Survey provided by the Healthcare Technology Foundation: 35 before implementation and 18 after implementation. Researchers measured CEASE alarm bundle adherence. χ and t-tests determined statistical significance.

RESULTS

Total number of monitoring alarms decreased 31% from 52 880 to 36 780 after CEASE Bundle implementation. Low-priority Level 1 alarms duration time significantly decreased 23 seconds (t = 1.994, P = .045). Level 2 duration time did not change. High-priority Level 3 alarms duration time significantly increased to 246 seconds (t = 4.432, P < .0001). CEASE alarm bundle adherence significantly improved to 22.4% (χ = 5.068, P = .0244). Nurses perceived a significant decrease in nuisance alarm occurrence (68% to 44%) postimplementation (χ = 3.243, P = .0417). No adverse patient events occurred.

CONCLUSIONS

Decreased total number of monitoring alarms improved nurse perception of alarm fatigue. Continued monitoring of CEASE Bundle adherence by nursing staff is required. Longer high-priority Level 3 alarms duration suggests need for further research.

The effectiveness of noise interventions in the ICU

PURPOSE OF REVIEW

Excessive noise has direct adverse physiological and psychological effects, and may also have indirect negative health consequences by reducing sleep quality and quantity. This review presents a synthesis of the epidemiology of noise in the ICU, and the potential interventions designed to attenuate noise and protect patients.

RECENT FINDINGS

Noise increases cortisol release, oxygen consumption, and vasoconstriction. ICU noise levels are excessive throughout the 24-h cycle, irrespective of level of intervention or whether the patient is in a side room or open ward. Direct measurement suggests that noise is a substantial contributor to poor sleep quantity and quality in the ICU and is frequently recalled by survivors of critical illness as a negative experience of ICU admission. Noise abatement, environmental masking and pharmacological interventions may all reduce the impact of noise on patients. However, the sustainability of behavioural interventions remains uncertain and high-quality evidence demonstrating the benefit of any intervention on patient-centered outcomes is lacking.

SUMMARY

Noise levels in the ICU are consistently reported to reach levels likely to have both direct and indirect adverse health consequences for both patients and staff. Noise reduction, abating the transmission of noise and pharmacological modulation of the adverse neural effects of noise are all potentially beneficial strategies, although definitive evidence of improved patient-centered outcomes is lacking.

Development and daily use of a numeric rating score to assess sleep quality in ICU patients

PURPOSE

Insufficient sleep burdens critically ill patients, optimizing sleep may enhance patient's outcomes. Current assessment methods may unnecessary burden patients. Therefore, a single numeric rating score was validated for sleep assessment.

MATERIALS AND METHODS

First, two cross-sectional measurements on two separate days, from cooperative patients from 19 centers assessed their sleep sufficiency, the numeric rating score (NRS) and the Richards Campbell Sleep Questionnaire (RCSQ). Assessments were compared using a Bland Altman plot. A NRS cut-off was determined using regression analysis. Second, daily sleep assessment was implemented and monitored single center for a year.

RESULTS

Multicenter, 194 patients assessed sleep quality, of which 53% was rated as sufficient. Mean (±SD) difference between RCSQ and NRS-Sleep using Bland-Altman analysis was 0.25 (±1.21, 95% limits of agreement -2.12 to 2.62). The optimal cut-off was >5. Single center, 1603 patients ranked 4532 ICU nights of sleep, of which 71% was sufficient; median NRS was 6 [IQR 5-7].

CONCLUSIONS

A single numeric rating score for sleep is interchangeable for the RCSQ score for assessment of sleep quality. Optimal cut-off is >5. Use of a numeric rating score for sleep is a practical way to evaluate and monitor sleep as perceived by patients in daily ICU practice.

Investigating the application of motion accelerometers as a sleep monitoring technique and the clinical burden of the intensive care environment on sleep quality: study protocol for a prospective observational study in Australia

INTRODUCTION

Sleep is a state of quiescence that facilitates the significant restorative processes that enhance individuals' physiological and psychological well-being. Patients admitted to the intensive care unit (ICU) experience substantial sleep disturbance. Despite the biological importance of sleep, sleep monitoring does not form part of standard clinical care for critically ill patients. There exists an unmet need to assess the feasibility and accuracy of a range of sleep assessment techniques that have the potential to allow widespread implementation of sleep monitoring in the ICU.

KEY MEASURES

The coprimary outcome measures of this study are to: determine the accuracy and feasibility of motion accelerometer monitoring (ie, actigraphy) and subjective assessments of sleep (nursing-based observations and patient self-reports) to the gold standard of sleep monitoring (ie, polysomnography) in evaluating sleep continuity and disturbance. The secondary outcome measures of the study will include: (1) the association between sleep disturbance and environmental factors (eg, noise, light and clinical interactions) and (2) to describe the sleep architecture of intensive care patients.

METHODS AND ANALYSIS

A prospective, single centre observational design with a within subjects' assessment of sleep monitoring techniques. The sample will comprise 80 adults (aged 18 years or more) inclusive of ventilated and non-ventilated patients, admitted to a tertiary ICU with a Richmond Agitation-Sedation Scale score between +2 (agitated) and -3 (moderate sedation) and an anticipated length of stay >24 hours. Patients' sleep quality, total sleep time and sleep fragmentations will be continuously monitored for 24 hours using polysomnography and actigraphy. Behavioural assessments (nursing observations) and patients' self-reports of sleep quality will be assessed during the 24-hour period using the Richards-Campbell Sleep Questionnaire, subjective sleepiness evaluated via the Karolinska Sleepiness Scale, along with a prehospital discharge survey regarding patients' perception of sleep quality and disturbing factors using the Little Sleep Questionnaire will be undertaken. Associations between sleep disturbance, noise and light levels, and the frequency of clinical interactions will also be investigated. Sound and luminance levels will be recorded at 1 s epochs via Extech SDL600 and SDL400 monitoring devices. Clinical interactions will be logged via the electronic patient record system Metavision which documents patient monitoring and clinical care.

ETHICS AND DISSEMINATION

The relevant institutions have approved the study protocol and consent procedures. The findings of the study will contribute to the understanding of sleep disturbance, and the ability to implement sleep monitoring methods within ICUs. Understanding the contribution of a clinical environment on sleep disturbance may provide insight into the need to address clinical environmental issues that may positively influence patient outcomes, and could dispel notions that the environment is a primary factor in sleep disturbance. The research findings will be disseminated via presentations at national and international conferences, proceedings and published articles in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12615000945527; Pre-results.