Sleep is essential for physical and psychological restoration in all patients (Aitken et al, 2017). Reduced and disturbed sleep leads to a state of sleep deprivation. Sleep deprivation prevents growth hormone secretion and weakens the immune system and is associated with a delay in the healing process (Ganz, 2012; Zakri, 2019) and potentially results in an increased vulnerability to infection (D'Souza et al, 2019).
One of the ways of encouraging a good night's sleep and therefore reducing patients' vulnerability to infection in hospital is by creating quieter wards and fewer disturbances from health professionals. However, to date, there is lack of consensus on the most effective strategy for different care settings. The majority of research has been focused on sleep-promotion strategies to improve patients' sleep in the intensive care unit (ICU) and only a few studies focus on acute ward settings. In this article an acute ward is defined as a non-critical, non-intensive medical or surgical ward.
This study aimed to summarise the strategies of sleep-promotion in both ICU and acute ward settings by reviewing the literature. Its objectives were:
Methods
A systematic review method was used to examine previously published literature on the topic of sleep promotion and sleep quality. This method of study was chosen because it is a rigorous and valid method of summarising and critically appraising evidence from previous studies (Jesson et al, 2012; Aveyard et al, 2016).
Eligibility criteria
The following study designs were included: randomised controlled trials (RCTs), cross-sectional, cohort and qualitative studies. Other literature reviews were excluded. Studies on adults and older patients admitted to ICU and acute ward settings were included, and those with participants under 18 years old were excluded. Studies on sleep-promoting interventions published in English from 2009 to 2019 were included.
Research question and search terms
The following question was posed: ‘What is done to improve sleep quality in ICU and acute ward settings, and what are the similarities and differences in sleep-promotion interventions between these two settings?’ This question is specific and is framed using the PICOS strategy, which is recommended for qualitative research (Methley et al, 2014; Jensen et al, 2018). The population (P) studied comprised adults and elderly patients admitted to both ICU and acute ward settings. The intervention (I) was the sleep-promoting interventions that were carried out in both settings. The comparison (C) was either no sleep-promoting interventions or no comparator; the outcome (O) was the improvement of sleep quality, and the study types (S) were all study designs as described in the eligibility criteria.
In order to answer this research question, specific search terms were used to find relevant articles. The search terms were key words extracted from the research question that related to a specific topic, combined using Boolean operators and truncation (*), to obtain all the articles relevant to such topic (Aveyard et al, 2016; EBSCO Connect, 2018). Therefore, the search terms for this review were: Reduc* Noise* AND Disturb* OR Interrupt* OR Disrupt* AND Sleep At Night OR Night-time OR Night time AND Improve* AND Sleep Deprivation AND Sleep Quality AND Adult AND Elderly AND Patients.
Search result
The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines for article selection were followed. PRISMA is one of the preferred guidelines used by healthcare services for evaluating and selecting articles for review (Moher et al, 2009). The initial result of the database search and a manual search produced 29 312 articles. This result was narrowed down by the process shown in Figure 1. The final result of the selection process led to the inclusion of eight articles in the literature review (see Table 1).
| Author, date, country | Research question/aim | Study setting | Design | Sleep inhibitor or sleep promotion | Key themes | Limitations |
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Delaney et al (2018)
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To investigate the perceived duration and quality of patients sleep and identify any environmental factors associated with patient-reported poor sleep in the hospital | Acute ward setting | Cross-sectional study (Cohort) | Sleep-disturbing factors |
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Dobing et al (2017)
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To test the efficacy of non-pharmacological interventions on the sleep quality of medicine inpatients | Acute ward setting | RCT | Non-pharmacological Intervention |
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Eliassen and Hopstock (2011)
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To investigate the perceptions of the sleep-promoting interventions that ICU nurses believe they provide | ICU setting | Survey (cohort without control) | Noise reduction, light reduction, patient comfort |
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Foreman et al (2015)
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Hypothesis: patients in ICU would demonstrate similar sleep disturbance and that combination of sleep-promoting interventions would increase sleep time | ICU setting | RCT | Pharmacological intervention (melatonin, propofol), non-pharmacological intervention (eye masks, headphones) |
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Litton et al (2017)
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To assess the feasibility of earplugs as a noise-abatement strategy to improve sleep and reduce delirium in patients admitted to the intensive care unit | ICU setting | RCT | Pharmacological intervention: propofol or fentanyl. Non-pharmacological intervention: earplug insertion |
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Lopez et al (2018)
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Minimise the unnecessary sleep interruption in patients and implement evidence-based night care | Acute ward setting | Mixed-method (cohort/qualitative) | Minimise sleep interruption Promoting sleep |
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Patel et al (2014)
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To investigate whether the implementation of a bundle of non-pharmacological interventions was associated with improved sleep and reduced incidence of delirium | ICU setting | Cohort study | Multi-component bundle of interventions |
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| Salzmann-Erikson et al (2015) |
Explore nurses' experiences and their strategies to promote inpatients' sleep | Acute ward setting | Qualitative research | Sleep promotion |
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Data extraction
The authors extracted data from the selected studies independently, and any disagreement was resolved through consensus. Table 1 presents the precise aims and objectives of studies on sleep-promoting interventions carried out in ICU and acute ward settings. It shows an equal number of studies from both settings, which was necessary for a balanced comparison between the two settings.
The study designs consisted of both quantitative and qualitative studies: three RCTs, three cohorts, one qualitative and one mixed-method study. Although quantitative methods dominated the included studies, the authors were interested in the quality of the evidence presented, not in the quantitative data.
Critical appraisal
We used three different Critical Appraisal Skill Programme (CASP) checklists to assess the selected studies and used CASP elements as guidelines (CASP, 2018). The allocation of studies to CASP checklist was determined by the study design. The CASP for cohort studies was used to appraise the studies by Delaney et al (2018), Eliassen and Hopstock, (2011), Lopez et al (2018) and Patel et al (2014). The studies by Dobing et al (2017), Foreman et al (2015) and Litton et al (2017) were appraised with CASP for RCTs. The studies by Salzmann-Erikson et al (2016) and Lopez et al (2018) were appraised with CASP for qualitative studies. The study by Lopez et al (2018) was a mixed-method study and therefore, was appraised with two different CASP checklists.
Data analysis
Themes identified and emerging themes
Thematic analysis was used. Themes from each study were identified (Table 2), then coded into similar groups, named and renamed accordingly, and then compared between the studies (Jesson et al, 2012; Aveyard et al, 2016). As a result, two broad themes emerged (Table 3): sleep-disturbing factors and sleep-promoting interventions.
| Themes from the selected studies | Delaney et al (2018) | Dobing et al (2017) | Salzmann-Erikson et al (2015) | Eliassen and Hopstock (2011) | Foreman et al (2015) | Litton et al (2017) | Lopez et al (2018) | Patel et al (2014) |
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| Noise from nurses | √ | √ | √ | √ | √ | |||
| Light | √ | √ | √ | |||||
| Temperature | √ | √ | √ | |||||
| Clinical environment, discomfort, the need for toilet | √ | √ | ||||||
| Clinical care and diagnostic | √ | √ | √ | √ | √ | |||
| Pain, anxiety, cough | √ | √ | √ | |||||
| Unfamiliar with surroundings | √ | |||||||
| Ward layout | √ | |||||||
| Nursed in a single room | √ | √ | ||||||
| Education and behavioural change | √ | √ | √ | √ | ||||
| Pharmacological | √ | √ | √ | √ | √ | √ | ||
| Non-pharmacological: eye mask, earplugs, massage, toilet, pull the curtain | √ | √ | √ | √ | √ | √ | ||
| Reduce noise | √ | √ | √ | |||||
| Prevent conversation near patients' bed | √ | |||||||
| Patients comfort foot or hand massage and music | √ | √ | √ | |||||
| Clustering clinical activities: adjust the time for vital signs | √ | √ | √ | √ | √ | |||
| Reduce disturbances | √ | √ | ||||||
| Involving patient in plan and implementations | √ | √ | √ | √ |
| Sleep-disturbing factors |
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| Sleep-promoting strategies |
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Sleep-disturbing factors
Noise, light, temperature and humidity
Sleep-disturbing factors are factors that prevent patients from sleeping in a hospital environment. Factors identified in both settings included environmental factors: noise, light, temperature and humidity (Dobing et al, 2017; Delaney et al, 2018). Of those factors, noise from health professionals was the most reported sleep inhibitor. Delaney et al (2018) investigated patients' quality of sleep in 15 clinical areas and revealed that the primary sleep-inhibitor was the noise from health professionals. The overall environmental noise recording showed that the average noise level was >60 decibels in all clinical areas. Similarly, Patel et al (2014) reported a significant noise-related sleep disruption in ICU, and this was backed by an objective measure of noise level at 68.8 decibels.
In terms of light disturbance, Delaney et al (2018) and Patel et al (2014) measured light luminance, using two different light meters with different results. Delaney et al (2018) used the Extech light meter (model SDL400) in an acute ward setting and found that the light brightness level was <100 lux. In comparison, Patel et al (2014) used a CEM DT-8820 light meter and found a level of 594 lux in ICU. The difference was significant; however, the use of two different light meters might explain the differences between readings.
Similarly, for temperature and humidity, Delaney et al (2018) recorded the temperatures overnight and showed that the range was between 22.64 and 22.27°C and the humidity level was high, above 2% until 02:00 am and then gradually declined by 1.5% (Delaney et al, 2018). However, regardless of these differences, light, temperature and humidity were not considered as sleep-inhibiting factors in the studies by Delaney et al (2018) and Patel et al (2014).
Illness-related factors
Previous research on pain and sleep deprivation showed that pain disrupts sleep and sleep deprivation increases pain sensitivity (Smith and Haythornthwaite, 2004; Chhangani et al, 2009; Finan et al, 2013). Chhangani et al (2009) investigated whether sleep deprivation increased pain sensitivity in 27 healthy, pain-free normal sleeper participants categorised into sleepy and non-sleepy groups (sleepy participants received 2-hour interval awakenings the night before the experiment). The participants' index finger was exposed to a controlled heat source. The experiment showed that sleepy participants experienced more rapid finger withdrawal than non-sleepy participants when exposed to heat. This showed that sleep deprivation increases sensitivity to pain. However, Lopez et al (2018) reported that patients' sleep interruptions due to pain were reflected in the frequency of requests for painkillers during the night. Moreover, the present review also found that anxiety and uncomfortable positions in bed were reported as sleep-inhibiting factors in both settings (Eliassen and Hopstock, 2011; Dobing et al, 2017; Lopez et al, 2018).
Clinical care and diagnostics
Several studies reported that clinical care, such as nursing care, physical observations, comfort care, medication administration, clinical diagnostics and doctors' rounds, disturbed patients' sleep at night (Patel et al, 2014; Dobing et al, 2017; Delaney et al, 2018). For example, Delaney et al (2018) and Dobing et al (2017) reported that clinical care, as well as environmental noise, were the sources of sleep disturbances in acute wards settings. Similarly, Patel et al (2014) reported that frequent observations and blood sampling disturbed patients' sleep. The only difference was the need for the toilet, which was reported in acute ward settings (Delaney et al, 2018; Lopez et al, 2018) but was not reported in ICU settings (Litton et al, 2017).
Sleep-promoting strategies
Use of medication
The use of medication was reported in both settings to aid sleep (Salzmann-Erikson et al, 2016; Dobing et al, 2017) and to control pain following surgery (Foreman et al, 2015). Zopiclone (a non-benzodiazepine hypnotic), antipsychotics, antidepressants, painkillers and melatonin were the most commonly prescribed medications to aid patients' sleep in acute ward settings (Dobing et al, 2017). Comparatively, ICU settings used more propofol (a sedative), fentanyl (an opioid) and sedatives (benzodiazepine) as well as melatonin (Foreman et al, 2015) to aid patients' sleep (Litton et al, 2017).
Reduce noise and minimise disturbances
Salzmann-Erikson et al (2016) discussed the use of single rooms to reduce noise in acute ward settings. However, single-room designs in acute ward settings have been considered to be too costly (Foreman et al, 2015; Salzmann-Erikson et al, 2016); therefore, acute ward settings typically use 4-bed rooms for economic reasons (Salzmann-Erikson et al, 2016; Delaney et al, 2018).
Other strategies for reducing noise and minimising disturbances such as closing doors, reducing the volume of medical equipment, offering toileting before bed and clustering care have significantly reduced noise (Lopez et al, 2018; Delaney et al, 2018). Eliassen and Hopstock (2011) explored noise and light reduction interventions and highlighted the priority of lowering the voice to reduce noise and adjusting observation times to reduce disturbances. Similarly, Patel et al (2014) implemented noise-reduction strategies in ICU, which resulted in longer sleep duration and fewer awakenings. Lopez et al (2018) implemented a night-time protocol (offering the toilet, turning off the light, shutting doors, and implementing care while patients were awake) to minimise unnecessary interruptions in acute ward settings. Data from medical records were checked against patient and staff interviews. Lopez et al (2018) concluded that the average number of interruptions decreased from 7.03 (SD 3.08) to 6.43 (SD 3.22) (P<0.05).
Use of eye masks, earplugs and complementary treatment
The benefits of using eye masks and earplugs to reduce light and noise in both settings were reported in the studies included in this review. Salzmann-Erikson et al (2016) and Eliassen and Hopstock (2011) reported that the use of eye masks reduced the disruptive effect of light in acute ward and ICU settings. Litton et al (2017) tested earplugs for noise reduction in the ICU setting, and reported an increase in sleep quality for patients who wore earplugs. Similar benefits from earplugs were also reported by Salzmann-Erikson et al (2016) in the acute ward setting.
The use of complementary treatments, such as foot and hand massage, music and aromatherapy, were discussed by Patel et al (2014) and have been reported in other studies (Jacobs et al, 2016; Pagnucci et al, 2019), but were not fully explored in the studies included in this review.
Patient and nurse collaboration
Salzmann-Erikson et al (2016) carried out a qualitative study to explore nurses' experiences and their strategies to promote sleep. A total of eight participants were recruited using purposeful sampling. The narrative account emphasised the importance of collaboration with patients and giving information to establish a sense of safety among the patients. This finding reflects the three core competencies of nursing's professional standard practice: prioritise people, preserve safety and promote professionalism and trust (Nursing and Midwifery Council, 2018). However, the authors acknowledged that the small sample size limited the generalisability to other settings.
Educational and behavioural change
All the studies included in this review indicated that health professionals were responsible for noise and sleep disturbances. However, is can be argued that if the planned care is not implemented because of the risk of disturbing patients, the consequences may worsen patients' clinical condition. The challenge is that there is no clear-cut balance of priority between sleep and care provision. Since both issues are closely related, it can only be solved with careful planning and prioritising of care (Patel et al, 2014; Lopez et al, 2018). Three studies recommended raising health professionals' awareness of sleep promotion techniques and the importance of minimising disturbances (Patel et al, 2014; Delaney et al, 2018; Lopez et al, 2018;).
Discussion
This review found that both ICU and acute ward settings share similar sleep-promoting strategies as well as sleep-inhibiting factors. In terms of sleep-promoting strategies, both settings synchronise care (implementing multiple tasks at one visit, for example, and administering painkillers and checking observations at the same time) to minimise sleep disturbances. This was also noted in reviews by Dolan et al, 2016; Garside et al, 2018; and Altman et al, 2018. Both settings also used medication to aid sleep. The only difference is that, in acute ward settings, patients were given antipsychotics, antidepressants and painkillers (owing to pre-existing medical conditions) more than patients in the ICU setting, who instead tended to be prescribed more sedatives.
Similarities in approach between ICUs and acute wards were also found in non-medicine-related interventions, as both settings reported the benefits of using eye masks and earplugs to reduce light and noise (Foreman et al, 2015; Dobing et al, 2017; Litton et al, 2017). In addition, complementary treatments such as foot and hand massage, music and aromatherapy have been cited but not fully explored (Foreman et al, 2015; Dobing et al, 2017; Litton et al, 2017). Although aromatherapy has been around for many years, its application as a complementary treatment for sleep in hospital is relatively new (Pagnucci et al, 2019). Pagnucci et al (2019) reported that aromatherapy in ICU patients had benefits, but the lack of skills and techniques of nurses limited the application of this treatment. This is also reported by Cooke et al, 2012; Bagheri-Nesami et al, 2015; Mofredj et al, 2016).
In terms of sleep-disturbing factors, the problems of pain, noise, clinical care, diagnostics and room layout were found in both ICUs and acute wards. This was consistent with a study by Macfarlane et al (2019), which reported that the significant barriers to sleep include the need for urinating, pain, noise and light. Noise was a very significant barrier to sleep, as shown by high noise levels recorded (above 60 decibels) within both settings. This recording exceeded the World Health Organization's (WHO) recommendations on night-time noise in hospitals, which stated that the range of noise level for night-time must be between 0 and 35 decibels, and the daytime range between 0 and 45 decibels (Berglund et al, 1999). However, the significant difference between this review's findings and WHO recommendation means that more efforts are required from health professionals to reduce night-time noise to meet WHO recommendations.
Differences were found in light and ward layout. Light luminance of ≤200 lux is known to suppress melatonin secretion (melatonin is a hormone that plays a vital role in maintaining the 24-hour internal clock that regulates the sleepiness and alertness in humans) (Brainard et al, 1997; Kamdar et al, 2012; Zisapel, 2018). The light measurements in two studies (Patel et al, 2014; Delaney et al, 2018) were very different. Delaney et al (2018) found the light brightness level was <100 lux in acute ward settings; Patel et al (2014) found that light level was 594 lux in ICU settings. However, regardless of the differences, the light luminosity was not considered as significant a sleep inhibitor as the other environmental factors. Similar to light, temperature and humidity were not considered as sleep-inhibiting factors in either setting.
Differences were also found in the ward layouts. Most ICUs used single rooms, while acute ward settings used 4-bed bays. The reason for this difference is to reduce costs, but bays are known to disperse and reflect noise (Foreman et al, 2015; Salzmann-Erikson et al, 2016; Delaney et al, 2018).
A notable finding is that all studies in this review reported that noise and disturbances from health professionals were the two main sleep inhibitors in both settings. This literature review agrees with the results of a previous study that noise from alarms and health professionals are similarly disturbing and stressful (Pagnucci et al, 2019). The studies made several suggestions to solve these issues, by providing single rooms and providing staff with education on noise reduction and minimal disturbances.
The former suggestion is an expensive option for non-acute wards. The latter suggestion seems more viable for future research as all studies in this review recommended education to raise awareness of sleep disturbance and the importance of noise reduction among health professionals.
Study strengths and limitations
This literature review followed strict PRISMA guidelines to minimise bias in literature selection, as well as using CASP to appraise the strength and validity of the literature. However, the database search was not extended to unpublished literature; this may have contributed to an incomplete summary of evidence on this topic. Furthermore, the population studied was too broad (adult and older patients) without distinguishing their age-related and medical conditions, such as hearing difficulties or sleep apnoea, which could impact on the validity of this review.
Conclusion
This literature review found that both ICU and acute ward settings can share strategies to improve patients' sleep quality. Noise and disturbances by health professionals remain the most critical sleep-inhibiting factors in both settings. Noise caused by health professionals is modifiable, although this can be challenging. One possible area for future research could be focused on raising health professionals' awareness of noise and educating them on behaviours that reduce noise and minimise sleep disturbances to improve patients' sleep.