Identifying determinants of noise in a medical intensive care unit

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.

Effects of Nighttime Noise Management in Intensive Care Units on Hormone Levels and Sleep Quality in Conscious Patients

OBJECTIVE

This study aims to investigate the effects of nighttime noise management in intensive care units (ICU) on hormone levels and sleep quality in conscious patients.

METHODS

From March 2020 to March 2021, the routine noise management for conscious patients was implemented in the ICU of Wenzhou TCM Hospital of Zhejiang Chinese Medical University. During this time, 86 patients were selected as the study subjects; five patients who did not meet the inclusion criteria were excluded, and 81 patients were included in the reference group. From April 2021 to April 2022, nighttime noise management for conscious patients was conducted, during which 93 patients were selected as the research subjects; six patients who did not meet the inclusion criteria were excluded, and 87 patients were included in the observation group. The hormone indicators, Pittsburgh Sleep Quality Index (PSQI) scores, and Symptom Checklist-90 (SCL-90) scores were collected and compared.

RESULTS

After management, the observation group had significantly lower noise level and hormone indicators (P < 0.05), significantly lower PSQI score (P < 0.001) and significantly lower SCL-90 score than the reference group (P < 0.01).

CONCLUSION

Nighttime noise in the ICU has an adverse effect on conscious patients. Nighttime noise management improves the hormone levels and sleep quality of ICU patients.

Analysis of noise levels in the neonatal intensive care unit: the impact of clinical microsystems

Reorganization of neonatal intensive care by introducing clinical microsystems may help to allocate nursing time more appropriately to the needs of patients. However, there is concern that cohorting infants according to acuity may enhance noise levels. This single-center study investigated the impact of reorganization of neonatal intensive care unit by implementing clinical microsystems in a Level III NICU on environmental noise. This prospective study measured 24-h noise levels over a period of 6 months during pre- and post-implementation of microsystems cohorting infants of similar acuity. Comparative analyses of the mixed acuity (i.e., before) and the cohorting (i.e., after) model were performed by creating daily profiles from continuous noise level measurements and calculating the length of exposure to predefined noise levels. Compared to baseline daytime measurements, noise levels were 3-6 dBA higher during physician handover. Noise levels were 2-3 dBA lower on weekends and 3-4 dBA lower at night, independent of the organizational model. The introduction of clinical microsystems slightly increased average noise levels for high-acuity pods (A and B) but produced a much more substantial decrease for low-acuity pods (E), leading to an overall reduction in unit-wide noise levels.    Conclusion: Our data show that noise levels are more driven by human behavior than by technical devices. Implementation of microsystems may help to reduce noise exposure in the lower acuity pods in a NICU. What is Known: • Excessive noise levels can lead to adverse effects on the health and development of premature infants and other critically ill newborns. • The reorganization of the neonatal intensive care unit following the clinical microsystems principles might improve quality of care but also affect noise exposure of staff and patients. What is New: • The transition from a mixed -acuity to cohorting model is associated with an overall reduction in noise levels, particularly in low-acuity pods requiring less nursing care. • Nevertheless, baseline noise levels in both models exceeded the standard permissible limits.

[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.

The Effectiveness of the Interventions to Reduce Sound Levels in the ICU: A Systematic Review

Excessive noise is ubiquitous in the ICU, and there is growing evidence of the negative impact on work performance of caregivers. This study aims to determine the effectiveness of interventions to reduce noise in the ICU.

DATA SOURCES

Databases of PubMed, EMBASE, PsychINFO, CINAHL, and Web of Science were systematically searched from inception to September 14, 2022.

STUDY SELECTION

Two independent reviewers assessed titles and abstracts against study eligibility criteria. Noise mitigating ICU studies were included when having at least one quantitative acoustic outcome measure expressed in A-weighted sound pressure level with an experimental, quasi-experimental, or observational design. Discrepancies were resolved by consensus, and a third independent reviewer adjudicated as necessary.

DATA EXTRACTION

After title, abstract, and full-text selection, two reviewers independently assessed the quality of each study using the Cochrane's Risk Of Bias In Nonrandomized Studies of Interventions tool. Data were synthesized according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, and interventions were summarized.

DATA SYNTHESIS

After screening 12,652 articles, 25 articles were included, comprising either a mixed group of healthcare professionals (n = 17) or only nurses (n = 8) from adult or PICU settings. Overall, the methodological quality of the studies was low. Noise reduction interventions were categorized into education (n = 4), warning devices (n = 3), multicomponent programs (n = 15), and architectural redesign (n = 3). Education, a noise warning device, and an architectural redesign significantly decreased the sound pressure levels.

CONCLUSIONS

Staff education and visual alert systems seem promising interventions to reduce noise with a short-term effect. The evidence of the studied multicomponent intervention studies, which may lead to the best results, is still low. Therefore, high-quality studies with a low risk of bias and a long-term follow-up are warranted. Embedding noise shielding within the ICU-redesign is supportive to reduce sound pressure levels.

Association of indoor noise level with depression in hotel workers: A multicenter study from 111 China's cities

Several studies have elucidated the link between outdoor noise and depression, but the relationship between indoor noise levels and depression symptoms in residential and public places remains unclear. This study was a multicenter observational study with a cross-sectional design. In 2019, a total of 10 545 indoor noise levels on-site and 26 018 health data from practitioners were collected from 2402 hotels in 111 cities. Indoor daily noise data levels were detected, and PHQ-9 questionnaires were used to collect health data. Logistic analysis was used to determine the association between depression score and noise level, negative binomial regression was used to determine potential risks. The geometric mean indoor noise level was 38.9 dB (A), with approximately 40.9% of hotels exceeding the 45 dB value (A). Approximately 19.1% of hotel workers exhibited mild and above depressive symptoms. In addition to functional zoning, geographic location, central air conditioner, decoration status, and other factors had an impact on noise levels (p < 0.05). Results of logistic and negative binomial regression showed the following: (1) there was significantly positive association between indoor noise and high depression scores above 2 (OR = 1.007, 95% CI: 1.002, 1.012) and (2) some sub-groups were more susceptible to this effect, especially for the younger female workers working in the first-tier cities, having higher education level, lower level of income, smoking, and longer working hours. This study confirms an early potential effect of indoor noise on depression. It is recommended to implement evidence-based measures to control noise sources in hotels.

Sleep Spindles and K-Complexes Are Favorable Prognostic Biomarkers in Critically Ill Patients

SUMMARY

In this narrative review, we summarize recent research on the prognostic significance of biomarkers of sleep in continuous EEG and polysomnographic recordings in intensive care unit patients. Recent studies show the EEG biosignatures of non-rapid eye movement 2 sleep (sleep spindles and K-complexes) on continuous EEG in critically ill patients better predict functional outcomes and mortality than the ictal-interictal continuum patterns. Emergence of more complex and better organized sleep architecture has been shown to parallel neurocognitive recovery and correlate with functional outcomes in traumatic brain injury and strokes. Particularly interesting are studies which suggest intravenous dexmedetomidine may induce a more biomimetic non-rapid eye movement sleep state than intravenous propofol, potentially providing more restorative sleep and lessening delirium. Protocols to improve intensive care unit sleep and neurophysiological studies evaluating the effect of these on sleep and sleep architecture are here reviewed.

Noise reduction in the ICU: a best practice implementation project

INTRODUCTION

Sleep deprivation is a relevant problem among patients hospitalized in ICUs. Further, noise is the most critical disruptive factor according to patients.

OBJECTIVE

To implement scientific evidence-based best practices for noise control in an adult ICU.

METHODS

This was an evidence-based implementation project of best practices in noise control, conducted in a high-complexity hospital's adult ICU. The intervention consisted of three steps: baseline audit and identification of barriers, implementation of best practices, and a follow-up audit.

RESULTS

No compliance with best practices was detected in the baseline audit. After the implementation phase, the unit reached compliance levels of 78-88% for most of these criteria only one criterion related to noise level did not match the expected compliance.

CONCLUSION

Adherence to best practices regarding noise control was satisfactory, achieving more than 70% compliance in the six audit criteria. Only the noise level did not reach the threshold recommended by the WHO - a difficulty reported in other studies.

RELEVANCE TO CLINICAL PRACTICE

Best practices related to noise control are essential for managing sleep deprivation in ICUs and include changes in the behaviour of involved professionals.

Non-pharmacological sleep interventions for adult patients in intensive care Units: A systematic review

OBJECTIVES

To synthesize and evaluate current non-pharmacological sleep interventions for critically ill adult patients in intensive care units and provide recommendations for future studies of non-pharmacological means of improving this population's sleep quality.

RESEARCH METHODOLOGY/DESIGN

The literature search was conducted following PRISMA guidelines. Seven databases CINAHL, PsycINFO, Embase, Medline, Cochrane Library, Web of Science, and Scopus and three keywords, sleep, intervention and intensive care unit were employed. All possible combinations of the keywords and similar words were considered. Included studies were primary studies, involved adult intensive care unit patients, focused on non-pharmacological sleep interventions, measured subjective and/or objective sleep quality and were published in English between January 2010 and September 2020.

RESULTS

The 20 included studies examined different types of non-pharmacological sleep interventions involving use of earplugs, an eye mask, white noise, music, aromatherapy, massage, acupressure, light intensity, a sleep hygiene protocol, quiet time and minimization of nursing care. Of 18 studies employing an experimental design, most reported that non-pharmacological interventions improved sleep quality. All these interventions involved environmental factors or complementary relaxation strategies.

CONCLUSIONS

Non-pharmacological sleep interventions can have a positive influence on sleep quality in critically ill patients, but more research is needed to determine their effectiveness.

Sleep and Delirium in Adults Who Are Critically Ill: A Contemporary Review

Sleep is important to health and well-being, and studies in healthy adults have demonstrated that sleep deprivation impacts respiratory, immune, and cognitive function. Historically, because of the nature of critical illness, sleep has not been considered a priority for patient care in the ICU. More recently, research has demonstrated that sleep is markedly abnormal in patients who are critically ill. In addition, there is often disruption of circadian rhythms. Delirium is a syndrome of acute alteration in mental status that occurs in the setting of contributing factors such as serious illness, medication, and drug or alcohol intoxication or withdrawal. Delirium is a frequent occurrence in critical illness, and research has demonstrated several adverse outcomes associated with delirium including persistent cognitive impairment and increased mortality. Sleep deprivation and delirium share many common symptoms. The similarity in symptoms between sleep disruption and delirium have prompted experts to draw links between the two and question both the relationship and its direction. In addition, the inclusion of sleep disturbance to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition in its constellation of symptoms used in diagnosing delirium has increased awareness of the link between sleep and delirium. This paper will review the literature on sleep in critical illness and the potential mechanisms and pathways that may connect sleep and delirium.