Noise Pollution in Intensive Care Unit: A Hidden Enemy affecting the Physical and Mental Health of Patients and Caregivers

Background Noise in intensive care units (ICUs) has always been a problem, but noise above the recommended range affects not only the patient but staff as well. It is clear that some noise in the ICU is inevitable, but exceeding the normal range brings various physiologic and psychologic changes, which directly affect health. This review presents a synthesis of noise sources in the ICU and the potential interventions designed to attenuate noise and protect patients.
Materials and Methods An extensive literature search, using electronic databases such as MEDLINE, PubMed, Google Scholar, and Research gate to understand the noise in ICU, effects of noise, and noise reduction interventions were undertaken.
Results Findings were such as noise enhances the release of cortisol, increases oxygen consumption, increases sleep disturbances, increases the need for analgesia and sedation, and disrupts circadian rhythm. Many studies reported that measurement was always higher despite implementing noise reduction interventions.
Conclusions ICU survivors always recall their memories, and for them, ICU admission becomes a negative experience for life. However, the sustainability of any single intervention did not show awe-inspiring results, whereas a bundle kind of interventions did show some effects. However, high-quality evidence demonstrating the benefit of any intervention on patient outcomes is still lacking.

Keywords: Health, health professionals, intensive care unit, intervention, noise, noise control, noise prevention, patients

How to cite this article:
Pal J, Taywade M, Pal R, Sethi D. Noise Pollution in Intensive Care Unit: A Hidden Enemy affecting the Physical and Mental Health of Patients and Caregivers. Noise Health 2022;24:130-6
How to cite this URL:
Pal J, Taywade M, Pal R, Sethi D. Noise Pollution in Intensive Care Unit: A Hidden Enemy affecting the Physical and Mental Health of Patients and Caregivers. Noise Health [serial online] 2022 [cited 2022 Sep 20];24:130-6. Available from: https://www.noiseandhealth.org/text.asp?2022/24/114/130/356134 Introduction

Noise pollution is always an essential concern to humankind on this planet. Control of environmental noise has been a priority of scientists and researchers across. The effect of noise has long-term consequences for health.[1],[2],[3]

Noise is undoubtedly not a wanted sound, but the fact is that what is noise to one person may not be the same for another one. Studies indicate that sound levels in hospitals have increased during the past 50 years and exceed World Health Organization (WHO) recommendations for community noise.[1],[2],[3] The extent of the noise problem is vast across the globe.

Aim

The aim of this review article was that, even after numerous publications in this field, whether it is about the source of noise, the impact of noise on patients, or the noise reduction strategies. However still, the problem persists so far. In our review, we focus on sources of noise in intensive care unit (ICU), its effects on patients and staff, which interventions are helpful, expensive and cost-effective, to reduce and protect the patients from noise.

Noise in intensive care

Despite an increased emphasis on the need for noise reduction in intensive care, several studies published in the past few years have found that sound levels in the ICU continue to exceed WHO noise recommendations.[2],[4],[5],[6] An appreciation of how quiet the ICU should aid in the interpretation of noise research. The WHO guidelines state that the average sound level should not exceed 30 dB in general hospital areas and 35 dB in rooms where patients are kept or observed; the maximum sound level indoors should not exceed 40 dB during the night.[7]

The Environmental Protection Agency recommends that hospital noise levels not exceed an average of 45 dB during the day and 35 dB at night.[8] Meeting these goals in practical and clinical situations is very challenging. According to these recommendations, the health-care staff has to whisper, which is impossible and noise from equipment, alarms, etc., further adds to the noise levels.

It is well known that ICU is for critically sick patients, utmost need multiple treatments at a given time; for example, when the IV infusion pump is in use, simultaneously patient is on a ventilator and attached with the monitor as well, and like that so, many other patients are there. Hence, these devices have safety alarms, and they beep for every patient, so sometimes ICU can be as noisy as some community halls.

A systematic review of 29 studies related to noise in the ICU reported that the significant chunks of noise were staff conversations, equipment alarms, electronic devices, opening and shutting the doors, walking people here and there, moving and shifting things, or objects, caregiver activities.[3] Another study was performed in five ICUs and reported that noise levels are more than 45 decibels most of the time; it rarely came to less than 45.[6]

Suppose we talk about the disturbed sleeping pattern in ICU mostly, studies have reported that staff conversations were the most common factor causing a sleeping disturbance. Staff conversations are an unavoidable factor, and even the outcome of all the noise reduction strategies has been limited in this area.

Many studies have reported that noise from nursing procedures is one of the most disturbing factors. If the nursing care is performed at night or in the early morning, it causes alterations in the sleep-wake rhythm, ultimately, circadian rhythm disruption. [Table 1] summarizes a brief essence about noise sources and the effectiveness of noise reduction strategies.

Table 1 Sources of noise and effectiveness of noise reduction strategies

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Sources of noise in ICU settings

A systematic review suggested that the noise levels increased at the highest level, so speech comprehension and communication are compromised.[9] Critical-care areas in hospitals rely heavily on alarms and pagers to signal urgent situations. It is, therefore, unsurprising that observational studies on ICUs identify these as primary disruptive noise sources. Nearly 80% of disruptive noise sources are monitor or ventilator alarms and speech.[10],[11] However, a significant proportion of the noise does not require much attention for patient care. Almost 90% of alarms from physiologic monitors are “false positives,” with no patient benefit.[12]

The shocking results of the above-stated studies are that most of the noise originates from specific areas such as the staff cafeteria near the ICU where conversations occur and nursing stations where handing and taking over the patients arise. These places are very close to the patient, although it cannot be denied that most of the communications are essential; yes, they do create noise in the ICU and in addition to this, equipment and devices near the patient are also there.

The alarming system designs in the devices are to stimulate the human senses. Still, the frequency range of these devices is equal to a baby’s scream or cry, which may help attract the staff’s attention but not for the patient’s comfort. The alarms designed to have default settings mean they can be adjusted routinely in high or low frequency and volumes, but in day-to-day clinical practice, it rarely occurs, and most of the time, alarms are high in volume and frequency.[6]

Patients undergo various procedures such as admission, positioning, invasive tubes, intravenous line insertion, and ventilator setting in a surgical ICU. Other essential practices are medication orders, administration, pain control, and a close observation and assessment of the patient, so it requires a workforce. Thus, the result is “the noisy ICU.”[13]

Alarm modification with the need but still the low-frequency and low-volume alarms make a health-care worker anxious because the patient is usually critical in ICUs. Due to this new modification, the chances of mishappenings and near-miss are significantly higher, so this problem requires a practical solution.[14]

Effect of ICU generated noise on patients

There is no doubt that noise affects both health-care workers and patients. Still, on sick patients, the intensity of the effect is much higher because it brings many physiologic and psychologic disequilibrium, which further leads to cognitive and comprehensive dysfunction.[15] These type of problems leads to ineffective communication and increase the chances of accidents.[16] Incredibly the critically ill who have sleep disturbances due to noise and elderly patient who is having hearing difficulty, all these factors collectively hinder communication and poor understanding of their surrounding environment.[17]

When critically ill patient stays in ICU, they have to go through various treatment modalities. The treatment various other precipitating factors in the ICU, bringing behavioral changes. The patient might develop delirium-like sleep disturbances due to noise; this sleep deficiency leads to many sequelae such as disrupted melatonin levels, circadian rhythm disruption, and disturbed neurocognition.[18]

Noise-induced sleep disturbance

Critical-care patients are especially prone to delirium, as their regular circadian pattern of adrenocorticotropic hormone and melatonin levels is changed markedly by sepsis. It encourages a disturbance in sleep patterns leading to sleep during the day, reduced sleep at night, and general sleep fragmentation.[19] During the stay in ICU, patients experience a variety of noises. Thus, the atmosphere creates a disturbance in their sleep, which is already fragmented. Due to that, hallucinations may occur during the transition from wakefulness into NREM sleep, and from NREM sleep to insomnia are a significant problem for critical-care patients.[20] During the sleep phase, noise activates the inflammatory response and alters endothelial function. This oxidative stress damages vital organs’ vasculature and leads to various other clinical conditions.[21]

Noise-induced annoyance

As expected, several ICU noises have irritating perceptions. There is evidence that the degree of annoyance depends not solely on acoustical but also on nonacoustical features (e.g., unpredictability, timing). Especially sudden and loud alarming signals and staff-generated noises seem the most annoying for patients and health-care professionals.[22]

Noise-induced cardiac and cerebral damage

European society of cardiology reported higher noise exposure could alter circadian rhythm, further leading to sympathetic nervous system activation. These changes alter the genetic expression of hematopoetic tissues and make them prone to endothelial dysfunction, endothelial damage. Posing the high risk of alteration of cardiovascular and neurologic disruptions.[23]

Noise-induced altered mental status/delirium

Studies show that noise causes cognitive impairment and oxidative stress in the brain. Noise pollution has become a risk factor for depression, cognitive impairment, and neurodegenerative disorders. Factors are industrialization and urbanization.[24] Exposure to noise influences the central nervous system leading to emotional stress, anxiety, cognitive, and memory defects.[25] Previous studies have suggested that the Limbic system in the brain is involved in vigorous activities; the Amygdala and the Hippocampus are two of the main parts within the Limbic system that receives sensory information directly and indirectly from the central auditory system.[26]

Noise can affect performance either by impairing information processing or by causing changes in strategic responses. In particular, noise increases general alertness or activation and attention. Noise can also reduce performance accuracy and working memory performance but not affect performance speed. Altered cognitive function leads to human error and subsequently increases accidents. This can ultimately lead to reduced performance and productivity.[25],[26]

Noise-induced disrupted circadian rhythm

An inflammatory response often accompanies critical illness, which may mediate the recovery from illness.[27],[28] Interestingly, systemic inflammatory response markers, including temperature, respiratory rate, blood pressure, hormones (cortisol, melatonin, leptin, prostaglandins), cytokines, white blood cells, and platelet counts, all display circadian rhythmicity.[29] The circadian regulation of inflammatory response ensures appropriate timing and maintenance of the immune response. Any deviation to the regular circadian system, or a stressor to the circadian system at an inconvenient time, could alter the immune response and the recovery from injury. The circadian rhythm appears to be disrupted commonly in critically ill patients and it gets worse when a noise like other disturbing factors are there.[30]

Increase need for analgesia and sedation

A study on anesthetic agents suggested that if the environmental influences such as noise, temperature, etc., are within the acceptable range, their requirement for sedation is likely less than the requirement needed for the disease process.[31] On the contrary, another study supports the thought that noise levels maintained below the national recommendation may play no clinically significant role in patient sedation and analgesia requirements.[32]

Hindrance in communication

Due to noise, impaired communication may occur; for example, look-alike sound-alike drugs look similar and sound similar in an emergency. There are very high chances of medication errors.[33] The same is with the communication between nurses; their communication should be legible, clear because only due to some miscommunication safety of the patient might get compromised. During the nursing handovers, the noise level must be low so that chances of miscommunication are also on the more downside.[34]

Effects on staff

Noise in ICUs has always been well above the recommended levels, which directly affects the patients or indirectly nurse’s job satisfaction and mental peace.[35] Many studies on nurses’ satisfaction suggest that a nurse’s good mental status can improve quality patient care. Noise in the ICU is always above the normal range sometimes; the reason is staff shortage. If the nurse–patient ratio has exceeded indeed, it will lead to noise-creating situations, and ultimately, quality care is compromised.[36],[37],[38]

A study performed on the staff in ICU has reported that noise-related burnout affects the team’s performance not only in the professional but also in personal life because noise-related burnout leads to irritation, disturbed mood, poor completion of tasks, and infuriation time. Indeed, coronary care patients have reported finding staff attitude much better in conditions with good acoustics. Higher background noise may impair communication between health-care workers and may lead to an elevation in speech amplitude. It has implications for patient confidentiality and may predispose to accidents due to a combination of impaired communication and poor concentration.[35]

Noise reduction strategies

The effect of noise reduction strategies solely depends on the patient’s perception because tolerance and patience level differs from individual to individual. Some of them find the alarming sound a chance to see someone or a kind of stimulation. On the contrary, some find the noise annoying.[39]

The following section summarizes the noise reduction strategies that have already come up and how successful and cost-effective they are in our Indian setting ICUs.

Few identified strategies

Educational programs

Multiple studies have reported that most of the noise comes from human behavior such as talking, movement, and taking and lifting of objects. Among noise reduction, behavioral modification and educational programs have been implemented to make the persons aware of the activities that create noise and motivate them to follow behavior modification and education consistently.[39],[40],[41]

But such programs have failed to show consistent or dramatic results. Teaching sessions intended to minimize staff communication close to patients’ rooms could not reduce noise in ICUs.

Introduction of noise limiting guidelines

Some of the studies investigated issuing guidelines to reduce noise such as low-volume and low-frequency alarm, minimal nursing care at night time, switching off the radio, TV, mobile phones on silent mode, close all the doors, no or minimal conversation at night time. These strategies brought a slight noise reduction but were not effectively significant.[39],[42]

A behavioral modification program

A study investigated the behavior modification program, which changes nursing and medical routines. The introduction of nondisturbance periods resulted in a reduction in disturbance activity and noise levels in a neuro-ICU.[43] For behavioral modification programs to succeed, there needs to be enthusiasm from health-care staff for a project.

The design of ICUs and high-frequency oscillatory ventilators

The design of ICU may influence the noise by implementing architectural modifications such as making handover stations, and entrances should be away from the patient’s room, each patient has a single designated space, the ceiling of ICU rooms made up of sound-absorbing tiles.[41] Efforts could also reduce noise production by purchasing equipment such as high-frequency oscillator ventilators.[44]

Such strategies are not cost-effective because it is a complex and costly affair to apply structural changes in the existing ICU’s and repurchasing of the latest ventilators requires a lot of financial support. It may cost a health facility a lot.

Music interventions with earplugs

A study reported that earplugs with soothing ear music could also influence ICU-related noise. When patients recover from surgeries, it is a beneficial intervention to reduce pain, irritation, and promote rest. However, the outcome of these techniques might differ because different patients’ cognitive levels in different ICUs vary.[45]

Music intervention with earplugs might be effective but not effective in the long run because the earplugs may harbor bacteria and can be a potential source of infection.

Repair of ICU equipment

A study reported that repairing all the malfunctioned equipment and devices in the ICU can significantly reduce noise.[43]

Implementation of quiet time: noise-reduction strategy

This study reported that patients should be provided with their designated rest periods apart from their routine care and make sure that during that period, no disturbance should be there. The rationale of this strategy is quite interesting. It is used in patients to encourage sound sleep. Many physiologic disorders alter due to sleep disturbance and disrupted circadian rhythm, although it is impossible to alleviate all the noise from the ICU.[46]

Night-time noise reduction bundle and a streamlined patient monitoring alarm profile

Bundles include switching off electronic items, silent mode phones, taking in whispering voices or not all taking, lowering the voice of the alarms, and a streamlined alarm profile for 2 weeks to significantly reduce the noise level.[47]

Effects of white noise

[TAG:2]Noise is the most common factor of sleep disturbances. The white noise masks the other annoying sounds and improves sleep quality.[48][/TAG:2]

Conclusion

Reduction of noise efficiently, no single strategy can be helpful. Either it should be a combination of strategies, or the staff must modify the workflow. The working team has to do a significant chunk of noise reduction during staff conversations. Their behavior modification can bring desired changes. There must be a mixed intervention program to control the noise, engineering noise control, and architectural design strategies to mitigate excessive noise levels.

Authors’ contribution

First draft: Jagriti Pal and Manish Taywade

Manuscript revision and a final version: Jagriti Pal and Manish Taywade

Concept, design, and writing manuscript: Jagriti Pal and Manish Taywade

Literature review: Divya Sethi, Rajni Pal, Jagriti Pal

The final manuscript was read and approved by all authors.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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