Sleep disruption due to hospital noises: A prospective evaluation

Harvard Medical School, Brigham and Women’s Hospital, Massachusetts General Hospital, and Berklee College of Music, Boston, MA, USA.
Annals of internal medicine (Impact Factor: 17.81). 08/2012; 157(3):170-9. DOI: 10.7326/0003-4819-157-3-201208070-00472
Source: PubMed


Sleep plays a critical role in maintaining health and well-being; however, patients who are hospitalized are frequently exposed to noise that can disrupt sleep. Efforts to attenuate hospital noise have been limited by incomplete information on the interaction between sounds and sleep physiology.
To determine profiles of acoustic disruption of sleep by examining the cortical (encephalographic) arousal responses during sleep to typical hospital noises by sound level and type and sleep stage.
3-day polysomnographic study.
Sound-attenuated sleep laboratory.
Volunteer sample of 12 healthy participants.
Baseline (sham) night followed by 2 intervention nights with controlled presentation of 14 sounds that are common in hospitals (for example, voice, intravenous alarm, phone, ice machine, outside traffic, and helicopter). The sounds were administered at calibrated, increasing decibel levels (40 to 70 dBA [decibels, adjusted for the range of normal hearing]) during specific sleep stages.
Encephalographic arousals, by using established criteria, during rapid eye movement (REM) sleep and non-REM (NREM) sleep stages 2 and 3.
Sound presentations yielded arousal response curves that varied because of sound level and type and sleep stage. Electronic sounds were more arousing than other sounds, including human voices, and there were large differences in responses by sound type. As expected, sounds in NREM stage 3 were less likely to cause arousals than sounds in NREM stage 2; unexpectedly, the probability of arousal to sounds presented in REM sleep varied less by sound type than when presented in NREM sleep and caused a greater and more sustained elevation of instantaneous heart rate.
The study included only 12 participants. Results for these healthy persons may underestimate the effects of noise on sleep in patients who are hospitalized.
Sounds during sleep influence both cortical brain activity and cardiovascular function. This study systematically quantifies the disruptive capacity of a range of hospital sounds on sleep, providing evidence that is essential to improving the acoustic environments of new and existing health care facilities to enable the highest quality of care.
Academy of Architecture for Health, Facilities Guidelines Institute, and The Center for Health Design.

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    • "Since neutrophils play a crucial role in the first-line immune response to microorganisms, an interesting future challenge will be to determine if strategies aiming to improve sleep of in-and outpatients (e.g. reducing hospital noise (Buxton et al., 2012), improved sleep hygiene, sleep medication) also help strengthen their immunity. "
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    ABSTRACT: Lack of sleep greatly affects our immune system. The present study investigates the acute effects of total sleep deprivation on blood neutrophils, the most abundant immune cell in our circulation and the first cell type recruited to sites of infection. Thus, the population diversity and function of circulating neutrophils were compared in healthy young men following one night of total sleep deprivation (TSD) or after 8 h regular sleep. We found that neutrophil counts were elevated after nocturnal wakefulness (2.0±0.2×109/l vs. 2.6±0.2×109/l, sleep vs. TSD, respectively) and the population contained more immature CD16dim/CD62Lbright cells (0.11±0.040×109/l [5.5±1.1%] vs. 0.26±0.020×109/l [9.9±1.4%]). As the rise in numbers of circulating mature CD16bright/CD62Lbright neutrophils was less pronounced, the fraction of this subpopulation showed a significant decrease (1.8±0.15×109/l [88±1.8%] vs. 2.1±0.12×109/l [82±2.8%]). The surface expression of receptors regulating mobilization of neutrophils from bone marrow was decreased (CXCR4 and CD49d on immature neutrophils; CXCR2 on mature neutrophils). The receptor CXCR2 is also involved in the production of reactive oxygen species (ROS), and in line with this, total neutrophils produced less ROS. In addition, following sleep loss, circulating neutrophils exhibited enhanced surface levels of CD11b, which indicates enhanced granular fusion and concomitant protein translocation to the membrane. Our findings demonstrate that sleep loss exerts significant effects on population diversity and function of circulating neutrophils in healthy men. To which extent these changes could explain as to why people with poor sleep patterns are more susceptible to infections warrants further investigation.
    Full-text · Article · Jun 2014 · Brain Behavior and Immunity
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    • "Finally, after esophagectomy patients usually spend at least 2 days in the ICU, where noise and full light are almost constant throughout the day. A recent study showed that a range of hospital sounds have a high disruptive capacity on sleep, influencing both cortical brain activity and cardiovascular function [11]. All these premises suggest that patients undergoing esophagectomy would need hypnotic drugs to cope with postoperative sleep disturbances. "
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    ABSTRACT: Background The aims of this prospective study were to analyze the predictors of postoperative sleep disturbance after esophagectomy for cancer and to identify patients at risk for postoperative hypnotic administration. Methods Sixty two consecutive patients who underwent cancer-related esophagectomy were enrolled in this study from May 2011 to February 2012. Data about perioperative management, postoperative complications, ICU stay, and vasopressor, hypnotic, and painkiller administration were retrieved. The EORTC QLQ-C30 was used and global quality of life (QL2 item) and sleep disturbance (SL item) were the primary endpoints. Univariate and multivariate analyses were performed. Results Postoperative request of hypnotics independently predicted bad quality of life outcome. Sleep disturbance after esophagectomy was independently predicted by the duration of dopamine infusion in the ICU and the daily request of benzodiazepines. Even in this case, only sleep disturbance at diagnosis revealed to be an independent predictor of hypnotic administration need. ROC curve analysis showed that sleep disturbance at diagnosis was a good predictor of benzodiazepine request (AUC = 73%, P = 0.02). Conclusions The use of vasopressors in the ICU affects sleep in the following postoperative period and the use of hypnotics is neither completely successful nor lacking in possible consequences. Sleep disturbance at diagnosis can successfully predict patients who can develop sleep disturbance during the postoperative period.
    Full-text · Article · May 2014 · World Journal of Surgical Oncology
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    • "Peak levels above 85 dBA occurred less frequently overnight, but a patient can still expect to be disturbed at least once every 7 to 16 minutes of every hour between 10:00 PM and 7:00 AM (Figure 4). At these dB levels, it is highly likely that this is alarm activity, and, as has been reported elsewhere [9], electronic sounds are more arousing than human voices, so they are very likely to continually disturb patients' sleep. Frequent and persistent arousal has been shown to have negative effects for both healthy volunteers and patients [10,11]. "
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    ABSTRACT: Patients in intensive care units (ICUs) suffer from sleep deprivation arising from nursing interventions and ambient noise. This may exacerbate confusion and ICU-related delirium. The World Health Organization (WHO) suggests that average hospital sound levels should not exceed 35dB with a maximum of 40dB overnight. We monitored five ICUs to check compliance with these guidelines. Sound levels were recorded in five adult ICUs in the UK. Two sound level monitors recorded concurrently for 24 hours at the ICU central stations and adjacent to patients. Sample values to determine levels generated by equipment and external noise were also recorded in an empty ICU side room. Average sound levels always exceeded 45dBA and for 50% of the time exceeded between 52 and 59dBA in individual ICUs. There was diurnal variation with values decreasing after evening handovers to an overnight average minimum of 51dBA at 4am. Peaks above 85dBA occurred at all sites, up to 16 times per hour overnight and more frequently during the day. WHO guidelines on sound levels could be only achieved in a side room by switching all equipment off. All ICUs had sound levels greater than WHO recommendations, but the WHO recommended levels are so low they are not achievable in an ICU. Levels adjacent to patients are higher than those recorded at central stations. Unit-wide noise reduction programmes or mechanical means of isolating patients from ambient noise, such as earplugs, should be considered.
    Full-text · Article · Sep 2013 · Critical care (London, England)
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