LETTERS Sleep in the Intensive Care Unit Is a Priority To the Editor: We read with interest the article by Kamdar and colleagues (1) reporting results of an international survey of critical care clinicians regarding perceptions of sleep and efforts to preserve sleep in intensive care units (ICUs). Most respondents observed that ICU patients sleep poorly, and most suspected that poor sleep contributes to negative outcomes such as delirium, delayed liberation from mechanical ventilation, and longer length of stay. These perceptions are in keeping with the results of previously published observational studies (2, 3). Nevertheless, only 32% of the survey respondents reported the implementation of sleep promoting protocols in their ICUs. To be effective, sleep promotion interventions in the ICU should address multiple aspects of care, such as the ICU organization, staff training, and work environment. At the micro level, staff should be trained to optimize the timing of bedside interventions, as these may disrupt sleep patterns at night. Nighttime staff–patient interactions may cause disrupted sleep (4) and may therefore worsen sleep quality. Background noise due to staff conversation, nighttime illumination, and especially alarms and sounds also contribute to a reduction in sleep (5). At the meso level, protocols should be implemented to allow for periods of reduced noise and illumination (quiet time) (6). At the macro level, ICUs should be designed physically to promote proper sleep. For example, single-patient rooms with noise reduction ceilings separated from noisy staff work areas may reduce ambient noise in patient rooms. We believe that a multicomponent, multidisciplinary bundle of interventions, with appropriate education and promotion, is safe, effective, and practical for use in the ICU, and may lead to more and better quality sleep. However, this would depend on a cultural change of attitude on the part of the hospital administration and the healthcare staff in pursuit of a healthcare model that would prioritize restorative sleep so as to avoid or prevent sleep deprivation phenomena. Such a healthcare model would promote

Reply From the Authors: We appreciate the letter by Giusti and colleagues regarding our recent publication in AnnalsATS (1). The letter highlights both the importance of sleep in the intensive care unit (ICU) and the increasing recognition of this problem by ICU providers. In addition, Giusti and colleagues propose changes to multiple aspects of care and delineate micro, meso, and macro level modifications of ICU workflow and environmental design, along with a “multicomponent, multidisciplinary bundle of interventions” aimed at providing patients with the opportunity for undisturbed sleep. As noted in our survey-based study, 81% of ICU physicians and nurses rate their patients’ sleep as “very” or “extremely” important, and 88% indicate that poor sleep affects the ICU recovery process. Moreover, the importance of sleep promotion 1868

both the quality and the quantity of sleep, recognizing as early as possible those patients who may suffer from sleep deprivation and giving due regard to the problem. Author disclosures are available with the text of this letter at www.atsjournals.org. Gian Domenico Giusti, R.N., M.S.N. Perugia University Hospital Perugia, Italy Federica Piergentili, R.N. ASL Umbria 1 Perugia, Italy Andrea Ceccagnoli, R.N. Beniamino Addey, R.N. Perugia University Hospital Perugia, Italy Nicola Ramacciati, R.N., M.S.N. University of Florence Florence, Italy

ORCID ID: 0000-0001-9167-9845 (G.D.G.).

References 1 Kamdar BB, Knauert MP, Jones SF, Parsons EC, Parthasarathy S, Pisani MA; Sleep in the ICU (SLEEPii) Task Force. Perceptions and practices regarding sleep in the intensive care unit: a survey of 1,223 critical care providers. Ann Am Thorac Soc 2016;13: 1370–1377. 2 McKinley S, Fien M, Elliott R, Elliott D. Sleep and psychological health during early recovery from critical illness: an observational study. J Psychosom Res 2013;75:539–545. 3 Solverson KJ, Easton PA, Doig CJ. Assessment of sleep quality posthospital discharge in survivors of critical illness. Respir Med 2016; 114:97–102. 4 Giusti GD, Tuteri D, Giontella M. Nursing interactions with intensive care unit patients affected by sleep deprivation: an observational study. Dimens Crit Care Nurs 2016;35:154–159. 5 Darbyshire JL. Excessive noise in intensive care units. BMJ 2016;353: i1956. 6 McAndrew NS, Leske J, Guttormson J, Kelber ST, Moore K, Dabrowski S. Quiet time for mechanically ventilated patients in the medical intensive care unit. Intensive Crit Care Nurs 2016;35:22–27. Copyright © 2016 by the American Thoracic Society

as it relates to delirium prevention was included in the 2013 Society for Critical Care Medicine Pain, Agitation, and Delirium (PAD) Clinical Practice Guidelines (2). The need for improved patient sleep has also been highlighted in major news outlets (3, 4). Despite these indicators of growing awareness, adoption of multi-faceted ICU sleep improvement bundles has been slow; only 32% of our respondents indicated that their institutions have sleep-promoting protocols in place. This disconnect is the very issue we wished to emphasize in our manuscript. We agree with Giusti and colleagues that micro- and meso-level changes to promote sleep in the ICU should involve protocols that leverage itemized checklists and bundled care to facilitate uninterrupted blocks of time to sleep (5). However, while designing such protocols may seem straightforward, it requires dedicated ICU champions, a multidisciplinary stakeholder team, effective implementation methods to achieve staff buy-in and alter practice, and mechanisms for regular auditing. AnnalsATS Volume 13 Number 10 | October 2016

LETTERS Currently, such efforts require stronger supporting evidence to earn attention and garner resources from hospital leadership. Moreover, as an overarching barrier to these efforts, measurement of sleep in the ICU is a major challenge and continues to hinder research aimed at linking improvements in ICU outcomes with sleep promotion. Polysomnography can be infeasible and expensive for use in large studies (6); actigraphy, while feasible to implement, has variable reliability in sedated or restrained patients (7). Subjective sleep measures can significantly overestimate sleep (8). Limited high-quality evidence and difficulty in measuring ICU sleep are also barriers to motivating cost intensive macro-level changes (i.e., improving room layout and building noise). In addition, providing patients an opportunity to sleep while ignoring the issue of ICU-related circadian disruption may cause sleep promotion interventions to fall short. Circadian rhythm disruption, defined as misalignment between the brain’s master clock and peripheral body clocks, is a distinct component of ICU sleep disruption. Circadian rhythms are core physiologic determinants and have broad implications for end organ function (9). Circadian alignment in the ICU could be promoted via increased exposure to daytime light and exercise, and via feeding schedules designed to mimic normal meals. In summary, most ICU physicians and nurses agree that sleep is poor and is a problem for their patients. In light of the 2013 PAD guidelines, ICUs are likely in varying phases of implementing interventions to promote sleep. As with any ICUwide intervention effort, promoting sleep is complex, and requires resources and meticulous planning to maximize success and sustainability. We need large, rigorous studies that include circadian alignment as part of an overall ICU sleep improvement strategy to validate and motivate these efforts.

Biren B. Kamdar, M.D., M.B.A., M.H.S. David Geffen School of Medicine at UCLA Los Angeles, California FOR THE SLEEP IN THE ICU (SLEEPii) TASK FORCE

ORCID IDs: 0000-0002-7341-850X (M.P.K.); 0000-0002-9245-6229 (B.B.K.).

References

Author disclosures are available with the text of this letter at www.atsjournals.org.

1 Kamdar BB, Knauert MP, Jones SF, Parsons EC, Parthasarathy S, Pisani MA; Sleep in the ICU (SLEEPii) Task Force. Perceptions and practices regarding sleep in the intensive care unit: a survey of 1,223 critical care providers. Ann Am Thorac Soc 2016;13:1370–1377. 2 Barr J, Fraser GL, Puntillo K, Ely EW, Gelinas ´ C, Dasta JF, Davidson JE, Devlin JW, Kress JP, Joffe AM, et al.; American College of Critical Care Medicine. Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit. Crit Care Med 2013;41:263–306. 3 Kolata G. Doctors strive to do less harm by inattentive care. The New York Times, February 18, 2015;Sect. A1. 4 Boodman SG. The perils of delirium. The Washington Post 2016 [accessed 2016 May 30]. Available from: http://wpo.st/a8rb1. 5 Kamdar BB, Yang J, King LM, Neufeld KJ, Bienvenu OJ, Rowden AM, Brower RG, Collop NA, Needham DM. Developing, implementing, and evaluating a multifaceted quality improvement intervention to promote sleep in an ICU. Am J Med Qual 2014;29:546–554. 6 Knauert MP, Yaggi HK, Redeker NS, Murphy TE, Araujo KL, Pisani MA. Feasibility study of unattended polysomnography in medical intensive care unit patients. Heart Lung 2014;43:445–452. 7 Kamdar BB, Kadden DJ, Vangala S, Elashoff DA, Ong MK, Martin JL, et al. Feasibility of continuous actigraphy in medical intensive care unit patients. Am J Crit Care (In press) 8 Beecroft JM, Ward M, Younes M, Crombach S, Smith O, Hanly PJ. Sleep monitoring in the intensive care unit: comparison of nurse assessment, actigraphy and polysomnography. Intensive Care Med 2008;34:2076–2083. 9 Knauert MP, Haspel JA, Pisani MA. Sleep loss and circadian rhythm disruption in the intensive care unit. Clin Chest Med 2015;36:419–429.

Melissa P. Knauert, M.D., Ph.D. Yale University School of Medicine New Haven, Connecticut

Copyright © 2016 by the American Thoracic Society

Connecting Dietary Fiber Directly with Good Lung Health To the Editor: In their editorial on the relationship between dietary fiber intake and lung function (1), Jacobs and Kalhan make two important points. First, diets associated with lower mortality are centered on plant foods, often high in dietary fiber (1). Second, it may be better to view lung function in the context of “lung health,” or lack of it, in preference to specific lung disease, for example, chronic obstructive pulmonary disease (1). Although we concur with these sentiments (2), we outline below epidemiological and preclinical data that suggest high dietary fiber is linked directly to better lung (health) function and reduced pulmonary-related mortality (3, 4). In a review of the epidemiological data linking poor lung function with an increase in all-cause mortality (3), we propose that lung function provides a “barometer” of the body’s response to high oxidant load, especially from smoking. In this setting, smokers with an exaggerated innate immune response develop accelerated lung aging (and remodeling) characterized by obstructive or restrictive Letters

lung disease, or both. These people have impaired spirometry (poor “lung health”) and greater mortality from respiratory disease, cardiovascular disease, stroke, and many cancers (3). There is growing evidence that, to varying degrees, an aberrant innate immune response driving accelerated aging may underlie all these diseases (5). Understanding this mechanistic connection may be critical to identifying truly disease-modifying interventions that lower mortality attributed to poor “lung health” (4). In a second review article we propose that dietary fiber, through modification of the gut microbiota, may directly attenuate (“dampen”) pulmonary inflammation and help maintain good lung health (4). In two large prospective studies, “high” fiber diets reduced mortality from infectious or inflammatory disease (50% reduction), respiratory disease (60% reduction), smoking-related cancers (25% reduction), and cardiovascular disease (25% reduction) (4). No benefit was seen from accidents or non-smokingrelated cancers. The observed mortality reductions were almost completely attributed to dietary fiber intake from whole grain or cereal sources (4). Several prospective studies have reported between a 20 and 40% reduction in the development of COPD with “high” fiber intake and a strong fiber–smoking interactive effect (4). In one 1869