Heart & Lung 44 (2015) 87
Contents lists available at ScienceDirect
Heart & Lung journal homepage: www.heartandlung.org
Editorial
Sleep in the intensive care unit: An oft-neglected key to health restoration
Humans spend about one-third of their lives asleep. Despite ongoing active research, the true function or importance of sleep has yet to be fully elucidated. Some theories include the role of sleep in survival, restoration of bodily functions, energy conservation and information consolidation. Much of our understanding of the role of sleep comes either from animal studies or studies of healthy humans who are sleep deprived. A study published in 2013 examined mechanisms of sleep deprivation in a mouse model and suggested that the restorative function of sleep may be due to the removal of neurotoxic waste products that accumulate in the central nervous system during wakefulness.1 The sum understanding from other research is that sleep deprivation can contribute to cognitive impairment, immune dysfunction, increased risk for metabolic syndrome and cardiovascular disease, as well as impairments in respiratory function. As one can imagine, all of these adverse outcomes attributed to sleep deprivation may impact vulnerable, critically ill patients. A recent review explored issues related to sleep in critical illness.2 One of the challenges to sleep research in the intensive care unit (ICU) is how to reliably measure sleep in a heterogenous group of patients who are critically ill and receiving medications that may alter sleep. Studies have used polysomnography,3 which is felt to be the gold standard, as well as actigraphy and questionnaires4 with varying success. These studies demonstrate that sleep in the ICU is fragmented with a predominance of N1 and N2 sleep and a lack of N3 and REM sleep. Since the development of intensive care units, there has been research examining the impact of the ICU environment on sleep. These studies have assessed the impact of noise, light and patient care activities on the ability of critically ill patients to sleep and universally pointed to all of these factors contributing to varying degrees to interrupted sleep. In addition, studies surveying patients report noise, ambient light, isolation, restriction of mobility, and an inability to sleep as the most stressful factors related to their ICU admission.5 A qualitative report by Hopper in this issue of Heart & Lung identifies uncertainties about the importance of sleep among ICU clinicians as well as institutional barriers that will need to be addressed to improve sleep. There is now evidence starting to emerge that in addition to experiencing poor sleep while in the ICU, more than 50% of survivors have persistent sleep problems.6
0147-9563/$ e see front matter Ó 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.hrtlng.2015.01.007
In this issue of Heart & Lung Parsons et al examine the impact of insomnia on survivors from a mixed medical-surgical ICU. Twentyeight percent of survivors met criteria for insomnia a year after ICU discharge that was associated with impairment in mental health related quality of life. Despite decades-long research on factors that disrupt sleep in the ICU, the problem of sleep deprivation in critical illness is still prevalent. Now is the time to truly work at implementing practice change in ICU’s across the country to allow for noise reduction, lighting designed to maintain normal circadian rhythm, and clustering of care to allow for uninterrupted periods of sleep. We need to develop protocols that can be customized to allow for variations in ICU size, staffing and acuity. This should be a goal for all ICU nurses, physicians, and administrators.
References 1. Xie L, Kang H, Xu Q, et al. Sleep drives metabolite clearance from the adult brain. Science. 2013;342(6156):373e377. 2. Pisani MA, Friese RS, Gehlbach BK, Schwab RJ, Weinhouse GL, Jones SF. Sleep in the intensive care unit. Am J Respir Crit Care Med; 2015. Published online January 16, 2015. 3. 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(5):445e452. 4. Kamdar BB, et al. Patient-nurse interrater reliability and agreement of the Richards-Campbell sleep questionnaire. Am J Crit Care. 2012;21(4): 261e269. 5. Tembo AC, Parker V, Higgins I. The experience of sleep deprivation in intensive care patients: findings from a larger hermeneutic phenomenological study. Intensive Crit Care Nurs. 2013;29(6):310e316. 6. 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(6):539e545.
Margaret Pisani, MD, MPH, Associate Professor* Yale University School of Medicine, 333 Cedar Street, P.O. Box 208057 New Haven, CT, USA * Corresponding author. Tel.: þ1 203 785 3207; fax: þ1 203 785 3826. E-mail address: [email protected]
Contents lists available at ScienceDirect
Heart & Lung journal homepage: www.heartandlung.org
Editorial
Sleep in the intensive care unit: An oft-neglected key to health restoration
Humans spend about one-third of their lives asleep. Despite ongoing active research, the true function or importance of sleep has yet to be fully elucidated. Some theories include the role of sleep in survival, restoration of bodily functions, energy conservation and information consolidation. Much of our understanding of the role of sleep comes either from animal studies or studies of healthy humans who are sleep deprived. A study published in 2013 examined mechanisms of sleep deprivation in a mouse model and suggested that the restorative function of sleep may be due to the removal of neurotoxic waste products that accumulate in the central nervous system during wakefulness.1 The sum understanding from other research is that sleep deprivation can contribute to cognitive impairment, immune dysfunction, increased risk for metabolic syndrome and cardiovascular disease, as well as impairments in respiratory function. As one can imagine, all of these adverse outcomes attributed to sleep deprivation may impact vulnerable, critically ill patients. A recent review explored issues related to sleep in critical illness.2 One of the challenges to sleep research in the intensive care unit (ICU) is how to reliably measure sleep in a heterogenous group of patients who are critically ill and receiving medications that may alter sleep. Studies have used polysomnography,3 which is felt to be the gold standard, as well as actigraphy and questionnaires4 with varying success. These studies demonstrate that sleep in the ICU is fragmented with a predominance of N1 and N2 sleep and a lack of N3 and REM sleep. Since the development of intensive care units, there has been research examining the impact of the ICU environment on sleep. These studies have assessed the impact of noise, light and patient care activities on the ability of critically ill patients to sleep and universally pointed to all of these factors contributing to varying degrees to interrupted sleep. In addition, studies surveying patients report noise, ambient light, isolation, restriction of mobility, and an inability to sleep as the most stressful factors related to their ICU admission.5 A qualitative report by Hopper in this issue of Heart & Lung identifies uncertainties about the importance of sleep among ICU clinicians as well as institutional barriers that will need to be addressed to improve sleep. There is now evidence starting to emerge that in addition to experiencing poor sleep while in the ICU, more than 50% of survivors have persistent sleep problems.6
0147-9563/$ e see front matter Ó 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.hrtlng.2015.01.007
In this issue of Heart & Lung Parsons et al examine the impact of insomnia on survivors from a mixed medical-surgical ICU. Twentyeight percent of survivors met criteria for insomnia a year after ICU discharge that was associated with impairment in mental health related quality of life. Despite decades-long research on factors that disrupt sleep in the ICU, the problem of sleep deprivation in critical illness is still prevalent. Now is the time to truly work at implementing practice change in ICU’s across the country to allow for noise reduction, lighting designed to maintain normal circadian rhythm, and clustering of care to allow for uninterrupted periods of sleep. We need to develop protocols that can be customized to allow for variations in ICU size, staffing and acuity. This should be a goal for all ICU nurses, physicians, and administrators.
References 1. Xie L, Kang H, Xu Q, et al. Sleep drives metabolite clearance from the adult brain. Science. 2013;342(6156):373e377. 2. Pisani MA, Friese RS, Gehlbach BK, Schwab RJ, Weinhouse GL, Jones SF. Sleep in the intensive care unit. Am J Respir Crit Care Med; 2015. Published online January 16, 2015. 3. 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(5):445e452. 4. Kamdar BB, et al. Patient-nurse interrater reliability and agreement of the Richards-Campbell sleep questionnaire. Am J Crit Care. 2012;21(4): 261e269. 5. Tembo AC, Parker V, Higgins I. The experience of sleep deprivation in intensive care patients: findings from a larger hermeneutic phenomenological study. Intensive Crit Care Nurs. 2013;29(6):310e316. 6. 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(6):539e545.
Margaret Pisani, MD, MPH, Associate Professor* Yale University School of Medicine, 333 Cedar Street, P.O. Box 208057 New Haven, CT, USA * Corresponding author. Tel.: þ1 203 785 3207; fax: þ1 203 785 3826. E-mail address: [email protected]
