Chest
Volume 136, Issue 1, July 2009, Pages 284-294
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Postgraduate Education Corner
Contemporary Reviews in Sleep Medicine
Sleep in the ICU: Potential Mechanisms and Clinical Implications

https://doi.org/10.1378/chest.08-1546Get rights and content

Patients in the ICU are known to have severely disrupted sleep with disturbed circadian pattern, decreased nocturnal sleep time, abnormally increased stages 1 and 2 sleep, and reduced or absent deep sleep. Recent data reveal that a subpopulation of critically ill patients manifests unique EEG sleep patterns. The etiology of sleep disruption in the ICU includes the inherent nature of the environment, medications, ventilator-patient interaction, and the effect of acute illness. How sleep disruption contributes to outcomes in critically ill patients, such as recovery time and weaning from mechanical ventilation, is unknown. This article reviews the literature describing sleep in ICU patients, including recent investigations in patients who require mechanical ventilation, factors that affect sleep in critically ill patients, and the potential mechanisms and clinical implications of disturbed sleep in the ICU setting with directions to consider for future investigations.

Section snippets

Normal Sleep Architecture and Regulation

Sleep is characterized by a variety of physiologic, behavioral, and EEG changes and is necessary for restoration of cognitive, mood, and physiologic functions.12, 14 Normal sleep architecture, measured by polysomnography (PSG) is divided into the following two distinct states: non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.14, 15, 16 NREM is composed of three distinct stages based on EEG criteria. Stage 1 and 2 are considered to reflect light sleep followed by deep

Implications of Sleep Deprivation

Studies of sleep-deprived animals and healthy humans reveal many derangements in physiologic parameters that could negatively affect the underlying pathophysiology, treatment, and recovery from acute critical illness in ICU patients.20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 Even short-term, partial sleep deprivation (6 nights of 4 to 5 h of sleep per night) results in untoward effects. Studies demonstrate decreased glucose tolerance and increased insulin resistance, which could impact

Sleep Patterns in ICU Patients

More than 60% of patients surviving ICU admission report poor sleep or being sleep deprived.32, 33 Other studies have shown that patients recall frequent interruptions and memories of pain, anxiety, and fear that impaired their ability to sleep.33, 34 In a study of 464 patients, 51% recalled experiencing dreams and nightmares over the course of their ICU admission; 14% of these patients, 6 months after ICU discharge, believed these dreams continued to negatively impact their quality of life.35

Factors Contributing to Sleep Disruption

Many factors can disturb sleep in ICU patients. These include the environment with disruptions due to noise, lighting, and patient care activities; disruption due to medical illness itself; and sleep disturbance due to medical treatments, such as respiratory care, drug therapies, and mechanical ventilation.7, 9, 10, 11

Summary

Sleep in the ICU is perceived by patients to be poor, often associated with fear, anxiety, and nightmares that impair later quality of life. Quantitative and qualitative sleep deprivation occurs and can have negative consequences on physiologic function, particularly immune mechanisms, as well as psychological well-being. Noise, particularly staff talking and patient-care activities, are clearly contributing factors and represent 40% of the source of sleep disruption. Medications such as

Acknowledgment

I would like to offer a special thanks to Dr. Mark Sanders for his advice and support in the preparation of this manuscript.

References (90)

  • AB Cooper et al.

    Sleep in critically ill patients requiring mechanical ventilation

    Chest

    (2000)
  • K Hardin et al.

    Sleep in critically ill chemically paralyzed patients requiring mechanical ventilation

    Chest

    (2006)
  • M Valente et al.

    Sleep organization pattern as a prognostic marker at the subacute stage of post-traumatic coma

    Clin Neurophysiol

    (2002)
  • DM Kahn et al.

    Identification and modification of environmental noise in an ICU setting

    Chest

    (1998)
  • MG Monsen et al.

    Noise and sleep disturbance factors before and after implementation of a behavioural modification programme

    Intensive Crit Care Nurs

    (2005)
  • ML Stanchina et al.

    The influence of white noise on sleep in subjects exposed to ICU noise

    Sleep Med

    (2005)
  • L Shilo et al.

    Patients in the intensive care unit suffer from severe lack of sleep associated with loss of normal melatonin secretion pattern

    Am J Med Sci

    (1999)
  • YF Guo et al.

    Respiratory patterns during sleep in obesity-hypoventilation patients treated with nocturnal pressure support: a preliminary report

    Chest

    (2007)
  • RC Van der Mast

    Delirium: the underlying pathophysiological mechanisms and the need for clinical research

    J Psychosom Res

    (1996)
  • MH Kollef et al.

    The use of continuous IV sedation is associated with prolongation of mechanical ventilation

    Chest

    (1998)
  • CJ Fowler

    Possible involvement of the endocannabinoid system in the actions of three clinically used drugs

    Trends Pharmacol Sci

    (2004)
  • MG Ibrahim et al.

    A double-blind placebo-controlled randomized pilot study of nocturnal melatonin in tracheostomised patients

    Crit Care Resusc

    (2006)
  • S Lautenbacher et al.

    Sleep deprivation and pain perception

    Sleep Med Rev

    (2006)
  • D McGinty et al.

    Keeping cool: a hypothesis about the mechanisms and functions of slow-wave sleep

    Trends Neurosci

    (1990)
  • GB Young

    Neurologic complications of systemic critical illness

    Neurol Crit Care

    (1995)
  • BA Hilton

    Quantity and quality of patients' sleep and sleep disturbing factors in a respiratory intensive care unit

    J Adv Nurs

    (1976)
  • KC Richards et al.

    A description of night sleep patterns in the critical care unit

    Heart Lung

    (1988)
  • J Aurell et al.

    Sleep in the surgical intensive care unit: continuous polygraphic recording of sleep in nine patients receiving post operative care

    BMJ

    (1985)
  • NS Freedman et al.

    Abnormal sleep/wake cycles and the effect of environmental noise on sleep disruption in the intensive care unit

    Am J Respir Crit Care Med

    (2001)
  • RS Friese et al.

    Quantity and quality of sleep in the surgical intensive care unit: are our patients sleeping?

    J Trauma

    (2007)
  • S Parthasarathy et al.

    Effect of ventilator mode on sleep quality in critically ill patients

    Am J Respir Crit Care Med

    (2002)
  • J Gabor et al.

    Contribution of the intensive care unit environment to sleep disruption in mechanically ventilated patients and healthy subjects

    Am J Respir Crit Care Med

    (2003)
  • S Parthasarathy et al.

    Sleep in the intensive care unit

    Intensive Care Med

    (2004)
  • MC Helton et al.

    The correlation between sleep deprivation and the intensive care unit syndrome

    Heart Lung

    (1980)
  • M Carskadon et al.

    Normal human sleep: an overview

  • C Iber et al.

    The AASM manual for the scoring of sleep and associated events

    (2007)
  • RS Bourne et al.

    Melatonin: possible implications for the postoperative and critically ill patient

    Intensive Care Med

    (2006)
  • GL Weinhouse et al.

    Sleep in the critically ill patient

    Sleep

    (2006)
  • K Speigel et al.

    Impact of sleep debt on metabolic and endocrine function

    Lancet

    (1999)
  • K Spiegel et al.

    Effect of sleep deprivation on response to immunization

    JAMA

    (2002)
  • L Osturk et al.

    Effects of 48 hours sleep deprivation on human immune profile

    Sleep Res Online

    (1999)
  • DP White et al.

    Sleep deprivation and control of ventilation

    Am Rev Respir Dis

    (1983)
  • JC Leiter et al.

    The effect of sleep deprivation on the activity of the genioglossus muscle

    Am Rev Respir Dis

    (1985)
  • H Chen et al.

    Sleep loss impairs inspiratory muscle endurance

    Am Rev Respir Dis

    (1989)
  • CM Spengler et al.

    Sleep deprivation per se does not decrease the hypercapnic ventilatory response in humans

    Am J Respir Crit Care Med

    (2000)
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