Normal Stages of Sleep

  • xxx

Sleep in the Intensive Care Unit (ICU)

Effects of Intensive Care Unit Stay on Sleep Architecture

  • Abnormal Sleep-Wake Cycle
  • Decreased REM and Slow-Wave Sleep
  • Decreased Total Sleep Time/Decreased Sleep Efficiency
  • Increased Sleep Fragmentation
  • Prolonged REM Latency

Factors Contributing to Sleep Disruption in the Intensive Care Unit

  • Noise
  • Acute Illness: alters sleep architecture
  • Ambient Light Dyssynchronization
  • Mechanical Ventilation: mechanical ventilation is a well-known cause of sleep disruption
    • Mechanisms by Which Mechanical Ventilation May Disturb Sleep
      • Anxiety/Pain Induced by Ventilator
      • Overventilation: leading to apneas with arousals
      • Patient/Ventilator Asynchrony
      • Underventilation: leading to increased respiratory effort and arousals
    • Sleep Architecture is Highly Abnormal in Mechanically-Ventilated Patients, with No Effect with Choice of Ventilator Mode (2008) [MEDLINE]
      • Conscious, mechanically-ventilated patients have high degree of sleep fragmentation (frequent arousals), decreased total sleep time, short REM stage
      • The sleep efficiency in a medical population is reduced compared to a surgical one (40% v. 89%), which may partly explain the higher rate weaning failure seen in the medical population
  • Sedation/Analgesic Regimen
    • Risk Factors for Sleep Disruption in Mechanically Ventilated Patients in the Intensive Care Unit (Assessed in Preceding 24 hrs) (2000) [MEDLINE]
      • Acute Physiologic Score (APS) <13
      • Glasgow Coma Score (GCS) >10
      • Opiate Doses with Morphine Equivalent <10 mg/kg/h
      • Sedation Doses with Lorazepam Equivalent <10 mg/kg/h
    • Benzodiazepines Decrease Total Sleep and Suppress REM/N3 Sleep (see Benzodiazepines, [[Benzodiazepines]])
    • Diphenhydramine (Benadryl) Inhibits Histamine-Induced Wakefulness and Does Not Improve Polysomnographic Sleep Quality (see Diphenhydramine, [[Diphenhydramine]])
    • Trazodone (xxx) Subjectively Improves Sleep and Sleep Efficiency (But Polysomnographic Data are Limited) (see Trazodone, [[Trazodone]])
    • Opiates Provoke Nocturnal Awakenings, Suppress REM/N3 Sleep, and May Cause Central Sleep Apneas (see xxxx, [[xxxx]])
    • Demedetomidine (Precedex) Preserves the Day/Night Sleep Cycle, But Does Not Improve REM or Slow Wave Sleep (see Demedetomidine, [[Demedetomidine]]) [MEDLINE]
    • Propofol Decreases REM and Does Not Improve Sleep Efficiency or Fragmentation [MEDLINE]

Clinical Effects of Sleep Deprivation in the Intensive Care Unit

  • Cognitive Deficits: leading to ICU delirium
  • Decreased Insulin Sensitivity
  • Decreased Ventilatory Drive
  • Impaired Inspiratory Muscle Endurance
  • Impaired Immune Responses
    • Impaired Phagocytosis
    • Decreased NK Cell/Lymphocyte/Granulocyte Proliferation
    • Decreased Immune Response to Influenza Vaccination
  • Post-Traumatic Stress Disorder (PTSD) (see xxxx, [[xxxx]])

Measures to Reduce Sleep Disruption in the Intensive Care Unit

Decrease ICU Noise Levels

  • xxx

Clustering of Care Activities

  • Avoid Activities During Nocturnal Sleep Times

Early Mobilization

  • xxx

Ear Plugs

  • Trial of Ear Plugs in the ICU (2012)[MEDLINE]
    • Nocturnal Ear Plugs Decreased the Incidence of Confusion: beneficial effects appeared to be strongest within 48 hrs after admission
    • Patients Sleeping with Earplugs Developed Confusion Later than the Patients Sleeping Without Earplugs
    • After the First Night in the ICU, Patients Sleeping with Earplugs Reported a Better Perception of Sleep
  • Quality of Evidence is Low [MEDLINE]

Eye Masks

  • Some Data Suggest Benefit in Terms of Promoting Sleep and Decreasing Delirium: however, quality of evidence is low [MEDLINE]

Restoration of Natural Diurnal Lighting

  • Quiet Time Protocols

Minimization of Sedation

  • Daily Sedation Vacation Improves Polysomnographic Sleep Parameters in the ICU (2011) [MEDLINE]: daily sedation vacation increased the amount of slow wave sleep and REM

Avoidance of Medications Which Suppress Slow-Wave Sleep and REM

Use of Sleep-Promoting Medications That Do Not Suppress Slow-Wave Sleep and REM

  • Gaboxadol (xxx) (see Gaboxadol, [[Gaboxadol]])
  • Melatonin (see Melatonin, [[Melatonin]]): antioxidant and sleep-promoting properties -> needs further study
  • Zolpidem (Ambien) (see Zolpidem, [[Zolpidem]]): GABA A receptor agonism -> might improve sleep in the ICU, but data are limited
  • Zopiclone (xxx) (see Zopiclone, [[Zopiclone]])

Multimodal Strategies to Enhance Sleep in the Intensive Care Unit

  • Multi-Faceted Trial of Sleep-Promoting Interventions in the ICU (2013) [MEDLINE]
    • Interventions Led to Significant Improvement in Perceived Nighttime Noise
    • Interventions Led to Significant Improvement in Daily Delirium/Coma-Free Status
    • Interventions Led to Non-Significant Improvement in Perceived Sleep Quality

Other Therapies

  • Music Therapy: needs further study
  • Back Massage: needs further study
  • Aromatherapy: needs further study


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