Sleep in Critical Illness: Physiology, Assessment, and Its Importance to ICU Care

Preface
Contents
List of Contributors
Characteristics of Sleep in Critically Ill Patients: Part I: Sleep Fragmentation and Sleep Stage Disruption
	1 Introduction
	2 Total Sleep Time
		2.1 Challenges with TST Measurement
	3 Sleep Fragmentation
		3.1 Studies Employing Objective Assessment Methods
		3.2 Studies Employing Subjective Assessment Methods
		3.3 Causes of Sleep Fragmentation
		3.4 Sleep and Clinical Outcomes
	4 Sleep Stage Disruption
		4.1 Summary of PSG Studies
		4.2 Causes of Sleep Stage Deprivation
		4.3 Consequences of Sleep Stage Deprivation
	5 Conclusion
	References
Characteristics of Sleep in Critically Ill Patients: Part II: Circadian Rhythm Disruption
	1 Introduction
	2 Circadian Timing System Physiology
		2.1 Molecular Basis
		2.2 Central Clock
		2.3 Entrainment
		2.4 Peripheral Clocks
	3 Measurement of Circadian Rhythms
		3.1 Melatonin, 6-Sulfatoxymelatonin Levels
		3.2 Cortisol Levels
		3.3 Core Body Temperature
		3.4 Actigraphy
		3.5 Circadian Gene Expression
		3.6 Challenges to Assessing CR in Critically Ill Adults
	4 Circadian Disrupters
		4.1 ICU Environment
		4.2 Acute and Chronic Disease
	5 Circadian Rhythms in the Critically Ill
		5.1 Core Body Temperature
		5.2 Melatonin
		5.3 Cortisol
		5.4 Genetic Changes
	6 Potential Clinical Consequences
	7 Conclusion
	References
Atypical Sleep and Pathologic Wakefulness
	1 Introduction
	2 Defining Characteristics
		2.1 Watson’s Criteria
		2.2 Drouot’s Criteria
		2.3 Comparisons Between the Watson and Drouot Criteria
	3 Monitoring Tools
	4 Prevalence
	5 Pathophysiology and Risk Factors
		5.1 Pathophysiology
		5.2 Risk Factors
	6 Clinical Consequences
		6.1 Respiratory Outcomes
		6.2 Neurologic Outcomes
	7 Treatment
	8 Conclusion
	References
Normal Sleep Compared to Altered Consciousness During Sedation
	1 Introduction
	2 Phenomenological and Behavioral Changes
	3 Mechanistic Correlates and Targets
	4 Electroencephalogram Signatures
	5 Changes in Brain Function
	6 Sleep Outcomes
	7 Conclusions
	References
Biologic Effects of Disrupted Sleep
	1 Introduction
	2 Sleep Disruption and Neurobehavioral Functions
		2.1 Mood
		2.2 Vigilant Attention
		2.3 Learning and Memory
	3 Sleep Disruption and Immune Function
		3.1 Cytokine Function
		3.2 Immunity and Illness Recovery
	4 Sleep Disruption and Endocrine Function
		4.1 Hypothalamic-Pituitary-Adrenal Axis
		4.2 Catecholamines
		4.3 Metabolism and Thermoregulation
	5 Sleep Disruption and Cardiovascular Function
	6 Sleep Disruption and Pulmonary Function
	7 Sleep Disruption and Gastrointestinal Function
	8 Sleep Disruption and Musculoskeletal Function
	9 Inter-Individual Vulnerability to Sleep Loss
	10 Conclusion
	References
Risk Factors for Disrupted Sleep in the ICU
	1 Introduction
	2 Characterizing and Identifying Risk Factors for Disrupted Sleep
		2.1 Risk Factor Characterization
		2.2 Risk Factor Identification
			2.2.1 Patient Perceived
			2.2.2 Objective
		2.3 A Systematic Approach to Summarizing the Sleep Risk Factor Literature
	3 Patient-Reported Risk Factors
		3.1 Illness-Associated
		3.2 ICU-Related
		3.3 Impact/Severity-Rated
	4 Patient-Related Risk Factors for Sleep Disruption
		4.1 Baseline (Premorbid)
		4.2 Illness-Associated
	5 ICU-Acquired Risk Factors
		5.1 ICU Environment
		5.2 ICU Medications
		5.3 Ventilatory Support Therapies
	6 Special Populations
		6.1 Neurological Injury
		6.2 Coronavirus Disease 2019
	7 Inter-patient Sleep Risk Factor Variability
	8 Risk Reduction and Sleep Improvement
	9 Research Opportunities and Future Directions
	References
Effects of Common ICU Medications on Sleep
	1 Introduction
	2 Medication Administration and Monitoring-Related Sleep Disruption
	3 Medications that Physiologically Impact Sleep
		3.1 Central Nervous System Agents
			3.1.1 Gabaminergics
			3.1.2 Alpha-2 Agonists
			3.1.3 Ketamine
			3.1.4 Antidepressants
			3.1.5 Antipsychotics
			3.1.6 Antihistamines
			3.1.7 Anticonvulsants
			3.1.8 Opioids
		3.2 Cardiovascular Agents
		3.3 Endocrine
		3.4 Pulmonary
		3.5 Withdrawal from Chronic Therapies and Substances
	4 Conclusions and Future Directions
	References
Sleep Disruption and Its Relationship with Delirium: Electroencephalographic Perspectives
	1 Introduction
	2 The Restorative Neurophysiology of Sleep
		2.1 Slow Oscillations and Delta Waves
		2.2 Sleep Spindles and K Complexes
		2.3 Theta Waves
		2.4 Functional Connectivity Patterns in Normal Sleep
	3 Neural Dynamics in Sleep Disruption
	4 Neural Dynamics in Delirium
	5 Sleep Deprivation: Toward a Hypothesis of Deliriogenesis
	6 Clinical Implications: Sleep in the ICU and Beyond
	7 Summary and Conclusions
	References
Sleep Disruption and Its Relationship with Delirium: Clinical Perspectives
	1 Introduction
	2 Risk Factors
	3 Epidemiology and Outcomes
		3.1 Disrupted Sleep
		3.2 Delirium
	4 Sleep Deprivation and Delirium Symptoms
	5 Assessment of Sleep and Delirium
		5.1 Sleep
		5.2 Delirium
	6 Patient-Centered Evaluations Linked to Both Sleep and Delirium
	7 The Relationship Between Sleep and Delirium Reported in ICU Clinical Studies
	8 Areas for Future Investigation
	9 Conclusions
	References
Mechanical Ventilation and Sleep
	1 Introduction
	2 Conceptual Framework
	3 Epidemiology and Scope of the Problem
	4 Modes of Mechanical Ventilation
		4.1 Assist Control Versus Pressure Support
		4.2 Proportional Assist Versus Pressure Support
		4.3 Pressure Control, Neurally Adjusted Ventilator Assistance, or Proportional Assist Plus Versus Pressure Support
		4.4 Summary
	5 Effect of Ventilator Management Strategies on Sleep; Low Tidal Volume Ventilation
	6 Effect of Sleep on Noninvasive Mechanical Ventilation and Monitoring
		6.1 Monitoring
		6.2 Noninvasive Ventilation
	7 Conclusion
	References
Sleep Disruption and its Relationship to ICU Outcomes
	1 Introduction
	2 Abnormal Sleep and Circadian Rhythms in Critical Illness
	3 Association Between Pre-Existing Sleep Disorders and ICU Outcomes
	4 Immune Function & Inflammation
	5 Disrupted Sleep and Organ System-Related Outcomes
		5.1 Psychiatric and Neurocognitive Outcomes
		5.2 Respiratory Outcomes
		5.3 Cardiovascular Outcomes
		5.4 Metabolic Outcomes
		5.5 Renal Function
		5.6 Physical Outcomes
	6 Outcomes after ICU Discharge
	7 Areas for Future Research
	8 Conclusion
	References
Long-Term Outcomes: Sleep in Survivors of Critical Illness
	1 Introduction
	2 Recovery from Critical Illness
		2.1 ICU Recovery Frameworks
	3 Assessment of Sleep during the ICU Recovery Period
		3.1 Objective Methods
			3.1.1 Polysomnography
			3.1.2 Actigraphy
		3.2 Subjective Measures
			3.2.1 Sleep Logs
			3.2.2 Self-Administered Questionnaires
	4 Sleep Quality and Quantity during ICU Recovery
		4.1 Potential Sleep Disturbances during the ICU Recovery Period
			4.1.1 Sleep Disordered Breathing (SDB)
			4.1.2 Circadian Rhythm
			4.1.3 Insomnia
		4.2 Sleep while Still Hospitalized but after the ICU
		4.3 Sleep after Hospital/Institutional Discharge
	5 Factors Associated with Disturbed Sleep during Recovery
		5.1 Prehospital
		5.2 During Critical Illness and Hospitalization
		5.3 After Discharge from Hospital
	6 Impact of Disturbed Sleep after Critical Illness on Recovery Outcomes
		6.1 Health-Related Quality of Life
		6.2 Psychological Symptoms
	7 Strategies for Sleep Promotion during Recovery
		7.1 Assessment and Referral
		7.2 Treatment for Chronic Insomnia
			7.2.1 Single Component Treatments
			7.2.2 Multicomponent Treatments
	8 Concluding Remarks and Future Directions
	References
Methods for Routine Sleep Assessment and Monitoring
	1 Introduction
	2 Objective Methods to Measure Sleep
		2.1 Polysomnography
			2.1.1 Data from ICU Application
			2.1.2 Limitations in the ICU
		2.2 Bispectral Index
			2.2.1 Data from ICU Application
			2.2.2 Limitations in the ICU
		2.3 Actigraphy
			2.3.1 Data from ICU Application
			2.3.2 Limitations in the ICU
	3 Subjective Methods to Measure Sleep (Table 1)
		3.1 Clinician Observation
		3.2 Patient-Perception: Richards-Campbell Sleep Questionnaire
			3.2.1 Data from ICU Application
			3.2.2 Limitations in the ICU
		3.3 Patient-Perception: Other Methods
			3.3.1 Leeds Sleep Evaluation Questionnaire
			3.3.2 St. Mary’s Hospital Sleep Questionnaire
			3.3.3 Verran/Snyder-Halpern Sleep Scale
			3.3.4 Sleep in the ICU Questionnaire
	4 Evolving and Future Assessment Methods
	5 Conclusion
	References
Best Practice for Improving Sleep in the ICU. Part I: Non-pharmacologic
	1 Introduction
	2 Patient Factors that Disrupt Sleep
		2.1 Psychologic Distress
		2.2 Pain and Discomfort
		2.3 Sleep History
	3 Environmental Factors that Disrupt Sleep
		3.1 Noise
		3.2 Light
		3.3 Bedside Care Interactions
		3.4 Multicomponent Sleep Improvement
		3.5 Earplugs and Eye Masks
		3.6 Light Interventions
	4 Acute Illness and Treatment Factors that Disrupt Sleep
		4.1 Sedation
		4.2 Enteral Nutrition Schedule
		4.3 Mobilization
		4.4 Naps
	5 Summary of Strategies to Improve ICU Sleep
	6 Future Directions
	7 Conclusions
	References
Best Practices for Improving Sleep in the ICU: Part II: Pharmacologic
	1 Introduction
		1.1 Methodologic Considerations when Evaluating ICU Pharmacologic Sleep Agents
	2 Dexmedetomidine
		2.1 Sleep-Related Pharmacology
		2.2 Comparative Trials Evaluating a Sleep Outcome
	3 Melatonin Agonists
		3.1 Melatonin
			3.1.1 Sleep-Related Pharmacology
			3.1.2 Comparative Trials Evaluating a Sleep Outcome
		3.2 Ramelteon
			3.2.1 Sleep-Related Pharmacology
			3.2.2 Comparative Trials Evaluating a Sleep Outcome
	4 Gabaminergic Agents
		4.1 Sleep-Related Pharmacology
		4.2 Comparative Trials Evaluating a Sleep Outcome
	5 Additional Agents: Antipsychotics, Antidepressants, and Non-benzodiazepine Hypnotics
	6 Continuation of Sleep Agents from Home
	7 Recommendations for Best Practices
	8 Future Areas of Research
	9 Conclusion
	References
Sleep Considerations in Critically Ill Children
	1 Introduction
	2 Neurobiological Considerations
		2.1 Circadian Rhythms
		2.2 Sleep Recommendations
	3 Sleep Assessment
		3.1 Quantitive Sleep Assessment
			3.1.1 Electroencephalographic (EEG) Monitoring
			3.1.2 Actigraphy
			3.1.3 Melatonin
		3.2 Qualitative Sleep Assessment
			3.2.1 Age-Appropriate Sleep Scales
			3.2.2 Sleep Diaries
	4 Risk Factors for Poor Sleep
		4.1 Medical Conditions
		4.2 Co-Administered Therapies
		4.3 Environmental Factors
		4.4 Psychological/Emotional Factors
	5 Sleep Restoration and Promotion
	6 Conclusion
	References
Sleep in Critical Illness: Future Directions
	1 Introduction
	2 Measures of Sleep in the Intensive Care Unit
		2.1 Objective Sleep Measures
		2.2 Measures of Patients’ Sleep Perception
		2.3 Circadian Measures
		2.4 Measurement Conclusions
	3 Prevalence and Risk Factors for ICU Sleep Disruption
		3.1 Prevalence
		3.2 Patient Risk Factors
		3.3 ICU Environment
	4 Sleep Promotion
		4.1 Addressing Patient Risk Factors
		4.2 Reducing Environmental and Care Interruptions
		4.3 Pharmacologic Interventions
		4.4 Treatment Conclusions
	5 Outcomes
		5.1 Delirium
		5.2 Respiratory Failure
		5.3 Other Outcomes
		5.4 Long Term Outcomes
	6 Conclusions
	References
Index