Have you ever tried to sleep in a brightly lit room, with tubes and wires attached, and with people periodically talking, touching, and moving you? It is not surprising that sleep disturbances and fatigue are among the most common symptoms in critically ill adults, regardless of the type of critical care hospital unit or disease process.1,2 Many factors contribute to sleep and fatigue symptoms during recovery from acute illness or injury. Preexisting sleep disorders, pathophysiology of the underlying illness/injury, therapeutic interventions, medications, and the intensive care unit (ICU) environment are major contributing factors in sleep disruption and fatigue.2-6 Regardless of the cause, consequences of sleep disturbances and fatigue include diminished physical and cognitive functioning, mood instability, emotional distress, and amplification of concurrent symptoms.2,7 Sleep disruption is a significant stressor in the ICU that can negatively affect recovery and even survival.8,9

Sleep disturbance and debilitating fatigue that originate during acute illness may continue months after discharge from the ICU.10 If these issues are unrecognized, lack of treatment may contribute to chronic sleep problems, impaired quality of life, and incomplete rehabilitation.11,12 Acute and chronic fatigue can diminish a patient's ability to participate in her or his own care. Experts have concluded that screening, evaluation, and management of sleep disturbances and fatigue are suboptimal in the critical care setting.1,13 An evidence-based approach to address these and related symptoms is recommended.2 As patient advocates, nurses are well positioned to identify patient and environmental issues that prevent effective sleep and generate fatigue. The purpose of this article is 2-fold: to discuss the literature related to the occurrence, etiology, and risk factors of sleep disturbance and fatigue; and to describe assessment and management options in critically ill adults.

Background

Adequate sleep is essential to survival of all mammals. Sleep provides necessary restorative, protective, and energy-conserving functions. Indications of restorative sleep include awaking/feeling refreshed and the absence of daytime sleepiness after nocturnal sleep periods. Sleep consists of 2 main types: rapid eye movement (REM) sleep and nonrapid eye movement (NREM) sleep. Nonrapid eye movement sleep consists of several stages of light, transitional (new classification: N1, N2; previously classified as stages 1-2) to deeper sleep (new classification: N3; previously classified as stages 3-4).14 Sleep "architecture" consists of several recurring 90-minute cycles of NREM and REM sleep. Sufficient quantities of both NREM and REM sleep stages are necessary for restoration of mental and physical processes.

Sleep disturbance is defined as the perceived or actual alterations in nighttime sleep (both quantity and quality) with subsequent daytime impairment.15 Sleep disturbance may be acute and transient, but often it is a recurrent problem. Common complaints include difficulty in 1 or more of these areas: falling asleep, staying asleep, early morning awakenings with inability to resume sleep, nonrestorative sleep, and excessive daytime sleepiness (EDS). Regardless of the cause, sleep disturbances have been associated with adverse physiologic outcomes, including alterations in immune function,16-18 metabolism, nitrogen balance, and protein catabolism.19,20 Sleep deprivation and disruption are known to diminish quality of life9 and cognitive abilities.21 In addition, sleep disturbance can increase pain intensity, depression, and anxiety.22-25

Sleep in ICU patients is characterized by fragmented nocturnal sleep, poor sleep efficiency, and prolonged sleep onset (sleep latency [SL]).12 Sleep periods of ICU patients are described as brief, interrupted by frequent arousals, and evenly distributed over the day and night. When a sleep period is fragmented by frequent arousals, sleep architecture is significantly altered. Alterations include a greater percentage of transitional, light sleep; reduced deep, restorative sleep; and decreased REM sleep.12

Estimates of Sleep Disturbance in Critically Ill Patients

Evidence suggests that acute illness/injury and the ICU environment diminish restorative sleep; however, it has been difficult to quantify occurrence rates due to varied definitions of sleep disturbance, measurement issues, and the challenges of conducting sleep studies in the ICU.26 Despite the challenges, evidence suggests that a substantial proportion of ICU patients experience poor sleep quality, prolonged SL, and frequent arousals/awakenings that contribute to physical and emotional distress.27-29

In a large study of medical and surgical ICU patients (n = 1625), 38% experienced difficulty falling asleep, and 61% reported a greater than usual need for sleep.10 In another study, nearly 70% of ICU patients with cancer experienced a moderate or severe level of sleep disturbance, and poor sleep was identified as one of the most stressful aspects of their ICU stay.30 Several months after hospital discharge, more than half of ICU survivors (n = 39) continued to experience worse interrupted sleep or altered sleep patterns compared with their prehospital patterns.31 Sleep research in the ICU is in its infancy, and further investigations of nurse-driven assessment and interventions are needed to minimize the negative consequences of sleep disturbance in critically ill patients.13

Risk Factor Model for Sleep Disturbance

Spielman's Three-Factor Model proposes the interaction between predisposing, precipitating, and perpetuating factors in the development and continuation of sleep disturbances.32 Predisposing factors are individual physiologic and psychologic traits that affect the likelihood of developing sleep problems (eg, age, hyperarousal). Precipitating factors are triggers that bring about or worsen sleep disturbances (eg, acute illness, stressful life events, changes in sleep environment). Perpetuating factors include behaviors and beliefs that sustain the sleep disturbance even after the initial precipitating factor has resolved (eg, substance use, poor sleep hygiene, maladaptive thoughts or behaviors related to sleep).32 Thus, acute physical and psychologic disorders in ICU patients may precipitate sleep disturbances that interact with the patient's innate predisposition for sleep problems.

Aging increases the incidence of sleep disorders and changes in sleep architecture. This risk factor is particularly significant to ICU clinicians, because more than half of all ICU days are attributable to patients older than 65 years.33 The amount of sleep spent in REM and deep sleep diminishes with age. In general, older adults have prolonged SL, shorter total sleep time, reduced sleep efficiency, and more awakenings.34 In addition to factors contributing to sleep disturbance in younger ICU patients, sleep of older adults may be even further disrupted by the physiologic processes of aging.

Etiology of ICU-Related Sleep Disturbance

Sleep disturbances in critically ill patients may result from preexisting primary sleep disorders, underlying injury or illness, therapeutic/diagnostic interventions, and environmental factors.2,35,36 Extant sleep disorders can exacerbate ICU-related sleep disruption. Conversely, underlying medical diseases may give rise to various sleep disorders (eg, sleep apnea, restless legs syndrome, circadian rhythm disorder).35-37

Primary Sleep Disorders

Obstructive sleep apnea syndrome (OSAS), central sleep apnea, parasomnias, and circadian rhythm sleep disorders occur in the general public with varying frequency and have been reported in substantial numbers of ICU patients.38Table 1 outlines common sleep disorders that may be present in ICU patients and describes characteristics, risk factors, and selected interventions.

Underlying Illness and Injury

Respiratory, endocrine, renal, cardiovascular, infectious, and neurologic diseases have been associated with a variety of symptoms that interfere with onset and maintenance of sleep.35-37 Patients with pulmonary disorders are more susceptible to oxygen desaturation due to frequent arousals and physiologic changes during REM sleep.36 Dyspnea, nocturnal cough, and wheezing symptoms in chronic obstructive pulmonary disease may decrease sleep duration, REM, and deeper sleep stages.40 Physical complications of type II diabetes (eg, neuropathic pain and nocturia) have been associated with sleep fragmentation and loss.41 Sleep disorders, including sleep apnea, insomnia, restless legs syndrome, and periodic limb movement disorder, are common in patients at all stages of renal disease.42,43 Underlying uremia, pain, nausea, and pruritus contribute to sleep fragmentation in end-stage renal disease.42

Neurodegenerative and neuromuscular disorders are associated with sleep fragmentation, daytime sleepiness, movement and breathing disturbances, and circadian rhythm disorders, which worsen with disease severity.44 The brain plays an integral role in the regulation of sleep and wakefulness; therefore, it is not surprising that patients with dementia, epilepsy, and traumatic brain injury have an increased risk of developing sleep disturbances.45 Following stroke, sleep-wake disturbance and sleep-disordered breathing are frequently observed as a direct or indirect (eg, pain, depression, medications) consequence of acute focal brain damage.46

Sleep disturbance and delirium in the ICU are frequently related, in part, to the shared etiology of sleep loss due to interruptions and sedatives.47 An imbalance in neurotransmitters and an alteration in melatonin production may contribute to the pathogenesis of both delirium and sleep disturbances.38 Delirium is strongly correlated with greater morbidity and mortality, and thus, effective interventions to address sleep disturbances may result in improved clinical outcomes.38,47

A majority of hospitalized patients with chronic pain syndromes22,48 or acute pain resulting from surgery or trauma30,36,49-51 experience sleep loss and fragmentation. For example, poor sleep has been correlated with acute burn pain, where poor sleep leads to reports of higher pain intensity and lower pain tolerance. In return, greater pain affects quality of sleep.51,52 Evidence suggests that increased pain sensitivity may be due to the effect of sleep deprivation on opioid protein synthesis or opioid receptor affinity.53 Effective analgesia, therefore, is indicated for both pain control and improved sleep.22

Sleep disturbances are common in psychiatric and behavioral disorders, notably anxiety, depression, and personality disorders. In turn, sleep disturbance and sleep deprivation can adversely influence the course of psychiatric disorders.37

Therapeutic/Diagnostic Interventions and Environmental Factors

Necessary therapeutic interventions/diagnostic procedures (eg, medications, surgery) and resultant adverse effects (eg, sedation, pain) contribute to sleep disturbance. It is important to consider the role of medications as a factor contributing to impaired sleep in critically ill patients. The most common medications that impair sleep include sedative and analgesic combinations used to facilitate mechanical ventilation.7,35,36 Cardiovascular, gastric protection, antiasthma, anti-infective, antidepressant, and anticonvulsant drugs have also been reported to cause a variety of sleep disturbances and are reviewed in detail elsewhere.36

Recent studies suggest that mechanical ventilation is associated with loss of circadian sleep pattern, sleep fragmentation, increasing proportions of transitional stages of sleep, and loss of deep, restorative and REM sleep, but the precise mechanism is not well understood.27,54-57 Sleep in ventilated patients may be further disrupted by dyssynchronous breathing, ventilator mode, sedation, discomfort from the endotracheal tube, and stress related to communication barriers.12 Optimizing ventilator settings is an area that needs further investigation.12 Measures to improve comfort, quantity, and quality of sleep include careful attention to sedative agents and the mode of mechanical ventilation.57

Environmental factors including patient care activities (eg, therapeutic interventions, monitoring), diagnostic procedures (eg, laboratory draws, x-rays), and the absence of diurnal cues (eg, excessive nocturnal noise and lighting)58,59 contribute to disrupted sleep in critically ill patients.2,60 Patients have reported that noise-specifically from conversations, but also from ventilators, alarms, television, phones, and beepers-causes sleep disruption.12 Although several questions remain unanswered, there is a growing interest in developing effective strategies to improve sleep quality through management of modifiable environmental factors.29

Evaluation of Sleep Disturbances

Assessment of sleep disturbances may be challenging at the onset of acute illness, trauma, or surgery. As the patient's physical condition stabilizes, the ICU team can better assess how the ICU environment, medications, and current treatments contribute to sleep problems. Sleep assessments may be categorized as objective, behavioral, and subjective. Table 2 describes selected examples of measurements in these categories and their applicability in ICU settings.

The most effective and accurate way to measure sleep is polysomnography (PSG), but this method may be limited in critical care settings because of expense and access.71 Bispectral index is an alternative method that has been used in some ICU settings to measure sleep.72 A behavioral option is actigraphy, a small wrist or leg accelerometer that records gross motor activity and rest over long periods.71 Continuous actigraph monitoring has been used in critically ill patients to guide the use of sedative medications and enhance recognition of agitation.73

Subjective evaluation methods (clinician observation and patient self-reports) may offer a more practical means of evaluating sleep quality and efficacy of sleep interventions. Clinicians may infer sleep and sedation based on patient behaviors, but the distinction between wakefulness (with eyes closed) and NREM and REM stages of sleep cannot be determined by observation alone.7 The validity of sleep observation may be subject to observer bias and fatigue. Sedation evaluation tools that use descriptive numerical scales are potentially more accurate than simple judgments of sleep/nonsleep states.

Using a patient's own appraisal of her or his sleep is desirable because she or he is able to compare usual sleep quality and quantity with the sleep quality and quantity during her or his acute illness. Daily sleep diaries, visual analog scales, questionnaires, and symptom or quality-of-life questionnaires with sleep items have been used in a variety of critical care studies,74-76 but they may prove challenging to implement outside a clinical trial.

When patient status permits, verbal complaints of difficulty falling asleep, interrupted sleep, or not feeling rested need to be elicited on a routine basis with or without the use of a formal measure. Assessment of past sleep patterns in a normal environment helps clinicians distinguish individual sleep problems from hospital-related causes. Premorbid health habits (eg, exercise, caffeine, tobacco) may suggest areas that need to be addressed during the patient's post-ICU recovery.77 Patients and family members may share insight on etiologic factors (eg, fear over results of diagnostic test), and assessment of their perception of sleep difficulties and possible relief measures may facilitate appropriate therapy. Although objective recording of the number of sleep hours and interruptions may differ from the patient's perception, observations of sleeping and wakeful behaviors over 24 hours, and notations of physical and psychologic sleep interruptions (eg, noise, pain, anxiety) can be helpful in developing a comprehensive care plan.78

Interventions for Sleep Disturbances

If assessment suggests a sleep disturbance (with or without a diagnosed primary sleep disorder), a multidisciplinary approach should begin as soon as possible. Treatment choices include medications, nonpharmacologic interventions, simple sleep-preserving environmental changes in the ICU, and referral to or consultation with a sleep specialist.

Pharmacologic Considerations

Pharmacologic treatment of sleep disturbance in the ICU begins with a careful review of each patient's pharmacologic treatment regimen and its impact on sleep. Many ICU patients receive medications to support blood pressure, improve urine and/or cardiac output, or enhance overall oxygen delivery. These agents are associated with changes in cortical activation and act through a variety of neurotransmitter pathways, receptors, and modulators that can adversely affect sleepwake patterns.79 Other common medications that have an effect on normal sleep physiology include sedatives, opioids, antidepressants, anticonvulsants, and medications for gastric protection, asthma, and infections.2,5,12 Sleep-disrupting medications started in the ICU, therefore, should be discontinued as soon as possible. If medications that are disrupting sleep cannot be discontinued, administration of these agents at the lowest possible dose to achieve desired therapeutic results may be a possible compromise.

Sedatives and analgesics are examples of medications that may require dose reduction to improve sleep quality and quantity. Although necessary for many ICU patients, particularly those requiring mechanical ventilation, sedatives and analgesics are known to alter normal sleep patterns and architecture.5,79 Reductions in sedative dosage may improve sleep but require careful titration and monitoring to prevent symptoms of withdrawal. Withdrawal symptoms (eg, restlessness, sleep disturbances, fatigue) are associated most often with prolonged use of sedative agents. Guidelines developed by the American College of Critical Care Medicine recommend systematic tapering of sedatives to reduce the risk of these sleep-related withdrawal symptoms.80 In addition to attention to sedative withdrawal reactions, nicotine and alcohol replacement may be indicated for heavy smokers or drinkers to manage sleep disturbance due to withdrawal of these substances.5

Before starting new sleep medications in ICU patients, a thorough appraisal of all current medications is advised.5 Medications for acute sleep disturbances should be used for short periods with ongoing reassessment, and they should be administered in conjunction with nonpharmacologic interventions. It is important to recognize that even if total sleep time is increased, sleep medications may not necessarily improve sleep quality.

Benzodiazepines are commonly prescribed in the treatment of sleep disorders, but they alter sleep architecture, specifically decreasing deeper NREM and REM sleep phases. Rapid eye movement sleep is associated with respiratory dysfunction, so benzodiazepine-induced REM reduction may be advantageous in some patients (eg, Cheyne-Stokes respiration and chronic obstructive pulmonary disease).81 Newer, shorter acting benzodiazepines (zolpidem, zaleplon) have fewer hangover effects and less deep sleep suppression than previous generations of benzodiazepines (diazepam, nitrazepam). Midazolam, a short acting benzodiazepine, is often used in ICUs for procedural sedation and sedation of ventilated patients because of its favorable therapeutic profile: short half-life, no active metabolites, water soluble, and available intravenously or subcutaneously.82 Limitations of benzodiazepines include tolerance within days of initiating therapy, risks of dependence, and adverse events (eg, nightmares, restlessness).5 Selected sleep medications are presented in Table 3.

Posttraumatic stress disorder (PTSD) and resultant nightmares are well-recognized complications of severe illness that have been described in ICU patients after multiple trauma, burns, myocardial infarction, acute respiratory distress syndrome, or septic shock.83 Pharmacologic agents for treatment of PTSD-associated nightmares may include prazosin and clonidine.84 Other medications may be considered for treatment of PTSD-related nightmares, but there is weak evidence for the use of the following: trazodone, atypical antipsychotic medications, topiramate, low-dose cortisol, fluvoxamine, triazolam, nitrazepam, phenelzine, gabapentin, cyproheptadine, and tricyclic antidepressants.84 Relaxation and other behavioral approaches may be considered for treatment of PTSD-associated nightmares based on patient needs and acceptance of therapy.84 In summary, a wide variety of medications are available to treat sleep disturbances and nightmares arising from multiple etiologies, yet further investigation is needed to establish efficacy and utility in the ICU setting.

Nonpharmacologic Approaches to Manage Sleep Disturbance

Nonpharmacologic approaches to improve sleep may be broadly grouped into 3 areas: cognitivebehavioral interventions, complementary therapies, and environmental strategies. Cognitive-behavioral therapy for insomnia (CBTI) is an established treatment of comorbid insomnia in the context of medical and psychiatric illness, as well as for primary chronic insomnia.85 For comorbid insomnia, some simple adaptations to standard CBTI may prove beneficial in ICU patients. The individual components, which include behavioral strategies (regular sleep scheduling, stimulus control), cognitive therapy, sleep hygiene education, and relaxation, can be delivered as monotherapies. Multicomponent delivery, however, is widely accepted as the preferred approach.86 The goal of CBTI is to reduce perpetuating factors below the insomnia threshold and to decondition the hyperarousal response.87 Cognitive therapy aims to decrease dysfunctional beliefs and attitudes that prevent sleep onset and maintenance. Sleep hygiene education addresses a variety of habits, environmental factors, and practices that influence the duration and quality of sleep. Educational subject matter typically includes simple guidelines to effectively promote sleep onset and maintenance. As with CBTI, sleep hygiene may need adaptation for the ICU setting.

Although still largely unexamined in the ICU, complementary therapies to improve sleep (eg, muscle relaxation, massage, healing touch) have been found to be effective in other patient groups.88 In recent reviews of complementary therapies tested in hospitalized and ICU patients,89,90 the reviewers concluded that massage,91 music,92 relaxation,93 and therapeutic touch94 are potentially beneficial nurse-driven interventions that promote sleep in critically ill adults. Additional well-designed studies are needed to evaluate the efficacy of complementary therapies on sleep in a variety of patient populations and settings.

Early mobility in the ICU is emerging as an important strategy to prevent and treat muscle weakness and improve long-term recovery.95 Stepwise progressive mobility programs have been tested in a few small studies and have shown favorable effects on sleep outcomes.96-98 Evidence to date shows a positive trend for early mobility that may lead to improved sleep in ICU patients, but results from larger studies are needed.

Most environmental interventions for sleep disturbances are centered on noise reduction or filtering,4,99-101 diurnal lighting practices,99,101,102 and scheduling uninterrupted time for adequate sleep.103 Intervention studies to reduce sleep disturbances resulting from environmental factors in ICU patients are presented in Table 4. In general, nursing interventions that focus on the abatement of ambient stressors in the ICU (light, noise, interruptions) were found to enhance patients' sleep.108,109 However, limitations of these studies include small samples (clinical and nonclinical), lack of standard measures, and nonrandomized study designs. Additional, well-designed trials with a sufficient sample size are needed. In addition to providing an environment conducive to sleeping in the ICU, general strategies to improve sleep quantity and quality in ICU patients are identified in Table 5.2,6,108

Sleep Specialist Consultation

Primary sleep disorders may present as comorbidities in ICU patients, so consultation with a sleep specialist may be appropriate. For example, if OSAS is suspected, referral to a sleep specialist and a PSG are indicated if the patient's condition permits. In the interim, 24-hour oximetry may be used as a screening measure. If repetitive oxygen desaturations are recorded during sleep, a continuous positive airway pressure system may prove beneficial to the patient's overall recovery. Once the patient's condition is stabilized and a PSG can be performed, it will be necessary to confirm the OSAS diagnosis and titrate the continuous positive airway pressure.77

Sleep and Fatigue

Patients often complain of fatigue related to disrupted sleep. Fatigue and sleep disturbances are often interrelated but also occur independently of each other. Sleep disturbances may lead to symptoms of EDS and diminished energy. Although frequently noted in combination, fatigue is distinct from EDS. Endocrine, metabolic disorders, and psychiatric disease such as depression are associated with fatigue without excessive sleepiness.39 Excessive daytime sleepiness and lack of energy in fatigued patients may subsequently lead to reduced physical activity and prolonged daytime napping, which in turn perpetuates sleep disturbances such as sleep onset insomnia. Understanding and simultaneously treating symptoms such as sleep disturbance and fatigue may lead to the most parsimonious, effective strategies to alleviate these symptoms.

Fatigue

Defining Features and Incidence Although ubiquitous in both acute and chronic illnesses, fatigue is not a trivial problem. The North American Nursing Diagnosis Association defines fatigue as an overwhelming sustained sense of exhaustion and decreased capacity for physical and mental work at a usual level.78 During an acute illness, fatigue may have a protective function that keeps the patient from further injury and harm. As with sleep disturbance, few studies have specifically addressed the incidence of fatigue during and after ICU admission. Although it has not been the focus of research in ICU patients, fatigue emerges as a common problem during and after acute illness and injury. In a heterogeneous group of ICU patients at high risk of dying (n = 245), the vast majority (75%) reported fatigue.110 Several studies have investigated the ongoing challenges of survivors after discharge from the ICU as the result of prolonged fatigue (eg, physical functioning, role, and vitality).9,48,111,112 In a study examining quality of life and physical functioning of ICU survivors in the first 6 months of recovery, investigators found that half the participants (n = 39) reported difficulty with vitality, mobility, and concentration, and 72% experienced a change in their responsibilities at home.31 Although fatigue may not be a top priority during ICU admission, early recognition and treatment when a patient's condition stabilizes is needed to reduce longterm negative patient outcomes.

Etiology of Fatigue

Fatigue may involve the interaction of several physiologic and psychobehavioral mechanisms, leading to its association with a variety of acute and chronic physical and psychologic illnesses (eg, cancer, hepatitis, rheumatoid arthritis, fibromyalgia, myasthenia gravis, and depression).78 In addition, fatigue has been found in 46% of brain-injured patients, in 85% of multiple sclerosis patients, and in 50% of HIV/AIDS patients.113 Psychologic, physiologic, and environmental/situational factors increase the risk of fatigue in many critical care patients. Factors such as stress, anxiety, and depression are common psychologic factors. Physiologic factors include sleep loss/poor sleep quality, weak physical condition, adverse effects of medications, malnutrition, and anemia. Factors in the ICU environment (eg, light, noise, temperature) and the illness/injury/surgery that lead to ICU admission influence the onset and duration of fatigue.

The clinical expression of fatigue is multidimensional and disease-related, often making evaluation challenging. Fatigue may be experienced and reported differently by individuals, and assessment may be impeded by communication impairments (eg, intubation and sedation). Personality and coping style may also influence the experience of fatigue. The association between sleep disturbance and fatigue has been established in a variety of patient populations.109,114-118 In a recent study, Redeker et al119 revealed that 51% of stable heart failure patients reported insomnia symptoms that were associated with increased fatigue, depression, EDS, and functional performance. Researchers continue to examine the relationships among fatigue, sleep disturbance, depression, and cognitive dysfunction to understand possible shared neurophysiologic mechanisms.120,121

Evaluating patients for fatigue is essential to improving management and is a key component of quality care. Brief screening measures for fatigue are available, sensitive, and applicable in critical care settings to identify patients who could benefit from further evaluation. Using a quantitative rating scale such as a 0 to 10 (where 0 = no fatigue and 10 = worst fatigue imaginable) allows the patient to describe the amount of fatigue experienced. Other rating scales can be developed using pictures or descriptive words. Routine screening should occur at regular intervals to determine whether the fatigue is constant or varies over time.

Evaluation of Fatigue

Identifying related factors in patients with moderate or severe fatigue via a detailed history can aid in establishing an effective collaborative plan of care. The causes and severity of fatigue may change over time. Etiologic factors such as comorbidities, anemia, imbalanced nutritional intake, and sleep disorders that may aggravate fatigue require ongoing assessment. Fatigue may be a symptom of protein-calorie malnutrition, vitamin deficiencies, or iron deficiencies. Monitoring for alterations in blood glucose, hemoglobin/hematocrit, blood urea nitrogen, and oxygen saturation provides information about the potential physiologic basis of fatigue. Changes in sleepwake pattern may contribute to the development of fatigue; therefore, sleep quality/quantity, SL, and feeling upon awakening need to be assessed. Periodically reviewing current medications identifies those with adverse effects likely to intensify fatigue. Particular attention should be given to [beta]-blockers, calcium channel blockers, tranquilizers, muscle relaxants, opioids, and sedatives.122 Medications may cause fatigue due to central nervous system (CNS) depression (ie, anticholinergic agents, centrally acting [alpha]-agonists, anticonvulsants) or increased CNS inhibitory activity (ie, benzodiazepines, barbiturates). Medications that cause bone marrow toxicity and resultant anemia include antineoplastic agents, anticonvulsants, antidepressants, and antimicrobial agents.122 In addition to a review of the current medications, clinicians will want to elicit information about the consequences of fatigue by exploring its effects on mood. Anxiety and depression can add to fatigue levels and may affect a patient's ability to participate in her or his plan of care in the ICU setting.

Interventions for Fatigue

Interventions to manage fatigue are multimodal, and they begin with treatment of comorbid factors (anemia, depression, poor nutrition), followed by nonpharmacologic approaches (eg, progressive mobility programs to counteract deconditioning). Clinicians, patients, and their families must work together to identify appropriate and acceptable management strategies during ICU stay and in preparation for discharge. Open communication will facilitate discussion about the experience of fatigue. Expected outcomes of fatigue interventions may include the patient's verbalization that she or he has sufficient energy to complete desired activities, or increasing capacity for physical and cognitive functioning.

Pharmacologic Considerations

Pharmacologic agents for fatigue have been evaluated primarily in patients with cancer,123 neuromuscular disease,124 and depression,125 although there is a scarcity of literature about these conditions in ICU patients. Pharmacologic treatment needs to be considered in the context of the etiology of fatigue, disease entity, and other medications. Optimizing cardiopulmonary function is critical. Patients with fatigue and concurrent anemia should be evaluated to determine the cause of the anemia and managed according to practice guidelines. Stimulants such as caffeine and modafinil may improve short-term performance and daytime alertness.

Nonpharmacologic Approaches to Manage Fatigue

The importance of remaining active and participating in a consistent program of gentle exercise, individualized to the patient's age, condition, and physical fitness level should be communicated to patients and families. Progressive mobility and limited exercise improve aerobic capacity, reduce muscle loss and deconditioning, and may produce favorable effects on sleep, mood, self-efficacy, body composition, immune system, and long-term disease outcomes.78

A physical therapy consultation may provide helpful recommendations about early mobility, and the type, intensity, and frequency of exercise for ICU patients who are stable but experiencing significant fatigue. Common elements in psychoeducational interventions include energyconservation strategies (such as daily planning and clustering of nursing activities to achieve optimal balance of rest and activity), and strategies to address sleep disturbances. Psychosocial interventions may include coaching to enhance engagement in the ICU plan of care and facilitating active coping with illness and hospitalization. Additional, general strategies to manage fatigue in ICU patients are described in Table 6.

Summary, Conclusions, and Future Directions

Sleep disturbances and fatigue are significant problems for patients in critical care units. Extant sleep disorders, underlying medical/surgical conditions, environmental factors, stress, medications, and other treatments all contribute to a patient's inability to sleep. A combined approach that incorporates assessment of sleep disturbances and fatigue, environmental controls, appropriate pharmacologic management, and educational and behavioral interventions is necessary to reduce the impact of sleep disturbances and fatigue in ICU patients.

Following a comprehensive assessment of environmental and patient factors, a care plan can be devised to provide periods of uninterrupted sleep, identify medication regimens that promote sleep and reduce fatigue, and suggest nonpharmacologic interventions based on individual patient needs and desires. Support from all members of the health care team is needed to implement changes and make progress in addressing patients' sleep and energy needs. Optimal management of patients' sleep disturbance and fatigue in the ICU may maximize patient progress and improve health outcomes long after discharge from the critical care setting. Nurses are well positioned to identify issues in their own units that prevent effective patient sleep. Education about sleep disturbance and fatigue assessment/management needs to be integrated into critical care courses and orientation programs.126

REFERENCES