Bench-to-bedside review: delirium in ICU patients - importance of sleep deprivation

The effect of chronotherapy on delirium in critical care - a systematic review

BACKGROUND

Delirium is highly prevalent within critical care and is linked to adverse clinical outcomes, increased mortality and impaired quality of life. Development of delirium is thought to be caused by multiple risk factors, including disruption of the circadian rhythm. Chronotherapeutic interventions, such as light therapy, music and use of eye shades, have been suggested as an option to improve circadian rhythm within intensive care units.

AIM

This review aims to answer the question: Can chronotherapy reduce the prevalence of delirium in adult patients in critical care?

DESIGN

This study is a systematic review of quantitative studies.

RESEARCH METHOD

Six major electronic databases were searched, and a hand search was undertaken using selected key search terms. Research quality was assessed using the critical appraisal skills programme tools. The studies were critically appraised by both authors independently, and data were extracted. Four themes addressing the research question were identified and critically evaluated.

FINDINGS

Six primary research articles that investigated different methods of chronotherapy were identified, and the results suggest that multi-component non-pharmacological interventions are the most effective for reducing the prevalence of delirium in critical care. The melatonergic agonist Ramelteon demonstrated statistically significant reductions in delirium; however, the reliability of the results in answering the review question was limited by the research design. The use of bright light therapy (BLT) and dynamic light application had mixed results, with issues with the research design and outcomes measured limiting the validity of the findings.

CONCLUSION

Multi-component non-pharmacological interventions, such as noise and light control, can reduce delirium in critical care, whereas other interventions, such as BLT, have mixed outcomes. Melatonin, as a drug, may be a useful alternative to sedative-hypnotics.

RELEVANCE TO CLINICAL PRACTICE

Chronotherapy can reduce the incidence of delirium within critical care, although further research is warranted. Staff education is essential in the implementation of chronotherapy.

Feasibility of melatonin for prevention of delirium in critically ill patients: a protocol for a multicentre, randomised, placebo-controlled study

INTRODUCTION

Delirium is highly prevalent in the intensive care unit (ICU) and is associated with adverse clinical outcomes. At this time, there is no drug that effectively prevents delirium in critically ill patients. Alterations in melatonin secretion and metabolism may contribute to the development of delirium. Administration of exogenous melatonin has been shown to prevent delirium in non-critically ill surgical and medical patients. This trial will demonstrate the feasibility of a planned multicentre, randomised controlled trial to test the hypothesis that melatonin can prevent delirium in critically ill patients compared with placebo.

METHODS AND ANALYSIS

This feasibility trial is a randomised, 3-arm, placebo-controlled study of melatonin (2 vs 0.5 mg vs placebo, administered for a maximum of 14 days) for the prevention of delirium in critically ill patients. A total of 69 patients aged 18 years and older with an expected ICU length of stay >48 hours will be recruited from 3 Canadian ICUs. The primary outcome is protocol adherence (ie, overall proportion of study drug doses administered in the prescribed administration window). Secondary outcomes include pharmacokinetic parameters, incidence, time to onset, duration of delirium, number of delirium-free days, adverse events, self-reported sleep quality, rest-activity cycles measured by wrist actigraphy, duration of mechanical ventilation, ICU length of stay and mortality. Data will be analysed using an intention-to-treat approach.

ETHICS AND DISSEMINATION

The study has been approved by Health Canada and the research ethics board of each study site. Trial results will be presented at international conferences and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT02615340: Pre-results.

Incidence and risk factors for delirium development in ICU patients - a prospective observational study

BACKGROUND AND AIMS

Delirium is an acute brain dysfunction and a frequent complication in critically ill patients. When present it significantly worsens the prognosis of patients. The aim of this study was to evaluate the incidence of delirium and risk factors for delirium in a mixed group of trauma, medical and surgical ICU patients.

METHODS

A prospective observational study was conducted in one of the six-bed Intensive Care Units of the University Hospital Ostrava in the Czech Republic during a 12-month period. We evaluated the incidence of delirium and its predisposing and precipitating risk factors. All patients were assessed daily using the Confusion Assessment Method for the ICU (CAM-ICU).

RESULTS AND CONCLUSIONS

Of the total of 332 patients with a median APACHE II (the Acute Physiology and Chronic Health Evaluation) score of 12, who were evaluated for delirium, 48 could not be assessed using CAM-ICU (47 due to prolonged coma, 1 due to language barriers). The incidence of delirium was 26.1%, with trauma and medical patients being more likely to develop delirium than surgical patients. Risk of delirium was significantly associated with age ≥ 65 years, and alcohol abuse in their anamnesis, with APACHE II score on admission, and with the use of sedatives and/or vasopressors. Delirious patients who remained in the ICU for a prolonged period showed a greater need for ventilator support and had a greater ICU-mortality.

Melatonin and melatonin agonists to prevent and treat delirium in critical illness: a systematic review protocol

BACKGROUND

Delirium is a syndrome characterized by acute fluctuations and alterations in attention and arousal. Critically ill patients are at particularly high risk, and those that develop delirium are more likely to experience poor clinical outcomes such as prolonged duration of ICU and hospital length of stay, and increased mortality. Melatonin and melatonin agonists (MMA) have the potential to decrease the incidence and severity of delirium through their hypnotic and sedative-sparing effects, thus improving health-related outcomes. The objective of this review is to synthesize the available evidence pertaining to the efficacy and safety of MMA for the prevention and treatment of ICU delirium.

METHODS

We will search Ovid MEDLINE, Web of Science, EMBASE, PsycINFO, the Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL to identify studies evaluating MMA in critically ill populations. We will also search http://apps.who.int/trialsearch for ongoing and unpublished studies and PROSPERO for registered reviews. We will not impose restrictions on language, date, or journal of publication. Authors will independently screen for eligible studies using pre-defined criteria; data extraction from eligible studies will be performed in duplicate. The Cochrane Risk of Bias Scale and the Newcastle-Ottawa Scale will be used to assess the risk of bias and quality of randomized and non-randomized studies, respectively. Our primary outcome of interest is delirium incidence, and secondary outcomes include duration of delirium, number of delirium- and coma-free days, use of physical and chemical (e.g., antipsychotics or benzodiazepines) restraints, duration of mechanical ventilation, ICU and hospital length of stay, mortality, long-term neurocognitive outcomes, hospital discharge disposition, and adverse events. We will use Review Manager (RevMan) to pool effect estimates from included studies. We will present results as relative risks with 95% confidence intervals for dichotomous outcomes and as mean differences, or standardized mean differences, for continuous outcomes.

DISCUSSION

Current guidelines make no pharmacological recommendations for either the prevention or treatment of ICU delirium. This systematic review will synthesize the available evidence on the efficacy and safety of MMA for this purpose, thus potentially informing clinical decision-making and improving patient outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015024713.

Low-dose Dexmedetomidine Improves Sleep Quality Pattern in Elderly Patients after Noncardiac Surgery in the Intensive Care Unit

Background

Patients admitted to the intensive care unit (ICU) after surgery often develop sleep disturbances. The authors tested the hypothesis that low-dose dexmedetomidine infusion could improve sleep architecture in nonmechanically ventilated elderly patients in the ICU after surgery.

Methods

This was a pilot, randomized controlled trial. Seventy-six patients age 65 yr or older who were admitted to the ICU after noncardiac surgery and did not require mechanical ventilation were randomized to receive dexmedetomidine (continuous infusion at a rate of 0.1 μg kg−1 h−1; n = 38) or placebo (n = 38) for 15 h, i.e., from 5:00 pm on the day of surgery until 8:00 am on the first day after surgery. Polysomnogram was monitored during the period of study-drug infusion. The primary endpoint was the percentage of stage 2 non–rapid eye movement (stage N2) sleep.

Results

Complete polysomnogram recordings were obtained in 61 patients (30 in the placebo group and 31 in the dexmedetomidine group). Dexmedetomidine infusion increased the percentage of stage N2 sleep from median 15.8% (interquartile range, 1.3 to 62.8) with placebo to 43.5% (16.6 to 80.2) with dexmedetomidine (difference, 14.7%; 95% CI, 0.0 to 31.9; P = 0.048); it also prolonged the total sleep time, decreased the percentage of stage N1 sleep, increased the sleep efficiency, and improved the subjective sleep quality. Dexmedetomidine increased the incidence of hypotension without significant intervention.

Conclusions

In nonmechanically ventilated elderly patients who were admitted to the ICU after noncardiac surgery, the prophylactic low-dose dexmedetomidine infusion may improve overall sleep quality.

Critical Illness Brain Injury

A growing body of literature has shown that survivors of critical illness often struggle with cognitive impairment that persists months to years after hospital discharge. We describe the epidemiology of this form of cognitive impairment-which we refer to as critical illness brain injury-and review the history and maturation of the investigation of this previously unrecognized, yet common problem. We then review the characteristics of critical illness brain injury, which can vary in severity and typically affects multiple domains of cognition. Finally, we examine known risk factors for critical illness brain injury and, based on these data, suggest approaches to patient management.

Pharmacological interventions to improve sleep in hospitalised adults: a systematic review

OBJECTIVES

Patients often suffer from disturbed sleep in hospital. Poor-quality sleep in hospitalised patients has been associated with significant morbidity and pharmacological sleep aids are often prescribed. The objective of this systematic review is to evaluate the comparative efficacy and safety of pharmacological interventions used for sleep in hospitalised patients.

SETTING/PARTICIPANTS

We searched MEDLINE, Embase, the Cochrane database and grey literature for prospective studies that evaluated sleep in hospitalised adults after a pharmacological intervention.

PRIMARY AND SECONDARY OUTCOME MEASURES

Two reviewers assessed studies for inclusion and extracted data for efficacy outcomes, including sleep efficiency, sleep latency, sleep fragmentation and objectively measured sleep stage distribution. Risk of bias was assessed and meta-analyses were planned contingent upon homogeneity of the included studies.

RESULTS

After screening 1920 citations, 15 studies involving 861 patients were included. Medications studied included benzodiazepines, nonbenzodiazepine sedatives, melatonin, propofol and dexmedetomidine. Five studies were deemed to be of high quality. Heterogeneity and variable outcome reporting precluded meta-analysis in most cases. No consistent trends with respect to sleep efficiency, quality or interruptions were observed identifying a drug or drug class as superior to another or no treatment. Benzodiazepines appeared to be better than no treatment with respect to sleep latency, but this was not consistently demonstrated across all studies. Sleep stage distribution shows that sleep in hospital is dominated by stages N1 and N2.

CONCLUSIONS

There is insufficient evidence to suggest that pharmacotherapy improves the quality or quantity of sleep in hospitalised patients suffering from poor sleep. No drug class or specific drug was identified as superior even when compared to placebo or no treatment. Although 15 studies were included, the quality of evidence was limited by their quality and size. Larger, better-designed trials in hospitalised adults are needed.

Rational Use of Second-Generation Antipsychotics for the Treatment of ICU Delirium

Delirium, described as an acute neuropsychiatric syndrome, occurs commonly in critically ill patients and leads to many negative outcomes including increased mortality and long-term cognitive deficits. Despite the lack of clinical data supporting the use of antipsychotics for the management of intensive care unit (ICU) delirium, pharmacological interventions are often needed to control acutely agitated patients. Given that the most current guidelines do not advocate the use of haloperidol for either the prevention or treatment of ICU delirium due to a lack of evidence, second-generation antipsychotics (SGAs) have been commonly used as alternatives to haloperidol for ICU patients with delirium. Nonetheless, the evidence supporting the use of SGAs to treat ICU delirium remains limited. This review is designed to assess the available clinical evidence and highlights the different neuropharmacological and safety properties of SGAs in order to guide the rational use of SGAs for the treatment of ICU delirium.

Application of Clinical Practice Guidelines for Pain, Agitation, and Delirium

Critically ill patients experience several severe, distressing, and often life-altering symptoms during their intensive care unit stay. A clinical practice guideline released by the American College of Critical Care Medicine provides a template for improving the care and outcomes of the critically ill through evidence-based pain, agitation, and delirium assessment, prevention, and management. Key strategies include the use of valid and reliable assessment tools, setting a desired sedation level target, a focus on light sedation, choosing appropriate sedative medications, the use of nonpharmacologic symptom management strategies, and engaging and empowering patients and their family to play an active role in their intensive care unit care.

Quiet time for mechanically ventilated patients in the medical intensive care unit

OBJECTIVE

Sleep disruption occurs frequently in critically ill patients. The primary aim of this study was to examine the effect of quiet time (QT) on patient sedation frequency, sedation and delirium scores; and to determine if consecutive QTs influenced physiologic measures (heart rate, mean arterial blood pressure and respiratory rate).

METHOD

A prospective study of a quiet time protocol was conducted with 72 adult patients on mechanical ventilation.

SETTING

A Medical Intensive Care Unit (MICU) in the Midwest region of the United States.

RESULTS

Sedation was given less frequently after QT (p=0.045). Those who were agitated prior to QT were more likely to be at goal sedation after QT (p<0.001). Although not statistically significant, the majority of patients who were negative on the Confusion Assessment Method (CAM-ICU) prior to QT remained delirium free after QT. Repeated measures analysis of variance (ANOVA) for three consecutive QTs showed a significant difference for respiratory rate (p=0.035).

CONCLUSION

QT may influence sedation administration and promote patient rest. Future studies are required to further understand the influence of QT on mechanically ventilated patients in the intensive care unit.

How do doctors and nurses manage delirium in intensive care units? A qualitative study using focus groups

OBJECTIVES

The aim of this study was to explore the experiences of doctors and nurses caring for patients with delirium in the intensive care unit (ICU) and to describe the process of delirium management.

SETTING

This study was performed in 5 ICUs located within 4 hospitals in Madrid (Spain).

PARTICIPANTS

Purposeful sampling was performed which included (1) doctors and nurses working in ICUs, (2) with >1 year experience in the ICU and (3) clinical experience with delirium. 38 professionals participated (19 doctors, 19 nurses), including 22 women and 16 men. The total mean age was 39 years.

DESIGN

A qualitative study using focus groups.

METHODS

7 focus groups were held to collect data: 3 nurse focus groups, 3 doctor focus groups and 1 mixed focus group. Each group comprised 6-10 participants. A semistructured questions guide was used. Thematic analysis methods were used to analyse the data.

RESULTS

3 themes were identified: (1) the professional perspective on delirium; (2) implementing pharmacological and non-pharmacological treatment for delirium and (3) work organisation in the ICU. The professionals regarded patients with delirium with uncertainty, and felt they were often underdiagnosed and poorly managed. Doctors displayed discrepancies regarding pharmacological prescriptions and decision-making. The choice of medication was determined by experience. Nurses felt that, for many doctors, delirium was not considered a matter of urgency in the ICU. Nurses encountered difficulties when applying verbal restraint, managing sleep disorders and providing early mobilisation. The lack of a delirium protocol generates conflicts regarding what type of care management to apply, especially during the night shift. A degree of group pressure exists which, in turn, influences the decision-making process and patient care.

CONCLUSIONS

Patients with delirium represent complex cases, requiring the implementation of specific protocols. These results serve to improve the process of care in patients with delirium.

Circadian dysrhythmias in the intensive care unit

Circadian rhythms underlie nearly all physiologic functions and organ systems. Circadian abnormalities have attendant implications for critical illness survival. The intensive care unit (ICU) environment, with its lack of diurnal variation in sound, light, and social cues, may precipitate circadian dysrhythmias. Additional features of critical care, including mechanical ventilation and sedation, likely perpetuate circadian misalignment. Critical illness itself, from sepsis to severe brain injury, can compromise circadian health. Use of daylight, time-restricted feedings, and administration of melatonin can possibly restore circadian rhythm. However, further study is necessary to assess the effectiveness of these interventions and their impact on ICU outcomes.

High prolactin levels are associated with more delirium in septic patients

PURPOSES

We investigated whether high prolactin levels were associated with delirium in septic patients because neuropsychiatric disorders are frequently associated with hyperprolactinemia.

MATERIALS AND METHODS

Prolactin levels were measured daily for 4 days in 101 patients with sepsis. Delirium was assessed using the Richmond Agitation Sedation Scale and the Confusion Assessment Method in the ICU.

RESULTS

Delirium developed in 79 patients (78%) and was more common in patients older than 65 years. Prolactin levels were higher in patients with delirium than in those without over the 4 days of observation (P = .032). In patients with delirium, higher prolactin levels were associated with a lower incidence of nosocomial infection (P = .006). Multivariable logistic regression showed that the Sequential Organ Failure Assessment score at intensive care unit admission (odds ratio, 1.24; 95% confidence interval, 1.04-1.48; P = .002) and the combined effect of prolactin levels with age (odds ratio, 1.018; 95% confidence interval, 1.01-1.031; P = .006) were associated with the development of delirium.

CONCLUSIONS

High prolactin levels may be a risk factor for delirium in septic patients.

Reversal of a Suspected Paradoxical Reaction to Zopiclone with Flumazenil

We describe the care for an elderly woman who was admitted to the intensive care unit (ICU) to receive noninvasive ventilation for acute exacerbation of chronic obstructive pulmonary disease. After administration of the sleeping pill zopiclone, a nonbenzodiazepine receptor agonist (NBRA), the patient became agitated and was confused, a possible paradoxical reaction to benzodiazepines. These symptoms were immediately resolved after treatment with flumazenil, usually used to reverse the adverse effects of benzodiazepines or NBRAs and to reverse paradoxical reactions to benzodiazepines. This case indicates that zopiclone induced behavioral changes resembling a paradoxical reaction to benzodiazepines and these symptoms may be treated with flumazenil.

Emerging Role of Melatonin and Melatonin Receptor Agonists in Sleep and Delirium in Intensive Care Unit Patients

Delirium, an acute state of mental confusion, can lead to many adverse sequelae in intensive care unit (ICU) patients. Although the etiology of ICU delirium is often multifactorial, and at times not fully understood, sleep deprivation is considered to be a major contributing factor to its development. It has been postulated that administration of exogenous melatonin and melatonin receptor agonists such as ramelteon may prevent delirium by promoting nocturnal sleep in ICU patients. The purpose of this review is to summarize the pharmacology of melatonin and melatonin receptor agonists and investigate their potential roles in sleep promotion and delirium prevention in ICU patients. Although few studies evaluating the impact of melatonergic agents on sleep and delirium in the ICU have been completed, some data suggest their potential positive effects on sleep and delirium. However, large-scale randomized controlled trials are warranted to determine the optimal role of melatonergic agents in the prevention of ICU delirium.

Sleep in the intensive care unit

Sleep is an important physiologic process, and lack of sleep is associated with a host of adverse outcomes. Basic and clinical research has documented the important role circadian rhythm plays in biologic function. Critical illness is a time of extreme vulnerability for patients, and the important role sleep may play in recovery for intensive care unit (ICU) patients is just beginning to be explored. This concise clinical review focuses on the current state of research examining sleep in critical illness. We discuss sleep and circadian rhythm abnormalities that occur in ICU patients and the challenges to measuring alterations in circadian rhythm in critical illness and review methods to measure sleep in the ICU, including polysomnography, actigraphy, and questionnaires. We discuss data on the impact of potentially modifiable disruptors to patient sleep, such as noise, light, and patient care activities, and report on potential methods to improve sleep in the setting of critical illness. Finally, we review the latest literature on sleep disturbances that persist or develop after critical illness.

Examining the evidence to guide practice: challenging practice habits

Nurses are the largest segment of the nation's health care workforce, which makes nurses vital to the translation of evidence-based practice as a practice norm. Critical care nurses are in a position to critically appraise and apply best evidence in daily practice to improve patients' outcomes. It is important for critical care nurses to continually evaluate their current practice to ensure that they are applying the current best evidence rather than practicing on the basis of tradition. This article is based on a presentation at the 2013 National Teaching Institute of the American Association of Critical-Care Nurses. Four practice interventions that are within the realm of nursing are critiqued on the basis of current best evidence: (1) turning critically ill patients, (2) sleep promotion in the intensive care unit, (3) feeding tube management in infants and children, and (4) prevention of venothromboembolism…again. The related beliefs, current evidence, and implications for practice associated with each topic are described.

Sleep in traumatic brain injury

More than one-half million patients are hospitalized annually for traumatic brain injury (TBI). One-quarter demonstrate sleep-disordered breathing, up to 50% experience insomnia, and half have hypersomnia. Sleep disturbances after TBI may result from injury to sleep-regulating brain tissue, nonspecific neurohormonal responses to systemic injury, ICU environmental interference, and medication side effects. A diagnosis of sleep disturbances requires a high index of suspicion and appropriate testing. Treatment starts with a focus on making the ICU environment conducive to normal sleep. Treating sleep-disordered breathing likely has outcome benefits in TBI. The use of sleep promoting sedative-hypnotics and anxiolytics should be judicious.

Delirium transitions in the medical ICU: exploring the role of sleep quality and other factors

OBJECTIVES

Disrupted sleep is a common and potentially modifiable risk factor for delirium in the ICU. As part of a quality improvement project to promote sleep in the ICU, we examined the association of perceived sleep quality ratings and other patient and ICU risk factors with daily transition to delirium.

DESIGN

Secondary analysis of prospective observational study.

SETTING

Medical ICU over a 201-day period.

PATIENTS

Two hundred twenty-three patients with greater than or equal to one night in the medical ICU in between two consecutive days of delirium assessment.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Daily perceived sleep quality ratings were measured using the Richards-Campbell Sleep Questionnaire. Delirium was measured twice daily using the Confusion Assessment Method for the ICU. Other covariates evaluated included age, sex, race, ICU admission diagnosis, nighttime mechanical ventilation status, prior day's delirium status, and daily sedation using benzodiazepines and opioids, via both bolus and continuous infusion. Perceived sleep quality was similar in patients who were ever versus never delirious in the ICU (median [interquartile range] ratings, 58 [35-76] vs 57 [33-78], respectively; p = 0.71), and perceived sleep quality was unrelated to delirium transition (adjusted odds ratio, 1.00; 95% CI, 0.99-1.00). In mechanically ventilated patients, receipt of a continuous benzodiazepine and/or opioid infusion was associated with delirium transition (adjusted odds ratio, 4.02; 95% CI, 2.19-7.38; p < 0.001), and patients reporting use of pharmacological sleep aids at home were less likely to transition to delirium (adjusted odds ratio, 0.40; 95% CI, 0.20-0.80; p = 0.01).

CONCLUSIONS

We found no association between daily perceived sleep quality ratings and transition to delirium. Infusion of benzodiazepine and/or opioid medications was strongly associated with transition to delirium in the ICU in mechanically ventilated patients and is an important, modifiable risk factor for delirium in critically ill patients.

Effects of earplugs and eye masks combined with relaxing music on sleep, melatonin and cortisol levels in ICU patients: a randomized controlled trial

Introduction

Intensive care unit (ICU) environmental factors such as noise and light have been cited as important causes of sleep deprivation in critically ill patients. Previous studies indicated that using earplugs and eye masks can improve REM sleep in healthy subjects in simulated ICU environment, and improve sleep quality in ICU patients. This study aimed to determine the effects of using earplugs and eye masks with relaxing background music on sleep, melatonin and cortisol levels in ICU patients.

Methods

Fifty patients who underwent a scheduled cardiac surgery and were expected to stay at least 2 nights in Cardiac Surgical ICU (CSICU) were included. They were randomized to sleep with or without earplugs and eye masks combined with 30-minute relaxing music during the postoperative nights in CSICU. Urine was analyzed for nocturnal melatonin and cortisol levels. Subjective sleep quality was evaluated using the Chinese version of Richards-Campbell Sleep Questionnaire (a visual analog scale, ranging 0–100).

Results

Data from 45 patients (20 in intervention group, 25 in control group) were analyzed. Significant differences were found between groups in depth of sleep, falling asleep, awakenings, falling asleep again after awakening and overall sleep quality (P < 0.05). Perceived sleep quality was better in the intervention group. No group differences were found in urinary melatonin levels and cortisol levels for the night before surgery, and the first and second nights post-surgery (P > 0.05). The urinary melatonin levels of the first and second postoperative nights were significantly lower than those of the night before surgery (P = 0.01). The opposite pattern was seen with urinary cortisol levels (P = 0.00).

Conclusion

This combination of non-pharmacological interventions is useful for promoting sleep in ICU adult patients; however, any influence on nocturnal melatonin levels and cortisol level may have been masked by several factors such as the timing of surgery, medication use and individual differences. Larger scale studies would be needed to examine the potential influences of these factors on biological markers and intervention efficacy on sleep.

Trial registration

Chinese Clinical Trial Registry: ChiCTR-IOR-14005511. Registered 21 November 2014.

Sleeping on a problem: the impact of sleep disturbance on intensive care patients - a clinical review

Sleep disturbance is commonly encountered amongst intensive care patients and has significant psychophysiological effects, which protract recovery and increases mortality. Bio-physiological monitoring of intensive care patients reveal alterations in sleep architecture, with reduced sleep quality and continuity. The etiological causes of sleep disturbance are considered to be multifactorial, although environmental stressors namely, noise, light and clinical care interactions have been frequently cited in both subjective and objective studies. As a result, interventions are targeted towards modifiable factors to ameliorate their impact. This paper reviews normal sleep physiology and the impact that sleep disturbance has on patient psychophysiological recovery, and the contribution that the clinical environment has on intensive care patients' sleep.

Delirium and sleep disturbances in the intensive care unit: can we do better?

PURPOSE OF REVIEW

Delirium in the ICU affects as many as 60-80% of mechanically ventilated patients and a smaller but substantial percentage of other critically ill patients. Poor sleep quality has been consistently observed in critically ill patients. These problems are associated with worse ICU outcomes and, in many cases, delirium and poor sleep quality may be related. This review will summarize the recent literature relevant to both the problems and provide a potential pathway toward improvement.

RECENT FINDINGS

Many cases of delirium and the poor sleep experienced by ICU patients may be iatrogenic. How critical care practitioners prescribe sedatives and analgesics and, perhaps more broadly, how all medications are administered to critically ill patients, may be at the root of some of these problems. Reducing the administration of some commonly used ICU medications, especially some sedatives and anticholinergic medications, and keeping patients more awake and actively engaged in their care during the day may lead to better outcomes.

SUMMARY

It is our responsibility to apply the best available, evidence-based medicine to our practice. Adherence to new guidelines for the treatment of pain, agitation, and delirium may be the best pathway toward reducing delirium, improving sleep quality, and improving related outcomes.

Risk factors for postoperative delirium in patients after coronary artery bypass grafting: A prospective cohort study

PURPOSE

This study was designed to identify the incidence and independent perioperative risk factors associated with postoperative delirium of patients who underwent coronary artery bypass grafting (CABG) in a large intensive care unit setting in China.

METHODS

Delirium was diagnosed by the confusion assessment method for the intensive care unit (CAM-ICU). Baseline demographics, perioperative data, and postoperative outcomes of 249 consecutive patients who underwent CABG were recorded prospectively and analyzed via univariate analysis and multivariate logistic regression to determine the independent risk factors of postoperative delirium.

RESULTS

Postoperative delirium was detected in 76 patients according to CAM-ICU criteria. The incidence was 30.52%. Patients with and without delirium differed significantly on 34 variables (P < .05). Multivariate logistic regression analysis revealed that preoperative atrial fibrillation (odds ratio [OR], 3.957; 95% confidence interval [CI], 1.727-9.066), elevated European system for cardiac operative risk evaluation (OR, 1.178; 95% CI, 1.018-1.364), cognitive impairment (OR, 3.231; 95% CI, 1.008-10.356), prolonged surgery duration (OR, 1.008; 95% CI, 1.003-1.014), postoperative poor quality of sleep (OR, 5.001; 95% CI, 2.476-10.101), and electrolyte disturbance (OR, 2.095; 95% CI, 1.041-4.216) were independently associated with postoperative delirium after CABG.

CONCLUSIONS

Delirium is a frequent complication. Factors independently associated with delirium are preoperative atrial fibrillation, elevated European system for cardiac operative risk evaluation and cognitive impairment, longer surgery duration, postoperative poor quality of sleep, and electrolyte disturbance. The study may be helpful in decreasing the incidence of postoperative delirium after CABG by treating these predictors properly.

The psychological and neurocognitive consequences of critical illness. A pragmatic review of current evidence

Mortality rates alone are no longer a sufficient guide to quality of care. Due to medical advances, patients are surviving for longer following critical illness and major surgery; therefore, functional outcomes and long-term quality of life are of increasing consequence. Post-operative cognitive dysfunction has been acknowledged as a complication following anaesthesia for many years, and interest in persistent cognitive dysfunction following a critical illness is growing. Psychological and neurocognitive sequelae following discharge from intensive care are acknowledged to occur with sufficient significance to have recently coined the term 'the post-intensive care syndrome'. Rehabilitation following critical illness has been highlighted as an important goal in recently published national UK guidelines, including the need to focus on both physical and non-physical recovery. Neuropsychological and cognitive consequences following anaesthesia and critical illness are significant. The exact pathophysiological mechanisms linking delirium, cognitive dysfunction and neuropsychological symptoms following critical illness are not fully elucidated but have been studied elsewhere and are outside the scope of this article. There is limited evidence as yet for specific peri-operative preventative strategies, but early management and rehabilitation strategies following intensive care discharge are now emerging. This article aims to summarise the issues and appraise current options for management, including both neuroprotective and neurorehabilitative strategies in intensive care.

Can intensive care unit delirium be prevented and reduced? Lessons learned and future directions

Delirium is a form of acute brain injury that occurs in up to 80% of critically ill patients. It is a source of enormous societal and financial burdens due to increased mortality, prolonged intensive care unit (ICU) and hospital stays, and long-term neuropsychological and functional deficits in ICU survivors. These poor outcomes are not only independently associated with the development of delirium but are also associated with increasing delirium duration. Therefore, interventions should strive both to prevent the occurrence of ICU delirium and to limit its persistence. Both patient-centered and ICU-acquired risk factors need to be addressed early in the ICU course to maximize the efficacy of prevention strategies and to improve long-term outcomes of ICU patients. In this article, we review strategies for early detection of patients who are delirious and who are at high risk for developing delirium, and we present a clinically useful ICU delirium prevention and reduction strategy for clinicians to incorporate into their daily practice.

Feasibility study of unattended polysomnography in medical intensive care unit patients

OBJECTIVES

To evaluate the feasibility of using unattended, portable polysomnography (PSG) to measure sleep among patients in the medical intensive care unit (MICU).

BACKGROUND

Accurate measurement of sleep is critical to studies of MICU sleep deprivation. Although PSG is the gold standard, there is limited data regarding the feasibility of utilizing unattended, portable PSG modalities in the MICU.

METHODS

MICU based observational pilot study. We conducted unattended, 24-h PSG studies in 29 patients. Indicators of feasibility included attainment of electroencephalography data sufficient to determine sleep stage, sleep efficiency, and arousal indices.

RESULTS

Electroencephalography data were not affected by electrical interference and were of interpretable quality in 27/29 (93%) of patients. Overnight sleep efficiency was 48% reflecting a mean overnight sleep duration of 3.7 h.

CONCLUSIONS

Unattended, portable PSG produces high quality sleep data in the MICU and can facilitate investigation of sleep deprivation among critically ill patients. Patient sleep was short and highly fragmented.

Sleep disturbance in older ICU patients

Maintaining a stable and adequate sleeping pattern is associated with good health and disease prevention. As a restorative process, sleep is important for supporting immune function and aiding the body in healing and recovery. Aging is associated with characteristic changes to sleep quantity and quality, which make it more difficult to adjust sleep–wake rhythms to changing environmental conditions. Sleep disturbance and abnormal sleep–wake cycles are commonly reported in seriously ill older patients in the intensive care unit (ICU). A combination of intrinsic and extrinsic factors appears to contribute to these disruptions. Little is known regarding the effect that sleep disturbance has on health status in the oldest of old (80+), a group, who with diminishing physiological reserve and increasing prevalence of frailty, is at a greater risk of adverse health outcomes, such as cognitive decline and mortality. Here we review how sleep is altered in the ICU, with particular attention to older patients, especially those aged ≥80 years. Further work is required to understand what impact sleep disturbance has on frailty levels and poor outcomes in older critically ill patients.

Intensive care unit depth of sleep: proof of concept of a simple electroencephalography index in the non-sedated

INTRODUCTION

Intensive care unit (ICU) patients are known to experience severely disturbed sleep, with possible detrimental effects on short- and long- term outcomes. Investigation into the exact causes and effects of disturbed sleep has been hampered by cumbersome and time consuming methods of measuring and staging sleep. We introduce a novel method for ICU depth of sleep analysis, the ICU depth of sleep index (IDOS index), using single channel electroencephalography (EEG) and apply it to outpatient recordings. A proof of concept is shown in non-sedated ICU patients.

METHODS

Polysomnographic (PSG) recordings of five ICU patients and 15 healthy outpatients were analyzed using the IDOS index, based on the ratio between gamma and delta band power. Manual selection of thresholds was used to classify data as either wake, sleep or slow wave sleep (SWS). This classification was compared to visual sleep scoring by Rechtschaffen & Kales criteria in normal outpatient recordings and ICU recordings to illustrate face validity of the IDOS index.

RESULTS

When reduced to two or three classes, the scoring of sleep by IDOS index and manual scoring show high agreement for normal sleep recordings. The obtained overall agreements, as quantified by the kappa coefficient, were 0.84 for sleep/wake classification and 0.82 for classification into three classes (wake, non-SWS and SWS). Sensitivity and specificity were highest for the wake state (93% and 93%, respectively) and lowest for SWS (82% and 76%, respectively). For ICU recordings, agreement was similar to agreement between visual scorers previously reported in literature.

CONCLUSIONS

Besides the most satisfying visual resemblance with manually scored normal PSG recordings, the established face-validity of the IDOS index as an estimator of depth of sleep was excellent. This technique enables real-time, automated, single channel visualization of depth of sleep, facilitating the monitoring of sleep in the ICU.

Patient education self-management during surgical recovery: combining mobile (iPad) and a content management system

OBJECTIVE

The objective of this investigation was to assess whether a new electronic health (e-health) platform, combining mobile computing and a content management system, could effectively deliver modular and "just-in-time" education to older patients following cardiac surgery.

SUBJECTS AND METHODS

Patients were provided with iPad(®) (Apple(®), Cupertino, CA) tablets that delivered educational modules as part of a daily "to do" list in a plan of care. The tablet communicated wirelessly to a dashboard where data were aggregated and displayed for providers.

RESULTS

A surgical population of 149 patients with a mean age of 68 years utilized 5,267 of 6,295 (84%) of education modules delivered over a 5.3-day hospitalization. Increased age was not associated with decreased use.

CONCLUSIONS

We demonstrate that age, hospitalization, and major surgery are not significant barriers to effective patient education if content is highly consumable and relevant to patients' daily care experience. We also show that mobile technology, even if unfamiliar to many older patients, makes this possible. The combination of mobile computing with a content management system allows for dynamic, modular, personalized, and "just-in-time" education in a highly consumable format. This approach presents a means by which patients may become informed participants in new healthcare models.