Correlation Between Sleep Continuity and Patient-Reported Sleep Quality in Conscious Critically Ill Patients at High Risk of Reintubation: A Pilot Study.

OBJECTIVES: It is well-established that sleep quality of ICU patients is poor, with sleep being highly fragmented by multiple awakenings. These sleep disruptions are associated with poor outcomes such as prolonged weaning duration from mechanical ventilation. Polysomnography can measure sleep continuity, a parameter associated positively with outcomes in patients treated with noninvasive ventilation, but polysomnography is not routinely available in all ICUs, and simple means to assess sleep quality are needed. The Richards-Campbell sleep questionnaire (RCSQ) assesses sleep quality in ICU patients but is difficult to administrate in patients who are not fully awake, and a simpler sleep numeric rating scale (sleep-NRS) has been proposed as an alternative. We here investigated the relationships between sleep continuity and patients-reported sleep quality. DESIGN: Single-center retrospective study. SETTING: Medical ICU of Poitiers University Hospital. PATIENTS: Seventy-two patients were extubated from mechanical ventilation and at high risk of reintubation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We analyzed 52 previously recorded polysomnographies in nonsedated and conscious ICU patients. Sleep was recorded the night after extubation. Sleep continuity was measured using an automated scoring algorithm from one electroencephalogram (EEG) channel of the polysomnography. Patient-reported sleep quality was assessed using RCSQ and sleep-NRS. Sleep continuity could be calculated on 45 polysomnographies (age: 68 [58-77], median [25th-75th]) RCSQ (62 [48-72]) and sleep-NRS (6.0 [5.0-7.0]) were obtained in 21 patients and 34 patients, respectively. Our results show a significant correlation between sleep continuity and sleep-NRS (p = 0.0037; ρ = 0.4844; n = 34) but not with RCSQ score (p = 0.6732; ρ = 0.1005; n = 20). CONCLUSION: Sleep continuity correlates with patient-reported sleep quality assessed using sleep-NRS and may capture the refreshing part of sleep. Sleep-NRS can be easily administered in ICU patients. Sleep continuity and sleep-NRS are simple tools that may prove useful to evaluate sleep quality in ICU patients.

[Sleep in intensive care: a crucial but little-known issue]. / Le sommeil en réanimation, enjeu crucial mais méconnu.

SLEEP IN INTENSIVE CARE: A CRUCIAL BUT LITTLE-KNOWN ISSUE. Polysomnography is the best tool to study sleep in intensive care unit (ICU), but this recording is complex to perform in such environment. Sleep alterations in ICU patients are specific and include electroencephalographic abnormalities during sleep and wake, rendering sleep scoring more complicated. Severe deficit in deep sleep, rapid eye movement sleep and an important sleep fragmentation are reported by most studies. Sleep cycles are disorganized with many sleep episodes during daytime. Sleep disruptions result from light levels, noisy environment, and 24-hours nurses care. Assisted ventilation, sedation, loss of circadian rhythms also contribute to these disruptions. Biological and neurobehavioral consequences of sleep alterations lengthen weaning from mechanical ventilation and have some deleterious impacts on morbidity and mortality. Procedures to promote sleep have been attempted, with limited results to date. However, recent innovation might help to monitor sleep and help patients to achieve some restorative sleep.

LE SOMMEIL EN RÉANIMATION, ENJEU CRUCIAL MAIS MÉCONNU. La polysomnographie est le meilleur moyen d'étudier le sommeil en réanimation, mais cet examen reste complexe à réaliser dans cet environnement. Les altérations du sommeil y sont spécifiques et incluent des anomalies de l'électroencéphalogramme de sommeil et de veille qui compliquent la reconnaissance des stades de sommeil. Un déficit en sommeil profond et paradoxal ainsi qu'une fragmentation importante sont rapportés par la plupart des études. Le sommeil est souvent très désorganisé, avec de nombreux épisodes de sommeil durant la journée. Les causes sont liées à l'environnement sonore et lumineux ainsi qu'aux soins continus. La ventilation assistée, la sédation, la perte des rythmes circadiens concourent à ces altérations. Les conséquences biologiques et neuropsychologiques de cette privation de sommeil ont un impact sur la morbidité et la mortalité des patients. Des procédures visant à protéger le sommeil dans les services de réanimation ont été tentées mais restent pour le moment peu concluantes. Des innovations récentes et prometteuses pourraient permettre des avancées diagnostiques et thérapeutiques significatives.

Sleep Assessment in Critically Ill Patients With Acute Hypoxemic Respiratory Failure.

BACKGROUND: Sleep deprivation alters respiratory muscle performance and may precipitate respiratory failure. This study aimed to assess sleep in subjects admitted to ICU for acute hypoxemic respiratory failure and its role in the risk of intubation. METHODS: This was a prospective observational single-center cohort study including subjects admitted to ICU for de novo acute hypoxemic respiratory failure defined as breathing frequency ≥ 25 breaths/min or clinical signs of respiratory distress and PaO2 /FIO2 < 300 mm Hg while receiving high-flow nasal oxygen. Subjects with altered consciousness, central nervous or psychiatric disorders, continuous sedation or neuroleptic medication, or were uncooperative were excluded. Sleep was assessed by complete polysomnography (PSG) the night following ICU admission. The main outcome was to assess sleep among subjects with acute hypoxemic respiratory failure and to compare sleep between subjects who eventually required intubation to those who did not. RESULTS: Over a 24-month inclusion period, 34 subjects had complete PSG, among whom 5 (15%) required intubation in the ICU. Total sleep time was 4.2 h in median (interquartile range 2.9-6.8); deep-sleep duration was 70 min (34-127), and rapid eye movement (REM) sleep duration was 9 min (0-28). Among them, 13 subjects (38%) had no REM sleep. Total sleep time and duration of deep and REM sleep stages did not differ between subjects who required intubation and those successfully treated with high-flow nasal oxygen. CONCLUSIONS: Whereas total sleep time remained relatively preserved in critically ill subjects with acute hypoxemic respiratory failure, REM sleep time was uncommon or completely absent in a large number of subjects. Sleep did not differ between subjects who required intubation and those who did not. However, given a trend toward an increased risk of intubation in subjects with a complete absence of REM sleep, further studies are needed to better explore the impact of REM sleep on the risk of intubation.

Causes, Consequences, and Treatments of Sleep and Circadian Disruption in the ICU: An Official American Thoracic Society Research Statement.

Background: Sleep and circadian disruption (SCD) is common and severe in the ICU. On the basis of rigorous evidence in non-ICU populations and emerging evidence in ICU populations, SCD is likely to have a profound negative impact on patient outcomes. Thus, it is urgent that we establish research priorities to advance understanding of ICU SCD. Methods: We convened a multidisciplinary group with relevant expertise to participate in an American Thoracic Society Workshop. Workshop objectives included identifying ICU SCD subtopics of interest, key knowledge gaps, and research priorities. Members attended remote sessions from March to November 2021. Recorded presentations were prepared and viewed by members before Workshop sessions. Workshop discussion focused on key gaps and related research priorities. The priorities listed herein were selected on the basis of rank as established by a series of anonymous surveys. Results: We identified the following research priorities: establish an ICU SCD definition, further develop rigorous and feasible ICU SCD measures, test associations between ICU SCD domains and outcomes, promote the inclusion of mechanistic and patient-centered outcomes within large clinical studies, leverage implementation science strategies to maximize intervention fidelity and sustainability, and collaborate among investigators to harmonize methods and promote multisite investigation. Conclusions: ICU SCD is a complex and compelling potential target for improving ICU outcomes. Given the influence on all other research priorities, further development of rigorous, feasible ICU SCD measurement is a key next step in advancing the field.

A real-time automated sleep scoring algorithm to detect refreshing sleep in conscious ventilated critically ill patients.

OBJECTIVES: Due to the noisy environment, a very large number of patients admitted to intensive care units (ICUs) suffer from sleep severe disruption. These sleep alterations have been associated with a prolonged need for assisted ventilation or even with death. Sleep scoring in the critically ill is very challenging and requires sleep experts, limiting relevant studies to a few experienced teams. In this context, an automated scoring system would be of interest for researchers. In addition, real-time scoring could be used by nurses to protect patients' sleep. We devised a sleep scoring algorithm working in real time and compared this automated scoring against visual scoring. METHODS: We analyzed retrospectively 45 polysomnographies previously recorded in non-sedated and conscious ICU patients during their weaning phase. For each patient, one EEG channel was processed, providing automated sleep scoring. We compared total sleep time obtained with visual scoring versus automated scoring. The proportion of sleep episodes correctly identified was calculated. RESULTS: Automated total sleep time and visual sleep time were correlated; the automatic system overestimated total sleep time. The median [25th-75th] percentage of sleep episodes lasting more than 10 min detected by algorithm was 100% [73.2 - 100.0]. Median sensitivity was 97.9% [92.5 - 99.9]. CONCLUSION: An automated sleep scoring system can identify nearly all long sleep episodes. Since these episodes are restorative, this real-time automated system opens the way for EEG-guided sleep protection strategies. Nurses could cluster their non-urgent care procedures, and reduce ambient noise so as to minimize patients' sleep disruptions.

Comorbid parasomnias in narcolepsy and idiopathic hypersomnia: more REM than NREM parasomnias.

STUDY OBJECTIVES: To assess the frequency, determinants, and clinical impact of clinical rapid eye movement (REM) and non-REM (NREM) parasomnias in adult patients with narcolepsy type 1 (NT1), narcolepsy type 2 (NT2), and idiopathic hypersomnia compared with healthy controls. METHODS: Familial and past and current personal parasomnias were assessed by questionnaire and medical interviews in 710 patients (220 NT1, 199 NT2, and 221 idiopathic hypersomnia) and 595 healthy controls. RESULTS: Except for sleep-related eating disorder, current NREM parasomnias were rare in all patient groups and controls. Sleep-related eating disorder was more frequent in NT1 patients (7.9% vs 1.8% in NT2 patients, 2.1% in patients with idiopathic hypersomnia, and 1% in controls) and associated with disrupted nighttime sleep (odds ratio = 3.9) and nocturnal eating in full awareness (odds ratio = 6.9) but not with sex. Clinical REM sleep behavior disorder was more frequent in NT1 patients (41.4%, half being violent) than in NT2 patients (13.2%) and affected men more often than women (odds ratio = 2.4). It was associated with disrupted nighttime sleep, depressive symptoms, and antidepressant use. Frequent (> 1/week) nightmares were reported by 39% of patients with NT1, 29% with NT2, and 27.8% with idiopathic hypersomnia (vs 8.3% in controls) and were associated with depressive symptoms in narcolepsy. No parasomnia (except sleep-related hallucinations) worsened daytime sleepiness. CONCLUSIONS: In patients with central disorders of hypersomnolence, comorbid NREM parasomnias (except for sleep-related eating disorder) are rare and do not worsen sleepiness. In contrast, REM parasomnias are prevalent (especially in NT1) and are associated with male sex, disrupted nighttime sleep, depressive symptoms, and antidepressant use. CITATION: Leu-Semenescu S, Maranci J-B, Lopez R, et al. Comorbid parasomnias in narcolepsy and idiopathic hypersomnia: more REM than NREM parasomnias. J Clin Sleep Med. 2022;18(5):1355-1364.

ß Agonist Delivery by High-Flow Nasal Cannula During COPD Exacerbation.

BACKGROUND: Whereas high-flow nasal cannula (HFNC) oxygen therapy is increasingly used in patients with exacerbation of COPD, the effectiveness of ß 2 agonist nebulization through HFNC has been poorly assessed. We hypothesized that salbutamol vibrating-mesh nebulization through HFNC improves pulmonary function tests in subjects with COPD. METHODS: We conducted a physiological crossover study including subjects admitted to the ICU for severe exacerbation of COPD. After subject improvement allowing a 3-h washout period without bronchodilator, pulmonary function tests were performed while breathing through HFNC alone and after salbutamol vibrating-mesh nebulization through HFNC. The primary end point consisted in the changes in FEV1 before and after salbutamol nebulization. Secondary end points included the changes in FVC, peak expiratory flow (PEF), airway resistance, and clinical parameters. RESULTS: Among the 15 subjects included, mean (SD) FEV1 significantly increased after salbutamol nebulization from 931 mL (383) to 1,019 (432), mean difference +87 mL (95% CI 30-145) (P = .006). Similarly, FVC and PEF significantly increased, +174 mL (95% CI 66-282) (P = .004) and +0.3 L/min (95% CI 0-0.6) (P = .037), respectively. Airway resistances and breathing frequency did not significantly differ, whereas heart rate significantly increased after nebulization. CONCLUSIONS: In subjects with severe exacerbation of COPD, salbutamol vibrating-mesh nebulization through HFNC induced a significant bronchodilator effect with volume and flow improvement.

Narcolepsy Type 1: A Remitting Disease? An Unusual Case Report.

We describe the case of a male patient who was diagnosed with narcolepsy type 1 on the basis of sleep and wake symptoms, and the results of investigations including video-polysomnography, multiple sleep latency test, human leukocyte antigen status and orexin level in cerebrospinal fluid. During the first years after disease onset, the patient did not show any significant improvement despite treatment with a variety of stimulant and anti-cataplectic drugs. However, spontaneous remission of disease occurred after 15 years.

Role of sleep on respiratory failure after extubation in the ICU.

BACKGROUND: Sleep had never been assessed immediately after extubation in patients still in the ICU. However, sleep deprivation may alter respiratory function and may promote respiratory failure. We hypothesized that sleep alterations after extubation could be associated with an increased risk of post-extubation respiratory failure and reintubation. We conducted a prospective observational cohort study performed at the medical ICU of the university hospital of Poitiers in France. Patients at high-risk of extubation failure (> 65 years, with any underlying cardiac or lung disease, or intubated > 7 days) were included. Patients intubated less than 24 h, with central nervous or psychiatric disorders, continuous sedation, neuroleptic medication, or uncooperative were excluded. Sleep was assessed by complete polysomnography just following extubation including the night. The main objective was to compare sleep between patients who developed post-extubation respiratory failure or required reintubation and the others. RESULTS: Over a 3-year period, 52 patients had complete polysomnography among whom 12 (23%) developed post-extubation respiratory failure and 8 (15%) required reintubation. Among them, 10 (19%) had atypical sleep, 15 (29%) had no deep sleep, and 33 (63%) had no rapid eye movement (REM) sleep. Total sleep time was 3.2 h in median [interquartile range, 2.0-4.4] in patients who developed post-extubation respiratory failure vs. 2.0 [1.1-3.8] in those who were successfully extubated (p = 0.34). Total sleep time, and durations of deep and REM sleep stages did not differ between patients who required reintubation and the others. Reintubation rates were 21% (7/33) in patients with no REM sleep and 5% (1/19) in patients with REM sleep (difference, - 16% [95% CI - 33% to 6%]; p = 0.23). CONCLUSIONS: Sleep assessment by polysomnography after extubation showed a dramatically low total, deep and REM sleep time. Sleep did not differ between patients who were successfully extubated and those who developed post-extubation respiratory failure or required reintubation.

Sleep deprivation reduces vagal tone during an inspiratory endurance task in humans.

STUDY OBJECTIVES: Sleep deprivation alters inspiratory endurance by reducing inspiratory motor output. Vagal tone is involved in exercise endurance. This study aimed to investigate the effect of sleep deprivation on vagal tone adaptation in healthy subjects performing an inspiratory effort. METHODS: Vagal tone was assessed using Heart Rate Variability normalized units of frequency domain component HF (high frequency) before, at the start, and the end of an inspiratory loading trial performed until exhaustion by 16 volunteers after one night of sleep deprivation and one night of normal sleep, where sleep deprivation reduced the inspiratory endurance by half compared to the normal sleep condition (30 min vs 60 min). RESULTS: At rest, heart rate was similar in sleep deprivation and normal sleep conditions. In normal sleep condition, heart rate increased during inspiratory loading task; this increase was greater in sleep deprivation condition. In normal sleep condition, vagal tone increased at the beginning of the trial. This vagal tone increase was absent in sleep deprivation condition. CONCLUSIONS: Sleep deprivation abolished vagal tone response to inspiratory load, possibly contributing to a higher heart rate during the trial and to a reduced inspiratory endurance. CLINICAL TRIAL REGISTRATION: NCT02725190.

A Systematic Review of Risk Factors for Sleep Disruption in Critically Ill Adults.

OBJECTIVES: Numerous risk factors for sleep disruption in critically ill adults have been described. We performed a systematic review of all risk factors associated with sleep disruption in the ICU setting. DATA SOURCES: PubMed, EMBASE, CINAHL, Web of Science, Cochrane Central Register for Controlled Trials, and Cochrane Database of Systematic Reviews. STUDY SELECTION: English-language studies of any design published between 1990 and April 2018 that evaluated sleep in greater than or equal to 10 critically ill adults (> 18 yr old) and investigated greater than or equal to 1 potential risk factor for sleep disruption during ICU stay. We assessed study quality using Newcastle-Ottawa Scale or Cochrane Risk of Bias tool. DATA EXTRACTION: We abstracted all data independently and in duplicate. Potential ICU sleep disruption risk factors were categorized into three categories based on how data were reported: 1) patient-reported reasons for sleep disruption, 2) patient-reported ratings of potential factors affecting sleep quality, and 3) studies reporting a statistical or temporal association between potential risk factors and disrupted sleep. DATA SYNTHESIS: Of 5,148 citations, we included 62 studies. Pain, discomfort, anxiety/fear, noise, light, and ICU care-related activities are the most common and widely studied patient-reported factors causing sleep disruption. Patients rated noise and light as the most sleep-disruptive factors. Higher number of comorbidities, poor home sleep quality, home sleep aid use, and delirium were factors associated with sleep disruption identified in available studies. CONCLUSIONS: This systematic review summarizes all premorbid, illness-related, and ICU-related factors associated with sleep disruption in the ICU. These findings will inform sleep promotion efforts in the ICU and guide further research in this field.

Impact of Sleep Deprivation on Respiratory Motor Output and Endurance. A Physiological Study.

Rationale: Sleep deprivation can alter endurance of skeletal muscles, but its impact on respiratory command is unknown.Objectives: We aimed to assess the effect of sleep deprivation on respiratory motor output and inspiratory endurance.Methods: Inspiratory endurance was investigated twice in random order, following a normal sleep night and a sleepless night. Healthy participants were asked to breathe as long as possible until task failure against a moderate inspiratory threshold constraint. Transdiaphragmatic pressure and diaphragm electrical activity were measured throughout the trial to assess pressure output of the diaphragm and overall respiratory motor output. Cortical contribution to respiratory motor output was assessed by measurement of preinspiratory motor potential amplitude and by cervical magnetic simulation.Measurements and Main Results: Twenty healthy male participants were studied. Time to task failure was significantly shorter after sleep deprivation than after normal sleep: (30 min [interquartile range [IQR], 17-41] vs. 60 min [IQR, 45-60], P = 0.002). At the beginning of the trial, preinspiratory motor potential amplitude was significantly lower in the sleep-deprivation condition (4.5 µV [IQR, 2.5-6.4] vs. 7.3 µV [IQR, 4.3-10.4], P = 0.02) and correlated significantly with the duration of the endurance trial. In the sleep-deprivation condition, preinspiratory motor potential amplitude, electrical activity of the diaphragm, pressure output of the diaphragm, and Vt decreased and the respiratory rate increased significantly from the beginning to the end of the trial. Such decreases did not occur in the normal-sleep condition.Conclusions: One night of sleep deprivation reduces respiratory motor output by altering its cortical component with subsequent reduction of inspiratory endurance by half. These results suggest that altered sleep triggers severe brain dysfunctions that could precipitate respiratory failure.

Sleep and Pathological Wakefulness at the Time of Liberation from Mechanical Ventilation (SLEEWE). A Prospective Multicenter Physiological Study.

Rationale: Abnormal patterns of sleep and wakefulness exist in mechanically ventilated patients. Objectives: In this study (SLEEWE [Effect of Sleep Disruption on the Outcome of Weaning from Mechanical Ventilation]), we aimed to investigate polysomnographic indexes as well as a continuous index for evaluating sleep depth, the odds ratio product (ORP), to determine whether abnormal sleep or wakefulness is associated with the outcome of spontaneous breathing trials (SBTs). Methods: Mechanically ventilated patients from three sites were enrolled if an SBT was planned the following day. EEG was recorded using a portable sleep diagnostic device 15 hours before the SBT. The ORP was calculated from the power of four EEG frequency bands relative to each other, ranging from full wakefulness (2.5) to deep sleep (0). The correlation between the right and left hemispheres' ORP (R/L ORP) was calculated. Measurements and Main Results: Among 44 patients enrolled, 37 had technically adequate signals: 11 (30%) passed the SBT and were extubated, 8 (21%) passed the SBT but were not deemed to be clinically ready for extubation, and 18 (49%) failed the SBT. Pathological wakefulness or atypical sleep were highly prevalent, but the distribution of classical sleep stages was similar between groups. The mean ORP and the proportion of time in which the ORP was >2.2 were higher in extubated patients compared with the other groups (P < 0.05). R/L ORP was significantly lower in patients who failed the SBT, and the area under the receiver operating characteristic curve of R/L ORP to predict failure was 0.91 (95% confidence interval, 0.75-0.98). Conclusions: Patients who pass an SBT and are extubated reach higher levels of wakefulness as indicated by the ORP, suggesting abnormal wakefulness in others. The hemispheric ORP correlation is much poorer in patients who fail an SBT.

Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU.

OBJECTIVE: To update and expand the 2013 Clinical Practice Guidelines for the Management of Pain, Agitation, and Delirium in Adult Patients in the ICU. DESIGN: Thirty-two international experts, four methodologists, and four critical illness survivors met virtually at least monthly. All section groups gathered face-to-face at annual Society of Critical Care Medicine congresses; virtual connections included those unable to attend. A formal conflict of interest policy was developed a priori and enforced throughout the process. Teleconferences and electronic discussions among subgroups and whole panel were part of the guidelines' development. A general content review was completed face-to-face by all panel members in January 2017. METHODS: Content experts, methodologists, and ICU survivors were represented in each of the five sections of the guidelines: Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption). Each section created Population, Intervention, Comparison, and Outcome, and nonactionable, descriptive questions based on perceived clinical relevance. The guideline group then voted their ranking, and patients prioritized their importance. For each Population, Intervention, Comparison, and Outcome question, sections searched the best available evidence, determined its quality, and formulated recommendations as "strong," "conditional," or "good" practice statements based on Grading of Recommendations Assessment, Development and Evaluation principles. In addition, evidence gaps and clinical caveats were explicitly identified. RESULTS: The Pain, Agitation/Sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) panel issued 37 recommendations (three strong and 34 conditional), two good practice statements, and 32 ungraded, nonactionable statements. Three questions from the patient-centered prioritized question list remained without recommendation. CONCLUSIONS: We found substantial agreement among a large, interdisciplinary cohort of international experts regarding evidence supporting recommendations, and the remaining literature gaps in the assessment, prevention, and treatment of Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) in critically ill adults. Highlighting this evidence and the research needs will improve Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) management and provide the foundation for improved outcomes and science in this vulnerable population.

Impact of sleep alterations on weaning duration in mechanically ventilated patients: a prospective study.

Sleep is markedly altered in intensive care unit (ICU) patients and may alter respiratory performance. Our objective was to assess the impact of sleep alterations on weaning duration.We conducted a prospective physiological study at a French teaching hospital. ICU patients intubated for at least 24 h and difficult to wean were included. Complete polysomnography (PSG) was performed after the first spontaneous breathing trial failure. Presence of atypical sleep, duration of sleep stages, particularly rapid eye movement (REM) sleep, and electroencephalogram (EEG) reactivity at eyes opening were assessed by a neurologist.20 out of 45 patients studied (44%) had atypical sleep that could not be classified according to the standard criteria. Duration of weaning between PSG and extubation was significantly longer in patients with atypical sleep (median (interquartile range) 5 (2-8) versus 2 (1-2) days; p=0.001) and in those with no REM sleep compared with the others. Using multivariate logistic regression analysis, atypical sleep remained independently associated with prolonged weaning (>48 h after PSG). Altered EEG reactivity at eyes opening was a good predictor of atypical sleep.Our results suggest for the first time that brain dysfunction may have an influence on the ability to breathe spontaneously.