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.

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.

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.

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.

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.

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.

Sleep disorders in Parkinsonian macaques: effects of L-dopa treatment and pedunculopontine nucleus lesion.

Patients with Parkinson's disease (PD) display significant sleep disturbances and daytime sleepiness. Dopaminergic treatment dramatically improves PD motor symptoms, but its action on sleep remains controversial, suggesting a causal role of nondopaminergic lesions in these symptoms. Because the pedunculopontine nucleus (PPN) regulates sleep and arousal, and in view of the loss of its cholinergic neurons in PD, the PPN could be involved in these sleep disorders. The aims of this study were as follows: (1) to characterize sleep disorders in a monkey model of PD; (2) to investigate whether l-dopa treatment alleviates sleep disorders; and (3) to determine whether a cholinergic PPN lesion would add specific sleep alterations. To this end, long-term continuous electroencephalographic monitoring of vigilance states was performed in macaques, using an implanted miniaturized telemetry device. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine treatment induced sleep disorders that comprised sleep episodes during daytime and sleep fragmentation and a reduction of sleep efficiency at nighttime. It also induced a reduction in time spent in rapid eye movement (REM) sleep and slow-wave sleep and an increase in muscle tone during REM and non-REM sleep episodes and in the number of awakenings and movements. l-Dopa treatment resulted in a partial but significant improvement of almost all sleep parameters. PPN lesion induced a transient decrease in REM sleep and in slow-wave sleep followed by a slight improvement of sleep quality. Our data demonstrate the efficacy of l-dopa treatment in improving sleep disorders in parkinsonian monkeys, and that adding a cholinergic PPN lesion improves sleep quality after transient sleep impairment.

Long-term safety and tolerability of ProSavin, a lentiviral vector-based gene therapy for Parkinson's disease: a dose escalation, open-label, phase 1/2 trial.

BACKGROUND: Parkinson's disease is typically treated with oral dopamine replacement therapies; however, long-term treatment leads to motor complications and, occasionally, impulse control disorders caused by intermittent stimulation of dopamine receptors and off-target effects, respectively. We aimed to assess the safety, tolerability, and efficacy of bilateral, intrastriatal delivery of ProSavin, a lentiviral vector-based gene therapy aimed at restoring local and continuous dopamine production in patients with advanced Parkinson's disease. METHODS: We undertook a phase 1/2 open-label trial with 12-month follow-up at two study sites (France and UK) to assess the safety and efficacy of ProSavin after bilateral injection into the putamen of patients with Parkinson's disease. All patients were then enrolled in a separate open-label follow-up study of long-term safety. Three doses were assessed in separate cohorts: low dose (1·9×10(7) transducing units [TU]); mid dose (4·0×10(7) TU); and high dose (1×10(8) TU). Inclusion criteria were age 48-65 years, disease duration 5 years or longer, motor fluctuations, and 50% or higher motor response to oral dopaminergic therapy. The primary endpoints of the phase 1/2 study were the number and severity of adverse events associated with ProSavin and motor responses as assessed with Unified Parkinson's Disease Rating Scale (UPDRS) part III (off medication) scores, at 6 months after vector administration. Both trials are registered at ClinicalTrials.gov, NCT00627588 and NCT01856439. FINDINGS: 15 patients received ProSavin and were followed up (three at low dose, six mid dose, six high dose). During the first 12 months of follow-up, 54 drug-related adverse events were reported (51 mild, three moderate). Most common were increased on-medication dyskinesias (20 events, 11 patients) and on-off phenomena (12 events, nine patients). No serious adverse events related to the study drug or surgical procedure were reported. A significant improvement in mean UPDRS part III motor scores off medication was recorded in all patients at 6 months (mean score 38 [SD 9] vs 26 [8], n=15, p=0·0001) and 12 months (38 vs 27 [8]; n=15, p=0·0001) compared with baseline. INTERPRETATION: ProSavin was safe and well tolerated in patients with advanced Parkinson's disease. Improvement in motor behaviour was observed in all patients. FUNDING: Oxford BioMedica.

Increased risk of narcolepsy in children and adults after pandemic H1N1 vaccination in France.

An increased incidence of narcolepsy in children was detected in Scandinavian countries where pandemic H1N1 influenza ASO3-adjuvanted vaccine was used. A campaign of vaccination against pandemic H1N1 influenza was implemented in France using both ASO3-adjuvanted and non-adjuvanted vaccines. As part of a study considering all-type narcolepsy, we investigated the association between H1N1 vaccination and narcolepsy with cataplexy in children and adults compared with matched controls; and compared the phenotype of narcolepsy with cataplexy according to exposure to the H1N1 vaccination. Patients with narcolepsy-cataplexy were included from 14 expert centres in France. Date of diagnosis constituted the index date. Validation of cases was performed by independent experts using the Brighton collaboration criteria. Up to four controls were individually matched to cases according to age, gender and geographic location. A structured telephone interview was performed to collect information on medical history, past infections and vaccinations. Eighty-five cases with narcolepsy-cataplexy were included; 23 being further excluded regarding eligibility criteria. Of the 62 eligible cases, 59 (64% males, 57.6% children) could be matched with 135 control subjects. H1N1 vaccination was associated with narcolepsy-cataplexy with an odds ratio of 6.5 (2.1-19.9) in subjects aged<18 years, and 4.7 (1.6-13.9) in those aged 18 and over. Sensitivity analyses considering date of referral for diagnosis or the date of onset of symptoms as the index date gave similar results, as did analyses focusing only on exposure to ASO3-adjuvanted vaccine. Slight differences were found when comparing cases with narcolepsy-cataplexy exposed to H1N1 vaccination (n=32; mostly AS03-adjuvanted vaccine, n=28) to non-exposed cases (n=30), including shorter delay of diagnosis and a higher number of sleep onset rapid eye movement periods for exposed cases. No difference was found regarding history of infections. In this sub-analysis, H1N1 vaccination was strongly associated with an increased risk of narcolepsy-cataplexy in both children and adults in France. Even if, as in every observational study, the possibility that some biases participated in the association cannot be completely ruled out, the associations appeared robust to sensitivity analyses, and a specific analysis focusing on ASO3-adjuvanted vaccine found similar increase.

Sleep continuity: a new metric to quantify disrupted hypnograms in non-sedated intensive care unit patients.

INTRODUCTION: Sleep in intensive care unit (ICU) patients is severely altered. In a large proportion of critically ill patients, conventional sleep electroencephalogram (EEG) patterns are replaced by atypical sleep. On the other hand, some non-sedated patients can display usual sleep EEG patterns. In the latter, sleep is highly fragmented and disrupted and conventional rules may not be optimal. We sought to determine whether sleep continuity could be a useful metric to quantify the amount of sleep with recuperative function in critically ill patients with usual sleep EEG features. METHODS: We retrospectively reanalyzed polysomnographies recorded in non-sedated critically ill patients requiring non-invasive ventilation (NIV) for acute hypercapnic respiratory failure. Using conventional rules, we built two-state hypnograms (sleep and wake) and identified all sleep episodes. The percentage of time spent in sleep bouts (<10 minutes), short naps (>10 and <30 minutes) and long naps (>30 minutes) was used to describe sleep continuity. In a first study, we compared these measures regarding good (NIV success) or poor outcome (NIV failure). In a second study performed on a different patient group, we compared these measurements during NIV and during spontaneous breathing. RESULTS: While fragmentation indices were similar in the two groups, the percentage of total sleep time spent in short naps was higher and the percentage of sleep time spent in sleep bouts was lower in patients with successful NIV. The percentage of total sleep time spent in long naps was higher and the percentage of sleep time spent in sleep bouts was lower during NIV than during spontaneous breathing; the level of reproducibility of sleep continuity measures between scorers was high. CONCLUSIONS: Sleep continuity measurements could constitute a clinically relevant and reproducible assessment of sleep disruption in non-sedated ICU patients with usual sleep EEG.

Sleep in hypercapnic critical care patients under noninvasive ventilation: conventional versus dedicated ventilators.

OBJECTIVE: To compare sleep quality between two types of ventilators commonly used for noninvasive ventilation: conventional ICU ventilators and dedicated noninvasive ventilators; and to evaluate sleep during and between noninvasive ventilation sessions in critically ill patients. DESIGN: Physiological sleep study with a randomized assessment of the ventilator type. SETTING: Medical ICU in a university hospital. PATIENTS: Twenty-four patients admitted for acute hypercapnic respiratory failure requiring noninvasive ventilation. INTERVENTIONS: Patients were randomly assigned to receive noninvasive ventilation with either an ICU ventilators (n = 12) or a dedicated noninvasive ventilators (n = 12), and their sleep and respiratory parameters were recorded by polysomnography from 4 PM to 9 AM on the second, third, or fourth day after noninvasive ventilation initiation. MEASUREMENTS AND MAIN RESULTS: Sleep architecture was similar between ventilator groups, including sleep fragmentation (number of arousals and awakenings/hr), but the dedicated noninvasive ventilators group showed a higher patient-ventilator asynchrony-related fragmentation (28% [17-44] vs. 14% [7.0-22]; p = 0.02), whereas the ICU ventilators group exhibited a higher noise-related fragmentation. Ineffective efforts were more frequent in the dedicated noninvasive ventilators group than in the ICU ventilators group (34 ineffective efforts/hr of sleep [15-125] vs. two [0-13]; p < 0.01), possibly as a result of a higher tidal volume (7.2 mL/kg [6.7-8.8] vs. 5.8 [5.1-6.8]; p = 0.04). More sleep time occurred and sleep quality was better during noninvasive ventilation sessions than during spontaneous breathing periods (p < 0.05) as a result of greater slow wave and rapid eye movement sleep and lower fragmentation. CONCLUSIONS: There were no observed differences in sleep quality corresponding to the type of ventilator used despite slight differences in patient-ventilator asynchrony. Noninvasive ventilation sessions did not prevent patients from sleeping; on the contrary, they seem to aid sleep when compared with unassisted breathing.

Comparison of sleep quality with mechanical versus spontaneous ventilation during weaning of critically III tracheostomized patients.

BACKGROUND: In mechanically ventilated patients under mechanical ventilation in the ICU, ventilatory mode or settings may influence sleep quality. The aim of this study was to evaluate the direct impact of mechanical ventilation per se on sleep quantity and quality in patients who were able to tolerate separation from mechanical ventilation over prolonged periods. DESIGN AND SETTING: Randomized crossover clinical trial in a medical ICU. PATIENTS: Sixteen conscious patients, free of sedation and tracheostomized because of prolonged weaning from mechanical ventilation, were included in the study when able to tolerate at least 5 hours of spontaneous ventilation. INTERVENTIONS: Patients were randomized to receive either spontaneous ventilation or mechanical ventilation at low levels of pressure support for two crossover periods of 5-hour duration each, from 22:00 to 08:00. Polysomnography was performed throughout the study. MEASUREMENTS AND RESULTS: Total sleep time was higher during mechanical ventilation than during spontaneous ventilation (183 min vs 132 min, p = 0.04). No significant differences between mechanical ventilation and spontaneous ventilation were observed in slow wave sleep time (45 min vs 28 min), rapid eye movement sleep time (11 min vs 3 min), or the fragmentation index (25 vs 23 arousals and awakenings per hr). In four patients, however, our analysis of patient-ventilator interaction suggested that the ventilatory settings were suboptimal and could have been improved to potentially improve sleep. CONCLUSIONS: In difficult-to-wean tracheostomized patients, sleep quality was similar with or without the ventilator. Sleep quantity was higher during mechanical ventilation. Reconnection to the ventilator during the night period may favor sleep efficiency in tracheostomized patients in prolonged weaning.

[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.

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.

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 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.