Measuring sleep in the intensive care unit: Electroencephalogram, actigraphy, or questionnaire?

Use of actigraphy for monitoring agitation and rest-activity cycles in patients with acute traumatic brain injury in the ICU

BACKGROUND

In traumatic brain injury patients (TBI) admitted to the intensive care unit (ICU), agitation can lead to accidental removal of catheters, devices as well as self-extubation and falls. Actigraphy could be a potential tool to continuously monitor agitation. The objectives of this study were to assess the feasibility of monitoring agitation with actigraphs and to compare activity levels in agitated and non-agitated critically ill TBI patients.

METHODS

Actigraphs were placed on patients' wrists; 24-hour monitoring was continued until ICU discharge or limitation of therapeutic efforts. Feasibility was assessed by actigraphy recording duration and missing activity count per day.

RESULTS

Data from 25 patients were analyzed. The mean number of completed day of actigraphy per patient was 6.5 ± 5.1. The mean missing activity count was 20.3 minutes (±81.7) per day. The mean level of activity measured by raw actigraphy counts per minute over 24 hours was higher in participants with agitation than without agitation.

CONCLUSIONS

This study supports the feasibility of actigraphy use in TBI patients in the ICU. In the acute phase of TBI, agitated patients have higher levels of activity, confirming the potential of actigraphy to monitor agitation.

Psychometric properties and structural validity of traditional Chinese version of the Richards-Campbell Sleep Questionnaire in intensive care unit patients without physical restraint

BACKGROUND

Sleep assessment in the intensive care unit (ICU) is difficult and often unreliable. The most commonly used questionnaire for assessing ICU sleep, the Richards-Campbell Sleep Scale (RCSQ), has not been tested for reliability and construct validity in the Mandarin-Taiwanese speaking population.

OBJECTIVE

The objective of this study was to test the construct validity and criterion validity of the traditional Chinese version of RCSQ (TC-RCSQ) in critically ill patients without physical restraint.

METHODS

We adopted a cross-sectional study design. Adults aged 20 years and above were recruited from a plastic surgery ICU of a medical center. The Cronbach's alpha was used to test internal consistency; the validity testing included content validity, criterion validity, and construct validity. Criterion validity was analysed by testing the association of TC-RCSQ with the Chinese version of Verran and Snyder-Halpern Sleep Questionnaire and sleep parameter of actigraphy using the Pearson correlation coefficient; construct validity was analysed using exploratory factor analysis.

RESULTS

A total of 100 patients were included with a mean age of 49.78 years. Internal consistency reliability suggested Cronbach's alpha of 0.93. Moderate to strong correlations of TC-RCSQ with Verran-Snyder-Halpern Sleep Questionnaire were identified (r = 0.36 to 0.80, P < 0.05). We found significant correlations of actigraphic sleep efficiency with difficulty of falling sleep, awakening times, sleep quality, and total score of the TC-RCSQ (r = 0.23, 0.23, 0.20, and 0.23, P < 0.05). One factor (named as overall sleep quality) was extracted by exploratory factor analysis with a total variance explained of 78.40 %, which had good construction validity.

CONCLUSIONS

The TC-RCSQ yields satisfactory reliability and validity in critically ill patients. Actigraphic sleep efficiency may be a single index for objectively sleep assessment of sleep quality in patients without physical restraint. Both the TC-RCSQ and actigraphy can aid nurses to evaluate the sleep quality in critically ill patients without physical restraint.

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.

Mobilisation in the EveNing to prevent and TreAt deLirium (MENTAL): a mixed-methods, randomised controlled feasibility trial

Background

Delirium is common in critically ill patients and associated with longer hospital stays, increased morbidity and higher healthcare costs. Non-pharmacological interventions have been advocated for delirium management, however there is little evidence evaluating feasibility and acceptability of physical interventions administered in the evening. The aim of this study was to conduct a feasibility trial of evening mobilisation to prevent and treat delirium in patients admitted to intensive care.

Methods

In this mixed-methods, randomised controlled feasibility trial we recruited participants from intensive care units at two university hospitals in the United Kingdom. Eligible participants who were able to respond to verbal stimulus (Richmond agitation and sedation scale ≥3) and expected to stay in intensive care for at least 24 h were randomly assigned (1:1) to receive usual care or usual care plus evening mobilisation. The evening mobilisation was delivered between 19:00 and 21:00, for up to seven consecutive evenings or ICU discharge, whichever was sooner. All outcome assessments were completed by a team member blinded to randomisation and group allocation. Primary objective was to assess feasibility and acceptability of evening mobilisation. Primary feasibility outcomes were recruitment, consent and retention rates, and intervention fidelity. Intervention acceptability was evaluated through semi-structured interviews of participants and staff. Secondary outcomes included prevalence in incidence and duration of delirium, measured using the Confusion Assessment Method for ICU. This trial is registered at ClinicalTrials.gov, NCT05401461.

Findings

Between July 16th, 2022, and October 31st, 2022, 58 eligible patients (29 usual care; 29 usual care plus evening mobilisation) were enrolled. We demonstrated the feasibility and acceptability of both the trial design and evening mobilisation intervention. Consent and retention rates over three months were 88% (58/66) and 90% (52/58) respectively, with qualitative analysis demonstrating good acceptability reported by both participants and staff. Secondary outcomes for the evening intervention group compared with the control group were: delirium incidence 5/26 (19%; 95% CI: 6-39%) vs 8/28 (29%; 95% CI: 13-49%) and mean delirium duration 2 days (SD 0.7) vs 4.25 days (SD 2.0).

Interpretation

Results of this trial will inform the development of a definitive full-scale randomised controlled trial investigating the effects of evening mobilisation to treat delirium and improve health-related outcomes.

Funding

None.

Sleep during and following critical illness: A narrative review

Sleep is a complex process influenced by biological and environmental factors. Disturbances of sleep quantity and quality occur frequently in the critically ill and remain prevalent in survivors for at least 12 mo. Sleep disturbances are associated with adverse outcomes across multiple organ systems but are most strongly linked to delirium and cognitive impairment. This review will outline the predisposing and precipitating factors for sleep disturbance, categorised into patient, environmental and treatment-related factors. The objective and subjective methodologies used to quantify sleep during critical illness will be reviewed. While polysomnography remains the gold-standard, its use in the critical care setting still presents many barriers. Other methodologies are needed to better understand the pathophysiology, epidemiology and treatment of sleep disturbance in this population. Subjective outcome measures, including the Richards-Campbell Sleep Questionnaire, are still required for trials involving a greater number of patients and provide valuable insight into patients’ experiences of disturbed sleep. Finally, sleep optimisation strategies are reviewed, including intervention bundles, ambient noise and light reduction, quiet time, and the use of ear plugs and eye masks. While drugs to improve sleep are frequently prescribed to patients in the ICU, evidence supporting their effectiveness is lacking.

Sleep staging in the ICU with heart rate variability and breathing signals. An exploratory cross-sectional study using deep neural networks

Introduction: To measure sleep in the intensive care unit (ICU), full polysomnography is impractical, while activity monitoring and subjective assessments are severely confounded. However, sleep is an intensely networked state, and reflected in numerous signals. Here, we explore the feasibility of estimating conventional sleep indices in the ICU with heart rate variability (HRV) and respiration signals using artificial intelligence methods Methods: We used deep learning models to stage sleep with HRV (through electrocardiogram) and respiratory effort (through a wearable belt) signals in critically ill adult patients admitted to surgical and medical ICUs, and in age and sex-matched sleep laboratory patients Results: We studied 102 adult patients in the ICU across multiple days and nights, and 220 patients in a clinical sleep laboratory. We found that sleep stages predicted by HRV- and breathing-based models showed agreement in 60% of the ICU data and in 81% of the sleep laboratory data. In the ICU, deep NREM (N2 + N3) proportion of total sleep duration was reduced (ICU 39%, sleep laboratory 57%, p < 0.01), REM proportion showed heavy-tailed distribution, and the number of wake transitions per hour of sleep (median 3.6) was comparable to sleep laboratory patients with sleep-disordered breathing (median 3.9). Sleep in the ICU was also fragmented, with 38% of sleep occurring during daytime hours. Finally, patients in the ICU showed faster and less variable breathing patterns compared to sleep laboratory patients Conclusion: The cardiovascular and respiratory networks encode sleep state information, which, together with artificial intelligence methods, can be utilized to measure sleep state in the ICU.

Sleep assessment in critically ill adults: A systematic review and meta-analysis

PURPOSE

To systematically review sleep evaluation, characterize sleep disruption, and explore effects of sleepdisruption on outcomes in adult ICU patients.

MATERIALS AND METHODS

We systematically searched databases from May 1969 to June 2021 (PROSPERO protocol number: CRD42020175581). Prospective and retrospective studies were included studying sleep in critically ill adults, excluding patients with sleep or psychiatric disorders. Meta-regression methods were applied when feasible.

RESULTS

132 studies (8797 patients) were included. Fifteen sleep assessment methods were identified, with only two validated. Patients had significant sleep disruption, with low sleep time, and low proportion of restorative rapid eye movement (REM). Sedation was associated with higher sleep efficiency and sleep time. Surgical versus medical patients had lower sleep quality. Patients on ventilation had a higher amount of light sleep. Meta-regression only suggested an association between total sleep time and occurrence of delirium (p < 0.001, 15 studies, 519 patients). Scarce data precluded further analyses. Sleep characterized with polysomnography (PSG) correlated well with actigraphy and Richards Campbell Sleep Questionnaire (RCSQ).

CONCLUSIONS

Sleep in critically ill patients is severely disturbed, and actigraphy and RCSQ seem reliable alternatives to PSG. Future studies should evaluate impact of sleep disruption on outcomes.

Non-contact physiological monitoring of post-operative patients in the intensive care unit

Prolonged non-contact camera-based monitoring in critically ill patients presents unique challenges, but may facilitate safe recovery. A study was designed to evaluate the feasibility of introducing a non-contact video camera monitoring system into an acute clinical setting. We assessed the accuracy and robustness of the video camera-derived estimates of the vital signs against the electronically-recorded reference values in both day and night environments. We demonstrated non-contact monitoring of heart rate and respiratory rate for extended periods of time in 15 post-operative patients. Across day and night, heart rate was estimated for up to 53.2% (103.0 h) of the total valid camera data with a mean absolute error (MAE) of 2.5 beats/min in comparison to two reference sensors. We obtained respiratory rate estimates for 63.1% (119.8 h) of the total valid camera data with a MAE of 2.4 breaths/min against the reference value computed from the chest impedance pneumogram. Non-contact estimates detected relevant changes in the vital-sign values between routine clinical observations. Pivotal respiratory events in a post-operative patient could be identified from the analysis of video-derived respiratory information. Continuous vital-sign monitoring supported by non-contact video camera estimates could be used to track early signs of physiological deterioration during post-operative care.

Actigraphy in mechanically ventilated pediatric ICU patients: comparison to PSG and evaluation of behavioral circadian rhythmicity

Sleep disruption is common in pediatric intensive care unit (PICU) patients, but measuring sleep in this population is challenging. We aimed to evaluate the utility of actigraphy for estimating circadian rhythmicity in mechanically ventilated PICU patients and its accuracy for measuring sleep by comparing it to polysomnogram (PSG). We conducted a single-center prospective observational study of children 6 months - 17 years of age receiving mechanical ventilation and standard, protocolized sedation for acute respiratory failure, excluding children with acute or historical neurologic injury. We enrolled 16 children and monitored them with up to 14 days of actigraphy and 24 hours of simultaneous limited (10 channel) PSG. Daily actigraphy-based activity profiles demonstrated that patients had a high level of nighttime activity (30-41% of total activity), suggesting disrupted circadian activity cycles. Among n = 12 patients with sufficient actigraphy and PSG data overlap, actigraphy-based sleep estimation showed poor agreement with PSG-identified sleep states, with good sensitivity (94%) but poor specificity (28%), low accuracy (70%,) and low agreement (Cohen's kappa = 0.2, 95% CI = 0.08-0.31). Using univariate linear regression, we identified that Cornell Assessment of Pediatric Delirium scores were associated with accuracy of actigraphy but that other clinical factors including sedative medication doses, activity levels, and restraint use were not. In this population, actigraphy did not reliably discern between sleep and wake states. However, in select patients, actigraphy was able to distinguish diurnal variation in activity patterns, and therefore may be useful for evaluating patients' response to circadian-oriented interventions.

Investigating the construct and concurrent validity of the Richards-Campbell Sleep Questionnaire with intensive care unit patients and home sleepers

BACKGROUND

Sleep is vital to our wellbeing. Critically ill patients are vulnerable with effects of sleep deprivation including weakened immune function, decreased glucose tolerance, and increased sympathetic activity. Intensive care unit (ICU) patients' sleep evaluation is difficult and often not reliable. The most commonly used instrument for assessing ICU patients' perspective of their sleep, Richards-Campbell Sleep Questionnaire (RCSQ), has not been reported to have undergone known-group construct validity testing or concurrent validity testing with the criterion measure of feeling refreshed.

OBJECTIVES

The aim of the study was to explore the construct validity of the RCSQ with known-groups technique and concurrent validity with the criterion measure of feeling refreshed on awakening.

METHODS

A cross-sectional descriptive survey study using the RCSQ was conducted on people sleeping at home (n = 114) over seven nights. The results were compared with the RCSQ sleep scores of nonintubated alert oriented adult ICU patients (n = 114). Home sleepers were also asked to rate how refreshed they felt on awakening. The study was executed and reported in accordance with the STROBE checklist for observational studies.

FINDINGS

RCSQ construct validity was supported because home sleepers' and ICU sleepers' sleep evaluations differed significantly. Home sleepers rated their sleep significantly better than ICU patients in all five sleep domains of the RCSQ. Concurrent validity was supported because the item "feeling refreshed on awakening" correlated strongly with all sleep domains.

CONCLUSIONS

Sleep quality may be accurately measured using the RCSQ in alert people both in the ICU and at home. This study has added to the validity discussion around the RCSQ. The RCSQ can be used for sleep evaluation in ICUs to promote wellbeing and recovery.

Temperature rhythms and ICU sleep: the TRIS study

BACKGROUND

Core body temperature (CBT) patterns associated with sleep have not been described in the critically ill. This study aimed to characterize night-time sleep and its relationship to CBT in ICU patients.

METHODS

A prospective study was performed in a 27-bed tertiary adult intensive care unit of 20 mechanically ventilated patients in the weaning stage of their critical illness. The study assessed sleep by polysomnography (PSG) during the evening between 21:00-7:00 hours, nursing interventions using the Therapeutic Intervention Scoring System (TISS), illness severity using SOFA and APACHE II scores and CBT 24-hour pattern.

RESULTS

Patients were awake for approximately half the study period (45.04%, IQR 13.81-77-17) with no REM (0%, IQR 0-0.04%) and median arousals of 19.5/hour (IQR 7.1-40.9). The 24-hour CBT had a rhythmic pattern in 13 (65%) patients with a highly variable phase of median peak time at 17:35 hours (IQR 12:40-19:39). No significant associations were found between CBT rhythmicity, sleep stages, sleep EEG frequency density, illness severity scores or TISS on the day of PSG. There was no relationship between time awake and CBT rhythmicity (P=0.48) or CBT peak time (P=0.82). The relationship between circadian rhythms and sleep patterns in the critically ill is complex.

CONCLUSIONS

Patients recovering in ICU commonly have CBT loss of rhythmicity or a significant phase shift with loss of normal night-time patterns of sleep architecture. Appropriate care plans to promote sleep and circadian rhythm require further investigation of contributing factors such as environment, clinical care routines, illness type and severity.

The Impact of Earplugs and Eye Masks on Sleep Quality in Surgical ICU Patients at Risk for Frequent Awakenings

OBJECTIVES

Sleep disturbances may contribute to the development of delirium, prolonged ICU stay, and increased mortality. There is conflicting data on the effectiveness of earplugs and eye masks for sleep promotion in the ICU. This study evaluates the impact of earplugs and eye masks on sleep quality in postoperative surgical ICU patients at risk for frequent awakenings.

DESIGN

Prospective randomized controlled trial.

SETTING

Surgical ICU within the University of Texas Southwestern Medical Center.

PATIENTS

Adult, female patients admitted to the surgical ICU requiring hourly postoperative assessments following breast free flap surgery between February 2018 and October 2019.

INTERVENTIONS

Patients were randomized into an intervention group or a control group. The intervention group received earplugs and eye masks in addition to standard postoperative care, whereas the control group received standard postoperative care.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was overall sleep quality assessed via the Richards-Campbell Sleep Questionnaire. Secondary outcomes of patient satisfaction and rates of ICU delirium were assessed with a modified version of the Family Satisfaction in the ICU survey and the Confusion Assessment Method for the ICU. After a planned interim analysis, the study was stopped early because prespecified criteria for significance were attained. Compared with the control group's average Richards-Campbell Sleep Questionnaire total score of 47.3 (95% CI, 40.8-53.8), the intervention group's average Richards-Campbell Sleep Questionnaire total score was significantly higher at 64.5 (95% CI, 58.3-70.7; p = 0.0007). There were no significant between-group differences for Confusion Assessment Method for the ICU scores or modified Family Satisfaction in the ICU survey scores.

CONCLUSIONS

These results suggest that earplugs and eye masks are effective in improving sleep quality in ICU patients undergoing frequent assessments. The results strengthen the evidence for nonpharmacologic sleep-promoting adjuncts in the ICU.

Sleep quality assessment in intensive care: actigraphy vs. Richards-Campbell sleep questionnaire

Introduction

It has been repeatedly shown that sleep of intensive care unit (ICU) patients is fragmented and its architecture is impaired. As sleep disorders have numerous negative effects on the organism, there have been efforts to implement sleep-promoting strategies into practice. When comparing the effectiveness of such measures, sleep quality assessment itself is a considerable problem.

Objective

The study aimed to assess the quality and quantity of night sleep in ICU patients simultaneously with actigraphy (ACT) and the Richards-Campbell Sleep Questionnaire (RCSQ). The secondary goals were to test the performance and effectiveness of the above methods and to verify correlations between selected RCSQ items and actigraph parameters.

Methods

A single-center prospective observational study (20 patients staying in a Interdisciplinary Intensive Care Unit). The quality of sleep was assessed using a Czech version of the RCSQ and ACT. The obtained data were analyzed and their dependence or correlations were verified by selected statistical tests.

Results

The mean RCSQ score was 47.6 (SD 24.4). The worst results were found for sleep latency (44.4; SD 31.2); the best results were for sleep quality (50.2; SD 29.4). The mean sleep effciency measured with ACT reached 86.6% (SD 9.2); the mean number of awakenings per night was 17.1 (SD 8.5). The RCSQ total parameter with a cutoff of 50 (RCSQ total = 50 good sleep / RCSQ total < 50 poor sleep) was shown to be suitable for discrimination of subjectively perceived sleep quality in ICU patients. However, the study failed to show statistically significant relations between subjectively perceived sleep quality (RCSQ) and ACT measurements.

Conclusion

The RCSQ appears to be a suitable instrument for assessing night sleep quality in ICU patients. On the other hand, the study showed a very low level of agreement between subjective sleep quality assessment and objective ACT measurements. The main drawback of ACT is low reliability of obtained data. Further research is needed to determine its role in sleep quality assessment in the ICU setting.