Predicting and mitigating fatigue effects due to sleep deprivation: A review

Total sleep deprivation alters spontaneous brain activity in medical staff during routine clinical work: a resting-state functional MR imaging study

Objectives

To assess the effect of total sleep deprivation (TSD) on spontaneous brain activity in medical staff during routine clinical practice.

Methods

A total of 36 medical staff members underwent resting-state functional MRI (rs-fMRI) scans and neuropsychological tests twice, corresponding to rested wakefulness (RW) after normal sleep and 24 h of acute TSD. The rs-fMRI features, including the mean fractional amplitude of low-frequency fluctuation (mfALFF), z-score transformed regional homogeneity (zReHo), and functional connectivity (zFC), were compared between RW and TSD. Correlation coefficients between the change in altered rs-fMRI features and the change in altered scores of neuropsychological tests after TSD were calculated. Receiver operating characteristic (ROC) and logistic regression analyses were performed to evaluate the diagnostic efficacy of significantly altered rs-fMRI features in distinguishing between RW and TSD states.

Results

Brain regions, including right superior temporal gyrus, bilateral postcentral gyrus, left medial superior frontal gyrus, left middle temporal gyrus, right precentral gyrus, and left precuneus, showed significantly enhanced rs-fMRI features (mfALFF, zReHo, zFC) after TSD. Moreover, the changes in altered rs-fMRI features of the right superior temporal gyrus, bilateral postcentral gyrus, left middle temporal gyrus, and left precuneus were significantly correlated with the changes in several altered scores of neuropsychological tests. The combination of mfALFF (bilateral postcentral gyrus) and zFC (left medial superior frontal gyrus and left precuneus) showed the highest area under the curve (0.870) in distinguishing RW from TSD.

Conclusion

Spontaneous brain activity alterations occurred after TSD in routine clinical practice, which might explain the reduced performances of these participants in neurocognitive tests after TSD. These alterations might be potential imaging biomarkers for assessing the impact of TSD and distinguishing between RW and TSD states.

Sleep Quality and its Daytime Effects among University Students in the UAE

Objectives

To determine the irregularity in the sleep schedule among university students in the UAE and determine its correlation with poor sleep quality, daytime sleepiness, and fatigue.

Methods

This observational cross-sectional survey was electronically conducted among undergraduate students of Ajman University during the academic year 2022-2023. The participants were selected using a simple random sampling method. The instruments for data collection comprised of sleep schedule questionnaire, Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Fatigue Severity Scale. Data was subjected to chi-square analysis, Mann-Whitney U test, Wilcoxon rank-sum test, and Spearman's correlation.

Results

Of the 537 participants, 353 (65.7%) were female. The majority (57.2%) kept highly irregular bedtimes. The cohort's mean global PSQI score was 8.9±3.0 indicating poor sleep quality. There was a positive correlation between the irregular bedtime frequency and the global PSQI score (r = 0.311; p < 0.010). Most (70.8%) participants had a total high Fatigue Severity Scale score of ≥ 36. The scores of women (41.0±10.5) were significantly higher than those of men (38.5±11.0) (p =0.006). Around 53.0% of the participants had high ESS scores indicating excessive daytime sleepiness. There was also a significant correlation between ESS score and irregular bedtime frequency (r = 0.113; p =0.009).

Conclusions

The students at Ajman University had a high prevalence of irregular bedtime and inadequate sleeping hours. This was affecting their sleep quality and causing excessive daytime sleepiness. The students, especially women, were suffering from fatigue, potentially affecting their normal functionality. It is crucial to encourage students to establish regular sleep patterns and improve sleep habits to promote their productivity and general well-being.

Post-COVID fatigue: Reduced quality-of-life associated with clinically relevant fatigue in mild disease courses

Fatigue is a pervasive symptom experienced by many individuals after COVID-19. Despite its widespread occurrence, fatigue remains a poorly understood and complex phenomenon. Our aim is to evaluate the subjective experience of mental fatigue after COVID-19 and to assess its significance for daily life functioning. In this online questionnaire study (N = 220), the Fatigue Severity Scale (FSS), World Health Organization Quality-of-Life assessment (WHOQoL) and a subjective severity rating of the COVID-19 disease progression were used. For our statistical analyses we utilized independent samples t-tests, one-way ANOVA with post-hoc analyses, and a multiple regression. As expected our findings revealed the COVID group reported significantly higher levels of subjective fatigue compared to the control group. Moreover, there was a significant difference between experienced fatigue across the four severity groups. Participants who had a milder course of disease also experienced severe subjective fatigue. Subjective fatigue explained 40% variance in quality-of-life. In conclusion, severe subjective fatigue appears to be associated with increased self-reported COVID-19 symptom severity and lower quality-of-life but is already observable in milder cases. This underscores, firstly, the importance of considering also less severe cases and, secondly, the need to develop rehabilitation and psychological interventions for fatigue.

Estimating vigilance from the pre-work shift sleep using an under-mattress sleep sensor

Predicting vigilance impairment in high-risk shift work occupations is critical to help to reduce workplace errors and accidents. Current methods rely on multi-night, often manually entered, sleep data. This study developed a machine learning model for predicting vigilance errors based on a single prior sleep period, derived from an under-mattress sensor. Twenty-four healthy volunteers (mean [SD] age = 27.6 [9.5] years, 12 male) attended the laboratory on two separate occasions, 1 month apart, to compare wake performance and sleep under two different lighting conditions. Each condition occurred over an 8 day protocol comprising a baseline sleep opportunity from 10 p.m. to 7 a.m., a 27 h wake period, then daytime sleep opportunities from 10 a.m. to 7 p.m. on days 3-7. From 12 a.m. to 8 a.m. on each of days 4-7, participants completed simulated night shifts that included six 10 min psychomotor vigilance task (PVT) trials per shift. Sleep was assessed using an under-mattress sensor. Using extra-trees machine learning models, PVT performance (reaction times <500 ms, reaction, and lapses) during each night shift was predicted based on the preceding daytime sleep. The final extra-trees model demonstrated moderate accuracy for predicting PVT performance, with standard errors (RMSE) of 19.9 ms (reaction time, 359 [41.6]ms), 0.42 reactions/s (reaction speed, 2.5 [0.6] reactions/s), and 7.2 (lapses, 10.5 [12.3]). The model also correctly classified 84% of trials containing ≥5 lapses (Matthews correlation coefficient = 0.59, F1 = 0.83). Model performance is comparable to current fatigue prediction models that rely upon self-report or manually entered data. This efficient approach may help to manage fatigue and safety in non-standard work schedules.

Music Nursing as Complementary Therapy Improves Anxiety, Fatigue, and Quality of Life in Children with Acute Leukaemia: A Retrospective Study

OBJECTIVE

To explore the effects of music nursing as a complementary therapy on anxiety, fatigue, and quality of life in children with acute leukemia (AL).

METHODS

This study included 150 children with AL admitted to our hospital from August 2021 to August 2023 and divided them into two groups based on treatment: the control (n = 76, received routine nursing) and observation (n = 74, received music nursing on the basis of routine nursing) groups. Comparison of groups was performed in terms of general information, anxiety, fatigue, and quality of life at admission (T0) and 1 month after admission (T1).

RESULTS

No significant differences were observed in the general data between the two groups (P > 0.05). Anxiety, fatigue, and quality of life of the two groups also showed no significant differences at T0 (P > 0.05). The observation group showed significantly lower anxiety than the control group at T1 (P < 0.05). At T1, the observation group exhibited a lower fatigue degree compared with the control group (P < 0.05). At T1, the observation group attained higher scores on physiological and emotional dimensions of the quality of life compared with the control group, and the differences were statistically significant (P < 0.05).

CONCLUSION

Music nursing for AL children, which has a certain clinical application value, can effectively reduce their anxiety and fatigue and improve their quality of life.

Psychomotor Performance after 30 h of Sleep Deprivation Combined with Exercise

Sleep deprivation (SD) usually impairs psychomotor performance, but most experiments are usually focused on sedentary conditions. The purpose of this study was to evaluate the influence of 30 h of complete SD combined with prolonged, moderate exercise (SDE) on human psychomotor performance. Eleven endurance-trained men accustomed to overnight exertion were tested twice: in well-slept and non-fatigued conditions (Control) and immediately after 30 h of SDE. They performed a multiple-choice reaction time test (MCRT) at rest and during each workload of the graded exercise test to volitional exhaustion. At rest, the MCRT was shorter after SDE than in the Control (300 ± 13 ms vs. 339 ± 11 ms, respectively, p < 0.05). During graded exercise, there were no significant differences in MCRT between groups, but the fastest reaction was observed at lower workloads after SDE (158 ± 7 W vs. 187 ± 11 W in Control, p < 0.05). The total number of missed reactions tended to be higher after SDE (8.4 ± 0.7 vs. 6.3 ± 0.8 in Control, p = 0.06). In conclusion, SDE is different from SD alone; however, well-trained men, accustomed to overnight exertion can maintain psychomotor abilities independently of the extent of central fatigue. Exercise can be used to enhance psychomotor performance in sleep-deprived subjects in whom special caution is required in order to avoid overload.

Fatigue and its impact on performance and health

An increasing body of evidence suggests that fatigue among healthcare staff is widespread, owing to a combination of high work intensity, long daytime hours and night-shift working. This has been linked to poorer outcomes for patients and longer inpatient stays, and to increased risks of work-related accidents, errors and injuries for practitioners. These include needlestick injuries and motor vehicle accidents, and other impacts on practitioner health, ranging from cancer, mental health problems, metabolic disorders to coronary disease. Other 24-hour safety-critical industries have fatigue policies that acknowledge the risks of staff fatigue and provide a system to manage it and mitigate harm, but these are still lacking within healthcare. This review explains the basic physiology behind fatigue and outlines its impacts on healthcare practitioners' clinical practice and wellbeing. It proposes methods to minimise these effects for individuals, organisations and the wider UK health service.

Effects of energy balance on cognitive performance, risk-taking, ambulatory vigilance and mood during simulated military sustained operations (SUSOPS)

Sustained operations (SUSOPS) require military personnel to conduct combat and training operations while experiencing physical and cognitive stress and limited sleep. These operations are often conducted in a state of negative energy balance and are associated with degraded cognitive performance and mood. Whether maintaining energy balance can mitigate these declines is unclear. This randomized crossover study assessed the effects of energy balance on cognitive performance, risk-taking propensity, ambulatory vigilance, and mood during a simulated 72-h SUSOPS.

METHODS

Ten male Soldiers (mean ± SE; 22.4 ± 1.7 y; body weight 87.3 ± 1.1 kg) completed two, 72-h simulated SUSOPS in random order, separated by 7 days of recovery. Each SUSOPS elicited ∼4500 kcal/d total energy expenditure and restricted sleep to 4 h/night. During SUSOPS, participants consumed either an energy-balanced or restricted diet that induced a 43 ± 3% energy deficit. A cognitive test battery was administered each morning and evening to assess: vigilance, working memory, grammatical reasoning, risk-taking propensity, and mood. Real-time ambulatory vigilance was assessed each morning, evening, and night via a wrist-worn monitoring device.

RESULTS

Participants exhibited heightened risk-taking propensity (p = 0.047) with lower self-reported self-control (p = 0.021) and fatigue (p = 0.013) during energy deficit compared to during energy balance. Vigilance accuracy (p < 0.001) and working memory (p = 0.040) performance decreased, and vigilance lapses increased (p < 0.001) during SUSOPS, but did not differ by diet. Percentage of correct responses to ambulatory vigilance stimuli varied during SUSOPS (p = 0.019) independent of diet, with generally poorer performance during the morning and night. Total mood disturbance (p = 0.001), fatigue (p < 0.001), tension (p = 0.003), and confusion (p = 0.036) increased whereas vigor decreased (p < 0.001) during SUSOPS, independent of diet.

CONCLUSION

Prolonged physical activity combined with sleep restriction is associated with impaired vigilance, memory, and mood state. Under such conditions, maintaining energy balance prevents increased risk-taking and improves self-control, but does not improve other aspects of cognitive function or mood. Given the small sample in the present study, replication in a larger cohort is warranted.

Image discrimination reversal learning is impaired by sleep deprivation in rats: Cognitive rigidity or fatigue?

Introduction

Insufficient sleep is pervasive worldwide, and its toll on health and safety is recapitulated in many settings. It is thus important to understand how poor sleep affects the brain and decision making. A robust literature documents the adverse effects of sleep deprivation on cognitive processes including cognitive flexibility, which is the capacity to appraise new feedback and make behavioral adjustments to respond appropriately. Animal models are often used to unravel the molecules, genes and neural circuits that are altered by sleep loss. Herein we take a translational approach to model the effects of sleep deprivation on cognitive rigidity, i.e., impaired cognitive flexibility in rats.

Methods

There are several approaches to assess cognitive rigidity; in the present study, we employ a pairwise discrimination reversal task. To our knowledge this is the first time this paradigm has been used to investigate sleep deprivation. In this touchscreen operant platform, we trained rats to select one of two images to claim a sucrose pellet reward. If the non-rewarded image was selected the rats proceeded to a correction trial where both images were presented in the same position as before. This image presentation continued until the rat selected the correct image. Once rats reached performance criteria, the reward contingencies were reversed. In one group of rats the initial reversal session was preceded by 10 h of sleep deprivation. We compared those rats to controls with undisturbed sleep on the number of sessions to reach performance criteria, number of trials per session, response latencies, correct responses, errors, perseverative errors and perseveration bouts in the initial training and reversal phases.

Results

We report that on reversal session one, sleep deprived rats completed a fraction of the trials completed by controls. On subsequent reversal sessions, the sleep deprived rats struggled to adapt to the reversed contingencies despite completing a similar number of trials, suggesting an effect of cognitive rigidity separate from fatigue.

Discussion

We discuss the delayed performance dynamics incurred by sleep loss in the context of fatigue and the implications of using pairwise discrimination reversal as a model to further examine the effects of sleep loss on adaptive decision making.