Association between sleep and fatigue in nurses who are engaged in 16 h night shifts in Japan: Assessment using actigraphy

Evaluation of fatigue in young female adults due to repeated exposure to heat in summer and cold in winter

PURPOSE

The magnitude of fatigue (MF) from psychological and physiological responses during repeated exposure to heat in summer and during repeated exposure to cold in winter was evaluated to test two hypotheses on fatigue models. The first hypothesis is that exposure time (ET, min) would be a factor determining the MF and the second hypothesis is that the same fatigue models as a function of the number of exposure repetitions (NR) could be applied to both repeated exposure to heat in summer and cold in winter.

METHODS

In summer, eight young adult female subjects with clothing insulation (Icl, clo) of 0.3 clo first stayed in the control room at 26 ℃ for 15 min, moved to the main testing room at 30 ℃ for 25 min, 33 °C for 15 min, or 36 ℃ for 10 min, and then returned to the control room. The product of air temperature difference (ΔTa, ℃) and ET was designed to be almost equal among these latter three conditions. The exposure was repeated five times. In winter, the same female subjects with Icl of 0.84 clo first stayed in the control room at 24 ℃ for 15 min, moved to the main testing room at 18 ℃ for 30 min, 15 ℃ for 20 min, or 12 ℃ for 15 min, and then returned to the control room. Again, the product of ΔTa and ET was designed to be equal among these latter three conditions. The exposure was repeated four times. The scores of subjective fatigue feeling (SFF) and salivary amylase value (SAV) were recorded when the subjects returned to the control room. Tympanic temperature, skin temperatures and local sweat rates (Sw, mg/cm2/min) at chest, forearm, front thigh, and front shin, and ECG were continuously monitored, except for Sw in the winter experiment.

RESULTS

In the summer experiment, the SFF showed a threshold value at ΔTa = 4 ℃ but continuously increased with NR at ΔTa = 7 ℃ and 10 ℃. It was not correlated with ECG variables, but was positively correlated with SAV (R2 = 0.50) and the mean Sw (R2 = 0.76) at ΔTa = 7 ℃ and 10 ℃. In the winter experiment, the SFF showed a threshold value at ΔTa =  - 6 ℃ but continuously increased with NR at ΔTa =  - 9 ℃ and - 12 ℃. It was correlated with SAV at ΔTa =  - 9 ℃ (R2 = 0.77) and score of LF: HF ratio at ΔTa =  - 6 ℃ and - 9 ℃ (R2 = 0.49).

CONCLUSION

It was confirmed that ET may be related to the MF and that different fatigue models may be applied dependent on ΔTa during repeated exposure to heat in summer and during repeated exposure to cold in winter. Thus, the two hypotheses were verified.

Effects of 90- and 30-min naps or a 120-min nap on alertness and performance: reanalysis of an existing pilot study

The aim of this study was to investigate alertness and cognitive performance immediately after and until the end of the night shift after taking a 120-min monophasic nap (One-nap) or a split 90-min and 30-min nap (Two-nap) during a 16-h simulated night shift, and the relationship between sleep quality and both alertness and performance. This study was performed in 41 females. Among them, 15 participants were included in the No-nap group, 14 in the One-nap group (22:00-00:00), and 12 in the Two-nap group (22:30-00:00 and 02:30-03:00). Participants were tested every hour from 16:00 to 09:00 for performance on the Uchida-Kraepelin test, as well as for subjective feelings of fatigue and drowsiness, body temperature, and heart rate variability. The shorter the sleep latency, the worse the alertness immediately after the 90-min nap. The 120-min and 30-min naps also revealed that prolonged total sleep time led to increased fatigue and drowsiness upon awakening. From 04:00 to 09:00, in the No-nap and One-nap groups, fatigue was higher than in the Two-nap group. The One-nap and Two-nap groups did not show improved morning performance. These results suggest that a split nap might improve drowsiness and fatigue during a long night shift.

Self-reported work-related accumulative fatigue of nurses: A cross-sectional study in public hospitals in China

Objectives

Work-related fatigue is a serious safety risk to nurses and their patients. This study aimed to assess self-reported work-related accumulative fatigue of nurses and its associated factors.

Methods

A questionnaire survey of 2,918 clinical nurses conveniently sampled from 48 public hospitals across six provinces in China was conducted. The "Self-diagnosis Checklist for Assessment of Workers' Accumulated Fatigue" was adopted to assess the level of work-related accumulative fatigue of the study participants. Chi-square tests and ordinal regression analyses were performed to determine the sociodemographic characteristics associated with work-related accumulative fatigue.

Results

About one third of respondents reported low work-related accumulative fatigue, compared with 23.1% reporting high and 24.6% reporting very high levels of work-related accumulative fatigue. Higher levels of work-related accumulative fatigue were associated with female gender (AOR = 0.614 for male relative to female, p = 0.005), age between 30 and 40 years (AOR = 1.346 relative to >40 years, p = 0.034), 5-10 years of work experience (AOR = 1.277 relative to >10 years, p = 0.034), and bachelor or above degree qualifications (AOR = 0.806 for associate degree relative to bachelor or above degree, p = 0.007). Those who worked in rural county hospitals (AOR = 0.816 for metropolitan relative to rural county hospitals, p = 0.006) and resided in central China (AOR = 1.276 relative to western China, p = 0.004) had higher odds of reporting higher levels of work-related accumulative fatigue.

Conclusion

High levels of work-related accumulative fatigue are evident in nurses of public hospitals in China. The problem is more serious in the female nurses in their mid-career and those who worked in the central region and rural setting.

Effects of 90 Min Napping on Fatigue and Associated Environmental Factors among Nurses Working Long Night Shifts: A Longitudinal Observational Study

For nurses working long night shifts, it is imperative that they have the ability to take naps to reduce fatigue, and that an appropriate environment is prepared where such naps can be taken. We verified the effects of 90 min napping on fatigue and the associated factors among nurses working 16-h night shifts. We investigated 196-night shifts among 49 nurses for one month. Wearable devices, data logging devices, and questionnaires were used to assess nap parameters, fatigue, and environmental factors such as the napping environment, ways of spending breaks, and working environment. Nurses who nap at least 90 min on most night shifts had more nursing experience. Multivariable logistic regression analysis showed that the environmental factors significantly associated with total nap duration (TND) ≥ 90 min were noise, time spent on electronic devices such as cellphones and tablets during breaks, and nap break duration. The night shifts with TND ≥ 90 min showed lower drowsiness after nap breaks and less fatigue at the end of night shift compared to those with TND < 90 min. Nurses and nursing managers should recognize the importance of napping and make adjustments to nap for at least 90 min during long night shifts.

Post-Work Recovery from Fatigue and Sleep Episodes among Nurses Who Are Engaged in 16-Hour Night Shifts: A Prospective Observational Study

Poor recovery from fatigue among shift-working nurses can cause a transition from acute to chronic fatigue. We aimed to clarify the relationship between nurses' recovery from fatigue and sleep episodes after 16 h night shifts while considering age. This prospective study included 62 nurses who worked 16 h night shifts. Fatigue was assessed by a questionnaire before, during, and after the night shift, and the morning following the night shift. Sleep episodes were continuously measured using a wearable device. We performed a hierarchical cluster analysis of multivariate sleep parameters in first and main sleep episodes after night shifts. A linear mixed model was used to estimate the difference between clusters in recovery from fatigue after the night shift, considering age. The participants were classified into a high sleep quality group (HSQG) and low sleep quality group (LSQG) in sleep episodes after the night shift. There was a significant main effect of clusters, and HSQG was significantly more effective than LSQG in recovering from fatigue. However, no main effects of age or interaction were observed. The quality of first and main sleep episodes at home was associated with recovery from the night shift to the next day, regardless of age.

Internet-Based Individualized Cognitive Behavioral Therapy for Shift Work Sleep Disorder Empowered by Well-Being Prediction: Protocol for a Pilot Study

Background

Shift work sleep disorders (SWSDs) are associated with the high turnover rates of nurses, and are considered a major medical safety issue. However, initial management can be hampered by insufficient awareness. In recent years, it has become possible to visualize, collect, and analyze the work-life balance of health care workers with irregular sleeping and working habits using wearable sensors that can continuously monitor biometric data under real-life settings. In addition, internet-based cognitive behavioral therapy for psychiatric disorders has been shown to be effective. Application of wearable sensors and machine learning may potentially enhance the beneficial effects of internet-based cognitive behavioral therapy.

Objective

In this study, we aim to develop and evaluate the effect of a new internet-based cognitive behavioral therapy for SWSD (iCBTS). This system includes current methods such as medical sleep advice, as well as machine learning well-being prediction to improve the sleep durations of shift workers and prevent declines in their well-being.

Methods

This study consists of two phases: (1) preliminary data collection and machine learning for well-being prediction; (2) intervention and evaluation of iCBTS for SWSD. Shift workers in the intensive care unit at Mie University Hospital will wear a wearable sensor that collects biometric data and answer daily questionnaires regarding their well-being. They will subsequently be provided with an iCBTS app for 4 weeks. Sleep and well-being measurements between baseline and the intervention period will be compared.

Results

Recruitment for phase 1 ended in October 2019. Recruitment for phase 2 has started in October 2020. Preliminary results are expected to be available by summer 2021.

Conclusions

iCBTS empowered with well-being prediction is expected to improve the sleep durations of shift workers, thereby enhancing their overall well-being. Findings of this study will reveal the potential of this system for improving sleep disorders among shift workers.

Trial Registration

UMIN Clinical Trials Registry UMIN000036122 (phase 1), UMIN000040547 (phase 2); https://tinyurl.com/dkfmmmje, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046284

International Registered Report Identifier (IRRID)

DERR1-10.2196/24799

The actual-ideal gap in work-life balance and quality of life among acute care ward nurses

AIMS

To describe the current situation of the work-life balance gap among acute care ward nurses and assess its association with quality of life (QOL).

BACKGROUND

Nurses who spend more time at work than on their personal lives are reported to have lower QOL. To capture the actual-ideal work-life balance gap among nurses with different backgrounds, time spent on work, family and private life must be examined.

METHODS

This cross-sectional study included 228 nurses from 3 Japanese acute care hospitals.

RESULTS

Work gap scores and family gap scores for nurses living alone were significantly higher and lower, respectively, than those for nurses living with family. Moreover, the QOL score decreased with increase in the work-life balance gap for nurses.

CONCLUSIONS

Nurses living alone had greater work burden than nurses living with family. Conversely, living with family may protect nurses' family lives. The work-life balance gap was associated with QOL.

IMPLICATIONS FOR NURSING MANAGEMENT

Addressing the gap between the actual-ideal proportions in work-life balance is important for improving nurses' QOL and work-life balance. Flexible working options and policy changes may also improve their work-life balance and QOL.

Pre-Exercise Glucose Ingestion May Improve Endurance Capacity in East Asian Student Athletes with Lower Blood Glucose Response

The main purpose of this study was to investigate the influence of pre-exercise glucose ingestion after a 2.5-h fast on the endurance capacity and blood glucose response in East Asian athletes who is expected to have genetically low insulin response. A total of 8 Japanese student athletes ingested 1.5 g/kg body mass of glucose (G trial) or 0.5 g/kg body mass of artificial sweetener dissolved in water (P trial) 30 min before exercise test after consuming a standardized breakfast. The exercise test comprised 40 min cycling exercise at 50% maximal oxygen uptake (VO_2max), immediately followed by cycling to exhaustion at 70% VO_2max. Before analyzing the data, we grouped the subjects into two groups depending on whether they showed rapid increase in blood glucose at the onset of exercise (increase rate in LOW group is <20% and HIGH group is ≥20%) to evaluate subject's insulin response to glucose feeding. No subjects developed rebound hypoglycemia (<70 mg/dL) in the G trial of both group. Significantly higher blood glucose during exercise was recognized only in the G trial of LOW group. Although no significant difference was observed between the two trials of both group, cycling time to exhaustion in the LOW group tended to increase because of glucose ingestion. These results suggest that pre-exercise ingestion of glucose in East Asian student athletes does not induce rebound hypoglycemia regardless of difference in individual insulin responses. Furthermore, individuals with low insulin responses seem to improve endurance performance with glucose ingestion before exercise.

Microscopic Ophthalmic Surgery Using a Freely Movable Arm Support Robot: Basic Experiment and Clinical Experience

INTRODUCTION

The disadvantage of conventional armrests is the difficulty to adjust their height and position during surgery.

OBJECTIVES

We investigated whether a freely movable armrest (FMA) that follows the surgeon's arm is useful for reducing surgeon fatigue and arm tremors and for improving surgical accuracy.

METHODS

In the basic study, a corneal suture was placed in porcine eyes with FMA (FMA group) or without FMA (non-FMA group). The suture was intended to pass through two points. Tremor was quantified using motion-tracking software when the needle was held. Subjective symptoms of arm-related fatigue were scored using a questionnaire. Suturing accuracy was compared between the groups. In the clinical study, the same surgeon performed corneal transplantation, cataract surgery, and glaucoma surgery with or without FMA. Fatigue scores from the questionnaire were then compared.

RESULTS

In the basic study, hand tremor at rest was significantly improved with FMA (p < 0.0001). The subjective arm fatigue score was significantly reduced (p = 0.0465), while the subjective tremor score was also significantly improved (p = 0.0453). There were no differences in the accuracy of corneal suturing with or without FMA. In the clinical study, the total and arm-related fatigue scores during corneal transplantation and glaucoma surgery tended to improve.

CONCLUSIONS

FMA is a useful tool for fixing the surgeon's arm in any position and may improve the quality of ophthalmic surgery by reducing hand tremor and fatigue.

Melatonin Is a Feasible, Safe, and Acceptable Intervention in Doctors and Nurses Working Nightshifts: The MIDNIGHT Trial

Nightshift working is associated with sleep deprivation, fatigue and attention/concentration deficits which, in healthcare workers, may impact on patient safety. Clinical staff in the UK routinely work several 12 h nightshifts in a row at about 1-3 month intervals. We investigated the feasibility and acceptability of a crossover trial of melatonin administration in clinical staff working nightshifts with an exploration of effects on sleep measures and attention/concentration tasks. This was a pilot, double-blinded, randomized, placebo-controlled crossover feasibility trial in doctors and nurses working 3 consecutive nightshifts at a tertiary referral hospital in the UK. Twenty five male and female subjects were randomized to receive either 6mg Circadin™ slow release melatonin or placebo before sleep after each consecutive nightshift, followed by a washout period, before crossing over to the other experimental arm. We used actigraphy for objective assessment of sleep parameters. The trial design was feasible and acceptable to participants with negligible side effects, but elevated melatonin levels were prolonged during the active arm (P=0.016). Double digit addition testing, a concentration/attention task, improved with melatonin treatment (P<0.0001). Lapses of vigilance or judgement while doctors or nurses are working nightshifts could impact on patient safety and melatonin may be a useful intervention. This study supports the conclusion that a larger definitive trial of this design is both feasible and safe. Clinical Trial Registration: identifier ISRCTN15529655. https://www.isrctn.com/.