Recovery after Three-shift Work: Relation to Sleep-related Cardiac Neuronal Regulation in Nurses

Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Tapei, Taiwan.
Industrial Health (Impact Factor: 1.12). 12/2011; 50(1):24-30. DOI: 10.2486/indhealth.MS1305
Source: PubMed


This study was to evaluate whether sleep-related autonomic function in nurses recovers during their days off following a rapidly rotating, clockwise shift schedule. Ten rotating-shift nurses and ten regular morning-shift nurses were included. Nurses slept at home and were allowed to sleep and wake spontaneously. For the rotating-shift workers, ambulatory polysomnographic recordings were taken during nighttime sleep (after the second morning shift, afternoon shift, and on days off) and during daytime sleep (after the second night shift). No significant differences were found between regular-shift nurses and rotating-shift nurses in terms of sleep patterns and cardiac autonomic functions during day shift. When comparing sleep patterns within shift groups, the total sleep time of night shift was lower than their other shifts. Controlling for the variable of total sleep time allowed us to compare cardiac autonomic functions following different shifts (for the rotating shift nurses). During the non-rapid eye movement and rapid eye movement periods, the high frequency (HF) value on rotating shift nurses' days off was found to be significantly higher than their other shifts. However, the low to high frequency ratio (LF/HF) on days off was found to be obviously lower than that during shift work. Two consecutive days off may be sufficient for nurses to recover sleep-related autonomic functions after a rapidly rotating, clockwise three-shift schedule. Sleep-related autonomic functions may be improved during days off to minimize health risks.

Full-text preview

Available from:
  • Source
    • "Whether nighttime sleep is also adversely affected beyond the first non-workday was not assessed in the present study, although some reports suggest that it may take two or three non-workdays to recover from consecutive night shifts (Chung et al., 2012). Moreover, in the present study, individual habitual sleep-wake characteristics including sleep duration, sleep onset latency, and sleep efficiency assessed from self-report sleep diaries did not correlate with the magnitude of change observed in sleep structure parameters under laboratory conditions at an individual level. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Circadian phase resetting is sensitive to visual short wavelengths (450-480 nm). Selectively filtering this range of wavelengths may reduce circadian misalignment and sleep impairment during irregular light-dark schedules associated with shiftwork. We examined the effects of filtering short wavelengths (<480 nm) during night shifts on sleep and performance in nine nurses (five females and four males; mean age ± SD: 31.3 ± 4.6 yrs). Participants were randomized to receive filtered light (intervention) or standard indoor light (baseline) on night shifts. Nighttime sleep after two night shifts and daytime sleep in between two night shifts was assessed by polysomnography (PSG). In addition, salivary melatonin levels and alertness were assessed every 2 h on the first night shift of each study period and on the middle night of a run of three night shifts in each study period. Sleep and performance under baseline and intervention conditions were compared with daytime performance on the seventh day shift, and nighttime sleep following the seventh daytime shift (comparator). On the baseline night PSG, total sleep time (TST) (p < 0.01) and sleep efficiency (p = 0.01) were significantly decreased and intervening wake times (wake after sleep onset [WASO]) (p = 0.04) were significantly increased in relation to the comparator night sleep. In contrast, under intervention, TST was increased by a mean of 40 min compared with baseline, WASO was reduced and sleep efficiency was increased to levels similar to the comparator night. Daytime sleep was significantly impaired under both baseline and intervention conditions. Salivary melatonin levels were significantly higher on the first (p < 0.05) and middle (p < 0.01) night shifts under intervention compared with baseline. Subjective sleepiness increased throughout the night under both conditions (p < 0.01). However, reaction time and throughput on vigilance tests were similar to daytime performance under intervention but impaired under baseline on the first night shift. By the middle night shift, the difference in performance was no longer significant between day shift and either of the two night shift conditions, suggesting some adaptation to the night shift had occurred under baseline conditions. These results suggest that both daytime and nighttime sleep are adversely affected in rotating-shift workers and that filtering short wavelengths may be an approach to reduce sleep disruption and improve performance in rotating-shift workers. (Author correspondence:
    Full-text · Article · Jul 2013 · Chronobiology International
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: HRV is an effective non-invasive method providing quantitative evaluation of the autonomic neural activity modulating the cardiac function. It has been widely used to study the sleep associated changes in sympathovagal balance.1 We present findings of HRV and ECG manual inspection from sleep time after TSD in chronic mild male patient of DSPS. His primary complaint was of frequent sleep onset insomnia episodes (last 2 years) and some issues with sleep maintenance. He is non-alcoholic, smoker (10 years) without suggestive symptoms of anxiety, depression and psychosis. The findings of mean Heart Rate (HR), mean RR (RRI time series), time domain measures of the standard deviation of NN intervals (SDNN) and the square root of the mean squared difference of successive NNs (RMSSD), and frequency domain measures of LF%, HF%, LF nu, HF nu, LF/HF nu are presented.
    Full-text · Article · Jan 2013

  • No preview · Article · Apr 2013 · Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine
Show more