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Effects of two 15-min naps on the subjective sleepiness, fatigue and heart rate variability of night shift nurses.

Oriyama S, Miyakoshi Y, Kobayashi T - Ind Health (2013)

Bottom Line: The purpose of this study was to examine the effects of two 15-min naps on nurses who work at night in a three-shift system.However, the low- to high-frequency ratio (LF/HF) in the Nap condition group was found to be significantly lower than in the No-nap condition group.The results of this study suggest that taking two short naps may effectively reduce tension and prevent a brief increase in HF values by suppressing sympathetic nervous activity in the morning.

View Article: PubMed Central - PubMed

Affiliation: Department of Nursing, Prefectural University of Hiroshima, Japan.

ABSTRACT
The purpose of this study was to examine the effects of two 15-min naps on nurses who work at night in a three-shift system. Of the 15 nurses who were included as study subjects on a night shift, eight took two short naps (the Nap condition), and seven worked without taking a nap (the No-nap condition) during the night shift. We measured sublingual temperature and the bispectral index (BIS), obtained heart rate and heart rate variability measures from an electrocardiogram (ECG), and evaluated sleepiness and fatigue levels every hour using the Visual Analog Scale (VAS). Both subjective sleepiness and fatigue increased between 4:00 and 5:00, with no significant differences observed between the two groups. However, the low- to high-frequency ratio (LF/HF) in the Nap condition group was found to be significantly lower than in the No-nap condition group. Furthermore, a sudden, brief increase in HF values was observed in the No-nap condition group in the morning. The results of this study suggest that taking two short naps may effectively reduce tension and prevent a brief increase in HF values by suppressing sympathetic nervous activity in the morning.

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Related in: MedlinePlus

Mean hourly values for (a) body movements, (b) Changes in HF, (c) Changes in LF/HF,(−), Nap condition; (−), No-nap condition. The Nap condition was between 2:30 and 3:00(first nap), and between 4:30 and 5:45 (second nap).
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fig_002: Mean hourly values for (a) body movements, (b) Changes in HF, (c) Changes in LF/HF,(−), Nap condition; (−), No-nap condition. The Nap condition was between 2:30 and 3:00(first nap), and between 4:30 and 5:45 (second nap).

Mentions: Mean ± SE hourly values for (a) Changes in temperature, (b) Changes in heart rate, (c)Subjective sleepiness, and (d) Subjective fatigue. (·), Nap condition; (△), No-napcondition. Significance was plotted compared with baseline values for nap and no-nap inall 4 graphs. (**: p<0.01;*: p<0.05).Significance was plotted compared with the No-nap condition in all graphs. (#:p<0.05). The Nap condition was between 2:30 and 3:00 (first nap),and between 4:30 and 5:45 (second nap).


Effects of two 15-min naps on the subjective sleepiness, fatigue and heart rate variability of night shift nurses.

Oriyama S, Miyakoshi Y, Kobayashi T - Ind Health (2013)

Mean hourly values for (a) body movements, (b) Changes in HF, (c) Changes in LF/HF,(−), Nap condition; (−), No-nap condition. The Nap condition was between 2:30 and 3:00(first nap), and between 4:30 and 5:45 (second nap).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4202767&req=5

fig_002: Mean hourly values for (a) body movements, (b) Changes in HF, (c) Changes in LF/HF,(−), Nap condition; (−), No-nap condition. The Nap condition was between 2:30 and 3:00(first nap), and between 4:30 and 5:45 (second nap).
Mentions: Mean ± SE hourly values for (a) Changes in temperature, (b) Changes in heart rate, (c)Subjective sleepiness, and (d) Subjective fatigue. (·), Nap condition; (△), No-napcondition. Significance was plotted compared with baseline values for nap and no-nap inall 4 graphs. (**: p<0.01;*: p<0.05).Significance was plotted compared with the No-nap condition in all graphs. (#:p<0.05). The Nap condition was between 2:30 and 3:00 (first nap),and between 4:30 and 5:45 (second nap).

Bottom Line: The purpose of this study was to examine the effects of two 15-min naps on nurses who work at night in a three-shift system.However, the low- to high-frequency ratio (LF/HF) in the Nap condition group was found to be significantly lower than in the No-nap condition group.The results of this study suggest that taking two short naps may effectively reduce tension and prevent a brief increase in HF values by suppressing sympathetic nervous activity in the morning.

View Article: PubMed Central - PubMed

Affiliation: Department of Nursing, Prefectural University of Hiroshima, Japan.

ABSTRACT
The purpose of this study was to examine the effects of two 15-min naps on nurses who work at night in a three-shift system. Of the 15 nurses who were included as study subjects on a night shift, eight took two short naps (the Nap condition), and seven worked without taking a nap (the No-nap condition) during the night shift. We measured sublingual temperature and the bispectral index (BIS), obtained heart rate and heart rate variability measures from an electrocardiogram (ECG), and evaluated sleepiness and fatigue levels every hour using the Visual Analog Scale (VAS). Both subjective sleepiness and fatigue increased between 4:00 and 5:00, with no significant differences observed between the two groups. However, the low- to high-frequency ratio (LF/HF) in the Nap condition group was found to be significantly lower than in the No-nap condition group. Furthermore, a sudden, brief increase in HF values was observed in the No-nap condition group in the morning. The results of this study suggest that taking two short naps may effectively reduce tension and prevent a brief increase in HF values by suppressing sympathetic nervous activity in the morning.

Show MeSH
Related in: MedlinePlus