Effect of oral melatonin and wearing earplugs and eye masks on nocturnal sleep in healthy subjects in a simulated intensive care unit environment: which might be a more promising strategy for ICU sleep deprivation?
Study Goal
The researchers aimed to determine the effect of simulated ICU noise and light on nocturnal sleep quality and compare the effectiveness of melatonin versus earplugs and eye masks in improving sleep quality under these conditions.
Results Summary
Melatonin (1 mg) significantly improved total sleep time, REM sleep, sleep onset latency, and perceived sleep quality compared to earplugs and eye masks, while also increasing serum melatonin levels. Both interventions reduced awakenings and anxiety, but melatonin showed superior results in subjective sleep quality.
Population
Healthy subjects exposed to simulated ICU noise and light conditions.
Effective Dosage
1 mg oral melatonin administered at 21:00.
Duration
Four consecutive days.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
simulated ICU noise and light (NL) | decrease | total sleep time (TST) | healthy subjects | - | shorter | #1 |
simulated ICU noise and light (NL) | decrease | rapid eye movement (REM) sleep | healthy subjects | - | shorter | #2 |
simulated ICU noise and light (NL) | increase | sleep onset latency | healthy subjects | - | longer | #3 |
simulated ICU noise and light (NL) | increase | light sleep | healthy subjects | - | more | #4 |
simulated ICU noise and light (NL) | increase | awakening | healthy subjects | - | more | #5 |
simulated ICU noise and light (NL) | decrease | subjective sleep quality | healthy subjects | - | poorer | #6 |
simulated ICU noise and light (NL) | increase | anxiety level | healthy subjects | - | higher | #7 |
simulated ICU noise and light (NL) | decrease | serum melatonin level | healthy subjects | - | lower | #8 |
NL plus use of earplugs and eye masks (NLEE) | decrease | awakenings | healthy subjects | - | less | #9 |
NL plus use of earplugs and eye masks (NLEE) | decrease | sleep onset latency | healthy subjects | - | shorter | #10 |
NL plus melatonin (NLM) | increase | total sleep time (TST) | healthy subjects | - | longer | #11 |
NL plus melatonin (NLM) | increase | rapid eye movement (REM) | healthy subjects | - | longer | #12 |
NL plus melatonin (NLM) | decrease | sleep onset latency | healthy subjects | - | shorter | #13 |
NL plus melatonin (NLM) | decrease | awakenings | healthy subjects | - | fewer | #14 |
NL plus melatonin (NLM) | increase | perceived sleep quality | healthy subjects | - | improved | #15 |
NL plus melatonin (NLM) | decrease | anxiety level | healthy subjects | - | improved | #16 |
NL plus use of earplugs and eye masks (NLEE) | increase | perceived sleep quality | healthy subjects | - | improved | #17 |
NL plus use of earplugs and eye masks (NLEE) | decrease | anxiety level | healthy subjects | - | improved | #18 |
NL plus melatonin (NLM) | increase | average maximal serum melatonin concentration | healthy subjects | - | greater | #19 |
simulated ICU noise and light (NL) | decrease | serum melatonin levels | healthy subjects | - | lower | #20 |
INTRODUCTION: Sleep deprivation is common in critically ill patients in the intensive care unit (ICU). Noise and light in the ICU and the reduction in plasma melatonin play the essential roles. The aim of this study was to determine the effect of simulated ICU noise and light on nocturnal sleep quality, and compare the effectiveness of melatonin and earplugs and eye masks on sleep quality in these conditions in healthy subjects. METHODS: This study was conducted in two parts. In part one, 40 healthy subjects slept under baseline night and simulated ICU noise and light (NL) by a cross-over design. In part two, 40 subjects were randomly assigned to four groups: NL, NL plus placebo (NLP), NL plus use of earplugs and eye masks (NLEE) and NL plus melatonin (NLM). 1 mg of oral melatonin or placebo was administered at 21:00 on four consecutive days in NLM and NLP. Earplugs and eye masks were made available in NLEE. The objective sleep quality was measured by polysomnography. Serum was analyzed for melatonin levels. Subjects rated their perceived sleep quality and anxiety levels. RESULTS: Subjects had shorter total sleep time (TST) and rapid eye movement (REM) sleep, longer sleep onset latency, more light sleep and awakening, poorer subjective sleep quality, higher anxiety level and lower serum melatonin level in NL night (P <0.05). NLEE had less awakenings and shorter sleep onset latency (P <0.05). NLM had longer TST and REM and shorter sleep onset latency (P <0.05). Compared with NLEE, NLM had fewer awakenings (P = 0.004). Both NLM and NLEE improved perceived sleep quality and anxiety level (P = 0.000), and NLM showed better than NLEE in perceived sleep quality (P = 0.01). Compared to baseline night, the serum melatonin levels were lower in NL night at every time point, and the average maximal serum melatonin concentration in NLM group was significantly greater than other groups (P <0.001). CONCLUSIONS: Compared with earplugs and eye masks, melatonin improves sleep quality and serum melatonin levels better in healthy subjects exposed to simulated ICU noise and light. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-IPR-14005458 . Registered 10 November 2014.