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?
What this study found
Melatonin improved nocturnal sleep in the simulated ICU environment, and it appeared more effective than earplugs plus eye masks. In the melatonin arm, total sleep time and REM sleep increased, sleep onset latency shortened, and awakenings were fewer than with earplugs and eye masks (P = 0.004); perceived sleep quality also improved more with melatonin (P = 0.000, and vs earplugs plus eye masks P = 0.01). Serum melatonin peaked at 1021.04 ± 50.58 pg/mL about 1 hour after dosing and was significantly higher than in the other groups (P < 0.001). No adverse events were observed.
- Study & population
- In this randomized simulated ICU sleep study, 40 healthy adults in Fuzhou, China were assigned in a 1:1:1:1 ratio to melatonin, placebo, earplugs plus eye masks, or no intervention.
- Intervention
- Oral fast-release melatonin, 1 mg, was administered at about 21:00 for 4 consecutive days in the melatonin arm.
- Key limitation
- This was a small study with only 10 participants in the melatonin arm and a short 4-day exposure.
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Open PDFOriginal abstract
IntroductionSleep 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.MethodsThis 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.ResultsSubjects 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).ConclusionsCompared 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 registrationChinese Clinical Trial Registry ChiCTR-IPR-14005458. Registered 10 November 2014.