title: Effects of earplugs and eye masks on nocturnal sleep, melatonin and cortisol in a simulated intensive care unit environment.
abstract: BACKGROUND
  Environmental stimulus, especially noise and light, is thought to disrupt sleep in patients in the intensive care unit (ICU). This study aimed to determine the physiological and psychological effects of ICU noise and light, and of earplugs and eye masks, used in these conditions in healthy subjects.
  
  
  METHODS
  Fourteen subjects underwent polysomnography under four conditions: adaptation, baseline, exposure to recorded ICU noise and light (NL), and NL plus use of earplugs and eye masks (NLEE). Urine was analyzed for melatonin and cortisol levels. Subjects rated their perceived sleep quality, anxiety levels and perception of environmental stimuli.
  
  
  RESULTS
  Subjects had poorer perceived sleep quality, more light sleep, longer rapid eye movement (REM) latency, less REM sleep when exposed to simulated ICU noise and light (P < 0.05). Nocturnal melatonin (P = 0.007) and cortisol secretion levels (P = 0.004) differed significantly by condition but anxiety levels did not (P = 0.06). Use of earplugs and eye masks resulted in more REM time, shorter REM latency, less arousal (P < 0.05) and elevated melatonin levels (P = 0.002).
  
  
  CONCLUSIONS
  Earplugs and eye masks promote sleep and hormone balance in healthy subjects exposed to simulated ICU noise and light, making their promotion in ICU patients reasonable.
authors.affiliation: School of Nursing, Fujian Medical University, Fuzhou, PR China. hulu2886@sina.com
authors.forename: Rong-fang
authors.initials: RF
authors.lastname: Hu
authors.forename: Xiao-ying
authors.initials: XY
authors.lastname: Jiang
authors.forename: Yi-ming
authors.initials: YM
authors.lastname: Zeng
authors.forename: Xiao-yang
authors.initials: XY
authors.lastname: Chen
authors.forename: You-hua
authors.initials: YH
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D004430:Ear Protective Devices; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000652:urine*; D007362:Intensive Care Units; D008027:Light / Q000009:adverse effects*; D008297:Male; D008397:Masks; D008550:Melatonin / Q000652:urine*; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D017286:Polysomnography; D012890:Sleep / Q000502:physiology*; D055815:Young Adult
chemical_list: D008550:Melatonin; D006854:Hydrocortisone
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