RESUMEN
AIMS: This study aimed to evaluate the effects of an intervention involving earplug placement during nocturnal sleep in non-ventilated intensive care unit patients. METHODS: A randomized controlled trial was conducted in 107 adult patients between January 2017 and December 2018. Participants in the intervention group (n = 55) slept with earplugs between 10 pm and 7 am on the second night of their intensive care unit stay. In the control group, participants slept with no earplugs. Outcome parameters included sleep, urinary 6-sulfatoxymelatonin levels, relaxation responses measured using the Richards-Campbell Sleep Questionnaire, liquid chromatography-mass spectrometry results and vital signs. Urine was collected between 10 pm and 7 am. RESULTS: Overall, 28.03% of participants showed virtually no 6-sulfatoxymelatonin excretion in the collected urine. Outcome parameters were not significantly different between the groups, indicating that wearing earplugs alone did not affect sleep quality, urinary 6-sulfatoxymelatonin and vital signs. CONCLUSIONS: The effects of using earplugs alone on sleep quality, urinary 6-sulfatoxymelatonin and relaxation responses in patients admitted to the intensive care unit were inconclusive. Additional research is required before earplugs alone can be widely used to improve sleep quality.