Wallace C., Robins J., Alvord L, Walker

¶ … Wallace C., Robins J., Alvord L, Walker J. The effects of earplugs on sleep measures during exposure to simulated intensive care unit noise. American Journal of Critical Care 8, 4:210-219. Six paid volunteers (self-selected) were tested on five 8-hour periods, at 7-day intervals. The first three nights were quiet. The subsequent nights the subjects were given earplugs, and they were subject to simulated ICU noise.

The study found that where elevated noise levels produced more awakenings, and rapid eye movement latency, the earplugs were effective in allowing the patients to reduce REM latency and increase the % of REM sleep. The authors note that the sample size was small, a key limitation. Scotto C., McClusky C., Spillan S., Kimmel J. Earplugs improve patients' subjective experience of sleep in critical care. Nursing in Critical Care 14, 4: 180-184. The study had 88 participants (49 intervention, 39 control). The subjects were admitted to critical care. The intervention group were given earplugs.

Their sleep was measured with self-reported subjective scale, 8-question visual analogue scale and the Verran-Snyder-Halpern scale. The earplugs were found to improve the subjective experience of sleep in the ICU. Seven patients were unable to complete the study because the earplugs fell out -- the authors should have counted them in the statistics of unsuccessful intervention, because not being able to sleep with earplugs in matters, too. The authors noted that there was low diversity among patients, and that the study size was relatively small.

Neyse F., Daneshmandi M., Sharme M., Ebadi A. The effects of earplugs on sleep quality in patients with acute coronary syndrome. Iranian Journal of Critical Care Nursing 4, 3:127-134 60 patients with acute coronary syndrome were selected via a purposeful sampling method, and randomly allocated into two groups. The intervention group was given earplugs on their second night in hospital. Measured using Petersburg's sleep quality questionnaire, the intervention group reported higher sleep quality. Using earplugs improves sleep quality in acute coronary patients spending overnight in hospital.

The authors did not note limitations, but they did compare their study with other similar studies, noting where the findings were compatible and incompatible. Van Rompaey B., Elseviers M., Van Drom W., Fromont V., Jorens, P. The effect of earplugs during the night on the onset of delirium and sleep perception: a randomized controlled trial in intensive care patients. Critical Care 2012, 16:R73-R82 A total of 69 patients received the intervention of earplugs, and there was a control group of 67 patients.

The patients were selected at random and assignment at random by a third party. The patients all spent overnight in the ICU. They were evaluated for delirium, and it was found that earplugs lowered the incidence of delirium, and the patients with earplugs also reported subjectively better sleep. The authors recommend further research to explore this topic in more depth. The note that the study was limited to ICU patients at their hospital and thus may be apply to all patients.

Mashayekhi F, Arab M., Abazari F., Rafati F., Rafiei H. The effects of earplug on perception of sleep in patients of coronary care unit (CCU) educators. Middle East Journal of Nursing 7,5:3-7 There were 30 patients in this study, and they were recruited. They were admitted to the CCU, and were divided into a control group and an intervention group. The VSH sleep scale and self-reporting were used. It was found that the earplugs delivered better perception of sleep. The authors did not discuss limitations, but the study was.