Objectives: The objective of this study was to determine if there was a significant difference between the sleep quality of patients who inhaled placebo and those who inhaled an aroma comprising a mixture of Lavandula x intermedia (Lavandin Super), Citrus bergamia (bergamot), and Cananga odorata (ylang ylang). Design: This was a randomized, double-blind crossover study, which compared a treatment with placebo. Settings/location: The study was conducted in an outpatient cardiac rehabilitation unit located in an urban, private nonprofit hospital in north Texas. Subjects: Participants included 42 adult patients referred to the rehabilitation service following hospitalizations by local cardiologists. Interventions: Cotton balls infused with a combination of lavender, bergamot, and ylang ylang or placebo were placed at subjects' bedsides for five nights. After a washout period, subjects crossed over to the other condition for five nights. Outcome measures: Participants completed the Pittsburgh Sleep Quality Index (PSQI) after treatment and placebo periods. Lower PSQI scores indicate better sleep quality. Results: The mean PSQI global score was statistically significantly lower when receiving the intervention oil (mean = 4.9) than the mean PSQI global score when receiving placebo (mean = 8). Duration of sleep and the time it took to fall asleep were no different between treatment groups, but patient-reported sleep quality was significantly better when participants were exposed to essential oils (χ2 = 4.5, p = 0.03) than when exposed to placebo. Although sleep efficiency (time asleep while lying in bed) was perceived as the same under both conditions, participants reported that they had to get up to use the bathroom significantly less often when exposed to the treatment than when exposed to placebo (t = -2.04, p = 0.05; Wilcoxon p = 0.05). Participants also reported that they had trouble sleeping because they felt too cold, which occurred significantly less often when exposed to the treatment than when exposed to placebo (t = -2.03, p = 0.05; Wilcoxon p = 0.05). Conclusions: Sleep quality of participants receiving intervention oils was significantly better than the sleep quality of participants receiving the placebo oil. Low-cost, nontraditional aromatherapy treatment is potentially effective for improving sleep quality among cardiac rehabilitation patients.
Keywords: bergamot; cardiac rehabilitation; essential oils; lavender; sleep; ylang ylang.