The effect of lavender oil and breastmilk smell on preterm infants'physiological parameters, stress and sleeping-waking state

This study was carried out as a clinical, randomized controlled experimental design to determine the effects of lavender oil and breast milk scent on physiological measurements, stress level and sleep-wake states of preterm newborns between 28-37 weeks of gestation. The research was carried out in Düzce University Health Application and Research Center Neonatal Intensive Care Unit between June 2022 and March 2023. The sample of the study consisted of 81 infants who met the criteria for participation in the study, according to the result of the determined power analysis. In the data collection process of the study, the Newborn and Mother Descriptive Characteristics Form, the Newborn Stress Evaluation Form and the Newborn Sleep-Awake Status Evaluation Form were used. The preterms in the control group were not treated other than their clinical care and treatment, and their physiological measurements, NSEF and NSWEF were applied. Breast milk scent was applied to preterms in the breast milk scent group for 3 hours, and physiology measurements, NSEF and NSWEF were recorded by the researcher before and during the application. Diluted lavender oil scent was applied to the lavender oil scent group for 3 hours, and physiology measurements were recorded by the NSEF and NSWEF researcher before and during the application. In the data obtained from the study, the normal distribution of the data belonging to the numerical variables was evaluated with the Shapiro Wilk normality test, skewness- kurtosis values, histogram and Normal Q-Q Plot graphics. Comparisons of groups over time for numerical variables were performed with Repeated Measures Two-way ANOVA. Bonferroni test was used as multiple comparison test. Pearson correlation analysis was used for the relationship between numerical variables. The relationship between categorical variables was examined with the Pearson Exact Chi-square test and the p<0.05 value was considered statistically significant. When the research data were examined, it was found that the heart rate and respiratory rate of the experimental groups were statistically significant compared to the control group (p<0.05), while a statistically significant increase was found only in the lavender scent group in the measurement of oxygen saturation (p<0.05). In the study, it was found that the scent of breast milk and lavender had a positive effect on stress scores, and the scent of lavender was more effective in reducing stress than the scent of breast milk. It has been determined that the scent of lavender has a positive effect on the sleep status of preterm newborns, and the behavior of maintaining sleep in the preterm newborn is prolonged. In the study, a high level of positive correlation was found between stress and sleep-wake states of preterms. Due to the positive effects of the aromatherapy method, it is recommended to be applied by neonatal nurses.