Evaluation of the effect of use of breast milk odor and white noise on pain management during heel lance in premature newborns: A randomized controlled study

This single-centered, single-blind, randomized controlled experimental study was conducted to investigate the effect of breast milk odor and white noise during heel lance on pain management in premature newborns. The data of the study were collected between 16th of May and 1th of October, 2022 in Ankara University, Faculty of Medicine, Cebeci Application and Research Hospital neonatal intensive care unit mother-baby rooms and postpartum service. The research contains 66 newborns born between 34 – 37 gestational weeks which meet the inclusion criteria. As a result of the power analysis carried out to determine the adequacy of the sample number, it is determined that type 1 error=0.05, effect size=0.737 and power level=0.99 for the difference between the groups in terms of pain scores. Data were collected using Premature Infant Pain Profile-Revised Form, descriptive information form which is prepared by the researcher, and Physiological Findings Follow-up Chart. Pain evaluation was performed 5 minutes before the procedure, 2 minutes before the procedure, at the time of the procedure and 5 minutes after the procedure, via video recordings by 2 different researchers who were not in the application phase of the study. Consistency between observers was statistically significant (p<0.05). The data were analyzed using the IBM SPSS Statistics 23 software. While evaluating the study data, frequency distributions (number, percentage) for categorical variables and descriptive statistics (mean, standard deviation) for numerical variables were used. While the one-way ANOVA test was used to analyze the differences of the measurements between the groups, the variation of the measurements over time was examined with the repeated measurements analysis of variance. Chi-square test was used for the differences between the groups in categorical measurements. In the study, gender, type of birth, nutritional status, birth week, postnatal hour, weight, height, head circumference, 1st and 5th minute Apgar scores of babies in the experimental and control groups were found to be similar (p>0.05). When the heart rate was examined, the heart rate values observed 2 minutes before (F= 4,026) and 5 minutes after (F=8,162) the procedure were found to be significantly lower in the breast milk odor and white noise group compared to the control group (p<0.05). When the findings related to oxygen saturation were examined, although the difference was found to be significantly higher (p<0.05) in the breast milk odor group 5 minutes before (F=3,945) the procedure, the averages were observed above 95% in all groups. Oxygen saturation levels in the control group 2 minutes before (F=7,145), at the time of the procedure (F=4,657) and 5 minutes after the procedure (F=6,123) were found to be significantly lower than in the breast milk odor and white noise groups (p<0.05). When the findings regarding the pain scores were examined, the pain scores of the white noise and breast milk odor groups at the time of the procedure (F=11,263) and 5 minutes after the procedure (F= 8,082) were significantly lower than the control group (p<0.05). It was observed that there was no significant difference between the breast milk smell and white noise groups in terms of heart rate, oxygen saturation and pain score averages at the time of the procedure and 5 minutes after the procedure (p>0.05). It is thought that white noise and breast milk odor as non-pharmacological methods in newborns can be effective in pain management and that neither method is superior to the other. Keywords: Breast milk odor, Pain, Premature newborn, White noise