Comparison of Breastmilk Odor and Vanilla Odor on Mitigating Premature Infants' Response to Pain During and After Venipuncture

Effect of non-pharmacological interventions on pain in preterm infants in the neonatal intensive care unit: a network meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the effectiveness of different non-pharmacological interventions for pain management in preterm infants and provide high-quality clinical evidence.

METHODS

Randomized controlled trials (RCTs) of various non-pharmacological interventions for pain management in preterm infants were searched from PubMed, Web of Science, Embase, and the Cochrane Library from 2000 to the present (updated March 2023). The primary outcome was pain score reported as standardized mean difference (SMD). The secondary outcomes were oxygen saturation and heart rate reported as the same form.

RESULTS

Thirty five RCTs of 2134 preterm infants were included in the meta-analysis, involving 6 interventions: olfactory stimulation, combined oral sucrose and non-nutritive sucking (OS + NNS), facilitated tucking, auditory intervention, tactile relief, and mixed intervention. Based on moderate-quality evidence, OS + NNS (OR: 3.92, 95% CI: 1.72, 6.15, SUCRA score: 0.73), facilitated tucking (OR: 2.51, 95% CI: 1.15, 3.90, SUCRA score: 0.29), auditory intervention (OR: 2.48, 95% CI: 0.91, 4.10, SUCRA score: 0.27), olfactory stimulation (OR: 1.80, 95% CI: 0.51, 3.14, SUCRA score: 0.25), and mixed intervention (OR: 2.26, 95% CI: 0.10, 4.38, SUCRA score: 0.14) were all superior to the control group for pain relief. For oxygen saturation, facilitated tucking (OR: 1.94, 95% CI: 0.66, 3.35, SUCRA score: 0.64) and auditory intervention (OR: 1.04, 95% CI: 0.22, 2.04, SUCRA score: 0.36) were superior to the control. For heart rate, none of the comparisons between the various interventions were statistically significant.

CONCLUSION

This study showed that there are notable variations in the effectiveness of different non-pharmacological interventions in terms of pain scores and oxygen saturation. However, there was no evidence of any improvement in heart rate.

The effects of breast milk odor on the physiological and behavioral responses caused by venipuncture pain in term infants: A clinical trial study

BACKGROUND

Pain management is very important for infants who are unable to express it verbally. Pain control is one of the nursing actions and part of their duties. This study attempted to determine the effects of breast milk odor on the physiological and behavioral responses caused by venipuncture pain in full-term infants at an educational hospital.

MATERIALS AND METHODS

This randomized clinical trial study was carried out on 3-5 days' term and healthy babies with a gestational age of 34 weeks and later in the 9-Day Hospital of Torbet Heydariyeh, Iran, 2021. The sample size, taking into account the possibility of a 10% dropout of samples included 20 babies for each group and a total of 40 babies were selected by convenience sampling. To collect data, a checklist of demographic characteristics, a registration form for physiological responses, and the modified behavioral pain scale were used.

RESULTS

The results of this study showed that breast milk odor has a positive effect on behavioral responses (P < 0.001) and also a significant relationship was observed between the effects of breast milk odor and physiological responses percentage of oxygen uptake and pulse (P < 0.001). However, no significant relationship was observed between breast milk odor and breathing variables (P > 0.05).

CONCLUSIONS

According to the results, olfactory stimulation with breast milk during venous blood sampling showed positive effects on physiological responses and pain reduction in infants. Therefore, it is recommended to use soothing stimuli such as the smell of breast milk during painful procedures in babies.

Non-pharmacological management of infant and young child procedural pain

BACKGROUND

Despite evidence of the long-term implications of unrelieved pain during infancy, it is evident that infant pain is still under-managed and unmanaged. Inadequately managed pain in infancy, a period of exponential development, can have implications across the lifespan. Therefore, a comprehensive and systematic review of pain management strategies is integral to appropriate infant pain management. This is an update of a previously published review update in the Cochrane Database of Systematic Reviews (2015, Issue 12) of the same title.

OBJECTIVES

To assess the efficacy and adverse events of non-pharmacological interventions for infant and child (aged up to three years) acute pain, excluding kangaroo care, sucrose, breastfeeding/breast milk, and music.

SEARCH METHODS

For this update, we searched CENTRAL, MEDLINE-Ovid platform, EMBASE-OVID platform, PsycINFO-OVID platform, CINAHL-EBSCO platform and trial registration websites (ClinicalTrials.gov; International Clinical Trials Registry Platform) (March 2015 to October 2020). An update search was completed in July 2022, but studies identified at this point were added to 'Awaiting classification' for a future update.  We also searched reference lists and contacted researchers via electronic list-serves.  We incorporated 76 new studies into the review.  SELECTION CRITERIA: Participants included infants from birth to three years in randomised controlled trials (RCTs) or cross-over RCTs that had a no-treatment control comparison. Studies were eligible for inclusion in the analysis if they compared a non-pharmacological pain management strategy to a no-treatment control group (15 different strategies). In addition, we also analysed studies when the unique effect of adding a non-pharmacological pain management strategy onto another pain management strategy could be assessed (i.e. additive effects on a sweet solution, non-nutritive sucking, or swaddling) (three strategies). The eligible control groups for these additive studies were sweet solution only, non-nutritive sucking only, or swaddling only, respectively. Finally, we qualitatively described six interventions that met the eligibility criteria for inclusion in the review, but not in the analysis.  DATA COLLECTION AND ANALYSIS: The outcomes assessed in the review were pain response (reactivity and regulation) and adverse events. The level of certainty in the evidence and risk of bias were based on the Cochrane risk of bias tool and the GRADE approach. We analysed the standardised mean difference (SMD) using the generic inverse variance method to determine effect sizes.  MAIN RESULTS: We included total of 138 studies (11,058 participants), which includes an additional 76 new studies for this update. Of these 138 studies, we analysed 115 (9048 participants) and described 23 (2010 participants) qualitatively. We described qualitatively studies that could not be meta-analysed due to being the only studies in their category or statistical reporting issues. We report the results of the 138 included studies here. An SMD effect size of 0.2 represents a small effect, 0.5 a moderate effect, and 0.8 a large effect. The thresholds for the I2 interpretation were established as follows: not important (0% to 40%); moderate heterogeneity (30% to 60%); substantial heterogeneity (50% to 90%); considerable heterogeneity (75% to 100%). The most commonly studied acute procedures were heel sticks (63 studies) and needlestick procedures for the purposes of vaccines/vitamins (35 studies). We judged most studies to have high risk of bias (103 out of 138), with the most common methodological concerns relating to blinding of personnel and outcome assessors. Pain responses were examined during two separate pain phases: pain reactivity (within the first 30 seconds after the acutely painful stimulus) and immediate pain regulation (after the first 30 seconds following the acutely painful stimulus). We report below the strategies with the strongest evidence base for each age group. In preterm born neonates, non-nutritive sucking may reduce pain reactivity (SMD -0.57, 95% confidence interval (CI) -1.03 to -0.11, moderate effect; I2 = 93%, considerable heterogeneity) and improve immediate pain regulation (SMD -0.61, 95% CI -0.95 to -0.27, moderate effect; I2 = 81%, considerable heterogeneity), based on very low-certainty evidence. Facilitated tucking may also reduce pain reactivity (SMD -1.01, 95% CI -1.44 to -0.58, large effect; I2 = 93%, considerable heterogeneity) and improve immediate pain regulation (SMD -0.59, 95% CI -0.92 to -0.26, moderate effect; I2 = 87%, considerable heterogeneity); however, this is also based on very low-certainty evidence. While swaddling likely does not reduce pain reactivity in preterm neonates (SMD -0.60, 95% CI -1.23 to 0.04, no effect; I2 = 91%, considerable heterogeneity), it has been shown to possibly improve immediate pain regulation (SMD -1.21, 95% CI -2.05 to -0.38, large effect; I2 = 89%, considerable heterogeneity), based on very low-certainty evidence. In full-term born neonates, non-nutritive sucking may reduce pain reactivity (SMD -1.13, 95% CI -1.57 to -0.68, large effect; I2 = 82%, considerable heterogeneity) and improve immediate pain regulation (SMD -1.49, 95% CI -2.20 to -0.78, large effect; I2 = 92%, considerable heterogeneity), based on very low-certainty evidence.  In full-term born older infants, structured parent involvement was the intervention most studied. Results showed that this intervention has little to no effect in reducing pain reactivity (SMD -0.18, 95% CI -0.40 to 0.03, no effect; I2 = 46%, moderate heterogeneity) or improving immediate pain regulation (SMD -0.09, 95% CI -0.40 to 0.21, no effect; I2 = 74%, substantial heterogeneity), based on low- to moderate-certainty evidence. Of these five interventions most studied, only two studies observed adverse events, specifically vomiting (one preterm neonate) and desaturation (one full-term neonate hospitalised in the NICU) following the non-nutritive sucking intervention. The presence of considerable heterogeneity limited our confidence in the findings for certain analyses, as did the preponderance of evidence of very low to low certainty based on GRADE judgements.

AUTHORS' CONCLUSIONS

Overall, non-nutritive sucking, facilitated tucking, and swaddling may reduce pain behaviours in preterm born neonates. Non-nutritive sucking may also reduce pain behaviours in full-term neonates. No interventions based on a substantial body of evidence showed promise in reducing pain behaviours in older infants. Most analyses were based on very low- or low-certainty grades of evidence and none were based on high-certainty evidence. Therefore, the lack of confidence in the evidence would require further research before we could draw a definitive conclusion.

State of the Science on the Benefits of Human Milk for Hospitalized, Vulnerable Neonates

Research on human milk has increased dramatically in recent years. The purpose of this review is to describe the literature on the health benefits of human milk for hospitalized, vulnerable neonates. PubMed, CINAHL, and Embase were searched for research articles reporting the health outcomes of hospitalized neonates who were exposed to human milk. Human milk, particularly a mother's own milk, has the potential to reduce the risk of death and the risk and severity of necrotizing enterocolitis, infection, retinopathy of prematurity, bronchopulmonary dysplasia, intraventricular hemorrhage, kidney disease, and liver disease. Dose and timing of human milk is important, with more human milk and earlier introduction having a greater impact on health. When a mother's own milk is not available, donor human milk provides benefits over infant formula.

Effect of Olfactory Stimulation with Breast Milk on Pain Responses to Heel Stick in Premature Infants: A Randomized Controlled Trial

Purpose: This study aimed to evaluate the effect of breast milk olfactory stimulation on pain response in premature infants during heel stick tests. Methods: A quasi-experimental randomized controlled trial was conducted in the neonatal intensive care unit of a tertiary-level hospital in Seoul, Korea. A breast milk group was provided olfactory stimulation with breast milk 30 seconds before the start of heel stick sampling, and a control group underwent heel stick sampling without olfactory stimulation. To evaluate infants' pain response, the heel stick procedure was video recorded, and pain response was assessed separately by two blinded research assistants using the Premature Infant Pain Scale (PIPS) through behavioral response, heart rate on physiological monitoring, and blood oxygen saturation on pulse oximetry through the video recording. Results: Forty-eight premature infants (gestational age, within 28-37 weeks, n = 24; control) were included in this study. The pain scores of the breast milk group were significantly lower than those of the control group (z = -2.04, p = 0.021). Conclusion: Breast milk odor may reduce pain in premature infants during heel stick tests.

Comprehensive mapping of NICU developmental care nursing interventions and related sensitive outcome indicators: a scoping review protocol

INTRODUCTION

Neurodevelopmental outcomes of preterm infant are still a contemporary concern. To counter the detrimental effects resulting from the hospitalisation in the neonatal intensive care unit (NICU), developmental care (DC) interventions have emerged as a philosophy of care aimed at protecting and enhancing preterm infant's development and promoting parental outcomes. In the past two decades, many authors have suggested DC models, core measures, practice guidelines and standards of care but outlined different groupings of interventions rather than specific interventions that can be used in NICU clinical practice. Moreover, as these DC interventions are mostly implemented by neonatal nurses, it would be strategic and valuable to identify specific outcome indicators to make visible the contribution of NICU nurses to DC.

OBJECTIVES

The overarching objective of this review is to identify the nature, range, and extent of the literature regarding DC nursing interventions for preterm infants in the NICU. The secondary twofold objectives are to highlight interventions that fall into identified categories of DC interventions and suggest nursing-sensitive outcome indicators related to DC interventions in the NICU.

INCLUSION CRITERIA

Papers reporting on or discussing a DC nursing intervention during NICU hospitalisation will be included.

METHODS AND ANALYSIS

The Joanna Briggs Institute's methodology for scoping reviews will be followed. CINAHL, MEDLINE, Embase, PubMed, Web of Science, Scopus, ProQuest and PsycInfo databases from 2009 to the present will be searched. Any type of paper, published in English or French, will be considered. Study selection and data extraction will be conducted by pairs of two review authors independently. A qualitative content analysis will be conducted.

ETHICS AND DISSEMINATION

No Institutional Review Board ethical approbation is needed. Results of this review will be presented in scientific meetings and published in refereed papers.

Comparison of the analgesic effect of inhaled lavender vs vanilla essential oil for neonatal frenotomy: a randomized clinical trial (NCT04867824)

It is necessary to treat neonatal pain because it may have short- and long-term adverse effects. Frenotomy is a painful procedure where sucking, a common strategy to relieve pain, cannot be used because the technique is performed on the tongue. In a previous randomized clinical trial, we demonstrated that inhaled lavender essential oil (LEO) reduced the signs of pain during neonatal frenotomy. We aimed to find out whether inhaled vanilla essential oil (VEO) is more effective in reducing pain during frenotomy than LEO. Randomized clinical trial with neonates who underwent a frenotomy for type 3 tongue-ties between May and October 2021. Pain was assessed using pre and post-procedure heart rate (HR) and oxygen saturation (SatO2), crying time, and NIPS score. Neonates were randomized into "experimental" and "control" group. In both groups, we performed swaddling, administered oral sucrose, and let the newborn suck for 2 min. We placed a gauze pad with one drop of LEO (control group) or of VEO (experimental group) under the neonate's nose for 2 min prior to and during the frenotomy. We enrolled 142 neonates (71 per group). Both groups showed similar NIPS scores (2.02 vs 2.38) and crying times (15.3 vs 18.7 s). We observed no differences in HR increase or in SatO2 decrease between both groups. We observed no side effects in either of the groups.

CONCLUSIONS

We observed no appreciable difference between LEO and VEO; therefore, we cannot conclude which of them was more effective in treating pain in neonates who underwent a frenotomy.

TRIAL REGISTRATION

 This clinical trial is registered with www.

CLINICALTRIALS

gov with NCT04867824.

WHAT IS KNOWN

• Pain management is one of the most important goals of neonatal care as it can have long-term neurodevelopmental effects. • Lavender essential oil can help relieve pain due to its sedative, antispasmodic, and anticolic properties.

WHAT IS NEW

• Lavender and vanilla essential oils are safe, beneficial, easy to use, and cheap in relieving pain in neonates who undergo a frenotomy for type 3 tongue-ties.

The Effect of Neonates' Exposure to Their Mother's Scent on Weight Gain: A Randomized Controlled Study

Objective: The aim of this study was to determine the effect of newborns' exposure to their mother's scent in the intensive care unit on their weight gain. Materials and Methods: This is an experimental randomized controlled study. One hundred and four neonates were included in the study. Two groups were observed in the research: the first group consisting of those exposed to their mother's scent (n = 52) and a second control group (n = 52). Data were collected with a data collection form and an infant body weight monitoring form. Significance for the study was accepted as p < 0.05. Results: Among the neonates, 61.5% were males, the gestational week of the infants was 38.49 ± 1.24, their mean weight was 3,213.32 ± 468.67 grams (g); the two groups were similar in terms of these characteristics (p > 0.05). The neonates exposed to their mother's scent at the beginning of the study were weighed, averaging 3,105.38 ± 487.69 g; at the end of Day 1 and Day 2, their mean weight was 3,150.77 ± 493.07 and 3,197.50 ± 489.06 g, respectively. It was seen that there were significant differences in the weight of the group of neonates exposed to their mother's scent before the experiment, on Day 1 and on Day 2 (p < 0.05). The neonates in the control group were weighed at the beginning of the experiment, exhibiting a mean of 3,119.42 ± 452.85 g. Their mean weight was 3,107.12 ± 463.30 g at the end of Day 1 and 3,116.63 ± 471.09 g at the end of Day 2. These differences, however, were not statistically significant (p > 0.05). Conclusion: We found that the newborns exposed to their mother's scent in the intensive care unit registered a higher increase in weight. Our recommendation is that a mother's scent be routinely factored into neonatal care in intensive care units.

Psychosocial and Neurobiological Vulnerabilities of the Hospitalized Preterm Infant and Relevant Non-pharmacological Pain Mitigation Strategies

Background: Preterm pain is common in the Neonatal Intensive Care Unit (NICU), with multiple invasive procedures occurring daily. Objective: To review the psychosocial and neurobiological vulnerabilities of preterm infants and to provide an updated overview of non-pharmacological strategies for acute procedural pain in hospitalized preterm infants. Methods: We utilized a narrative review methodology, which also included a synthesis of key pieces of published systematic reviews that are relevant to the current work. Results and Conclusions: Preterm infants are uniquely susceptible to the impact of painful procedures and prolonged separation from caregivers that are often inherent in a NICU stay. Non-pharmacological interventions can be efficacious for mitigating procedural pain for preterm infants. Interventions should continue to be evaluated with high quality randomized controlled trials, and should endeavor to take into account the neurobiological and psychosocial aspects of preterm vulnerability for pain prevention and management strategies.

Central Nervous System Processing of Floral Odor and Mother's Milk Odor in Infants

Newborns have a functioning sense of smell at birth, which appears to be highly significant for feeding and bonding. Still, little is known about the cerebral odor processing in this age group. Studies of olfactory function relied mostly on behavioral, autonomic, and facial responses of infants. The aim of the present study was to investigate central odor processing in infants focusing on electroencephalography (EEG)-derived responses to biologically significant odors, namely a food and a non-food odor. A total of 21 term-born, healthy infants participated (11 boys and 10 girls; age range 2-9 months, mean 5.3 ± 2.2 months). Odor stimuli were presented using a computer-controlled olfactometer. Breast milk was used as food odor. Farnesol was presented as a non-food odor. In addition, odorless air was used as a control stimulus. Each stimulus was presented 30 times for 1 s with an interstimulus interval of 20 s. EEG was recorded from 9 electrodes and analyzed in the frequency domain. EEG amplitudes in the delta frequency band differed significantly after presentation of food (breast milk) odor in comparison to the control condition and the non-food odor (farnesol). These changes were observed at the frontal recording positions. The present study indicates that central odor processing differs between a food and a non-food odor in infants. Results are interpreted in terms of focused attention towards a physiologically relevant odor (breast milk), suggesting that olfactory stimuli are of specific significance in this age group.

A Randomized Controlled Trial: The Effect of Own Mother's Breast Milk Odor and Another Mother's Breast Milk Odor on Pain Level of Newborn Infants

Objective: Our research was conducted empirically to determine whether another mother's breast milk could be used to reduce the pain of newborns who were not able to access their own mother's milk for any reason. Materials and Methods: The sample group of the research included 90 newborns [smell of own mother's milk (30), smell of another mother's milk (30), and the control group (30)] hospitalized in the unit. A neonatal information form was used as the data collection tool, the Neonatal Pain, Agitation, and Sedation Scale (N-PASS) was used to assess the newborn's pain, and an evaluation form prepared by the researcher was used to record the findings. Results: The group which was exposed to their own mother's milk had a significantly lower N-PASS mean score compared to other groups and the group which was exposed to another mother's milk was observed to have a significantly lower N-PASS mean score compared to the control group (p < 0.05). While the median values for the total time spent crying of the "own mother's milk" group and the "another mother's milk" group were similar; the total time spent crying of the control group had a significantly higher median value. Conclusion: Our research determined that, while the most effective method for reducing pain in newborns was the smell of their own mother's breast milk, for newborns who were not able to access their own mother's breast milk, the smell of breast milk from a different mother could also be used.

Pain Control with Lavender Oil in Premature Infants: A Double-Blind Randomized Controlled Study

Objectives: Aromatherapy has become popular in pain control in recent years compared with other complementary methods. Lavender (Lavandula angustifolia Miller) is a fragrant essential oil used in aromatherapy for its antibacterial, antifungal, muscle-relaxing, and analgesic effects. The smell of lavender oil, known for its soothing effect on adults, has not been adequately investigated in regards to pain control in premature infants. The purpose of our study was to assign the effect of the scent of lavender oil on pain in preterm infants during heel lancing. Design: A double-blind randomized controlled clinical study. Settings/Location: The study was conducted in a third-level neonatal intensive care unit of Bezmialem Vakif University Hospital from March 2019 to November 2019. It consisted of two groups. Subjects: Sixty-one premature babies (24-37 weeks of gestation) were enrolled in the study. Interventions: Heel stick sampling for metabolic screening was used for both study groups. The interventions were performed by two experienced nurses. Heart rate, oxygen saturation, and the baby's facial expression were recorded by a camera 3 min before the intervention, during the sampling, and 3 min after the procedure. After collecting the data, the head researcher and the assistant researcher separately watched the videos and scored them by using the Premature Infant Pain Profile-Revised (PIPP-R). Outcome measures: The difference of pain scores (PIIP-R) between two groups. Results: There was a statistically significant difference between the two groups in terms of PIPP-R scores during and after the sampling (p = 0.008 and p = 0.03 respectively). The PIPP-R scores at the beginning of the procedure were not found to be significantly different between the groups (p > 0.05). Conclusions: Inhalation of lavender scent is effective in pain control in premature infants. It is safe and low cost; it does not interfere with medical care.

The Effect of the Smell of Breast Milk and Non-Nutritious Sucking on Pain Behavioral Response and to First-Time Hepatitis B Vaccine in Term Newborns

Background:

The issue of Pain Management finds special significance in infants who are unable to verbally express pain. Studies have shown that the use of non-pharmacological pain control techniques can be effective in reducing neonatal pain. The aim of this study was to compare the effects of olfactory stimulation (with breast milk) and non-nutritive sucking (with a pacifier) on the physiological and behavioral responses in term neonates to the hepatitis B vaccine.

Methods:

In this clinical trial, which was done in 2015 at the Nohom-e Dey Hospital of Torbat Heidariyeh, 90 eligible infants were randomly selected and divided into two intervention and one control groups. In the breast-milk odor group (n = 30), the neonates were exposed to the mother's odor during vaccination. In the non-nutritive sucking group (n = 30), a standard soft pacifier was used, whereas, in the control group (n = 30), no intervention was carried out. Data collection tools included demographic information forms and the Neonatal Pain Response Scale. Data were edited and analyzed using SPSS 20 software.

Results:

This study showed that there was a statistically significant difference between the mean scores of neonatal behavioral responses after intervention in the three groups (p <0.05). The mean behavioral response was 0.73 lower in the breast-milk odor group than in the control group, and the mean behavioral response in the non-nutritive sucking group was 0.6 lower than that of the control group.

Conclusion:

The results of the study showed that both olfactory stimulations with breast milk and non-nutritive sucking have a positive impact on neonatal pain reduction, nearly equally.

The Effects of a Continuous Olfactory Stimulation Using Breast Milk (COSB) on Behavioral State and Physiological Responses in Korean Premature Infants

PURPOSE

This study aimed to evaluate the effects of continuous olfactory stimulation with breast milk (COSB) on behavioral and physiologic states of Korean premature infants.

DESIGN AND METHODS

We examined the COSB effects on the behavioral states and physiological responses, including heart rate and oxygen saturation, in 30 premature infants using a non-equivalent control group pre- and post-test design. Sterile 2 cm × 2 cm gauzes wet with 2 cc breast milk were placed 10 cm away from the infants' nostrils 8 times per day for 3 consecutive days. We obtained five measurements each of the behavioral state, heart rate, and oxygen saturation of the premature infants in the neonatal intensive care unit (NICU). Statistical analysis was conducted using descriptive statistics and two-way repeated-measures ANOVA.

RESULTS

The experiment group presented significantly reduced heart rate variations (p = .039). There were significant differences in the heart rate at all time-points in the control group (p < .001) but not in the experimental group, indicating more stable (p > .089) heart rates in the latter group. There were positive COSB effects on the behavioral states of premature infants at some time points.

CONCLUSIONS

COSB can be a useful intervention program for high-risk infants for partial behavioral state stabilization and significant heart rate stabilization.

PRACTICE IMPLICATIONS

COSB might enable NICU nurses to provide a useful and safe developmental care plan for the premature infants hospitalized in the NICU to improve their physiologic and behavioral condition.

Systematic review and meta-analysis of olfactive stimulation interventions to manage procedural pain in preterm and full-term neonates

BACKGROUND

Preterm and full-term neonates undergo many painful procedures during their hospitalization in the neonatal intensive care unit. Unrelieved and repeated pain can have important repercussions on their motor and intellectual development. Still, pain management interventions are limited for neonates.

OBJECTIVE

This systematic review aimed to evaluate the effectiveness of olfactive stimulation interventions on the pain response of preterm and full-term infants during painful procedures.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

An electronic search was conducted from inception to August 2019 in PubMed, MEDLINE, Embase, CINAHL, PsycINFO, Web of Sciences, CENTRAL, Scopus and ProQuest.

REVIEW METHODS

Study selection, data extraction, assessment of risk of bias and quality of evidence were performed by two independent reviewers.

RESULTS

3311 studies were screened. Of the 14 studies included studies (n = 1028 infants), results from 10 were combined in meta-analysis. The latter demonstrated that olfactive stimulation interventions using a familiar odor were effective compared to standard care on pain reactivity (SMD -0.69; 95% CI -0.93 to -0.44; I² = 20%, p < 0.00001), pain regulation (SMD -0.40; 95% CI -0.66 to -0.14; I² = 13%, p = 0.002), crying duration during (SMD -0.42; 95% CI -0.73 to -0.10; I² = 47%, p = 0.009) and after the procedure (SMD -0.37; 95% CI -0.68 to -0.07; I² = 0%, p = 0.01), heart rate after the procedure (MD -3.87; 95% CI -7.36 to -0.38; I² = 99%, p = 0.03), oxygen saturation during (MD -0.47; 95% CI -0.86 to -0.08; I² = 91%, p = 0.02) and after the procedure (MD -0.56; 95% CI -0.99 to -0.13; I² = 99%, p = 0.01). No adverse event was reported.

CONCLUSION

These findings are based on low to very low quality of evidence limiting our confidence in effect estimates. More rigorous trials with a larger sample size are needed to enhance the comprehension of the mechanisms underlying olfactive stimulation interventions and the interventions' efficacy.

Odor-mediated contextual learning induced memory consolidation and hippocampus development in neonate rat

The hippocampus in neonatal rats is not fully developed after birth, and the effect of odor-aversion learning on memory consolidation in the immature hippocampus is not well understood. Therefore, the aim of the present study was to explore the effects of odor-aversion learning in neonatal rats on memory consolidation and neurodevelopment in the immature hippocampus. The effect of hippocampal-induced learning was measured at two different developmental stages using the Y-maze and c-Fos protein levels. Furthermore, hippocampal cell proliferation and growth-associated protein 43 (GAP-43) expression were evaluated at different developmental stages, namely, postnatal day 7 (PN7) and PN24, after odor-aversion learning. Both PN7 and PN24 rats avoided conditioned odor stimuli after odor-aversion learning. PN7 and PN24 rats in the odor-averse learning groups exhibited high c-Fos protein levels. PN7 rats exhibited high cell proliferation rates and GAP-43 protein levels after odor-aversion learning. These results showed that the immature hippocampus can participated in odor-aversion learning, which may induce cell proliferation and axonal development.

Culturally Based Practice in Neonatal Procedural Pain Management: A Mini Review

Cultural factors have gradually become important considerations in health services, including in pain management for adult and pediatric patients. However, research on culturally based pain management in neonates remains limited. This mini review aims to provide an overview of procedural pain management in neonates based on cultural approaches from various countries. The review found that there are several analyses of pain management procedures for neonates developed from cultural practices, namely, acupuncture, foot massage and reflexology, Yakson touch therapy, and aromatherapy. The acupuncture method (invasive and non-invasive) is more widely studied using randomized controlled trials (RCTs) than the other methods because the techniques applied can be standardized and measured. There are indications of the positive impact of all the methods examined in this review, but the results of studies have not been consistent because of the diversity of outcome measurement methods used and because of the difficulty of creating standardized procedures to measure pain management methods that are based on cultural practices.

Sniffin' Away the Feeding Tube: The Influence of Olfactory Stimulation on Oral Food Intake in Newborns and Premature Infants

Because of their immaturity, many premature infants are fed via nasogastric tube. One objective of the neonatal care is to feed infants orally early. The olfactory function of premature infants is developed before birth and odorants have a significant impact on nutrition in infants. The aim of the study was to test whether odor stimulation has a positive effect on the transition from gavage to oral feeding in infants. Participants were premature infants with gestational age of more than 27 weeks, with full or partial gavage feeding, stable vital parameters and without invasive ventilation. Before each feeding procedure an odorant was presented in front of the infant's nose. Infants were randomized into 1 of 3 groups and received either rose odor (not food-associated), vanilla odor (food-associated), or placebo (no odor). The primary outcome of the study was defined as the time until complete oral nutrition. About 150 children born at a postnatal age of 9.5 ± 7.8 days were included in this study. The duration until complete oral nutrition was reached after 11.8 ± 7.7 (vanilla), 12.2 ± 7.7 (rose), and 12.9 ± 8.8 (control) days. A nearly linear relation between odor presentation frequency and effect size was detectable. For infants that received the intervention for more than 66.7% of the time the length of gavage feeding (8 ± 5.4) and hospitalization (11 ± 6.5) was significantly lower in the vanilla group when compared with control (15 ± 7.3 and 21 ± 13.7, respectively). Odor stimulation with vanilla has an impact on oral feeding in premature infants, however the odor has to be presented on regular basis.

The Analgesic Effects of Maternal Milk Odor on Newborns: A Meta-Analysis

OBJECTIVE

The objective of this study was to evaluate the analgesic effects of maternal milk odor on newborns.

MATERIALS AND METHODS

We searched the literature in PubMed, MEDLINE, CINAHL, EMBASE, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) and collected all the randomized controlled trials (RCTs) investigating the effects of maternal milk odor versus scentless or other odors on procedural pain in newborns. The quality of included studies was assessed by the Cochrane Collaboration Risk of Bias tool. A meta-analysis was undertaken with the Review Manager 5.3 software and Stata version 11.0. Subgroup comparisons were prespecified according to the types of control groups.

RESULTS

Eight RCTs included a total of 453 participants. The results of meta-analysis showed that compared with the scentless group, the maternal milk odor group had lower pain scores during blood sampling (standardized mean difference, -0.81; 95% confidence interval [95% CI], -1.18 to -0.44; p < 0.001) and shorter crying time afterward (mean difference, -8.10; 95% CI, -15.46 to 0.73; p = 0.03). The maternal milk odor group had lower heart rate variability and oxygen saturation variability during and after a procedure, compared with both the scentless group and the vanilla group. However, no significant difference was identified in the mean heart rate and mean oxygen saturation in terms of the maternal milk odor group compared with amniotic fluid odor or mother's scent. The maternal milk odor group versus the formula milk odor group had shorter crying duration and lower levels of salivary cortisol after sampling.

CONCLUSIONS

Maternal milk odor appears to play an analgesic role in newborns. However, more high-quality studies are needed to confirm and quantitate the effect.

The Impact of Preterm Infants' Continuous Exposure to Breast Milk Odor on Stress Parameters: A Pilot Study

OBJECTIVE

This pilot study aimed to assess the effect of continuous exposure to the odor of own mothers' breast milk (BM) on the stress parameters of preterm infants.

MATERIALS AND METHODS

Fifteen healthy preterm infants were included. Mean heart rate and salivary cortisol were measured over three consecutive time periods, each lasting 2 days: (1) preintervention (odor free); (2) intervention, during which a cotton pad soaked with 1.5 mL of BM was placed near the infant's head with the aim of providing continuous exposure to its odor; (3) postintervention period (odor free).

RESULTS

Saliva cortisol levels differed significantly between the three exposure periods (pre-, during, and post-BM odor exposure): 11.38 ± 5.03, 9.51 ± 4.38, and 4.99 ± 3.42 nmol/L, respectively. A repeated univariate analysis of the cortisol measure showed a significant difference (F = 9.34; df = 2.28, p < 0.001). There was no difference in mean heart rate over the three study periods.

CONCLUSIONS

Preterm infants exposed to BM odor from their own mothers demonstrate a persistent decrease in saliva cortisol levels, which continues after termination of the intervention. This finding may suggest that exposure to own mothers' BM odor has a soothing effect on preterm infants. Further randomized controlled studies are needed to evaluate this simple, safe, and inexpensive intervention.

ABM Clinical Protocol #23: Nonpharmacological Management of Procedure-Related Pain in the Breastfeeding Infant, Revised 2016

A central goal of The Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient. These guidelines are not intended to be all-inclusive, but to provide a basic framework for physician education regarding breastfeeding.

Breastfeeding for procedural pain in infants beyond the neonatal period

BACKGROUND

Randomised controlled trials (RCTs) show that breastfeeding newborn infants during painful procedures reduces pain. Mechanisms are considered to be multifactorial and include sucking, skin-to-skin contact, warmth, rocking, sound and smell of the mother, and possibly endogenous opiates present in the breast milk.

OBJECTIVES

To determine the effect of breastfeeding on procedural pain in infants beyond the neonatal period (first 28 days of life) up to one year of age compared to no intervention, placebo, parental holding, skin-to-skin contact, expressed breast milk, formula milk, bottle feeding, sweet-tasting solutions (e.g. sucrose or glucose), distraction, or other interventions.

SEARCH METHODS

We searched the following databases to 18 February 2016: the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library), MEDLINE including In-Process & Other Non-Indexed Citations (OVID), Embase (OVID), PsycINFO (OVID), and CINAHL (EBSCO); the metaRegister of Controlled Trials (mRCT), ClinicalTrials.gov (clinicaltrials.gov), and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) (apps.who.int/trialsearch/) for ongoing trials.

SELECTION CRITERIA

We included RCTs and quasi-RCTs involving infants aged 28 days postnatal to 12 months and receiving breastfeeding while undergoing a painful procedure. Comparators included, but were not limited to, oral administration of water, sweet-tasting solutions, expressed breast or formula milk, no intervention, use of pacifiers, positioning, cuddling, distraction, topical anaesthetics, and skin-to-skin care. Procedures included, but were not limited to: subcutaneous or intramuscular injection, venipuncture, intravenous line insertion, heel lance, and finger lance. We applied no language restrictions.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently considered trials for inclusion in the review, assessed risk of bias, and extracted data. The main outcome measures were behavioural or physiological indicators and composite pain scores, as well as other clinically important outcomes reported by the authors of included studies. We pooled data for the most comparable outcomes and where data from at least two studies could be included. We used mean difference (MD) with 95% confidence interval (CI), employing a random-effects model for continuous outcomes measured on the same scales. For continuous outcomes measured on different scales, we pooled standardised mean differences (SMDs) and associated 95% CIs. For dichotomous outcomes, we planned to pool events between groups across studies using risk ratios (RRs) and 95% CIs. However, as insufficient studies reported dichotomous outcomes, we did not pool such events. We assessed the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

We included 10 studies with a total of 1066 infants. All studies were conducted during early childhood immunisation. As the breastfeeding intervention cannot be blinded, we rated all studies as being at high risk of bias for blinding of participants and personnel. We assessed nine studies as being at low risk of bias for incomplete outcome data. In addition, we rated nine studies as high risk for blinding of outcome assessment. We scored risk of bias related to random sequence generation, allocation concealment, and selective reporting as unclear for the majority of the studies due to lack of information.Our primary outcome was pain. Breastfeeding reduced behavioural pain responses (cry time and pain scores) during vaccination compared to no treatment, oral water, and other interventions such as cuddling, oral glucose, topical anaesthetic, massage, and vapocoolant. Breastfeeding did not consistently reduce changes in physiological indicators, such as heart rate. We pooled data for duration of cry from six studies (n = 547 infants). Breastfeeding compared to water or no treatment resulted in a 38-second reduction in cry time (MD -38, 95% CI -50 to -26; P < 0.00001). The quality of the evidence according to GRADE for this outcome was moderate, as most infants were 6 months or younger, and outcomes may be different for infants during their 12-month immunisation. We pooled data for pain scores from five studies (n = 310 infants). Breastfeeding was associated with a 1.7-point reduction in standardised pain scores (SMD -1.7, 95% CI -2.2 to -1.3); we considered this evidence to be of moderate quality as data were primarily from infants younger than 6 months of age. We could pool heart rate data following injections for only two studies (n = 186); we considered this evidence to be of low quality due to insufficient data. There were no differences between breastfeeding and control (MD -3.6, -23 to 16).Four of the 10 studies had more than two study arms. Breastfeeding was more effective in reducing crying duration or pain scores during vaccination compared to: 25% dextrose and topical anaesthetic cream (EMLA), vapocoolant, maternal cuddling, and massage.No included studies reported adverse events.

AUTHORS' CONCLUSIONS

We conclude, based on the 10 studies included in this review, that breastfeeding may help reduce pain during vaccination for infants beyond the neonatal period. Breastfeeding consistently reduced behavioural responses of cry duration and composite pain scores during and following vaccinations. However, there was no evidence that breastfeeding had an effect on physiological responses. No studies included in this review involved populations of hospitalised infants undergoing other skin-breaking procedures. Although it may be possible to extrapolate the review results to this population, further studies of efficacy, feasibility, and acceptability in this population are warranted.

Comparative Effect of the Smells of Amniotic Fluid, Breast Milk, and Lavender on Newborns' Pain During Heel Lance

INTRODUCTION

The aim of this randomized controlled experimental study was to evaluate the effect of the smells of amniotic fluid, breast milk, and lavender on the pain of newborns during heel lance.

METHODS

The sample of the study consisted of 102 newborn infants who complied with the sampling criteria between August and November, 2011. The newborns smelled the samples (lavender, breast milk, amniotic fluid, and distilled water) for 5 minutes before the heel lance until 5 minutes afterward. The Neonatal Infant Pain Scale (NIPS), heart rate, and oxygen saturation were evaluated 1 minute before, during, and 1 minute after the heel lance. Data were evaluated by descriptive statistics, chi-square, intraclass correlation analysis, Spearman's rho correlation, Bonferroni's advanced analysis, Shapiro-Wilk, Kruskal-Wallis, Mann-Whitney U, Friedman, and Dunnett's tests.

RESULTS

The newborns in the control group had severe pain and the newborns in the breast milk, amniotic fluid, and lavender groups had moderate pain during the heel lance (p < 0.05). While the NIPS score of the newborns in the lavender group was lower than the breast milk and amniotic fluid groups during the heel lance, it was lower in the breast milk and amniotic fluid groups than the lavender group afterward. The lowest falls in oxygen saturation and increased in heart rate were in the breast milk and lavender groups during heel the lance.

CONCLUSION

The smells of lavender and breast milk prevent the increased heart rates, NIPS, falling oxygen saturation, and reduced pain during the invasive procedures in newborns more than amniotic fluid or control group.