Effects of Combined Use of Mother's Breast Milk, Heartbeat Sounds, and Non-Nutritive Sucking on Preterm Infants' Behavioral Stress During Venipuncture: A Randomized Controlled Trial

Musical and vocal interventions to improve neurodevelopmental outcomes for preterm infants

BACKGROUND

Preterm birth interferes with brain maturation, and subsequent clinical events and interventions may have additional deleterious effects. Music as therapy is offered increasingly in neonatal intensive care units aiming to improve health outcomes and quality of life for both preterm infants and the well-being of their parents. Systematic reviews of mixed methodological quality have demonstrated ambiguous results for the efficacy of various types of auditory stimulation of preterm infants. A more comprehensive and rigorous systematic review is needed to address controversies arising from apparently conflicting studies and reviews.

OBJECTIVES

We assessed the overall efficacy of music and vocal interventions for physiological and neurodevelopmental outcomes in preterm infants (< 37 weeks' gestation) compared to standard care. In addition, we aimed to determine specific effects of various interventions for physiological, anthropometric, social-emotional, neurodevelopmental short- and long-term outcomes in the infants, parental well-being, and bonding.

SEARCH METHODS

We searched Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, PsycINFO, Web of Science, RILM Abstracts, and ERIC in November 2021; and Proquest Dissertations in February 2019. We searched the reference lists of related systematic reviews, and of studies selected for inclusion and clinical trial registries.

SELECTION CRITERIA

We included parallel, and cluster-randomised controlled trials with preterm infants < 37 weeks` gestation during hospitalisation, and parents when they were involved in the intervention. Interventions were any music or vocal stimulation provided live or via a recording by a music therapist, a parent, or a healthcare professional compared to standard care. The intervention duration was greater than five minutes and needed to occur more than three times.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data. We analysed the treatment effects of the individual trials using RevMan Web using a fixed-effects model to combine the data. Where possible, we presented results in meta-analyses using mean differences with 95% CI. We performed heterogeneity tests. When the I2 statistic was higher than 50%, we assessed the source of the heterogeneity by sensitivity and subgroup analyses. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included 25 trials recruiting 1532 infants and 691 parents (21 parallel-group RCTs, four cross-over RCTs). The infants gestational age at birth varied from 23 to 36 weeks, taking place in NICUs (level 1 to 3) around the world. Within the trials, the intervention varied widely in type, delivery, frequency, and duration. Music and voice were mainly characterised by calm, soft, musical parameters in lullaby style, often integrating the sung mother's voice live or recorded, defined as music therapy or music medicine. The general risk of bias in the included studies varied from low to high risk of bias. Music and vocal interventions compared to standard care Music/vocal interventions do not increase oxygen saturation in the infants during the intervention (mean difference (MD) 0.13, 95% CI -0.33 to 0.59; P = 0.59; 958 infants, 10 studies; high-certainty evidence). Music and voice probably do not increase oxygen saturation post-intervention either (MD 0.63, 95% CI -0.01 to 1.26; P = 0.05; 800 infants, 7 studies; moderate-certainty evidence). The intervention may not increase infant development (Bayley Scales of Infant and Toddler Development (BSID)) with the cognitive composition score (MD 0.35, 95% CI -4.85 to 5.55; P = 0.90; 69 infants, 2 studies; low-certainty evidence); the motor composition score (MD -0.17, 95% CI -5.45 to 5.11; P = 0.95; 69 infants, 2 studies; low-certainty evidence); and the language composition score (MD 0.38, 95% CI -5.45 to 6.21; P = 0.90; 69 infants, 2 studies; low-certainty evidence). Music therapy may not reduce parental state-trait anxiety (MD -1.12, 95% CI -3.20 to 0.96; P = 0.29; 97 parents, 4 studies; low-certainty evidence). The intervention probably does not reduce respiratory rate during the intervention (MD 0.42, 95% CI -1.05 to 1.90; P = 0.57; 750 infants; 7 studies; moderate-certainty evidence) and post-intervention (MD 0.51, 95% CI -1.57 to 2.58; P = 0.63; 636 infants, 5 studies; moderate-certainty evidence). However, music/vocal interventions probably reduce heart rates in preterm infants during the intervention (MD -1.38, 95% CI -2.63 to -0.12; P = 0.03; 1014 infants; 11 studies; moderate-certainty evidence). This beneficial effect was even stronger after the intervention. Music/vocal interventions reduce heart rate post-intervention (MD -3.80, 95% CI -5.05 to -2.55; P < 0.00001; 903 infants, 9 studies; high-certainty evidence) with wide CIs ranging from medium to large beneficial effects. Music therapy may not reduce postnatal depression (MD 0.50, 95% CI -1.80 to 2.81; P = 0.67; 67 participants; 2 studies; low-certainty evidence). The evidence is very uncertain about the effect of music therapy on parental state anxiety (MD -0.15, 95% CI -2.72 to 2.41; P = 0.91; 87 parents, 3 studies; very low-certainty evidence). We are uncertain about any further effects regarding all other secondary short- and long-term outcomes on the infants, parental well-being, and bonding/attachment. Two studies evaluated adverse effects as an explicit outcome of interest and reported no adverse effects from music and voice.

AUTHORS' CONCLUSIONS

Music/vocal interventions do not increase oxygen saturation during and probably not after the intervention compared to standard care. The evidence suggests that music and voice do not increase infant development (BSID) or reduce parental state-trait anxiety. The intervention probably does not reduce respiratory rate in preterm infants. However, music/vocal interventions probably reduce heart rates in preterm infants during the intervention, and this beneficial effect is even stronger after the intervention, demonstrating that music/vocal interventions reduce heart rates in preterm infants post-intervention. We found no reports of adverse effects from music and voice. Due to low-certainty evidence for all other outcomes, we could not draw any further conclusions regarding overall efficacy nor the possible impact of different intervention types, frequencies, or durations. Further research with more power, fewer risks of bias, and more sensitive and clinically relevant outcomes are needed.

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.

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.