Heart rate variability responses of a preterm infant to kangaroo care

Inpatient Skin-to-Skin Care Predicts 12-month Neurodevelopmental Outcomes in Very Preterm Infants

Objective

Limited research links hospital-based experiences of skin-to-skin (STS) care to longer-term neurodevelopmental outcomes in preterm children. The present study examined relations between inpatient STS and neurodevelopmental scores measured at 12 months in a sample of very preterm (VPT) infants.

Study Design and Methods

From a retrospective study review of medical records of 181 VPT infants (<32 weeks gestational age (GA)) we derived the STS rate, i.e., the total minutes of STS each infant received/day of hospital stay. We used scores on the Capute Scales from routine follow-up care at 12 months as the measure of neurodevelopmental outcome (n=181).

Results

Families averaged approximately 17 minutes/day of STS care (2 days/week, 70 minutes/session), although there was substantial variability. Variation in STS rate was positively associated with outcomes at 12 months corrected age ( r = 0.25, p < .001). STS rate significantly predicted 6.2% unique variance in 12-month neurodevelopmental outcomes, after controlling for GA, socioeconomic status (SES), health acuity, and visitation frequency. A 20-minute increase in STS per day was associated with a 10-point increase (.67 SDs) in neurodevelopmental outcomes at 12 months. SES, GA, and infant health acuity did not moderate these relations.

Conclusion

VPT infants who experienced more STS during hospitalization demonstrated higher scores on 12-month assessments of neurodevelopment. Results provide evidence that STS care may confer extended neuroprotection on VPT infants through the first year of life.

The effects of kangaroo mother care on physiological parameters of premature neonates in neonatal intensive care unit: A systematic review

PURPOSE

The effects of Kangaroo mother care (KMC) on physiological parameters in preterm infants have been reported in the literature by experimental and quasi-experimental studies, and varying findings have been presented. The present study was conducted to determine the effects of KMC on the physiological parameters of premature newborns in the Neonatal Intensive Care Unit.

DESIGN AND METHOD

The review was conducted according to the specified keywords by scanning the EBSCO-host, Cochrane Library, Medline, PubMed, ScienceDirect, Web of Science, and TR index databases using the keywords "kangaroo care AND preterm AND vital signs." The pool mean differences (MDs) were calculated, adopting a 95% confidence interval (CIs) using the Stata 16 software for the meta-analysis [PROSPERO: CRD42021283475].

RESULTS

Eleven studies for systematic review and nine studies for meta-analysis, including 634 participants, were found eligible for inclusion. It was determined that the "temperature" (z = 3.21; p = 0.000) and "oxygen saturation" (z = 2.49; p = 0.000) values created a positive effect in general in the kangaroo care group; however, there was no sufficient evidence to state that it affected the "heart rate" (z = -0.60; p = 0.55) and "respiratory rate" (z = -1.45; p = 0.15) values. In the present study, the duration of KMC application had statistically different effects on temperature and oxygen saturation (SpO₂) (p < 0.05). One-hour or shorter applications of KMC had a higher effect on the temperature and oxygen saturation values (1.83; 1.62, respectively).

CONCLUSION

Our results provided references for clinical implications, and the "temperature" and "oxygen saturation (SpO₂)" values created a positive effect in general in the KMC group. However, there was no sufficient evidence to state that it affected the "heart rate" and "respiratory rate" values. The duration of KMC application had statistically different effects on temperature and oxygen saturation. One-hour or shorter applications of KMC had a higher effect on the temperature and SpO₂ values. Longitudinal, randomized, controlled studies examining the effects of KMC on vital signs in premature newborns with vital parameters outside the normal reference range are recommended.

PRACTICE IMPLICATIONS

The goal of the NICU nurse is to improve the infant's well-being. The application of KMC is a unique care for the nurse in maintaining the newborn's well-being. The vital signs of newborns hospitalized in the NICU with critical problems may be out of normal limits. KMC is an essential developmental care practice that ensures that the neonate's vital signs are kept within normal limits by relaxing the neonate, reducing stress, increasing comfort, and supporting interventions and treatments. KMC application is unique for each mother‑neonate pair. Depending on the tolerance of the mother and infant in terms of duration, it is recommended to perform KMC in the NICU under the supervision of a nurse. Neonatal nurses should support mothers in giving KMC in the NICU since KMC has ameliorative effects on the vital signs of premature neonates.

Comparing Full and Pre-Term Neonates' Heart Rate Variability in Rest Condition and during Spontaneous Interactions with Their Parents at Home

BACKGROUND

Preterm neonates show decreased HRV compared to those at full-term. We compared HRV metrics between preterm and full-term neonates in transfer periods from neonate rest state to neonate-parent interaction, and vice versa.

METHODS

Short-term recordings of the HRV parameters (time and frequency-domain indices and non-linear measurements) of 28 premature healthy neonates were compared with the metrics of 18 full-term neonates. HRV recordings were performed at home at term-equivalent age and HRV metrics were compared between the following transfer periods: from first rest state of the neonate (TI1) to a period in which the neonate interacted with the first parent (TI2), from TI2 to a second neonate rest state (TI3), and from TI3 to a period of neonate interaction with the second parent (TI4).

RESULTS

For the whole HRV recording period, PNN50, NN50 and HF (%) was lower for preterm neonates compared to full-terms. These findings support the reduced parasympathetic activity of preterm compared to full-term neonates. The results of comparisons between transfer period simply a common coactivation of SNS and PNS systems for both full and pre-term neonates.

CONCLUSIONS

Spontaneous interaction with the parent may reinforce both full and pre-term neonates' ANS maturation.

Soothing Effect of an Edible Teether: A Pilot Study in Children during Primary Dentition Age

Background

Irritability and discomfort are common symptoms during teething periods in infants and toddlers. Non-pharmacological remedies to relieve teething symptoms include teethers and food for chewing. However, the efficacy of such remedies for their soothing effect has been poorly investigated.

Materials and methods

In this home-based pilot study, the soothing effect of a novel edible teether with a slowly dissolvable texture was investigated in 12 children aged 5 to 19 months old during primary dentition age. After parents observed their child getting irritable, the child received the edible teether for an exposure duration of 15 to 20 minutes. Parental ratings of children's mood states (crankiness, stress, happiness, and calmness) were collected using visual analog scales, and child cardiac measurements (heart rate and heart rate variability) were assessed using a wearable device. The soothing effect was quantified via mood ratings and physiological calming responses as a before-after comparison using Wilcoxon signed-rank tests.

Results

Parents perceived their child as significantly calmer and happier, less stressed, and marginally less cranky after edible teether exposure than before. The child cardiac variables showed no significant changes; however, exposure to the teether induced a marginal increase in HR within normal ranges, potentially indicating a stimulation effect.

Conclusion

The pilot study provides the first insight on the soothing effect of a novel edible teether on parent-reported mood states in young children during primary dentition age. Further research is needed to understand the relative contribution of the different components of an edible teether to the observed effects, such as texture and exposure duration, and to demonstrate its efficacy against a control product.

Trial registration

Swiss registry of clinical trial: CER-VD 2019-02155.

How to cite this article

Lerond C, Hudry J, Zahar S, et al. Soothing Effect of an Edible Teether: A Pilot Study in Children during Primary Dentition Age. Int J Clin Pediatr Dent 2021;14(4):525–530.

Effects of Live Music Therapy on Autonomic Stability in Preterm Infants: A Cluster-Randomized Controlled Trial

Unbuffered stress levels may negatively influence preterm-infants’ autonomic nervous system (ANS) maturation, thus affecting neurobehavior and psycho-emotional development. Music therapy (MT) is an evidence-based treatment modality in neonatal care. When coupled with skin-to-skin care (SSC), it may reduce stress responses in both preterm infants and their parents and enhance family-centered care. Accordingly, we aimed to compare the effects of combined MT and SSC and SSC alone on ANS stabilization in preterm infants. In a single-center, cluster-randomized trial design, ten two-month time-clusters were randomized to either combined MT and SSC or SSC alone. Families of preterm infants were offered two sessions of the allocated condition in the NICU, and a three-month follow up session at home. The primary outcome variable was stabilization of the ANS, defined by change in the high frequency (HF) power of heart rate variability (HRV) during the second session. Secondary outcomes included other HRV measures, parent–infant attachment, and parental anxiety at each session. Sixty-eight families were included. MT combined with SSC improved infants’ ANS stability, as indicated by a greater increase in HF power during MT compared to SSC alone (mean difference 5.19 m²/Hz, SE = 1.27, p < 0.001) (95% confidence interval 0.87 to 2.05). Most secondary outcomes were not significantly different between the study groups. MT contributes to preterm-infants’ autonomic stability, thus laying an important foundation for neuro-behavioral and psycho-emotional development. Studies evaluating longer-term effects of MT on preterm infants’ development are warranted.

Preterm infant heart rate is lowered after Family Nurture Intervention in the NICU: Evidence in support of autonomic conditioning

BACKGROUND

Cardiac complications after premature birth are associated with negative long-term consequences to health. The Family Nurture Intervention (FNI) has been designed to support mother-infant parasympathetic calming sessions in the neonatal intensive care unit (NICU). FNI has shown neurodevelopmental and autonomic benefit across infant development.

AIMS

We tested the hypothesis that heart rate (HR) will decrease after FNI over the course of the NICU stay, compared to matched controls.

STUDY DESIGN

We used a case-matched design. The intervention included on average four ~1-hour facilitated mother-infant 'calming' sessions per week. We collected 24/7 real time heart rate data from a central monitoring system and analyzed data from two time-periods.

SUBJECTS

The intervention group comprised 37 infants born ~30 weeks gestational age (GA) in a level IV NICU, treated with FNI. From the same NICU and time-period, we created a contemporaneous comparison group of 32 infants who were case-matched to each intervention infant for sex, age-at-birth, singleton or twin status, month of admission and length of stay.

OUTCOME MEASURES

Using generalized estimating equation (GEE) modeling, we analyzed 24/7 HR data during a 1-hour period between 4:30 and 5:30 am each day in the NICU, when all infants were least disturbed. Using repeated measures ANOVA, we analyzed 24/7 HR data during a 6-week period starting 1 week prior to the start of FNI and ending 5 weeks after start.

RESULTS

GEE modeling of the 1-hour data from all subjects showed significant lower HR in the FNI group, compared with controls. ANOVA modeling on a subset of subjects over the five-week period showed that FNI infant HR decreased in a dose-response manner relative to SC HR.

CONCLUSION

This study suggests FNI may condition lower infant HR in a dose-response manner during the NICU stay.

Exploring infant hip position and muscle activity in common baby gear and orthopedic devices

Infant positioning in daily life may affect hip development. While neonatal animal studies indicate detrimental relationships between inactive lower extremities and hip development and dysplasia, no research has explored infant hip biomechanics experimentally. This study evaluated hip joint position and lower extremity muscle activity of healthy infants in common body positions, baby gear, and orthopedic devices used to treat hip dysplasia (the Pavlik harness and the Rhino cruiserabduction brace). Surface electromyography(EMG) and marker-based motion capture recorded lower extremity muscle activity and kinematics of 22 healthy full-term infants (4.2±1.6 months, 13M/9F) during five conditions: Pavlik harness, Rhino brace, inward-facing soft-structured baby carrier, held in arms facing inwards, and a standard car seat. Mean filtered EMG signal, time when muscles were active, and hip position (angles) were calculated. Compared to the Pavlik harness, infants exhibited similar adductor activity (but lower hamstring and gluteus maximus activity) in the Rhino abduction brace, similar adductor and gluteus maximus activity (but lower quadriceps and hamstring activity) in the baby carrier, similar but highly variable muscle activity in-arms, and significantly lower muscle activity in the car seat. Hip position was similar between the baby carrier and the Pavlik harness. This novel infant biomechanics study illustrates the potential benefits of using inward-facing soft-structured baby carriers for healthy hip development and highlights the potential negative impact of using supine-lying container-type devices such as car seats for prolonged periods of time. Further study is needed to understand the full picture of how body position impacts infant musculoskeletal development.

Designing dress (Sarbebe) for kangaroo care, the effect of kangaroo care provided with this dress on mother and newborn's comfort†

The aims of the researchers were to design the clothes to be worn by the mothers in kangaroo care (KC) and to determine the effect of the KC provided with these clothes on the comfort of the mother and infant. This study was experimentally carried out as a methodological, randomized controlled trial for the designing of clothes for KC. Data were collected using the "Parent and Newborn Information Form", "KC Comfort Scale" and "Newborn Comfort Behavior Scale (Comfort-Neo)". The body temperature, heart rate, oxygen saturation, respiration rate parameters of the newborns were evaluated. The data were transferred to the IBM SPSS Statistics 23 program and evaluated. Our results showed that the KC Comfort Scale total score was 71.1 ± 14.8 in the control group and 84.0 ± 1.5 in the intervention group and "Newborn Comfort Behavior Scale" total scores were found to be 12.47 ± 6.90 in the control group and 8.67 ± 3.46 in the intervention group. It was determined that the KC Comfort Scale (z: -4.785 p: 0.000) in the intervention group were significantly higher compared to the control group (p < 0.05). Pain (z: -4.439 p: 0.000) and distress (z: -4.601 p: 0.000) levels of the control group were found to be significantly higher compared to the intervention group. Sarbebe is recommended to be used in KC practices since it was concluded that maternal comfort and satisfaction was high and the pain and distress scores of the newborn were low after KC provided with Sarbebe.

Heart rate variability in the evaluation of the autonomic nervous system of premature infants

One way to analyze the function of the autonomic nervous system (ANS) is through heart rate variability (HRV). This approach is based on the analysis of the distance between the peaks of two consecutive R waves expressed in electrocardiograms. HRV evaluations have been developed and have become more accessible and reliable through technological advances that enable the data collection in a simpler, non-invasive, and reliable way. However, there is little information in the scientific literature on the implementation of this methodology to assess the ANS of preterm infants. In this article, we survey the barriers, potential uses, and other topics regarding the assessment of the ANS in preterm infants using HRV.

Technical Innovation for Visual Assessment of Preterm Newborns in a Neonatal Intensive Care Unit: Exploratory Study

Objective

The present study is aimed at assessing heart rate variability (HRV) and its correlation with visual acuity (VA) assessment of preterm newborns (PTNB) in neonatal intensive care units.

Method

Cross-sectional study analyzing HRV during assessment of VA with the aid of a Polar RS800CX heart rate monitor (Polar Electro Oy, Finland). HRV was analyzed according to time and frequency domains and the chaos domain used the autocorrelation coefficient and entropy. The sample consisted of hospitalized PTNB, and static analysis included simple regression diagnosis.

Results

A total of 14 PTNB were included in the sample. VA varied between 0.23 and 1.60 cpd, and only five PTNB obtained below-expected values for age. Statistical analysis demonstrated a negative correlation between VA and time domain (SDDN and SD2) and a positive correlation between frequency domain (heart rate and hertz), but in simple linear regression analysis, these variables did not influence VA.

Conclusion

The results of the study demonstrate that visual acuity was inversely correlated with SDNN and SD2 and during stimulation, showing that the higher the visual performance, the lower the autonomic modulation response.

Positioning and baby devices impact infant spinal muscle activity

Infant positioning in daily life, particularly in relation to active neck and back muscles, may affect spinal development, psychosocial progression, and motor milestone achievement. Yet the impact of infant body position on muscle activity is unknown. The objective of this study was to evaluate neck and back muscle activity of healthy infants in common positions and baby devices. Healthy full-term infants (n = 22, 2-6 months) participated in this experimental study. Daily sleep and positioning were reported by caregivers. Cervical paraspinal and erector spinae muscle activity was measured using surface electromyography (EMG) in five positions: lying prone, lying supine, held in-arms, held in a baby carrier, and buckled into a car seat. Mean filtered EMG signal and time that muscles were active were calculated. Paired t-tests were used to compare positions to the prone condition. Caregivers reported that infants spent 12% of daily awake time prone, 43% in supine-lying baby gear, and 44% held in-arms or upright in a baby carrier. Infants exhibited highest erector spinae activity when prone, and lowest cervical paraspinal muscle activity in the car seat. No differences were found between in-arms carrying and babywearing. This first evaluation of the muscle activity of healthy infants supports the importance of prone time in infants' early spinal development because it promotes neck and back muscle activity. Carrying babies in-arms or in baby carriers may also be beneficial to neck muscle development, while prolonged time spent in car seats or containment devices may be detrimental to spinal development.

Evaluation of the autonomic nervous system by analysis of heart rate variability in the preterm infants

BACKGROUND

Premature infants may present with damage to the autonomic nervous system (ANS), which may be related to poorer neurological development. Among the techniques used to evaluate the ANS, heart rate variability (HRV) emerged as a simple, non-invasive, and easy to apply tool. The aim of the present study was to analyze and compare HRV in preterm infants at different times of hospitalization in order to verify the possible environmental relationships or clinical evolution with HRV.

METHODS

A longitudinal, prospective, and descriptive study with non-probabilistic sampling composed of 25 collections of preterm infants of HRV at two moments: moment I (within 15 days of birth) and moment II (after 45 days post-birth). The Polar V800 heart rate monitor was used with the Polar H10 cardiac transducer to collect HRV, which was collected in the supine position for 15 min. The HRV data were analyzed by the linear method in frequency domain and time domain and by the nonlinear method using Kubios HRV analysis software, version 3.0.2.

RESULTS

There was an increase in HRV values at moment II, these being statistically significant in the SD1, ApEn, and SampEn. Data related to increased sympathetic nervous system activity, parasympathetic nervous system activity, and increased index complexity.

CONCLUSIONS

The data demonstrate an increase in HRV values in premature infants at moment II, demonstrating a possible development in the maturation of the ANS during hospitalization.

TRIAL REGISTRATION

RBR-3x7gz8 retrospectively registered.

An integrative review: maternal engagement in the neonatal intensive care unit and health outcomes for U.S.-born preterm infants and their parents

Hospitals and perinatal organizations recognize the importance of family engagement in the neonatal intensive care unit (NICU). The Agency for Healthcare Research and Quality (AHRQ) defines family engagement as "A set of behaviors by patients, family members, and health professionals and a set of organizational policies and procedures that foster both the inclusion of patients and family members as active members of the health care team and collaborative partnerships with providers and provider organizations." In-unit barriers and facilitators to enhance family engagement are well studied; however, less is known specifically about maternal engagement's influence in the NICU on the health of infants and mothers, particularly within U.S. social and healthcare contexts. In this integrative review, we examine the relationship between maternal engagement in the NICU and preterm infant and maternal health outcomes within the U.S. Results from the 33 articles that met inclusion criteria indicate that maternal engagement in the NICU is associated with infant outcomes, maternal health-behavior outcomes, maternal mental health outcomes, maternal-child bonding outcomes, and breastfeeding outcomes. Skin-to-skin holding is the most studied maternal engagement activity in the U.S. preterm NICU population. Further research is needed to understand what types of engagement are most salient, how they should be measured, and which immediate outcomes are the best predictors of long-term health and well-being.

Pilot Testing a Robot for Reducing Pain in Hospitalized Preterm Infants

Optimizing neurodevelopment is a key goal of neonatal occupational therapy. In preterm infants, repeated procedural pain is associated with adverse effects on neurodevelopment long term. Calmer is a robot designed to reduce infant pain. The objective of this study was to examine the effects of Calmer on heart rate variability (HRV) during routine blood collection in preterm infants. In a randomized controlled pilot trial, 10 infants were assigned to either standard care ( n = 5, facilitated tucking [FT]) or Calmer treatment ( n = 5). HRV was recorded continuously and quantified using the area (power) of the spectrum in high and low frequency (HF: 0.15-0.40Hz/ms2; LF: 0.04-0.15 Hz/ms2) regions. Changes in HRV during three, 2-min phases (Baseline, Heel Poke, and Recovery) were compared between groups. Calmer infants had 90% greater parasympathetic activation ([PS] reduced stress) during Baseline, 82% greater PS activation during Poke, and 24% greater PS activation during Recovery than FT infants. Calmer reduced physiological preterm infant pain reactivity during blood collection.

Effect of skin-to-skin contact on parents' sleep quality, mood, parent-infant interaction and cortisol concentrations in neonatal care units: study protocol of a randomised controlled trial

INTRODUCTION

Separation after preterm birth is a major stressor for infants and parents. Skin-to-skin contact (SSC) is a method of care suitable to use in the neonatal intensive care unit (NICU) to minimise separation between parents and infants. Less separation leads to increased possibilities for parent-infant interaction, provided that the parents' sleep quality is satisfactory. We aimed to evaluate the effect of continuous SSC on sleep quality and mood in parents of preterm infants born <33 weeks of gestation as well as the quality of parent-infant interaction and salivary cortisol concentrations at the time of discharge.

METHODS AND ANALYSIS

A randomised intervention study with two arms-intervention versus standard care. Data will be collected from 50 families. Eligible families will be randomly allocated to intervention or standard care when transferred from the intensive care room to the family-room in the NICU. The intervention consists of continuous SSC for four consecutive days and nights in the family-room. Data will be collected every day during the intervention and again at the time of discharge from the hospital. Outcome measures comprise activity tracker (Actigraph); validated self-rated questionnaires concerning sleep, mood and bonding; observed scorings of parental sensitivity and emotional availability and salivary cortisol. Data will be analysed with pairwise, repeated measures, Mann Whitney U-test will be used to compare groups and analysis of variance will be used to adjust for different hospitals and parents' gender.

ETHICS AND DISSEMINATION

The study is approved by the Regional Research Ethics Board at an appropriate university (2016/89-31). The results will be published in scientific journals. We will also use conferences and social media to disseminate our findings.

TRIAL REGISTRATION NUMBER

NCT03004677.

Safety of Reiki Therapy for Newborns at Risk for Neonatal Abstinence Syndrome

The incidence of opioid abuse and subsequent drug withdrawal is exponentially on the rise in the United States for many populations including newborns who are born to drug-addicted mothers. These newborns often exhibit symptoms of neonatal abstinence syndrome (NAS) within 24 to 72 hours of birth. Treatment of NAS includes monitoring of withdrawal symptoms, managing physiological parameters, and the use of supportive and pharmacologic treatments. Although a few randomized controlled trials exist, studies on supportive intervention are generally limited by small sample sizes, case study reports, expert opinions, and descriptive design. Few studies address the safety of Reiki for newborns at risk for NAS using neonatal parameters. This pilot study addresses feasibility and demonstrates that Reiki is safe when administered to this high-risk population. Considerations for future studies are discussed.

Impact of skin-to-skin contact on the autonomic nervous system in the preterm infant and his mother

Before, during and after mother-newborn skin-to-skin contact (SSC), parasympathetic activity was evaluated by heart rate variability (HRV) analysis. SSC had a favorable impact on maternal and premature infant parasympathetic activities with a more pronounced response for neonates when the basal HRV values were lower, without modifications of EDIN scores, temperatures or oxygen saturation.

Features of Heart Rate Variability Capture Regulatory Changes During Kangaroo Care in Preterm Infants

OBJECTIVE

To determine whether heart rate variability (HRV) can serve as a surrogate measure to track regulatory changes during kangaroo care, a period of parental coregulation distinct from regulation within the incubator.

STUDY DESIGN

Nurses annotated the starting and ending times of kangaroo care for 3 months. The pre-kangaroo care, during-kangaroo care, and post-kangaroo care data were retrieved in infants with at least 10 accurately annotated kangaroo care sessions. Eight HRV features (5 in the time domain and 3 in the frequency domain) were used to visually and statistically compare the pre-kangaroo care and during-kangaroo care periods. Two of these features, capturing the percentage of heart rate decelerations and the extent of heart rate decelerations, were newly developed for preterm infants.

RESULTS

A total of 191 kangaroo care sessions were investigated in 11 preterm infants. Despite clinically irrelevant changes in vital signs, 6 of the 8 HRV features (SD of normal-to-normal intervals, root mean square of the SD, percentage of consecutive normal-to-normal intervals that differ by >50 ms, SD of heart rate decelerations, high-frequency power, and low-frequency/high-frequency ratio) showed a visible and statistically significant difference (P <.01) between stable periods of kangaroo care and pre-kangaroo care. HRV was reduced during kangaroo care owing to a decrease in the extent of transient heart rate decelerations.

CONCLUSION

HRV-based features may be clinically useful for capturing the dynamic changes in autonomic regulation in response to kangaroo care and other changes in environment and state.

Skin-to-skin care for procedural pain in neonates

BACKGROUND

Skin-to-skin care (SSC), often referred to as 'kangaroo care' (KC) due to its similarity with marsupial behaviour of ventral maternal-infant contact, is one non-pharmacological intervention for pain control in infants.

OBJECTIVES

The primary objectives were to determine the effect of SSC alone on pain from medical or nursing procedures in neonates compared to no intervention, sucrose or other analgesics, or additions to simple SSC such as rocking; and to determine the effects of the amount of SSC (duration in minutes), method of administration (e.g. who provided the SSC) of SSC in reducing pain from medical or nursing procedures in neonatesThe secondary objectives were to determine the safety of SSC care for relieving procedural pain in infants; and to compare the SSC effect in different postmenstrual age subgroups of infants.

SEARCH METHODS

For this update, we used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 1); MEDLINE via PubMed (1966 to 25 February 2016); Embase (1980 to 25 February 2016); and CINAHL (1982 to 25 February 2016). We also searched clinical trials' databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.

SELECTION CRITERIA

Studies with randomisation or quasi-randomisation, double- or single-blinded, involving term infants (≥ 37 completed weeks' postmenstrual age (PMA) to a maximum of 44 weeks' PMA and preterm infants (< 37 completed weeks PMA) receiving SSC for painful procedures conducted by healthcare professionals.

DATA COLLECTION AND ANALYSIS

The main outcome measures were physiological or behavioural pain indicators and composite pain scores. A mean difference (MD) with 95% confidence interval (CI) using a fixed-effect model was reported for continuous outcome measures. We included variations on type of tissue-damaging procedure, provider of care, and duration of SSC.

MAIN RESULTS

Twenty-five studies (n = 2001 infants) were included. Nineteen studies (n = 1065) used heel lance as the painful procedure, one study combined venepuncture and heel stick (n = 50), three used intramuscular injection (n = 776), one used 'vaccination' (n = 60), and one used tape removal (n = 50). The studies were generally strong and had low or uncertain risk of bias. Blinding of the intervention was not possible, making them subject to high risk, depending on the method of scoring outcomes.Seventeen studies (n = 810) compared SSC to a no-treatment control. Although 15 studies measured heart rate during painful procedures, data from only five studies (n = 161) could be combined for a mean difference (MD) of -10.78 beats per minute (95% CI -13.63 to -7.93) favouring SSC. Meta-analysis of four studies (n = 120) showed no difference in heart rate following the painful procedure (MD 0.08, 95% CI -4.39 to 4.55). Two studies (n = 38) reported heart rate variability with no significant differences. Two studies (n = 101) in a meta-analysis on oxygen saturation at 30 and 60 seconds following the painful procedure did not show a difference. Duration of crying meta-analysis was performed on four studies (n = 133): two (n = 33) investigated response to heel lance (MD = -34.16, 95% CI -42.86 to -25.45), and two (n = 100) following IM injection (MD = -8.83, 95% CI -14.63 to -3.02), favouring SSC. Five studies, one consisting of two substudies (n = 267), used the Premature Infant Pain Profile (PIPP) as a primary outcome, which favoured SCC at 30 seconds (MD -3.21, 95% CI -3.94 to -2.47), at 60 seconds (3 studies; n = 156) (MD -1.64, 95% CI -2.86 to -0.43), and at 90 seconds (n = 156) (MD -1.28, 95% CI -2.53 to -0.04); but at 120 seconds there was no difference (n = 156) (MD 0.07, 95% CI -1.11 to 1.25). No studies on return of heart rate to baseline level, cortisol levels, and facial actions could be combined for meta-analysis findings.Eight studies compared SSC to another intervention with or without a no-treatment control. Two cross-over studies (n = 80) compared mother versus other provider (father, another female) on PIPP scores at 30, 60, 90, and 120 seconds with no significant difference. When SSC was compared to other interventions, there were not enough similar studies to pool results in an analysis. One study compared SSC (n = 640) with and without dextrose and found that the combination was most effective and that SSC alone was more effective than dextrose alone. Similarly, in another study SSC was more effective than oral glucose for heart rate (n = 95). SSC either in combination with breastfeeding or alone was favoured over a no-treatment control, but not different to breastfeeding. One study compared SSC alone and in combination with both sucrose and breastfeeding on heart rate (HR), NIPS scores, and crying time (n = 127). The combinations were more effective than SSC alone for NIPS and crying. Expressed breast milk was compared to SSC in one study (n = 50) and found both equally effective on PIPP scores. There were not enough participants with similar outcomes and painful procedures to compare age groups or duration of SSC. No adverse events were reported in any of the studies.

AUTHORS' CONCLUSIONS

SSC appears to be effective as measured by composite pain indicators with both physiological and behavioural indicators and, independently, using heart rate and crying time; and safe for a single painful procedure. Purely behavioural indicators tended to favour SSC but with facial actions there is greater possibility of observers not being blinded. Physiological indicators were mixed although the common measure of heart rate favoured SSC. Two studies compared mother-providers to others, with non-significant results. There was more heterogeneity in the studies with behavioural or composite outcomes. There is a need for replication studies that use similar, clearly defined outcomes. Studies examining optimal duration of SSC, gestational age groups, repeated use, and long-term effects of SSC are needed. Of interest would be to study synergistic effects of SSC with other interventions.

A Case Study of Infant Physiologic Response to Skin-to-Skin Contact After Surgery for Complex Congenital Heart Disease

BACKGROUND

Infants with complex congenital heart disease requiring surgical intervention within the first days or weeks of life may be the most seriously ill infants needing intensive nursing and medical care. Skin-to-skin contact (SSC) is well accepted and practiced as a positive therapeutic intervention in premature infants but is not routinely offered to infants in cardiac intensive care units. The physiologic effects of SSC in the congenital heart disease population must be examined before recommending incorporation of SSC into standard care routines.

OBJECTIVE

The purpose of this case study was to describe the physiologic response to a single session of SSC in an 18-day-old infant with hypoplastic left heart syndrome.

METHODS

Repeated measures of heart rate, respiratory rate, oxygen saturation, blood pressure, and temperature were recorded 30 minutes before SSC, during SSC (including interruptions for bottle and breast feedings), and 10 minutes after SSC was completed.

RESULTS

All physiologic parameters were clinically acceptable throughout the 135-minute observation.

CONCLUSION

This case study provides beginning evidence that SSC is safe in full-term infants after surgery for complex congenital heart disease. Further research with a larger sample is needed to examine the effects of SSC on infant physiology before surgery and earlier in the postoperative time period as well as on additional outcomes such as length of stay, maternal-infant interaction, and neurodevelopment.

Pain management in newborns

As a standard of care for preterm/term newborns effective pain management may improve their clinical and neurodevelopmental outcomes. Neonatal pain is assessed using context-specific, validated, and objective pain methods, despite the limitations of currently available tools. Therapeutic approaches reducing invasive procedures and using pharmacologic, behavioral, or environmental measures are used to manage neonatal pain. Nonpharmacologic approaches like kangaroo care, facilitated tucking, non-nutritive sucking, sucrose, and others can be used for procedural pain or adjunctive therapy. Local/topical anesthetics, opioids, NSAIDs/acetaminophen and other sedative/anesthetic agents can be incorporated into NICU protocols for managing moderate/severe pain or distress in all newborns.

Skin-to-skin care for procedural pain in neonates

BACKGROUND

Skin-to-skin care (SSC), otherwise known as Kangaroo Care (KC) due to its similarity with marsupial behaviour of ventral maternal-infant contact, is one non-pharmacological intervention for pain control in infants.

OBJECTIVES

The primary objectives were to determine the effect of SSC alone on pain from medical or nursing procedures in neonates undergoing painful procedures compared to no intervention, sucrose or other analgesics, or additions to simple SSC such as rocking; and the effects of the amount of SSC (duration in minutes) and the method of administration (who provided the SSC, positioning of caregiver and neonate pair).The secondary objectives were to determine the incidence of untoward effects of SSC and to compare the SSC effect in different postmenstrual age subgroups of infants.

SEARCH METHODS

The standard methods of the Cochrane Neonatal Collaborative Review Group were used. Databases searched in August 2011: Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library); Evidence-Based Medicine Reviews; MEDLINE (1950 onwards); PubMed (1975 onwards); EMBASE (1974 onwards); CINAHL (1982 onwards); Web of Science (1980 onwards); LILACS database (1982 onwards); SCIELO database (1982 onwards); PsycInfo (1980 onwards); AMED (1985 onwards); Dissertation-Abstracts International (1980 onwards). Searches were conducted throughout September 2012.

SELECTION CRITERIA

Studies with randomisation or quasi-randomisation, double or single-blinded, involving term infants (> 37 completed weeks postmenstrual age (PMA)) to a maximum of 44 weeks PMA and preterm infants (< 37 completed weeks PMA) receiving SSC for painful procedures conducted by doctors, nurses, or other healthcare professionals.

DATA COLLECTION AND ANALYSIS

The main outcome measures were physiological or behavioural pain indicators and composite pain scores. A weighted mean difference (WMD) with 95% confidence interval (CI) using a fixed-effect model was reported for continuous outcome measures. We included variations on type of tissue-damaging procedure, provider of care, and duration of SSC.

MAIN RESULTS

Nineteen studies (n = 1594 infants) were included. Fifteen studies (n = 744) used heel lance as the painful procedure, one study combined venepuncture and heel stick (n = 50), two used intramuscular injection, and one used 'vaccination' (n = 80). The studies that were included were generally strong and free from bias.Eleven studies (n = 1363) compared SSC alone to a no-treatment control. Although 11 studies measured heart rate during painful procedures, data from only four studies (n = 121) could be combined to give a mean difference (MD) of 0.35 beats per minute (95% CI -6.01 to 6.71). Three other studies that were not included in meta-analyses also reported no difference in heart rate after the painful procedure. Two studies reported heart rate variability outcomes and found no significant differences. Five studies used the Premature Infant Pain Profile (PIPP) as a primary outcome, which favoured SCC at 30 seconds (n = 268) (MD -3.21, 95% CI -3.94 to -2.48), 60 seconds (n = 164) (MD -1.85, 95% CI -3.03 to -0.68), and 90 seconds (n = 163) (MD -1.34, 95% CI -2.56 to -0.13), but at 120 seconds (n = 157) there was no difference. No studies provided findings on return of heart rate to baseline level, oxygen saturation, cortisol levels, duration of crying, and facial actions that could be combined for analysis.Eight studies compared SSC to another intervention with or without a no-treatment control. Two cross-over studies (n = 80) compared mother versus other provider on PIPP scores at 30, 60, 90, and 120 seconds with no significant difference. When SSC was compared to other interventions, there were not enough similar studies to pool results in an analysis. One study compared SSC with and without dextrose and found that the combination was most effective and that SSC alone was more effective than dextrose alone. Similarly, in another study SSC was more effective than oral glucose for heart rate but not oxygen saturation. SSC either in combination with breastfeeding or alone was favoured over a no-treatment control, but was not different to breastfeeding. There were not enough participants with similar outcomes and painful procedures to compare age groups or duration of SSC. No adverse events were reported in any of the studies.

AUTHORS' CONCLUSIONS

SSC appears to be effective, as measured by composite pain indicators and including both physiological and behavioural indicators, and safe for a single painful procedure such as a heel lance. Purely behavioural indicators tended to favour SSC but there remains questionable bias regarding behavioural indicators. Physiological indicators were typically not different between conditions. Only two studies compared mother providers to others, with non-significant results. There was more heterogeneity in the studies with behavioural or composite outcomes. There is a need for replication studies that use similar, clearly defined outcomes. New studies examining optimal duration of SSC, gestational age groups, repeated use, and long-term effects of SSC are needed.

[Impact of cocooning and maternal voice on the autonomic nervous system activity in the premature newborn infant]

INTRODUCTION

Discomfort, pain, and stress have an adverse impact on the psychomotor development in the premature newborn infant. Recent studies indicate that pain and stress are associated with a reduction of parasympathetic outflow. We hypothesized that cocooning associated with the human voice has a favorable impact on parasympathetic activity in the premature newborn infant.

METHOD

We compared heart rate variability (HRV) before and after standardized cocooning phases associated with the human voice and carried out: 1) by the mother and 2) by a third person. HRV was assessed and expressed as an index reflecting the parasympathetic tone.

RESULTS

Ten children were included (median gestational age, 33 weeks (30(+4)-33(+2))). We observed a higher HRV index after the period of cocooning associated with the human voice compared with the baseline measurement (P<0.05), whether the procedure was carried out by the mother or a third person.

CONCLUSION

This study shows that cocooning associated with the human voice enhances HRV in the preterm newborn infant, indicating an increase in parasympathetic activity after cocooning associated with the human voice. However, the impact is similar whether the cocooning associated with the human voice is performed by the mother or a third person. This result suggests that cocooning associated with the human voice carried out either by the mother or a third person contributes to decreasing stress and discomfort in the premature newborn infant.

Should neonates sleep alone?

BACKGROUND

Maternal-neonate separation (MNS) in mammals is a model for studying the effects of stress on the development and function of physiological systems. In contrast, for humans, MNS is a Western norm and standard medical practice. However, the physiological impact of this is unknown. The physiological stress-response is orchestrated by the autonomic nervous system and heart rate variability (HRV) is a means of quantifying autonomic nervous system activity. Heart rate variability is influenced by level of arousal, which can be accurately quantified during sleep. Sleep is also essential for optimal early brain development.

METHODS

To investigate the impact of MNS in humans, we measured HRV in 16 2-day-old full-term neonates sleeping in skin-to-skin contact with their mothers and sleeping alone, for 1 hour in each place, before discharge from hospital. Infant behavior was observed continuously and manually recorded according to a validated scale. Cardiac interbeat intervals and continuous electrocardiogram were recorded using two independent devices. Heart rate variability (taken only from sleep states to control for level of arousal) was analyzed in the frequency domain using a wavelet method.

RESULTS

Results show a 176% increase in autonomic activity and an 86% decrease in quiet sleep duration during MNS compared with skin-to-skin contact.

CONCLUSIONS

Maternal-neonate separation is associated with a dramatic increase in HRV power, possibly indicative of central anxious autonomic arousal. Maternal-neonate separation also had a profoundly negative impact on quiet sleep duration. Maternal separation may be a stressor the human neonate is not well-evolved to cope with and may not be benign.

Early life experience shapes the functional organization of stress-responsive visceral circuits

Emotions are closely tied to changes in autonomic (i.e., visceral motor) function, and interoceptive sensory feedback from body to brain exerts powerful modulatory control over motivation, affect, and stress responsiveness. This manuscript reviews evidence that early life experience can shape the structure and function of central visceral circuits that underlie behavioral and physiological responses to emotive and stressful events. The review begins with a general discussion of descending autonomic and ascending visceral sensory pathways within the brain, and then summarizes what is known about the postnatal development of these central visceral circuits in rats. Evidence is then presented to support the view that early life experience, particularly maternal care, can modify the developmental assembly and structure of these circuits in a way that impacts later stress responsiveness and emotional behavior. The review concludes by presenting a working hypothesis that endogenous cholecystokinin signaling and subsequent recruitment of gastric vagal sensory inputs to the caudal brainstem may be an important mechanism by which maternal care influences visceral circuit development in rat pups. Early life experience may contribute to meaningful individual differences in emotionality and stress responsiveness by shaping the postnatal developmental trajectory of central visceral circuits.

Randomized crossover trial of kangaroo care to reduce biobehavioral pain responses in preterm infants: a pilot study

Kangaroo care (KC), skin-to-skin contact between mother and infant, is a promising method for blunting pain responses. This crossover pilot tested KC effects on biobehavioral responses to heel stick in preterm infants (30-32 weeks' gestational age, 2-9 days old) measured by Premature Infant Pain Profile (PIPP) and salivary and serum cortisol. Mother-infant dyads were randomly assigned to KC heel stick (KCH) first or incubator heel stick (IH) first. Study 1 (80-min study, N = 18) tested the effect of 80 min of KC before and throughout the heel stick procedure versus incubator care. Study 2 (30-min study, N = 10) tested 30 min of KC before and throughout the heel stick versus incubator care. KCH and IH began during a premeasurement phase and continued through four data collection phases: baseline, heel warming, heel stick, and recovery. PIPP responses were measured every 30 s during data collection; salivary cortisol was measured at the end of baseline and recovery; and serum cortisol was measured during heel stick. Study 1 showed no differences between KCH and IH. Study 2 showed lower PIPP scores at four time points during recovery (p < .05 to p < .001), lower salivary cortisol at the end of recovery (p < .05), and lower serum cortisol during heel stick for the KCH condition (p < .05) as well as clinically lower PIPP scores in the KCH condition during heel stick. Thirty minutes of KC before and throughout the heel stick reduced biobehavioral responses to pain in preterm infants.

Meta-analysis of physiological effects of skin-to-skin contact for newborns and mothers

BACKGROUND

Skin-to-skin care has been adopted all over the world, although physiological changes during or after it have not been evaluated very well. The purpose of the present study was therefore to investigate whether skin-to-skin contact for newborn babies and their mothers affects body temperature, heart rate and oxygen saturation of the babies.

METHODS

Studies investigating body temperature, heart rate and oxygen saturation of babies during and/or after skin-to-skin contact were systematically searched and reviewed. Meta-analyses to examine the effects and meta-regression analyses to investigate correlations between the effects and birthweight, duration of the care, environmental temperature, and resources of the setting, were conducted.

RESULTS

A total of 23 studies were included. Meta-analyses showed evidence of an increase in body temperature (weighted mean difference [WMD] 0.22 degrees C, P < 0.001) and a decrease in saturation of babies (WMD -0.60%; P= 0.01) during skin-to-skin care, compared with those before skin-to-skin care. Increase in body temperature was more evident in middle-low-income settings (WMD, 0.61 degrees C, P < 0.001) than high-income settings (WMD 0.20 degrees C, P < 0.001). Both the positive effect on body temperature and the negative effect on saturation were more marked in cold environments than where the environmental temperature was higher (WMD 0.18 degrees C, P < 0.001; WMD -0.82%, P= 0.02).

CONCLUSION

Skin-to-skin care is effective in increasing the body temperature of babies, especially where resources are limited and the environment is cold. Decreased oxygen saturation of the babies, however, warrants further prospective studies to confirm the findings.

Postnatal autonomic activity in the preterm lamb

BACKGROUND

Early postnatal abnormalities of autonomic nervous system (ANS) activity, including at baseline and following cardiorespiratory challenge, are involved in apneas-bradycardias of prematurity, apparent life-threatening events of infancy and sudden infant death syndrome. Literature data suggest that baseline ANS activity does not mature normally after premature birth.

OBJECTIVES

This study performed in preterm lambs was aimed at assessing ANS maturation at baseline and following laryngeal chemoreflexes (LCR), a group of reflexes triggered by the contact of liquids with the laryngeal mucosa.

METHODS

Heart rate variability (HRV) and baroreflex sensitivity (BRs) were measured at baseline and after LCR during polysomnographic recordings performed in five non-sedated lambs born 15 days prematurely. Laryngeal chemoreflexes were induced by distilled water or acid (pH 2) during sleep and wakefulness on postnatal days 7 (D7) and 14 (D14, full-term equivalence).

RESULTS

While the life-threatening cardiorespiratory events of the LCR observed at D7 were no longer present at D14, baseline and post-LCR HRV and BRs indices were significantly lower at D14 compared to D7 (up to p<0.001). These results suggest that an initial autonomic overactivity was present at D7 and normalized at D14.

CONCLUSION

The autonomic cardiac and baroreflex control appears to follow a specific evolution in the preterm compared to the full-term newborn lamb, with an important initial autonomic stress, which normalizes at an age equivalent to full-term. Potential relevance of these findings in relation to anomalies of cardiac control in the early postnatal period, such as apneas-bradycardias of prematurity, apparent life-threatening events of infancy and sudden infant death syndrome, awaits further studies.

Repeated brief postnatal maternal separation enhances hypothalamic gastric autonomic circuits in juvenile rats

Maternal separation of rat pups for 15 min each day over the first one to two postnatal weeks (MS15) has been shown to increase the active maternal care received by pups and to decrease their later neuroendocrine and behavioral stress reactivity compared to non-separated (NS) controls. Stress responses prominently feature altered gastric secretion and motility, and we previously reported that the developmental assembly of forebrain circuits underlying gastric autonomic control, including gastric responses to stress, is delayed by MS15 in neonatal rats [Card JP, Levitt P, Gluhovsky M, Rinaman L (2005) J Neurosci 25(40):9102-9111]. To determine how this early delay affects the later organization of central gastric autonomic circuits, the present study examined the effects of neonatal MS15 on central pre-gastric circuits assessed in post-weaning, juvenile rats. For this purpose, the retrograde transynaptic viral tracer, pseudorabies virus (PRV), was microinjected into the stomach wall of 28-30 day old male rats with an earlier developmental history of either MS15 or NS. Rats were perfused 72 h later and tissue was processed to reveal PRV-positive cells. Transynaptic PRV immunolabeling was quantified in selected preautonomic brainstem and forebrain regions, including the area postrema, bed nucleus of the stria terminalis, central nucleus of the amygdala, paraventricular nucleus of the hypothalamus (PVN), and visceral cortices. Compared to NS controls, MS15 rats displayed a significantly greater amount of PRV labeling within the PVN, including both the dorsal cap and ventral subnuclei. There were no postnatal group differences in the amount of PRV labeling within any other brain region examined in this study. This effect of MS15 to enhance hypothalamic preautonomic circuit structure indicates a strengthening of this pathway and may provide insight into how early life experience produces differential effects on later stress reactivity, including gastric secretory and motor responses to stress.

Kangaroo care with twins: a case study in which one infant did not respond as expected

PURPOSE

The purposes were to relate responses (including unacceptable ones) of twins to shared kangaroo care (KC), to provide explanations for the unexpected responses, and to offer suggestions for safe nursing practice.

DESIGN

A descriptive, evaluative case study was conducted. Both twins received KC while their vital signs and maternal breast temperatures were manually recorded every 30 seconds. Descriptive statistics were computed.

SAMPLE

Identical twins, born to a 19-year-old African-American primigravada, were 34 3/7 weeks postconceptional age with weights of 1,760 and 1,480 g, respectively, when tested. Preterm labor resulted in spontaneous vaginal birth at 30 weeks gestation.

MAIN OUTCOME VARIABLES

Infant heart and respiratory rates, oxygen saturations, abdominal temperatures, and maternal breast temperatures.

RESULTS

Infant A's vital signs exceeded acceptable clinical limits during shared KC; vital signs returned to normal range once Infant A was returned to the incubator. Infant B's vital signs approximated clinically acceptable ranges throughout the session. Breast temperatures did not differ. Individuality mandates vigilant assessment of infant responses to shared KC.

Kangaroo Care modifies preterm infant heart rate variability in response to heel stick pain: pilot study

BACKGROUND

Heel stick is the most common painful procedure for preterm infants in neonatal intensive care units. Resultant pain causes adverse physiological effects in major organ systems. Kangaroo Care (KC), involving mother-infant skin-to-skin contact is a promising analgesic for infant pain; however, the effect of KC on the autonomic nervous system's response to pain is unknown.

AIM

To determine if KC results in improved balance in autonomic responses to heel stick pain than the standard method where infants remain in an incubator care (IC) for the heel stick.

STUDY DESIGN

A randomized cross-over trial.

SUBJECTS

Fourteen preterm infants, 30-32 weeks gestational age and less than 9 days postnatal age.

OUTCOME MEASURES

Infant behavioral state, heart rate, heart rate variability (HRV) indices including low frequency (LF) and high frequency (HF) power, and the LF/HF ratio measured over Baseline, Heel Warming, Heel Stick, and Recovery periods in KC and IC conditions.

RESULTS

HRV differences between KC and IC were that LF was higher in KC at Baseline (p<.01) and at Heel Stick (p<.001), and HF was higher in KC at Baseline than in the IC condition (p<.05). The LF/HF ratio had less fluctuation across the periods in KC than in IC condition and was significantly lower during Recovery in KC than in IC (p<.001).

CONCLUSIONS

Infants experienced better balance in response in KC than IC condition as shown by more autonomic stability during heel stick. KC may be helpful in mediating physiologic response to painful procedures in preterm infants.

Cerebral oxygenation responses during kangaroo care in low birth weight infants

Background

Kangaroo care (KC) has been widely using to improve the care of low birth weight infants. However, very little is known about cerebral hemodynamics responses in low birth weight infants during KC intervention. The objective of this study was to elucidate the response of cerebral hemodynamics during KC in low birth weight infants.

Methods

Near infrared spectroscopy measured regional cerebral oxygenation (rSO₂), heart rate (HR), respiration rate (RR) measured by electrocardiogram, and percentages of oxygen saturation (SpO₂) measured by pulse oxymetry was monitored in 16 preterm infants (< 1600 g) in three sessions: before, during, and after KC. Using power spectral analysis, total power (TP), low-frequency (LF, 0.02–0.20 Hz) and high-frequency (HF, 0.20–0.50 Hz) bands, the ratio of LF/HF were calculated and normalized as %LF or %HF = LF or HF/TP × 100 (%).

Results

Significant differences were not observed in the mean rSO₂, HR, and SpO₂ throughout sessions; however, the TP of these parameters was significantly decreased during KC and increased after KC (p < 0.001). The %LF of LrSO₂ and RrSO₂ was decreased during KC (p < 0.05) with decreased %HF in RrSO₂ (p < 0.05). The %LF of HR was significantly increased during KC while %HF was decreased (p < 0.05). Mean and TP of RR was increased during KC (p < 0.01 respectively) with the increase of quiet sleep state (p < 0.05) and decreased after KC (p < 0.01). The %LF of RR was increased after KC (p < 0.05) with decreased %HF (p < 0.05); however, significant changes were not observed during KC.

Conclusion

KC intervention appears to have influence on cerebral hemodynamics as well as cardiorespiratory parameters. The results of rSO₂ and HR might be associated with quiet sleep states. The results of this study may indicate the contribution of KC intervention to the activation of central nervous system and brain function. Further study is needed to determine the underlying physiology responsible for these differences.

Autonomic cardiac control of very preterm newborns: a prolonged dysfunction

BACKGROUND

Autonomic nervous system (ANS) activity is fundamental to infant health. ANS activity of preterm newborns seems to be reduced at term equivalent age, but follow-up of ANS activity has rarely been performed in that population during the weeks after birth. The aim of the study was to perform such a follow-up in preterm newborns of different gestational ages, up to their term equivalent ages.

METHODS

Prolonged electrocardiographic recordings were prospectively performed in a group of 39 premature newborns, each week, up to term equivalent age before discharge. Control values were obtained from a group of 19 full-term newborns, recorded at the first week of their life. ANS indices were calculated from recordings during quiet sleep periods by spectral-domain analysis (Fourier transform): Ptot (total power), VLF (very low-frequencies), LF (low-frequencies), HF (high-frequencies), LF/HF ratio, LFnu (normalized low-frequencies) and HFnu (normalized high-frequencies) values.

RESULTS

Ptot, VLF, LF and HF were significantly lower in the preterm group at birth compared to the control group, while LFnu, HFnu and LF/HF ratio were not significantly different. The results were similar when comparing the control group to any ANS values at a given post-natal corrected age of preterm newborns. Furthermore, preterm newborns did not demonstrate any significant increase in ANS values from birth to theoretical term.

CONCLUSION

The finding of substantial reduced ANS activity and failure of maturation in preterm infants up to term equivalent age needs confirming by other research groups, and mechanisms and implications for infant health explored.

Autonomic nervous system activity in premature and full-term infants from theoretical term to 7 years

The premature population reaching theoretical term suffers from a major deficit in autonomic nervous system (ANS) activity, as can be seen from heart rate variability indices. Whether this autonomic function recovers in the long term is not yet established. Thus, we analyzed and compared ANS activity indices, at birth or at the time of the theoretical term, and at ages 2-3 and 6-7 years, in two populations: a group of 30 premature children and a reference group of 14 full-term age-matched newborns. Using Fourier Transform analysis, we studied 24-h ECG Holter recordings to establish heart rate variability indices: Ptot, VLF, LF, HF, ratio LF/HF, LFnu, HFnu. In the neonatal period, sympathetic and even more markedly, parasympathetic activities were very low in prematures compared to the reference full-term group. At ages 2-3 and 6-7 years, prematures had recovered and had similar ANS activity as the full-term group. These data suggest a fast ANS maturation in prematures during the two first years of life, with a higher speed of recovery for the parasympathetic arm. Furthermore, compared evolution shows a faster ANS maturation in premature. Potential mechanisms are discussed.