Developmental changes in pain expression in premature, full-term, two- and four-month-old infants

Breastfeeding or breast milk for procedural pain in neonates

BACKGROUND

Pain in the neonate is associated with acute behavioural and physiological changes. Cumulative pain is associated with morbidities, including adverse neurodevelopmental outcomes. Studies have shown a reduction in changes in physiological parameters and pain score measurements following pre-emptive analgesic administration in neonates experiencing pain or stress. Non-pharmacological measures (such as holding, swaddling and breastfeeding) and pharmacological measures (such as acetaminophen, sucrose and opioids) have been used for analgesia. This is an update of a review first published in 2006 and updated in 2012.

OBJECTIVES

The primary objective was to evaluate the effectiveness of breastfeeding or supplemental breast milk in reducing procedural pain in neonates. The secondary objective was to conduct subgroup analyses based on the type of control intervention, gestational age and the amount of supplemental breast milk given.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL and trial registries (ICTRP, ISRCTN and clinicaltrials.gov) in August 2022; searches were limited from 2011 forwards. We checked the reference lists of included studies and relevant systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs of breastfeeding or supplemental breast milk versus no treatment/other measures in neonates. We included both term (≥ 37 completed weeks postmenstrual age) and preterm infants (< 37 completed weeks' postmenstrual age) up to a maximum of 44 weeks' postmenstrual age. The study must have reported on either physiological markers of pain or validated pain scores.

DATA COLLECTION AND ANALYSIS

We assessed the methodological quality of the trials using the information provided in the studies and by personal communication with the authors. We extracted data on relevant outcomes, estimated the effect size and reported this as a mean difference (MD). We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Of the 66 included studies, 36 evaluated breastfeeding, 29 evaluated supplemental breast milk and one study compared them against each other. The procedures conducted in the studies were: heel lance (39), venipuncture (11), intramuscular vaccination (nine), eye examination for retinopathy of prematurity (four), suctioning (four) and adhesive tape removal as procedure (one). We noted marked heterogeneity in the control interventions and pain assessment measures amongst the studies. Since many studies included multiple arms with breastfeeding/supplemental breast milk as the main comparator, we were not able to synthesise all interventions together. Individual interventions are compared to breastfeeding/supplemental breast milk and reported. The numbers of studies/participants presented with the findings are not taken from pooled analyses (as is usual in Cochrane Reviews), but are the overall totals in each comparison. Overall, the included studies were at low risk of bias except for masking of intervention and outcome assessment, where nearly one-third of studies were at high risk of bias. Breastfeeding versus control Breastfeeding may reduce the increase in heart rate compared to holding by mother, skin-to-skin contact, bottle feeding mother's milk, moderate concentration of sucrose/glucose (20% to 33%) with skin-to-skin contact (low-certainty evidence, 8 studies, 784 participants). Breastfeeding likely reduces the duration of crying compared to no intervention, lying on table, rocking, heel warming, holding by mother, skin-to-skin contact, bottle feeding mother's milk and moderate concentration of glucose (moderate-certainty evidence, 16 studies, 1866 participants). Breastfeeding may reduce percentage time crying compared to holding by mother, skin-to-skin contact, bottle feeding mother's milk, moderate concentration sucrose and moderate concentration of sucrose with skin-to-skin contact (low-certainty evidence, 4 studies, 359 participants). Breastfeeding likely reduces the Neonatal Infant Pain Scale (NIPS) score compared to no intervention, holding by mother, heel warming, music, EMLA cream, moderate glucose concentration, swaddling, swaddling and holding (moderate-certainty evidence, 12 studies, 1432 participants). Breastfeeding may reduce the Neonatal Facial Coding System (NFCS) score compared to no intervention, holding, pacifier and moderate concentration of glucose (low-certainty evidence, 2 studies, 235 participants). Breastfeeding may reduce the Douleur Aigue Nouveau-né (DAN) score compared to positioning, holding or placebo (low-certainty evidence, 4 studies, 709 participants). In the majority of the other comparisons there was little or no difference between the breastfeeding and control group in any of the outcome measures. Supplemental breast milk versus control Supplemental breast milk may reduce the increase in heart rate compared to water or no intervention (low-certainty evidence, 5 studies, 336 participants). Supplemental breast milk likely reduces the duration of crying compared to positioning, massage or placebo (moderate-certainty evidence, 11 studies, 1283 participants). Supplemental breast milk results in little or no difference in percentage time crying compared to placebo or glycine (low-certainty evidence, 1 study, 70 participants). Supplemental breast milk results in little or no difference in NIPS score compared to no intervention, pacifier, moderate concentration of sucrose, eye drops, gentle touch and verbal comfort, and breast milk odour and verbal comfort (low-certainty evidence, 3 studies, 291 participants). Supplemental breast milk may reduce NFCS score compared to glycine (overall low-certainty evidence, 1 study, 40 participants). DAN scores were lower when compared to massage and water; no different when compared to no intervention, EMLA and moderate concentration of sucrose; and higher when compared to rocking or pacifier (low-certainty evidence, 2 studies, 224 participants). Due to the high number of comparator interventions, other measures of pain were assessed in a very small number of studies in both comparisons, rendering the evidence of low certainty. The majority of studies did not report on adverse events, considering the benign nature of the intervention. Those that reported on adverse events identified none in any participants. Subgroup analyses were not conducted due to the small number of studies.

AUTHORS' CONCLUSIONS

Moderate-/low-certainty evidence suggests that breastfeeding or supplemental breast milk may reduce pain in neonates undergoing painful procedures compared to no intervention/positioning/holding or placebo or non-pharmacological interventions. Low-certainty evidence suggests that moderate concentration (20% to 33%) glucose/sucrose may lead to little or no difference in reducing pain compared to breastfeeding. The effectiveness of breast milk for painful procedures should be studied in the preterm population, as there are currently a limited number of studies that have assessed its effectiveness in this population.

Pain assessment tools for use in infants: a meta-review

BACKGROUND

Identifying pain in infants is challenging due to their inability to self-report pain, therefore the availability of valid and reliable means of assessing pain is critical.

OBJECTIVE

This meta-review sought to identify evidence that could guide the selection of appropriate tools in this vulnerable population.

METHODS

We searched Scopus, Medline, Embase, CINAHL, MIDRIS, EMCare and Google Scholar for eligible systematic reviews. Eligible reviews documented psychometric properties of available observational tools used to assess pain in infants.

RESULTS

A total of 516 reviews were identified of which 11 met our inclusion criteria. We identified 36 pain assessment tools (evaluated in 11 reviews) of which seven were reported in at least three reviews. The level of evidence reported on the psychometric properties of pain assessment tools varied widely ranging from low to good reliability and validity, whilst there are limited data on usability and clinical utility.

CONCLUSIONS

Currently, no observer administered pain assessment tool can be recommended as the gold standard due to limited availability and quality of the evidence that supports their validity, reliability and clinical utility. This meta-review attempts to collate the available evidence to assist clinicians to decide on what is the most appropriate tool to use in their clinical practice setting. It is important that researchers adopt a standard approach to evaluating the psychometric properties of pain assessment tools and evaluations of the clinical utility in order that the highest level of evidence can be used to guide tool selection.

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.

Physical pain among Indigenous Peoples in Canada: a scoping review

PURPOSE

Pain is a multifaceted experience shaped by various factors including context of pain, previous life events, and ongoing ethnocultural circumstances. Moreover, the definition of pain is inconsistent across cultures. Western medicine views physical pain (e.g., associated with a bone fracture) and nonphysical mental pain (e.g., depression) as two distinct conditions. Indigenous perspectives are often more wholistic, encompassing mental, spiritual, emotional, and physical hurt. The subjective nature of pain invites ample opportunity for discrimination in both its assessment and management. As such, it is important to consider Indigenous perspectives of pain in research and clinical practice. To investigate which aspects of Indigenous pain knowledge are currently considered by Western research, we conducted a scoping review of the literature on pain in Indigenous Peoples of Canada.

SOURCE

In June 2021, we searched nine databases and downloaded 8,220 papers after removal of duplicates. Two independent reviewers screened abstracts and full-text articles.

PRINCIPLE FINDINGS

Seventy-seven papers were included in the analysis. Using grounded theory, five themes emerged: pain measures/scales (n = 7), interventions (n = 13), pharmaceuticals (n = 17), pain expression/experiences (n = 45), and pain conditions (n = 70).

CONCLUSION

This scoping review shows that there is a paucity of research on pain measurement in Indigenous Peoples of Canada. This finding is concerning in light of numerous studies reporting that Indigenous Peoples experience their pain as ignored, minimized, or disbelieved. Furthermore, a clear disconnect emerged between pain expression in Indigenous Peoples and assessment in medical professionals. We hope that this scoping review will serve to translate current knowledge to other non-Indigenous academics and to initiate meaningful collaboration with Indigenous partners. Future research led by Indigenous academics and community partners is critically needed to better address pain needs in Canada.

Correlation between FLACC scale score and analgesic requirement in children undergoing Minimally Invasive Surgery

Postoperative pain presents several challenges in pediatric Minimally Invasive Surgery. The Faces, Legs, Activity, Cry, and Consolability (FLACC) scale is a valid scale for pediatric postoperative pain. The aim of our study was to assess postoperative pain using FLACC scale and to analyze the correlation between FLACC scale score and analgesic requirement in children underwent Minimally Invasive Surgery. We retrospectively analyzed data of 153 children aged 2 months-3 years who underwent Minimally Invasive Surgery in our unit from January 2019 and December 2019. Postoperative pain assessment was established using FLACC scale. In each patient were analyzed the correlation between FLACC score and analgesic requirement. Pain evaluation was assigned immediately after surgery and at 15 and 60 minutes. 36.6% of patients (56 children) were asleep so considered pain free; 21.6% of patients (33 children) had a FLACC score more than 7 so they required analgesics and the pain assessment 15 and 60 minutes after was significantly lower. 41.8% of patients (64 children) had a postoperative FLACC score less than 3, so they didn't require any analgesic treatment. On the basis of our results, we recommend FLACC scale for postoperative pain assessment in children underwent MIS aged 2 months-3 years. FLACC scale is an effective and precise scale in detection of postoperative analgesic requirement in children and it could be extended in different age groups with further research.

Clinical thresholds in pain-related facial activity linked to differences in cortical network activation in neonates

ABSTRACT

In neonates, a noxious stimulus elicits pain-related facial expression changes and distinct brain activity as measured by electroencephalography, but past research has revealed an inconsistent relationship between these responses. Facial activity is the most commonly used index of neonatal pain in clinical settings, with clinical thresholds determining if analgesia should be provided; however, we do not know if these thresholds are associated with differences in how the neonatal brain processes a noxious stimulus. The objective of this study was to examine whether subclinical vs clinically significant levels of pain-related facial activity are related to differences in the pattern of nociceptive brain activity in preterm and term neonates. We recorded whole-head electroencephalography and video in 78 neonates (0-14 days postnatal age) after a clinically required heel lance. Using an optimal constellation of Neonatal Facial Coding System actions (brow bulge, eye squeeze, and nasolabial furrow), we compared the serial network engagement (microstates) between neonates with and without clinically significant pain behaviour. Results revealed a sequence of nociceptive cortical network activation that was independent of pain-related behavior; however, a separate but interleaved sequence of early activity was related to the magnitude of the immediate behavioural response. Importantly, the degree of pain-related behavior is related to how the brain processes a stimulus and not simply the degree of cortical activation. This suggests that neonates who exhibit clinically significant pain behaviours process the stimulus differently and that neonatal pain-related behaviours reflect just a portion of the overall cortical pain response.

A self-training automatic infant-cry detector

Infant cry is one of the first distinctive and informative life signals observed after birth. Neonatologists and automatic assistive systems can analyse infant cry to early-detect pathologies. These analyses extensively use reference expert-curated databases containing annotated infant-cry audio samples. However, these databases are not publicly accessible because of their sensitive data. Moreover, the recorded data can under-represent specific phenomena or the operational conditions required by other medical teams. Additionally, building these databases requires significant investments that few hospitals can afford. This paper describes an open-source workflow for infant-cry detection, which identifies audio segments containing high-quality infant-cry samples with no other overlapping audio events (e.g. machine noise or adult speech). It requires minimal training because it trains an LSTM-with-self-attention model on infant-cry samples automatically detected from the recorded audio through cluster analysis and HMM classification. The audio signal processing uses energy and intonation acoustic features from 100-ms segments to improve spectral robustness to noise. The workflow annotates the input audio with intervals containing infant-cry samples suited for populating a database for neonatological and early diagnosis studies. On 16 min of hospital phone-audio recordings, it reached sufficient infant-cry detection accuracy in 3 neonatal care environments (nursery—69%, sub-intensive—82%, intensive—77%) involving 20 infants subject to heterogeneous cry stimuli, and had substantial agreement with an expert’s annotation. Our workflow is a cost-effective solution, particularly suited for a sub-intensive care environment, scalable to monitor from one to many infants. It allows a hospital to build and populate an extensive high-quality infant-cry database with a minimal investment.

Neonatal pain assessment: Do we have the right tools?

BACKGROUND

The assessment and management of neonatal pain is crucial for the development and wellbeing of vulnerable infants. Specifically, neonatal pain is associated with adverse health outcomes but is often under-identified and therefore under-treated. Neonatal stress may be misinterpreted as pain and may therefore be treated inappropriately. The assessment of neonatal pain is complicated by the non-verbal status of patients, age-dependent variation in pain responses, limited education on identifying pain in premature infants, and the clinical utility of existing tools.

OBJECTIVE

We review research surrounding neonatal pain assessment scales currently in use to assess neonatal pain in the neonatal intensive care unit.

METHODS

We performed a systematic review of original research using PRISMA guidelines for literature published between 2016 and 2021 using the key words "neonatal pain assessment" in the databases Web of Science, PubMed, and CINAHL. Fifteen articles remained after review, duplicate, irrelevant, or low-quality articles were eliminated.

RESULTS

We found research evaluating 13 neonatal pain scales. Important measurement categories include behavioral parameters, physiological parameters, continuous pain, acute pain, chronic pain, and the ability to distinguish between pain and stress. Provider education, inter-rater reliability and ease of use are important factors that contribute to an assessment tool's success. Each scale studied had strengths and limitations that aided or hindered its use for measuring neonatal pain in the neonatal intensive care unit, but no scale excelled in all areas identified as important for reliably identifying and measuring pain in this vulnerable population.

CONCLUSION

A more comprehensive neonatal pain assessment tool and more provider education on differences in pain signals in premature neonates may be needed to increase the clinical utility of pain scales that address the different aspects of neonatal pain.

Nonpharmacological Methods for Reducing Parental Concern for Infant Vaccine-Associated Pain

INTRODUCTION

Numerous studies demonstrate that parental concern for infant pain contributes to vaccine hesitancy. The purpose of this project was to alleviate parental concern for pain and facilitate infant immunization.

METHOD

Pediatric nurses at an urban ambulatory clinic implemented evidence-based nonpharmacological methods (breastfeeding or 24% sucrose solution) for managing vaccine pain in infants aged up to 6 months. A validated survey measured parental concern for vaccine-related pain before and after the implementation of pain relief interventions.

RESULTS

There was a statistically significant decrease in parental concern for vaccine pain from pre- to postintervention between both treatment groups (p = .035).

DISCUSSION

Nurses can effectively use nonpharmacological methods to alleviate the pain of infants undergoing routine vaccination while reducing the parental concern for vaccine-associated pain. Reducing infant pain and parental concern may increase vaccination rates.

Investigating convergence of cardiac and behavioral indicators of distress during routine vaccinations over the second year of life

There is considerable variability regarding the convergence between behavioral and biological aspects of distress responses in toddlerhood, and little research has investigated the convergence of these measures in high distress. The aim of the current study was to describe patterns of distress responses to vaccinations as indexed by both pain-related behavioral distress and heart rate (HR) at 12 and 18 months. Caregiver-toddler dyads were part of an ongoing longitudinal cohort observed during 12- (N = 158) and 18-month (N = 122) well-baby vaccinations. Parallel-process growth mixture models discerned two distinct groups at 12 months and three distinct groups at 18 months. All groups had comparable pain-related behavioral distress and HR responses post-vaccination, with most participants displaying high arousal and regulation to baseline levels following the vaccination. However, at 18 months, an important minority had a blunted response or did not regulate to a low level of distress by 3 min post-needle. Post hoc analyses revealed that higher baseline pain-related behavioral distress predicted membership in the majority groups at 12 and 18 months. These results highlight the developmental differences and variability in behavioral and cardiac indicators of distress regulation across the second year of life.

Neonatal pain: A journey spanning three decades

From 1980 into present day, 2020, the evolution of neonatal pain research is told as a journey by one researcher, Celeste Johnston. At the beginning of her work, there was essentially no interest or work in the area. She was fortunate to be led into the area by a clinical problem: how to determine the amount of pain babies in the NICU were experiencing. That question resulted in over three decades of work with neonates. Measuring pain was the first challenge and is one that remains a focus of current research. Initially, the only choices for treating pain in neonates were either opioids or anesthetics, each with problems. Research on sweet taste and more recently on skin‐to‐skin contact has offered effective and safe options for procedural pain. Although progress has been made in the incidence of pain management in infants, it still is far less than it could be. Steps along the way of measurement, treatment, and knowledge utilization are chronicled by this researcher.

A child in pain: A psychologist’s perspective on changing priorities in scientific understanding and clinical care

My research and clinical career followed a trajectory of increasing appreciation for the importance of social factors as determinants of pain experience and expression. The social contexts of children’s lives determine whether infants and children are exposed to pain, how socialization in family and ethnocultural contexts lead to pain as a social experience, comprised of thoughts and feelings as well as sensory input, how others shape pain experience and expression, less so for automatic/reflexive features than purposeful representations, and how other's appraisals of children’s pain reflect the observer's unique background and capacities for intervening in the child’s interests. A greater understanding of the social dimensions of pain, as reflected in the social communication model of pain, would support innovation of psychological and social interventions.

The challenge of developing pain medications for children: therapeutic needs and future perspectives

It is broadly accepted that children of all age groups including (preterm) neonates and young infants can perceive pain and that there is an absolute need to treat their pain safely and effectively. The approved treatment options for children, particularly (preterm) neonates and young infants, are very limited with only a few medications specifically labelled for this population. This article presents the challenges of developing pain medications for children. A short overview gives information on pain in children, including pain perception, prevalence of pain and the long-term consequences of leaving pain untreated in this vulnerable population. Current pain management practices are briefly discussed. The challenges of conducting pediatric clinical trials in general and trials involving analgesic medications in particular within the regulatory framework available to develop these medications for children are presented. Emphasis is given to the operational hurdles faced in conducting a pediatric clinical trial program. Some suggestions to overcome these hurdles are provided based on our experience during the pediatric trial program for the strong analgesic tapentadol used for the treatment of moderate to severe acute pain.

Video and audio processing in paediatrics: a review

OBJECTIVE

Video and sound acquisition and processing technologies have seen great improvements in recent decades, with many applications in the biomedical area. The aim of this paper is to review the overall state of the art of advances within these topics in paediatrics and to evaluate their potential application for monitoring in the neonatal intensive care unit (NICU).

APPROACH

For this purpose, more than 150 papers dealing with video and audio processing were reviewed. For both topics, clinical applications are described according to the considered cohorts-full-term newborns, infants and toddlers or preterm newborns. Then, processing methods are presented, in terms of data acquisition, feature extraction and characterization.

MAIN RESULTS

The paper first focuses on the exploitation of video recordings; these began to be automatically processed in the 2000s and we show that they have mainly been used to characterize infant motion. Other applications, including respiration and heart rate estimation and facial analysis, are also presented. Audio processing is then reviewed, with a focus on the analysis of crying. The first studies in this field focused on induced-pain cries and the newest ones deal with spontaneous cries; the analyses are mainly based on frequency features. Then, some papers dealing with non-cry signals are also discussed.

SIGNIFICANCE

Finally, we show that even if recent improvements in digital video and signal processing allow for increased automation of processing, the context of the NICU makes a fully automated analysis of long recordings problematic. A few proposals for overcoming some of the limitations are given.

The human newborn's umwelt: Unexplored pathways and perspectives

Historically, newborns, and especially premature newborns, were thought to "feel nothing." However, over the past decades, a growing body of evidence has shown that newborns are aware of their environment, but the extent and the onset of some sensory capacities remain largely unknown. The goal of this review is to update our current knowledge concerning newborns' perceptual world and how ready they are to cope with an entirely different sensory environment following birth. We aim to establish not only how and when each sensory ability arises during the pre-/postbirth period but also discuss how senses are studied. We conclude that although many studies converge to show that newborns are clearly sentient beings, much is still unknown. Further, we identify a series of internal and external factors that could explain discrepancies between studies, and we propose perspectives for future studies. Finally, through examples from animal studies, we illustrate the importance of this detailed knowledge to pursue the enhancement of newborns' daily living conditions. Indeed, this is a prerequisite for assessing the effects of the physical environment and routine procedures on newborns' welfare.

The influence of gestational age in the psychometric testing of the Bernese Pain Scale for Neonates

BACKGROUND

Assessing pain in neonates is challenging because full-term and preterm neonates of different gestational ages (GAs) have widely varied reactions to pain. We validated the Bernese Pain Scale for Neonates (BPSN) by testing its use among a large sample of neonates that represented all GAs.

METHODS

In this prospective multisite validation study, we assessed 154 neonates between 24 2/7 and 41 4/7 weeks GA, based on the results of 1-5 capillary heel sticks in their first 14 days of life. From each heel stick, we produced three video sequences: baseline; heel stick; and, recovery. Five blinded nurses rated neonates' pain responses according to the BPSN. The underlying factor structure of the BPSN, interrater reliability, concurrent validity with the Premature Infant Pain Profile-Revised (PIPP-R), construct validity, sensitivity and specificity, and the relationship between behavioural and physiological indicators were explored. We considered GA and gender as individual contextual factors.

RESULTS

The factor analyses resulted in a model where the following behaviours best fit the data: crying; facial expression; and, posture. Pain scores for these behavioural items increased on average more than 1 point during the heel stick phases compared to the baseline and recovery phases (p < 0.001). Among physiological items, heart rate was more sensitive to pain than oxygen saturation. Heart rate averaged 0.646 points higher during the heel stick than the recovery phases (p < 0.001). GA increased along with pain scores: for every additional week of gestation, the average increase of behavioural pain score was 0.063 points (SE = 0.01, t = 5.49); average heart rate increased 0.042 points (SE = 0.01, t = 6.15). Sensitivity and specificity analyses indicated that the cut-off should increase with GA. Modified BPSN showed good concurrent validity with the PIPP-R (r = 0.600-0.758, p < 0.001). Correlations between the modified behavioural subscale and the item heart rate were low (r = 0.102-0.379).

CONCLUSIONS

The modified BPSN that includes facial expression, crying, posture, and heart rate is a reliable and valid tool for assessing acute pain in full-term and preterm neonates, but our results suggest that adding different cut-off points for different GA-groups will improve the BPSN's clinical usefulness.

TRIAL REGISTRATION

The study was retrospectively registered in the database of Clinical Trial gov. Study ID-number: NCT 02749461 . Registration date: 12 April 2016.

Fundamental Frequency Variation of Neonatal Spontaneous Crying Predicts Language Acquisition in Preterm and Term Infants

Spontaneous cries of infants exhibit rich melodic features (i.e., time variation of fundamental frequency [F0 ]) even during the neonatal period, and the development of these characteristics might provide an essential base for later expressive prosody in language. However, little is known about the melodic features of spontaneous cries in preterm infants, who have a higher risk of later language-related problems. Thus, the present study investigated how preterm birth influenced melodic features of spontaneous crying at term-equivalent age as well as how these melodic features related to language outcomes at 18 months of corrected age in preterm and term infants. At term, moderate-to-late preterm (MLP) infants showed spontaneous cries with significantly higher F0 variation and melody complexity than term infants, while there were no significant differences between very preterm (VP) and term infants. Furthermore, larger F0 variation within cry series at term was significantly related to better language and cognitive outcomes, particularly expressive language skills, at 18 months. On the other hand, no other melodic features at term predicted any developmental outcomes at 18 months. The present results suggest that the additional postnatal vocal experience of MLP preterm infants increased F0 variation and the complexity of spontaneous cries at term. Additionally, the increases in F0 variation may partly reflect the development of voluntary vocal control, which, in turn, contributes to expressive language in infancy.

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.

EDIN Scale Implemented by Gestational Age for Pain Assessment in Preterms: A Prospective Study

Background. Chronic neonatal pain can lead to long-term adverse effects on the immature brain. EDIN scale for prolonged pain might not be fully suitable for premature infants. We aimed to test a modified EDIN scale, adding postmenstrual age (PMA) as a sixth item (EDIN6). Methods. In a two-phase prospective study, pain was assessed in all neonates admitted in our NICU. In T1 EDIN was applied; in T2 EDIN6 with additional scores of 2, 1, and 0, respectively, for 25–32, 33–37, and >37 weeks PCA was tested. Scores > 6 suggested pain. The nursing staff was given a questionnaire to evaluate EDIN and EDIN6. Results. A total of 15960 pain assessments were recorded (8693 in T1; 7267 in T2). With EDIN6, cumulative detection of pain almost tripled (117/7267 versus 52/8693, p = 0.001). Main differences were found among less mature categories (50/1472 versus 17/1734, p = 0.001 in PCA 25–32; 26/2606 versus 10/4335, p = 0.001 in PMA 33–37; 41/3189 versus 25/2624, p = 0.26 in PMA > 37). Adequacy of pain assessment in lower PMA was judged “medium-high” in 13,4% of nurses in T1 and 71,4% in T2. Conclusions. EDIN6 may allow improved evaluation of pain in preterm infants.

Should Surgery for Hypospadias Be Performed Before An Age of Consent?

Hypospadias is a relatively common genital condition in which the urethral opening forms on the underside of the penis, as opposed to at the tip of the glans. Patients with hypospadias are typically referred for surgery during infancy or early childhood. Recent evidence, however, indicates that many individuals with hypospadias do not experience the functional or psychosocial difficulties commonly attributed to the condition, and that surgical intervention for hypospadias carries substantial risk of adverse outcomes. In this article, we review published outcomes data and conduct an in-depth analysis of the typical rationales for hypospadias surgery, taking into consideration both the potential benefits and harms of the procedure, as well as the existence of nonsurgical alternatives. We argue, first, that most childhood surgeries for hypospadias are performed for anticipated future problems concerning function and cosmesis, rather than extant physical and/or psychosocial problems that are adversely affecting the child's well-being. Second, we contend that the surgery can be safely performed after an age of consent without increasing the absolute risk of surgical complications to an ethically meaningful degree. We conclude, therefore, that surgery for hypospadias should be performed only if requested by the affected individual, under conditions of informed consent.

Associations between respiratory arrhythmia and fundamental frequency of spontaneous crying in preterm and term infants at term-equivalent age

This study investigated whether lower vagal function in preterm infants is associated with increased fundamental frequency (F₀; frequency of vocal fold vibration) of their spontaneous cries. We assessed respiratory sinus arrhythmia (RSA) during quiet sleep as a measure of vagal function, and its relationship with the F₀ of spontaneous cries in healthy preterm and term infants at term‐equivalent age. The results showed that preterm infants have significantly lower RSA, and higher overall F₀ than term infants. Moreover, lower RSA was associated with higher overall F₀ in preterm infants, whereas higher RSA was positively associated with mean and maximum F₀, and a larger F₀ range in term infants. These results suggest that individual differences in vagal function may be associated with the F₀ of spontaneous cries via modulation of vocal fold tension in infants at an early developmental stage. © 2016 The Authors. Developmental Psychobiology Published by Wiley Periodicals, Inc. Dev Psychobiol 58:724–733, 2016.

Pain-Related Reactions among Premature Infants with Gestational Age Less than 26 Weeks: An Observational Cohort Study

INTRODUCTION

There is insufficient information regarding acute pain reactions among premature infants with a gestational age of less than 26 weeks and no appropriate scale for pain measurement in this age group. We hypothesized that these infants present specific reactions to a standardized pain stimulus within the first 3 days of life.

METHODOLOGY

Mixed-methods, prospective, open-label, single-arm, observational study. Routine capillary or peripheral blood takes were filmed. The model consisting of a baseline, a preparatory, an interventional and a return-to-baseline phase was filmed. After a pilot evaluation, experienced medical and nursing neonatal intensive care unit (NICU) staff analysed the videos.

RESULTS

Twenty infants with gestational ages ranging from 22 weeks and 3 days to 26 weeks (mean 24 weeks) were recruited. Nineteen infants showed pain reactions, with a mean latency of 8.3 s (range 2-30). The majority presented eye movements, changes of the breath pattern and a slight increase in the mean SpO2 value. A high degree of interrater and intrarater reliability was found.

DISCUSSION

Premature infants with a gestational age of up to 26 weeks can present a variety of discrete reactions as response to a pain stimulus within the first 72 h of life. Experienced NICU staff can perform a valid and reliable evaluation of these reactions.

Non-pharmacological management of infant and young child procedural pain

BACKGROUND

Infant acute pain and distress is commonplace. Infancy is a period of exponential development. Unrelieved pain and distress can have implications across the lifespan.  This is an update of a previously published review in the Cochrane Database of Systematic Reviews, Issue 10 2011 entitled 'Non-pharmacological management of infant and young child procedural pain'.

OBJECTIVES

To assess the efficacy of non-pharmacological interventions for infant and child (up to three years) acute pain, excluding kangaroo care, and music. Analyses were run separately for infant age (preterm, neonate, older) and pain response (pain reactivity, immediate pain regulation). 

SEARCH METHODS

For this update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 2 of 12, 2015), MEDLINE-Ovid platform (March 2015), EMBASE-OVID platform (April 2011 to March 2015), PsycINFO-OVID platform (April 2011 to February 2015), and CINAHL-EBSCO platform (April 2011 to March 2015). We also searched reference lists and contacted researchers via electronic list-serves. New studies were incorporated into the review. We refined search strategies with a Cochrane-affiliated librarian. For this update, nine articles from the original 2011 review pertaining to Kangaroo Care were excluded, but 21 additional studies were added.

SELECTION CRITERIA

Participants included infants from birth to three years. Only randomised controlled trials (RCTs) or RCT cross-overs that had a no-treatment control comparison were eligible for inclusion in the analyses. However, when the additive effects of a non-pharmacological intervention could be assessed, these studies were also included. We examined studies that met all inclusion criteria except for study design (e.g. had an active control) to qualitatively contextualize results. There were 63 included articles in the current update.

DATA COLLECTION AND ANALYSIS

Study quality ratings and risk of bias were based on the Cochrane Risk of Bias Tool and GRADE approach. We analysed the standardized mean difference (SMD) using the generic inverse variance method.

MAIN RESULTS

Sixty-three studies, with 4905 participants, were analysed. The most commonly studied acute procedures were heel-sticks (32 studies) and needles (17 studies). The largest SMD for treatment improvement over control conditions on pain reactivity were: non-nutritive sucking-related interventions (neonate: SMD -1.20, 95% CI -2.01 to -0.38) and swaddling/facilitated tucking (preterm: SMD -0.89; 95% CI -1.37 to -0.40). For immediate pain regulation, the largest SMDs were: non-nutritive sucking-related interventions (preterm: SMD -0.43; 95% CI -0.63 to -0.23; neonate: SMD -0.90; 95% CI -1.54 to -0.25; older infant: SMD -1.34; 95% CI -2.14 to -0.54), swaddling/facilitated tucking (preterm: SMD -0.71; 95% CI -1.00 to -0.43), and rocking/holding (neonate: SMD -0.75; 95% CI -1.20 to -0.30). Fifty two of our 63 trials did not report adverse events. The presence of significant heterogeneity limited our confidence in the findings for certain analyses, as did the preponderance of very low quality evidence.

AUTHORS' CONCLUSIONS

There is evidence that different non-pharmacological interventions can be used with preterms, neonates, and older infants to significantly manage pain behaviors associated with acutely painful procedures. The most established evidence was for non-nutritive sucking, swaddling/facilitated tucking, and rocking/holding. All analyses reflected that more research is needed to bolster our confidence in the direction of the findings. There are significant gaps in the existing literature on non-pharmacological management of acute pain in infancy.

Intraurethral Lidocaine for Urethral Catheterization in Children: A Randomized Controlled Trial

OBJECTIVES

To determine whether lidocaine is superior to nonanesthetic lubricant (NAL) for relieving pain in children undergoing urethral catheterization (UC).

METHODS

Children 0 to 24 months requiring UC were randomized to NAL or topical and intraurethral 2% lidocaine gel. Primary outcome was facial grimacing in the pre to during drug administration and catheterization phases. Secondary outcome was caregiver satisfaction by using a Visual Analog Scale.

RESULTS

There were 133 participants (n = 68 lidocaine, n = 65 NAL). There were no significant differences in mean (SD) scores during UC between lidocaine and NAL (86.4% [121.5%] vs 85.2% [126.6%]), respectively (Δ [confidence interval (CI)] = -1.2 [-21.0 to 49.0], P = .4). There was a significantly greater difference in mean (SD) scores during instillation of lidocaine versus NAL (61.8% [105.6%] vs 3.2% [84.9%]), respectively (Δ [CI] -58.6 [-95.0 to -32.0], P < .001). There were no significant differences in mean (SD) parental satisfaction scores between lidocaine and NAL (4.8 [3.2] vs 5.9 [2.9]), respectively (CI-0.1 to 2.2; P = .06). In the subgroup analysis, age, gender, and positive urine culture did not significantly influence between-group differences in facial grimacing.

CONCLUSIONS

Compared with NAL, topical and intraurethral lidocaine is not associated with significant pain reduction during UC, but significantly greater pain during instillation. Therefore, clinicians may consider using noninvasive pain-reducing strategies for young children who require UC.

Cerebral Oxygenation and Pain of Heel Blood Sampling Using Manual and Automatic Lancets in Premature Infants

Heel blood sampling is a common but painful procedure for neonates. Automatic lancets have been shown to be more effective, with reduced pain and tissue damage, than manual lancets, but the effects of lancet type on cortical activation have not yet been compared. The study aimed to compare the effects of manual and automatic lancets on cerebral oxygenation and pain of heel blood sampling in 24 premature infants with respiratory distress syndrome. Effectiveness was measured by assessing numbers of pricks and squeezes and duration of heel blood sampling. Pain responses were measured using the premature infant pain profile score, heart rate, and oxygen saturation (SpO2). Regional cerebral oxygen saturation (rScO2) was measured using near-infrared spectroscopy, and cerebral fractional tissue oxygen extraction was calculated from SpO2 and rScO. Measures of effectiveness were significantly better with automatic than with manual lancing, including fewer heel punctures (P = .009) and squeezes (P < .001) and shorter duration of heel blood sampling (P = .002). rScO2 was significantly higher (P = .013) and cerebral fractional tissue oxygen extraction after puncture significantly lower (P = .040) with automatic lancing. Premature infant pain profile scores during (P = .004) and after (P = .048) puncture were significantly lower in the automatic than in the manual lancet group. Automatic lancets for heel blood sampling in neonates with respiratory distress syndrome significantly reduced pain and enhanced cerebral oxygenation, suggesting that heel blood should be sampled routinely using an automatic lancet.

Early postnatal nociceptive stimulation results in deficits of spatial memory in male rats

Prematurely-born infants are exposed to multiple invasive procedures while in the intensive care unit. Newborn rats and humans have similar behavioral responses to noxious stimulation. Previous studies have shown that early noxious stimuli may alter dentate gyrus neurogenesis and the behavioral repertoire of adult rats. We evaluated the late effects of noxious stimulation administered during different phases of development on two spatial memory tests; object recognition (OR) and Morris water maze (WM) tests. Noxious stimulation was induced by an intra-plantar injection of complete Freund's adjuvant (CFA) on postnatal (P) day 1 (group P1) or 8 (P8). Control animals were not stimulated. Behavioral tests were conducted on P60 in both male and female animals. In the WM, three domains were evaluated: acquisition, probe trial performance and reversal re-acquisition. The number of Nissl stained cells in the dentate granule cell layer was assessed by stereological counting. The OR test revealed that P1 male rats had poor long-term memory compared to the control and P8 groups. In the WM, no short- or long-term memory differences were detected between early postnatal-stimulated male and female rats and their respective controls. However, the ability to find the hidden platform in a new position was reduced in P1 male rats. The number of dentate granule cells in P8 males was higher than in all other groups. This study demonstrates that noxious stimulation on P1 results in spatial learning deficits in male animals, but does not disrupt the development of the hippocampus-dependent strategies of learning and memory.

Sensitive periods in human social development: New insights from research on oxytocin, synchrony, and high-risk parenting

Sensitive periods (SP) in behavioral development appeared in the biological sciences during the first decade of the 20th century, and research in animal models beginning in the 1950s provide terminology and evidence for SP effects. This paper proposes a rigorous program for human SP research and argues that the complexity of the human brain and variability of the human ecology necessitate that SP effects must be studied in humans, employ longitudinal designs starting at birth, test mechanism-based hypotheses based on animal studies that manipulate early environments, and utilize high-risk conditions as “natural experiments.” In light of research on the molecular basis of critical periods and their sequential cascades, it is proposed that the oxytocin (OT) system, an ancient and integrative system that cross-talks with the stress, reward, immune, and brain stem mediated homeostatic systems and supports mammalian sociality, plays a unique role in experience-dependent plasticity that buttresses SP effects due to its (a) dendritic mode of release leading to autoregulated functioning primed by early experience, (b) pulsatile pattern of activity, and (c) special role in neural plasticity at the molecular and network assembly levels. Synchrony, the coordination of biology and behavior during social contact, is suggested as a mechanism by which SP exert their effect on OT functionality, the social brain, and adult sociality. Findings from four high-risk birth cohorts, each followed repeatedly from birth to 10 years, provide unique “natural experiments” for human SP research based on specific programs in animal models. These include prematurity (maternal proximity), multiple birth (peer rearing), postpartum depression (low licking and grooming), and chronic unpredictable trauma (maternal rotation, variable foraging demands). In each cohort, hypotheses are based on the missing environmental component during SP, and findings on social synchrony, OT functionality, stress response, emotion regulation, and mental health accord with the multilevel and dynamic principles of developmental psychopathology. The results on the potential for reparation versus chronicity following early deprivation highlight a flexible conceptualization of resilience based on human SP research. Consideration of SP effects at the molecular, endocrine, brain, and behavioral levels and in relation to the neural plasticity and multifinality of human social functions may assist in fine-tuning early detection and the construction of targeted individualized interventions.

Preterm birth is associated with an increased fundamental frequency of spontaneous crying in human infants at term-equivalent age

Human infant crying has been researched as a non-invasive tool for assessing neurophysiological states at an early developmental stage. Little is known about the acoustic features of spontaneous cries in preterm infants, although their pain-induced cries are at a higher fundamental frequency (F₀) before term-equivalent age. In this study, we investigated the effects of gestational age, body size at recording and intrauterine growth retardation (IUGR) on the F₀ of spontaneous cries in healthy preterm and full-term infants at term-equivalent age. We found that shorter gestational age was significantly associated with higher F₀, although neither smaller body size at recording nor IUGR was related to increased F₀ in preterm infants. These findings suggest that the increased F₀ of spontaneous cries is not caused by their smaller body size, but instead might be caused by more complicated neurophysiological states owing to their different intrauterine and extrauterine experiences.

A systematic review and meta-analyses of nonsucrose sweet solutions for pain relief in neonates

BACKGROUND

Sucrose has been demonstrated to provide analgesia for minor painful procedures in infants. However, results of trials investigating other sweet solutions for neonatal pain relief have not yet been synthesized.

OBJECTIVE

To establish the efficacy of nonsucrose sweet-tasting solutions for pain relief during painful procedures in neonates.

METHOD

The present article is a systematic review and meta-analyses of the literature. Standard methods of the Cochrane Neonatal Collaborative Review Group were used. Literature searches were reviewed for randomized controlled trials investigating the use of sweet solutions, except sucrose, for procedural pain management in neonates. Outcomes assessed included validated pain measures and behavioural and physiological indicators.

RESULTS

Thirty-eight studies (3785 neonates) were included, 35 of which investigated glucose. Heel lancing was performed in 21⁄38 studies and venipuncture in 11⁄38 studies. A 3.6-point reduction in Premature Infant Pain Profile scores during heel lances was observed in studies comparing 20% to 30% glucose with no intervention (two studies, 124 neonates; mean difference -3.6 [95% CI -4.6 to -2.6]; P<0.001; I2=54%). A significant reduction in the incidence of cry after venipuncture for infants receiving 25% to 30% glucose versus water or no intervention was observed (three studies, 130 infants; risk difference -0.18 [95% CI -0.31 to -0.05]; P=0.008, number needed to treat = 6 [95% CI 3 to 20]; I2=63%).

CONCLUSIONS

The present systematic review and meta-analyses demonstrate that glucose reduces pain scores and crying during single heel lances and venipunctures. Results indicate that 20% to 30% glucose solutions have analgesic effects and can be recommended as an alternative to sucrose for procedural pain reduction in healthy term and preterm neonates.

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.

Sex-related long-term behavioral and hippocampal cellular alterations after nociceptive stimulation throughout postnatal development in rats

Early noxious stimuli may alter the neurogenesis rate in the dentate gyrus and the behavioral repertoire of adult rats. This study evaluated the long-term effects of noxious stimulation, imposed in different phases of development, on nociceptive and anxiety-like behaviors, hippocampal activation, cell proliferation, hippocampal BDNF and plasma corticosterone levels in 40 day-old male and female adolescents. Noxious stimulation was induced by intra-plantar injection of Complete Freund's adjuvant (CFA), on postnatal days (P) 1 (group P1), 8 (P8) or 21 (P21). Control animals were not stimulated in any way. On P21 a subset of animals from each group received BrdU and was perfused on P40 for identification of proliferating cells in the granule cell layer of the dentate gyrus. Another subset of rats was subjected to behavioral testing on P40 and one week later, to magnetic resonance imaging (MRI) acquisition. Noxious stimulation evoked hypoalgesia in adolescents, mainly in females (P < 0.02), reflected by greater latency to withdraw the paw and less paw lickings in the hot plate test than controls (P < 0.001). It also resulted in more time spent in the open arms, e.g., less anxiety-like behavior than controls (P < 0.01), especially in females (P < 0.01, compared with males). Proliferative cell rate in the dentate gyrus was the highest in P8 males and females (P < 0.001), with males exhibiting more proliferation than females on P1 and P8, which was directly related to the hippocampal levels of BDNF and inversely related to plasma corticosterone. Sex differences were also detected in manganese-enhanced MRI signal, which was more prominent in P1 females than males (P < 0.01). This study represents the first step of investigation on the cellular basis of the sex-dependent long-term consequences of nociceptive stimuli in newborns.

Neonatal Food Restriction Induces Hypoplasia in Developing Facial Motor Neurons of Rats

The effects of neonatal food restriction upon the dendritic development of facial nucleus (FN) motor neurons of Wistar rats were analyzed. Rats neonatally underfed by daily (12 h) mother-litter separation in an incubator from 5-30 days after birth exhibited, in brain stem Golgi-Cox sections, significant reductions in the number and extension of stellate, triangular and bipolar FN neuronal dendritic prolongations with negligible effects upon perikarya measurements. Data suggest that in the underfed newborn, the ability of FN neurons to establish synaptic contacts with afferent fibers is reduced, which then interferes with their capacities for the integration and triggering of nerve impulses to modulate facial motor expression in response to sensory cues.

Expressed breast milk for procedural pain in preterm neonates: a randomized, double-blind, placebo-controlled trial

AIM

To determine whether expressed breast milk (milk) reduces procedural pain associated with heel lancing in preterm neonates.

METHODS

In this placebo-controlled trial, preterm neonates received 5 mL of distilled water as placebo (water, n = 44), 25% glucose water (glucose, n = 39) or milk (n = 40). Heel lancing was performed 2 min later. The primary outcome was the duration of first cry after lancing.

RESULTS

Participants had similar baseline demographic and clinical characteristics. There was a significant difference in the median duration of first cry among the groups: water = 70.5 sec [interquartile range (IQR) = 5.5-104.5]; glucose = 2.0 sec (IQR = 0.0-45.0); milk = 29.5 sec (IQR = 0.0-65.0). Specifically, the duration of first cry was significantly shorter in the glucose group compared with the water group (Bonferroni adjustment, p = 0.011). Pain scores were significantly lower in the glucose and milk groups compared with the water group 1, 2 and 3 min after heel lancing (p < 0.05).

CONCLUSIONS

Although milk did not significantly reduce crying time, our finding that pain scores were significantly lower in the milk group suggests that milk may reduce pain associated with heel lancing in preterm neonates.

Breastfeeding or breast milk for procedural pain in neonates

BACKGROUND

Physiological changes brought about by pain may contribute to the development of morbidity in neonates. Clinical studies have shown reduction in changes in physiological parameters and pain score measurements following pre-emptive analgesic administration in situations where the neonate is experiencing pain or stress. Non-pharmacological measures (such as holding, swaddling and breastfeeding) and pharmacological measures (such as acetaminophen, sucrose and opioids) have been used for this purpose.

OBJECTIVES

The primary objective was to evaluate the effectiveness of breastfeeding or supplemental breast milk in reducing procedural pain in neonates. The secondary objective was to conduct subgroup analyses based on the type of control intervention, gestational age and the amount of supplemental breast milk given.

SEARCH METHODS

We performed a literature search using the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 10), MEDLINE (1966 to February 2011), EMBASE (1980 to February 2011), CINAHL (1982 to February 2011), abstracts from the annual meetings of the Society for Pediatric Research (1994 to 2011), and major paediatric pain conference proceedings. We did not apply any language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs of breastfeeding or supplemental breast milk versus no treatment/other measures in neonates were eligible for inclusion in this review. The study must have reported on either physiologic markers of pain or validated pain scores.

DATA COLLECTION AND ANALYSIS

We assessed the methodological quality of the trials using the information provided in the studies and by personal communication with the authors. We extracted data on relevant outcomes, estimated the effect size and reported this as a risk ratio (RR), risk difference (RD) and weighted mean difference (MD) as appropriate.

MAIN RESULTS

Of twenty eligible studies, ten evaluated breastfeeding and ten evaluated supplemental breast milk. Sixteen studies analysed used heel lance and four used venepuncture as procedure. We noted marked heterogeneity in control intervention and pain assessment measures among the studies. Neonates in the breastfeeding group had statistically a significantly lower increase in heart rate, reduced proportion of crying time and reduced duration of first cry and total crying time compared to positioning (swaddled and placed in a crib), holding by mother, placebo, pacifier use, no intervention or oral sucrose group, or both.Premature Infant Pain Profile (PIPP) scores were significantly lower in the breastfeeding group compared to positioning, placebo or oral sucrose group, or both. However, there was no statistically significant difference in PIPP scores when compared to no intervention. Douleur Aigue Nouveau-ne scores (DAN) were significantly lower in the breastfeeding group compared to the placebo group and the group held in mother's arms, but not when compared to the glucose group. Neonatal Infant Pain Scale (NIPS) was significantly lower in the breastfeeding group compared to the no intervention group, but there was no difference when compared to the oral sucrose group. The Neonatal Facial Coding System (NFCS) was significantly lower in the breastfeeding group when compared to oral glucose, pacifier use, holding by mother and no intervention, but no difference was found when compared to formula feeding.Supplemental breast milk yielded variable results. Neonates in the supplemental breast milk group had a significantly lower increase in heart rate, a reduction in duration of crying and a lower NFCS compared to the placebo group. Neonates in the supplemental breast milk group had a significantly higher increase in heart rate changes when compared to the sucrose group. Sucrose (in any concentration, i.e. 12.5%, 20%, 25%) was found to reduce the duration of cry when compared to breast milk, as did glycine, pacifier use, rocking, or no intervention. Breast milk was found not to be effective in reducing validated and non-validated pain scores such as NIPS, NFCS, and DAN; only being significantly better when compared to placebo (water) or massage. We did not identify any study that has evaluated safety/effectiveness of repeated administration of breastfeeding or supplemental breast milk for pain relief.

AUTHORS' CONCLUSIONS

If available, breastfeeding or breast milk should be used to alleviate procedural pain in neonates undergoing a single painful procedure rather than placebo, positioning or no intervention. Administration of glucose/sucrose had similar effectiveness as breastfeeding for reducing pain. The effectiveness of breast milk for painful procedure should be studied in the preterm population, as there are currently a limited number of studies in the literature that have assessed it's effectiveness in this population.

Analgesic effect of 30% glucose, milk and non-nutritive sucking in neonates

Background

The aim of this study was to evaluate nondrug management practices concerning pain induced by blood sampling in newborns in a Moroccan neonatal unit and to determine whether the results reported from a randomized clinical study of nondrug analgesia could be reproduced in a routine care setting.

Methods

Standardized prospective observation of analgesic practices used during blood sampling was performed. Pain was assessed using the Douleur Aiguë Nouveau-né (DAN, [Newborn Acute Pain]) scale that incorporates facial expression, vocal expression, and limb movements of the newborn during realization of a painful procedure. Five different nondrug analgesic practices were investigated in 125 infants.

Results

Median DAN scores for the five methods were 6 (1–10) for venous sampling with oral administration of 30% glucose, 5 (1–10) for venous sampling with sucking, 3 (0–6) for venous sampling with oral administration of 30% glucose combined with sucking, 4 (0–10) for venous sampling with oral administration of 30% glucose combined with sucking and administration of 2 mL of adapted infant formula, and 6 (3–8) for venous sampling with administration of 2 mL of adapted infant formula.

Conclusion

Oral administration of 30% glucose combined with sucking provided better control of pain induced by blood sampling in newborns at our neonatal unit.

'I was just screeching!': comparing child and parent derived measures of distress

Two studies explored relationships between children's (2-13 years old) descriptions of how much they had cried and two other ways of assessing children's distress during injuries and subsequent hospital treatment, one parent-generated and the other child-generated. In the first study, 201 2- to 13-year-old children's descriptions of crying were compared with parental ratings of child distress, and in the second, these two measures plus a Faces Pain Scale were compared for 71 2- to 6-year-olds. Children's self-descriptions of crying were highly similar to parental ratings at all ages, but the Faces Pain Scale had less similarity to other measures, especially for younger preschoolers. Findings suggest that children's self-descriptions of emotional reactions may be a useful tool for assessing children's distress for real-world events with no adult witnesses.

Ontogeny of the pain

The article gives an overview of developmental aspects of the ontogeny of pain both in experimental models and in children. The whole article is devoted to the ontogenesis in pain perception and the possible influence on it. The role of endogenous opioids on the development of pain and other important substances such as serotonin, nerve growth factor (NGF) and nicotine are mentioned. There are also important differences of the ontogenesis of thermal and mechanical nociceptive stimulation. The physiological and pathophysiological findings are the backgrounds for principles of treatment, taking into account the special status of analgesics during ontogeny. In particular there are mentioned the special effects of endogenous opioids and especially morphine. It describes the role of vitamin D and erythropoietin during the development of pain perception. This article also mentioned the critical developmental periods in relation to the perception of pain. The attention is paid to stress and immunological changes during the ontogeny of pain. Another important role is played by microglia. The work is concluded by some statements about the use of physiological and pathophysiological findings during the treatment of pain in pediatric practice. Codein analgesia is also described because codein starts to be very modern drug with the dependence.

Nonpharmacological management of procedural pain in infants and young children: an abridged Cochrane review

BACKGROUND

Acute pain and distress during medical procedures are commonplace for young children.

OBJECTIVE

To assess the efficacy of nonpharmacological interventions for acute procedural pain in children up to three years of age.

METHODS

Study inclusion criteria were: participants <3 years of age, involved in a randomized controlled or crossover trial, and use of a 'no treatment' control group (51 studies; n=3396). Additional studies meeting all criteria except for study design (eg, use of active control group) were qualitatively described (n=20).

RESULTS

For every intervention, data were analyzed separately according to age group (preterm-born, term-born neonate and older infant ⁄ young child) and type of pain response (pain reactivity, immediate pain-related regulation). The largest standardized mean differences (SMD) for pain reactivity were as follows: sucking-related interventions (preterm: -0.42 [95% CI -0.68 to -0.15]; neonate -1.45 [CI -2.34 to -0.57]), kangaroo care (preterm -1.12 [95% CI -2.04 to -0.21]), and swaddling ⁄ facilitated tucking (preterm -0.97 [95% CI -1.63 to -0.31]). For immediate pain-related regulation, the largest SMDs were: sucking-related interventions (preterm -0.38 [95% CI -0.59 to -0.17]; neonate -0.90 [CI -1.54 to -0.25]), kangaroo care 0.77 (95% CI -1.50 to -0.03]), swaddling ⁄ facilitated tucking (preterm -0.75 [95% CI -1.14 to -0.36]), and rocking ⁄ holding (neonate -0.75 [95% CI -1.20 to -0.30]). The presence of significant heterogeneity limited confidence in nonsignificant findings for certain other analyses.

CONCLUSIONS

Although a number of nonpharmacological treatments have sufficient evidence supporting their efficacy with preterm infants and healthy neonates, no treatments had sufficient evidence to support efficacy with healthy older infants ⁄ young children.