Somatosensory function and pain in extremely preterm young adults from the UK EPICure cohort: sex-dependent differences and impact of neonatal surgery

Macrophage memories of early-life injury drive neonatal nociceptive priming

The developing peripheral nervous and immune systems are functionally distinct from those of adults. These systems are vulnerable to early-life injury, which influences outcomes related to nociception following subsequent injury later in life (i.e., "neonatal nociceptive priming"). The underpinnings of this phenomenon are unclear, although previous work indicates that macrophages are trained by inflammation and injury. Our findings show that macrophages are both necessary and partially sufficient to drive neonatal nociceptive priming, possibly due to a long-lasting remodeling in chromatin structure. The p75 neurotrophic factor receptor is an important effector in regulating neonatal nociceptive priming through modulation of the inflammatory profile of rodent and human macrophages. This "pain memory" is long lasting in females and can be transferred to a naive host to alter sex-specific pain-related behaviors. This study reveals a mechanism by which acute, neonatal post-surgical pain drives a peripheral immune-related predisposition to persistent pain following a subsequent injury.

Neonatal nociceptive stimulation results in pain sensitization, reduction of hippocampal 5-HT1A receptor, and p-CREB expression in adult female rats

Painful invasive procedures are often performed on newborns admitted to intensive care units (ICU). The acute and long-term effects caused by these stimuli can be investigated in animal models, such as newborn rats. Previous studies have shown that animals subjected to nociceptive stimuli in the neonatal period show sex-specific behavioral changes such as signs of anxiety or depression. Under the same conditions, neonatal stimuli also provoke an increase in the rate of neurogenesis and cell activation in the hippocampal dentate gyrus. So, this study aims to identify the possible roles of central monoamines, receptor expression (5-HT1A), and signaling factors (p-CREB) underlying the long-term effects of neonatal nociceptive stimulation. For this, noxious stimulation was induced by intra-plantar injection of Complete Freund´s adjuvant (CFA) on the postnatal day 1 (P1) or 8 (P8). Control animals were not stimulated. On P75 the behavioral tests were conducted (hotplate and elevated plus maze), followed by sacrifice and molecular studies. Our results showed that neonatal nociceptive stimulation alters pain sensitization specially in females, while stimulation on P1 increases pain threshold, P8-stimulated animals respond with reduced pain threshold (P < 0.001). Hippocampal expression of 5-HT1A receptor and p-CREB were reduced in P8 F group (P < 0.001) in opposition to the increased utilization rate of dopamine and serotonin in this group (P < 0.05). This study shows sex- and age-specific responses of signaling pathways within the hippocampus accompanied by altered behavioral repertoire, at long-term after neonatal painful stimulation.

A comparison of the effect of procedural pain on cerebral oxygen saturation between late preterm and term infants

OBJECTIVES

We prospectively compared cerebral oxygen saturation (CrSO2) and pain score changes during procedures in late preterm (LPT) versus term infants.

METHODS

Near-infrared spectroscopy, pulse oximetry, Neonatal Infant Pain Scale (NIPS) and Premature Infant Pain Profile-Revised (PIPP-R) scores were assessed and CrSO2 data analyzed.

RESULTS

Thirty infants in each group were evaluated. LPT infants displayed a milder significant drop in Minimum post-procedural CrSO2 and smaller Maximum-Minimum post-procedural CrSO2 disparity. CrSO2 minute changes between the groups were non-significant. Moderate correlations were observed in both groups between NIPS and Minimum post-procedural CrSO2, and a moderate correlation was found in the Maximum-Minimum post-procedural CrSO2 difference in LPT infants. No correlation between PIPP-R and CrSO2 values was noted.

CONCLUSION

LPT and term infants demonstrated decreased CrSO2 in response to painful procedures. Correlations between CrSO2 and PIPP-R or NIPS scores were poor to moderate, reflecting the complex nature of these associations relative to gestational age.

Repetitive neonatal procedural pain affects stress-induced plasma corticosterone increase in young adult females but not in male rats

Exposure to repetitive painful procedures in the neonatal intensive care unit results in long-lasting effects, especially visible after a "second hit" in adulthood. As the nociceptive system and the hypothalamic-pituitary-adrenal (HPA) axis interact and are vulnerable in early life, repetitive painful procedures in neonates may affect later-life HPA axis reactivity. The first aim of the present study was to investigate the effects of repetitive neonatal procedural pain on plasma corticosterone levels after mild acute stress (MAS) in young adult rats. Second, the study examined if MAS acts as a "second hit" and affects mechanical sensitivity. Fifty-two rats were either needle pricked four times a day, disturbed, or left undisturbed during the first neonatal week. At 8 weeks, the animals were subjected to MAS, and plasma was collected before (t0), after MAS (t20), and at recovery (t60). Corticosterone levels were analyzed using an enzyme-linked immunosorbent assay, and mechanical sensitivity was assessed with von Frey filaments. Results demonstrate that repetitive neonatal procedural pain reduces stress-induced plasma corticosterone increase after MAS only in young adult females and not in males. Furthermore, MAS does not affect mechanical sensitivity in young adult rats. Altogether, the results suggest an age- and sex-dependent effect of repetitive neonatal procedural pain on HPA axis reprogramming.

Understanding the unique and common perspectives of partners engaged in knowledge mobilization activities within pediatric pain management: a mixed methods study

BACKGROUND

Knowledge mobilization (KM) is essential to close the longstanding evidence to practice gap in pediatric pain management. Engaging various partners (i.e., those with expertise in a given topic area) in KM is best practice; however, little is known about how different partners engage and collaborate on KM activities. This mixed-methods study aimed to understand what different KM partner groups (i.e., health professionals, researchers, and patient/caregiver partners) perceive as supporting KM activities within pediatric pain management.

METHODS

This study used a convergent mixed-methods design. Ten partners from each of the three groups participated in interviews informed by the Consolidated Framework for Implementation Research, where they discussed what impacted KM activities within pediatric pain. Participants then rated and ranked select factors discussed in the interview. Transcripts were analyzed within each group using reflexive thematic analysis. Group-specific themes were then triangulated to identify convergence and divergence among groups. A matrix analysis was then conducted to generate meta-themes to describe overarching concepts. Quantitative data were analyzed using descriptive statistics.

RESULTS

Unique themes were developed within each partner group and further analysis generated four meta-themes: (1) team dynamics; (2) role of leadership; (3) policy influence; (4) social influence. There was full agreement among groups on the meaning of team dynamics. While there was partial agreement on the role of leadership, groups differed on who they described as taking on leadership positions. There was also partial agreement on policy influence, where health professionals and researchers described different institutions as being responsible for providing funding support. Finally, there was partial agreement on social influence, where the role of networks was seen as serving distinct purposes to support KM. Quantitative analyses indicated that partner groups shared similar priorities (e.g., team relationships, communication quality) when it came to supporting KM in pediatric pain.

CONCLUSIONS

While partners share many needs in common, there is also nuance in how they wish to be engaged in KM activities as well as the contexts in which they work. Strategies must be introduced to address these nuances to promote effective engagement in KM to increase the impact of evidence in pediatric pain.

Central Autonomic Network and heart rate variability in premature neonates

INTRODUCTION

The Central Autonomic Network (CAN) is a hierarchy of brain structures that collectively influence cardiac autonomic input, mediating the majority of brain-heart interactions, but has never been studied in premature neonates. In this study, we use heart rate variability (HRV), which has been described as the "primary output" of the CAN, and resting state functional MRI to characterize brain-heart relationships in premature neonates.

METHODS

We studied premature neonates who underwent resting state functional MRI (rsfMRI) at term, (37-weeks postmenstrual age [PMA] or above) and had HRV data recorded during the same week of their MRI. HRV was derived from continuous electrocardiogram data during the week of the rsfMRI scan. For rsfMRI, a seed-based approach was used to define regions of interest (ROI) pertinent to the CAN, and blood oxygen level-dependent signal was correlated between each ROI as a measure of functional connectivity. HRV was correlated with CAN connectivity (CANconn) for each region, and sub-group analysis was performed based on sex and clinical comorbidities.

RESULTS

Forty-seven premature neonates were included in this study, with a mean gestational age at birth of 28.1 +/- 2.6 weeks. Term CANconn was found to be significantly correlated with HRV in approximately one-fifth of CAN connections. Two distinct patterns emerged among these HRV-CANconn relationships. In the first, increased HRV was associated with stronger CANconn of limbic regions. In the second pattern, stronger CANconn at the precuneus was associated with impaired HRV maturation. These patterns were especially pronounced in male premature neonates.

CONCLUSION

We report for the first time evidence of brain-heart relationships in premature neonates and an emerging CAN, most striking in male neonates, suggesting that the brain-heart axis may be more vulnerable in male premature neonates. Signatures in the heart rate may eventually become an important non-invasive tool to identify premature males at highest risk for neurodevelopmental impairment.

"Seeing the light in the shade of it": primary caregiver and youth perspectives on using an inpatient portal for pain care during hospitalization

ABSTRACT

Studies from multiple countries report that most hospitalized children, especially the youngest and sickest, experience pain that is often severe yet inadequately treated. Evidence suggests this can lead to immediate and lifelong consequences affecting children, families, and communities. Partnership and shared decision-making by children, families, and clinicians is the ideal pediatric healthcare model and can improve care quality and safety, including pain care. A growing evidence base demonstrates that inpatient portals (electronic personal health record applications linked to hospital electronic medical or health records) can improve child and family engagement, outcomes, and satisfaction during hospitalization. This study examined the perspectives of caregivers of hospitalized children and of hospitalized youth about using an inpatient portal to support their engagement in pain care while in hospital. A qualitative descriptive study design was used and 20 participants (15 caregivers and 5 youth) with various painful conditions in one pediatric hospital participated in semistructured interviews. The authors applied a reflexive content analysis to the data and developed 3 broad categories: (1) connecting and sharing knowledge about pain, (2) user-centred designs, and (3) preserving roles. These findings outlined caregiver and youth recommendations for portal configurations that deeply engage and empower children and families in pain care through multidirectional knowledge sharing, supporting caregiver and clinicians' roles without burdening, or replacing human interaction implicit in family-centered pain care. Further research should measure the impact of portals on pain-related outcomes and explore the perspectives of clinicians.

Sensitivity and Specificity of a Neuropathic Screening Tool (Self-Report Leeds Assessment of Neuropathic Symptoms and Signs, S-LANSS) in Adolescents With Moderate-Severe Chronic Pain

Neuropathic screening tools improve recognition of neuropathic pain in adults. Although utilized in pediatric populations, the sensitivity, specificity and methodology of screening tool delivery have not been compared in children. We evaluated the Self-Report Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) in adolescents (10-18 years) referred to a tertiary pediatric pain clinic. History and examination by specialist clinicians and multidisciplinary assessment informed classification of the primary pain type. In a prospective cohort, scores were obtained at interview (S-LANSS interview; n = 161, 70% female), and following substitution of self-reported signs with examination findings in the primary pain region (Leeds Assessment of Neuropathic Symptoms and Signs, LANSS examination). Secondly, we retrospectively retrieved questionnaires self-completed by adolescents at their initial clinic appointment (S-LANSS self-completed; n = 456, 73% female). Thirdly, we explored relationships between patient-reported outcomes and S-LANSS scores. S-LANSS interview scores varied with pain classification, and S-LANSS self-completed scores were similarly highest with neuropathic pain (median [interquartile range]: 18 [11, 21]) and complex regional pain syndrome (21 [14, 24]), variable with musculoskeletal pain (13 [7, 19]) and lowest with visceral pain (6.5 [2, 11.5]) and headache (8.5 [4, 14]). As in adults, the cutpoint score of 12/24 was optimal. Sensitivity was highest with inclusion of examination findings and lowest with self-completion (LANSS examination vs S-LANSS interview vs S-LANSS self-completed: 86.3% vs 80.8% vs 74.7%), but specificity was relatively low (37.8% vs 36.7% vs 48%). High S-LANSS scores in non-neuropathic groups were associated with female sex and high pain catastrophizing. The S-LANSS is a sensitive screening tool for pain with neuropathic features in adolescents, but needs to be interpreted in the context of clinical evaluation (clinicaltrials.gov NCT03312881). PERSPECTIVE: This article reports high sensitivity of the S-LANSS screening tool for identifying pain with neuropathic features in adolescents with moderate-severe chronic pain. However, as sensitivity is lower than in adult populations, further interdisciplinary evaluation is necessary to inform diagnosis and management.

Impact of preterm birth on the onset of panic disorder in later life - Results from the Gutenberg Prematurity Study (GPS)

BACKGROUND

The present study aimed to investigate whether prematurity and perinatal stress exert long-term effects on the onset of panic disorder in later life.

METHODS

From 40,189 adults born in Germany between 1969 and 2002, a study cohort (n = 427) stratified by gestational age (GA) (extremely preterm: GA < 29 weeks; very preterm: GA 29-32 weeks; moderately preterm: GA 33-36 weeks; and full-term GA ≥ 37 weeks) was selected (age 28.5 ± 8.7 years). Multivariable logistic regression analyses were conducted to investigate associations between gestational age at birth and panic disorder adjusting for age, gender, socioeconomic status, and perinatal factors.

RESULTS

The prevalence of panic disorder was roughly equal in moderate to very preterm and full-term birth groups at 1.9%-3.8%. However, this rate significantly increased to 14.3% in the extreme preterm category (GA <2 9: 14.3 %, p = 0.002). In multivariable analyses, female gender and GA were independently associated with panic disorder. Adjusting for age, gender and socioeconomic status, panic disorder was associated with lower GA at birth (OR = 1.12 per week (CI95%: 1.01-1.26, p = 0.037). Whereas adjustment for nutrition status or indicators of perinatal stress had no effect, correction for the length of postnatal ICU-stay eliminated the association between preterm birth and later panic disorder.

LIMITATIONS

Limitations include the small number of cases and the reliance on questionnaires to assess mental status.

CONCLUSIONS

Prematurity likely increases the risk of panic disorder later in life, and the subsequent postnatal ICU-stay appears to be of critical importance. However, due to strong collinearity and other associated factors with preterm births, it remains unclear which is the primary determinant.

Macrophage epigenetic memories of early life injury drive neonatal nociceptive priming

The developing peripheral nervous and immune systems are functionally distinct from adults. These systems are vulnerable to early life injury, which influences outcomes related to nociception following subsequent injury later in life (neonatal nociceptive priming). The underpinnings of this phenomenon are largely unknown, although previous work indicates that macrophages are epigenetically trained by inflammation and injury. We found that macrophages are both necessary and partially sufficient to drive neonatal nociceptive priming possibly due to a long-lasting epigenetic remodeling. The p75 neurotrophic factor receptor (NTR) was an important effector in regulating neonatal nociceptive priming through modulation of the inflammatory profile of rodent and human macrophages. This pain memory was long lasting in females and could be transferred to a naive host to alter sex-specific pain-related behaviors. This study reveals a novel mechanism by which acute, neonatal post-surgical pain drives a peripheral immune-related predisposition to persistent pain following a subsequent injury.

Pediatricians' focus of sight at pain assessment during a neonatal heel puncture

OBJECTIVE

To evaluate the focus of pediatricians' gaze during the heel prick of neonates.

METHODS

Prospective study in which pediatricians wearing eye tracker glasses evaluated neonatal pain before/after a heel prtick. Pediatricians scored the pain they perceived in the neonate in a verbal analogue numerical scale (0=no pain; 10=maximum pain). The outcomes measured were number and time of visual fixations in upper face, lower face, and hands, in two 10-second periods, before (pre) and after the puncture (post). These outcomes were compared between the periods, and according to pediatricians' pain perception: absent/mild (score: 0-5) and moderate/intense (score: 6-10).

RESULTS

24 pediatricians (31 years old, 92% female) evaluated 24 neonates. The median score attributed to neonatal pain during the heel prick was 7.0 (Interquartile range: 5-8). Compared to pre-, in the post-periods, more pediatricians fixed their gaze on the lower face (63 vs. 92%; p=0.036) and the number of visual fixations was greater on the lower face (2.0 vs. 5.0; p=0.018). There was no difference in the number and time of visual fixations according to the intensity of pain.

CONCLUSIONS

At bedside, pediatricians change their focus of attention on the neonatal face after a painful procedure, focusing mainly on the lower part of the face.

Intravenous acetaminophen for postoperative pain in the neonatal intensive care unit: A protocol for a pilot randomized controlled trial (IVA POP)

BACKGROUND

In neonates, uncontrolled pain and opioid exposure are both correlated with short- and long-term adverse events. Therefore, managing pain using opioid-sparing approaches is critical in neonatal populations. Multimodal pain control offers the opportunity to manage pain while reducing short- and long-term opioid-related adverse events. Intravenous (IV) acetaminophen may represent an appropriate adjunct to opioid-based postoperative pain control regimes. However, no trials assess this drug in patients less than 36 weeks post-conceptual age or weighing less than 1500 g.

OBJECTIVE

The proposed study aims to determine the feasibility of conducting a randomized control trial to compare IV acetaminophen and fentanyl to a saline placebo and fentanyl for patients admitted to the neonatal intensive care unit (NICU) undergoing major abdominal or thoracic surgery.

METHODS AND DESIGN

This protocol is for a single-centre, external pilot randomized controlled trial (RCT). Infants in the NICU who have undergone major thoracic or abdominal surgery will be enrolled. Sixty participants will undergo 1:1 randomization to receive intravenous acetaminophen and fentanyl or saline placebo and fentanyl. After surgery, IV acetaminophen or placebo will be given routinely for eight days (192 hours). Appropriate dosing will be determined based on the participant's gestational age. Patients will be followed for eight days after surgery and will undergo a chart review at 90 days. Primarily feasibility outcomes include recruitment rate, follow-up rate, compliance, and blinding index. Secondary clinical outcomes will be collected as well.

CONCLUSION

This external pilot RCT will assess the feasibility of performing a multicenter RCT comparing IV acetaminophen and fentanyl to a saline placebo and fentanyl in NICU patients following major abdominal and thoracic surgery. The results will inform the design of a multicenter RCT, which will have the appropriate power to determine the efficacy of this treatment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05678244, Registered December 6, 2022.

Sex differences in the effects of prematurity and/or low birthweight on neurodevelopmental outcomes: systematic review and meta-analyses

BACKGROUND

Premature birth and/or low birthweight have long-lasting effects on cognition. The purpose of the present systematic review is to examine whether the effects of prematurity and/or low birth weight on neurodevelopmental outcomes differ between males and females.

METHODS

Web of Science, Scopus, and Ovid MEDLINE were searched for studies of humans born premature and/or of low birthweight, where neurodevelopmental phenotypes were measured at 1 year of age or older. Studies must have reported outcomes in such a way that it was possible to assess whether effects were greater in one sex than the other. Risk of bias was assessed using both the Newcastle-Ottawa scale and the National Institutes of Health Quality assessment tool for observational cohort and cross-sectional studies.

RESULTS

Seventy-five studies were included for descriptive synthesis, although only 24 presented data in a way that could be extracted for meta-analyses. Meta-analyses found that severe and moderate prematurity/low birthweight impaired cognitive function, and severe prematurity/low birthweight also increased internalizing problem scores. Moderate, but not severe, prematurity/low birthweight significantly increased externalizing problem scores. In no case did effects of prematurity/low birthweight differ between males and females. Heterogeneity among studies was generally high and significant, although age at assessment was not a significant moderator of effect. Descriptive synthesis did not identify an obvious excess or deficiency of male-biased or female-biased effects for any trait category. Individual study quality was generally good, and we found no evidence of publication bias.

CONCLUSIONS

We found no evidence that the sexes differ in their susceptibility to the effects of severe or moderate prematurity/low birthweight on cognitive function, internalizing traits or externalizing traits. Result heterogeneity tended to be high, but this reflects that one sex is not consistently more affected than the other. Frequently stated generalizations that one sex is more susceptible to prenatal adversity should be re-evaluated.

The impact of gender medicine on neonatology: the disadvantage of being male: a narrative review

This narrative non-systematic review addresses the sex-specific differences observed both in prenatal period and, subsequently, in early childhood. Indeed, gender influences the type of birth and related complications. The risk of preterm birth, perinatal diseases, and differences on efficacy for pharmacological and non-pharmacological therapies, as well as prevention programs, will be evaluated. Although male newborns get more disadvantages, the physiological changes during growth and factors like social, demographic, and behavioural reverse this prevalence for some diseases. Therefore, given the primary role of genetics in gender differences, further studies specifically targeted neonatal sex-differences will be needed to streamline medical care and improve prevention programs.

What is the association between childhood adversity and subsequent chronic pain in adulthood? A systematic review

Background

Adverse childhood experiences and chronic pain are complex problems affecting millions of people worldwide, and result in significant healthcare utilisation. Our review aimed to determine known associations between adversity in childhood and chronic pain in adulthood.

Methods

We performed a prospectively registered systematic review (PROSPERO ID: 135625). Six electronic databases (Pubmed, Medline, Cochrane, Scopus, APA PsycNet, Web of Science) were searched from January 1, 2009 until May 30, 2022. Titles and abstracts were screened, and all original research studies examining associations between adverse childhood experiences and chronic pain in adulthood were considered for inclusion. Full texts were reviewed, and a narrative synthesis was used to identify themes from extracted data. Ten percent of studies were dual reviewed to assess inter-rater reliability. Quality assessment of study methodology was undertaken using recognised tools.

Results

Sixty-eight eligible studies describing 196 130 participants were included. Studies covered 15 different types of childhood adversity and 10 different chronic pain diagnoses. Dual reviewed papers had a Cohen's kappa reliability rating of 0.71. Most studies were of retrospective nature and of good quality. There were consistent associations between adverse childhood experiences and chronic pain in adulthood, with a 'dose'-dependent relationship. Poor mental health was found to mediate the detrimental connection between adverse childhood experiences and chronic pain.

Conclusion

A strong association was found between adverse childhood experiences and chronic pain in adulthood. Adverse childhood experiences should be considered in patient assessment, and early intervention to prevent adverse childhood experiences may help reduce the genesis of chronic pain. Further research into assessment and interventions to address adverse childhood experiences is needed.

Long-lasting effects of very preterm birth on brain structure in adulthood: A systematic review and meta-analysis

Early life experiences, such as very preterm (VP) birth, can affect brain and cognitive development. Several prior studies investigated brain structure in adults born VP; synthesising these studies may help to provide a clearer understanding of long-term effects of VP birth on the brain. We systematically searched Medline and Embase for articles that investigated brain structure using MRI in adulthood in individuals born VP (<32 weeks' gestation) or with very low birth weight (VLBW; <1500 g), and controls born at term or with normal birth weight. In total, 77 studies met the review inclusion criteria, of which 28 studies were eligible for meta-analyses, including data from up to 797 VP/VLBW participants and 518 controls, aged 18-33 years. VP/VLBW adults exhibited volumetric, morphologic and microstructural alterations in subcortical and temporal cortical regions compared with controls, with pooled standardised mean differences up to - 1.0 (95% confidence interval: -1.2, -0.8). This study suggests there is a persisting neurological impact of VP birth, which may provide developmental neurobiological insights for adult cognition in high-risk populations.

Current pain management practices for preterm infants with necrotizing enterocolitis: a European survey

BACKGROUND

Necrotizing enterocolitis (NEC) is a highly painful intestinal complication in preterm infants that requires adequate pain management to prevent short- and long-term effects of neonatal pain. There is a lack of international guidelines for pain management in NEC patients. Therefore, this study aims to describe current pain management for NEC patients in European neonatal intensive care units (NICUs).

METHODS

An online survey was designed and conducted to assess current practices in pain management for NEC patients in European NICUs. The survey was distributed via neonatal societies, digital platforms, and professional contacts.

RESULTS

Out of the 259 responding unique European NICUs from 36 countries, 61% had a standard protocol for analgesic therapy, 73% assessed pain during NEC, and 92% treated NEC patients with intravenous analgosedatives. There was strong heterogeneity in the used pain scales and initial analgesic therapy, which mainly included acetaminophen (70%), fentanyl (56%), and/or morphine (49%). A third of NICU representatives considered their pain assessment adequate, and half considered their analgesic therapy adequate for NEC patients.

CONCLUSIONS

Various pain scales and analgesics are used to treat NEC patients in European NICUs. Our results provide the first step towards an international guideline to improve pain management for NEC patients.

IMPACT

This study provides an overview of current pain management practices for infants with necrotizing enterocolitis (NEC) in European neonatal intensive care units. Choice of pain assessment tools, analgosedatives, and dosages vary considerably among NICUs and countries. A third of NICU representatives were satisfied with their current pain assessment practices and half of NICU representatives with their analgesic therapy practices in NEC patients in their NICU. The results of this survey may provide a first step towards developing a European pain management consensus guideline for patients with NEC.

Surfactant Replacement Therapy: What’s the New Future?

Surfactant replacement therapy (SRT) can be lifesaving for preterm babies with respiratory distress because of surfactant deficiency. Attempts have been made over the last two decades to make surfactant administration as smooth and as nontraumatic as possible. Lesser invasive techniques, such as less invasive surfactant administration, minimally invasive surfactant therapy, intrapartum pharyngeal surfactant therapy, and the laryngeal mask airway, are preferred over invasive techniques like intubate surfactant extubation to reduce trauma and peridosing adverse effects. However, at present, aerosolized surfactant (AS) via nebulization remains the only truly noninvasive method of SRT. Many animal and human studies have shown promising results with the use of AS with similar clinical effects to an instilled surfactant with greater safety potential. But still AS has not been adapted to routine neonatal care. There is still scope for studies to further strengthen the role of AS. Also, SRT is a constantly changing field with new innovations revolutionizing and replacing old techniques.

Ketamine Analgesia as an Alternative to General Anesthesia During Laser Treatment for Retinopathy of Prematurity

PURPOSE

To determine the safety and efficacy of ketamine analgesia as an alternative to general anesthesia during laser treatment for retinopathy of prematurity (ROP).

METHODS

Eighteen premature neonates with ROP underwent laser treatment. The procedure was performed in the operating room, and the neonates were admitted to the neonatal intensive care unit (NICU) after the procedure. An initial dose of 1 mg/kg of ketamine was administered. If the neonate exhibited movement or distress during the procedure, incremental doses of ketamine were administered. Perioperative ventilation status, severity of pain during the procedure, surgeon satisfaction, and perioperative events were recorded.

RESULTS

Eighteen premature neonates underwent ketamine analgesia during laser treatment for ROP. The procedure was performed in 16 patients with good tolerance and without events. The Premature Infant Pain Profile (PIPP) scores during the procedure were 5 or less in 12 neonates (44.4%), 5 to 10 in 4 neonates (22.2%), and greater than 10 in 2 (11.1%) neonates. Three neonates had perioperative events, which resolved completely with minimal intervention. None of the neonates needed intubation perioperatively, and hemodynamic instability, hypotension, and bradycardia were not recorded in any of the neonates during or after the procedure.

CONCLUSIONS

The ROP laser treatment under ketamine sedation could be performed in premature neonates with few perioperative complications and provide satisfactory operative conditions. [J Pediatr Ophthalmol Strabismus. 2022;59(6):416-421.].

Effectiveness of Non-Pharmacological Methods, Such as Breastfeeding, to Mitigate Pain in NICU Infants

Neonates do experience pain and its management is necessary in order to prevent long-term, as well as, short-term effects. The most common source of pain in the neonatal intensive care unit (NICU) is caused by medically invasive procedures. NICU patients have to endure trauma, medical adhesive related skin injuries, heel lance, venipuncture and intramuscular injection as well as nasogastric catheterization besides surgery. A cornerstone in pain assessment is the use of scales such as COMFORT, PIPP-R, NIPS and N-PASS. This narrative review provides an up to date account of neonate pain management used in NICUs worldwide focusing on non-pharmacological methods. Non-steroidal anti-inflammatory drugs have well established adverse side effects and opioids are addictive thus pharmacological methods should be avoided if possible at least for mild pain management. Non-pharmacological interventions, particularly breastfeeding and non-nutritive sucking as primary strategies for pain management in neonates are useful strategies to consider. The best non-pharmacological methods are breastfeeding followed by non-nutritive sucking coupled with sucrose sucking. Regrettably most parents used only physical methods and should be trained and involved for best results. Further research in NICU is essential as the developmental knowledge changes and neonate physiology is further uncovered together with its connection to pain.

Lack of placental neurosteroid alters cortical development and female somatosensory function

Placental endocrine function is essential to fetal brain development. Placental hormones include neurosteroids such as allopregnanolone (ALLO), a regulator of neurodevelopmental processes via positive allosteric modulation of the GABAA receptor (GABAA-R). Using a mouse model (plKO) in which the gene encoding the ALLO synthesis enzyme is specifically deleted in trophoblasts, we previously showed that placental ALLO insufficiency alters cerebellar white matter development and leads to male-specific autistic-like behavior. We now demonstrate that the lack of placental ALLO causes female-predominant alterations of cortical development and function. Placental ALLO insufficiency disrupts cell proliferation in the primary somatosensory cortex (S1) in a sex-linked manner. Early changes are seen in plKO embryos of both sexes, but persist primarily in female offspring after birth. Adolescent plKO females show significant reduction in pyramidal neuron density, as well as somatosensory behavioral deficits as compared with plKO males and control littermates. Assessment of layer-specific markers in human postmortem cortices suggests that preterm infants may also have female-biased abnormalities in cortical layer specification as compared with term infants. This study establishes a novel and fundamental link between placental function and sex-linked long-term neurological outcomes, emphasizing the importance of the growing field of neuroplacentology.

Sciatic nerve block downregulates the BDNF pathway to alleviate the neonatal incision-induced exaggeration of incisional pain via decreasing microglial activation

Sciatic nerve block is under investigation as a possible therapeutic strategy for neonatal injury-induced exaggeration of pain responses to reinjury. Spinal microglial priming, brain-derived neurotrophic factor (BDNF) and Src homology-2 domain-containing protein tyrosine phosphatase-2 (SHP2) participate in exaggerated incisional pain induced by neonatal incision. However, effects of sciatic nerve block on exacerbated incisional pain and underlying mechanisms remain unclear. Here, we demonstrated that sciatic nerve block alleviates pain hypersensitivity and microglial activation in rats subjected to neonatal incision and adult incision (nIN-IN). Chemogenetic activation or inhibition of spinal microglia attenuates or mimics effects of sciatic nerve block on pain hypersensitivity, respectively. Moreover, α-amino-3-hydroxy- 5-methy- 4-isoxazole propionate (AMPA) receptor subunit GluA1 contributes to the exaggeration of incisional pain. The inhibition of BDNF or SHP2 blocks upregulations of downstream molecules in nIN-IN rats. Knockdown of SHP2 attenuates the increase of GluA1 induced by injection of BDNF in adult rats with only neonatal incision. The inhibition of microglia or ablation of microglial BDNF attenuates upregulations of SHP2 and GluA1. Additionally, sciatic nerve block downregulates the expression of these three molecules. Upregulation of BDNF, SHP2 or AMPA receptor attenuates sciatic nerve block-induced reductions of downstream molecules and pain hypersensitivity. Microglial activation abrogates reductions of these three molecules induced by sciatic nerve block. These results suggest that decreased activation of spinal microglia contributes to beneficial effects of sciatic nerve block on the neonatal incision-induced exaggeration of incisional pain via downregulating BDNF/SHP2/GluA1-containing AMPA receptor signaling. Thus, sciatic nerve block may be a promising therapy.

Enhanced nociceptive behavior and expansion of associated primary afferents in a rabbit model of cerebral palsy

Spastic cerebral palsy (CP) is a movement disorder marked by hypertonia and hyperreflexia; the most prevalent comorbidity is pain. Since spinal nociceptive afferents contribute to both the sensation of painful stimuli as well as reflex circuits involved in movement, we investigated the relationship between prenatal hypoxia-ischemia (HI) injury which can cause CP, and possible changes in spinal nociceptive circuitry. To do this, we examined nociceptive afferents and mechanical and thermal sensitivity of New Zealand White rabbit kits after prenatal HI or a sham surgical procedure. As described previously, a range of motor deficits similar to spastic CP was observed in kits born naturally after HI (40 min at ~70%-80% gestation). We found that HI caused an expansion of peptidergic afferents (marked by expression of calcitonin gene-related peptide) in both the superficial and deep dorsal horn at postnatal day (P)5. Non-peptidergic nociceptive afferent arborization (labeled by isolectin B4) was unaltered in HI kits, but overlap of the two populations (peptidergic and non-peptidergic nociceptors) was increased by HI. Density of glial fibrillary acidic protein was unchanged within spinal cord white matter regions important in nociceptive transmission at P5. We found that mechanical and thermal nociception was enhanced in HI kits even in the absence of motor deficits. These findings suggest that prenatal HI injury impacts spinal sensory pathways in addition to the more well-established disruptions to descending motor circuits. In conclusion, changes to spinal nociceptive circuitry could disrupt spinal reflexes and contribute to pain experienced by individuals with CP.

Evidence-Based Nursing Practices for the Prevention of Newborn Procedural Pain in Neonatal Intensive Therapy-An Exploratory Study

BACKGROUND

Due to the progress in neonatology, in particular, in the past three decades, the mortality rate among patients of intensive care units has decreased. However, this is connected not only with newborns needing to stay longer in the unit, but also with the exposure of newborns to many painful procedures and stresses. Lack of or insufficient pain prevention has a negative impact on the sensory or locomotor development of newborns. Despite the presence of guidelines based on scientific evidence, the use of pharmacological and non-pharmacological pain-management methods in newborns is still insufficient.

AIM

The aim of the study was to: identify the knowledge nurses/midwives have of recommended non-pharmacological and/or pharmacological methods, in particular, in relation to medical intervention procedures; assess the interventions for pain relief applied by midwives/nurses most often in their clinical practice; examine the role of age, general work experience, education level and years of work of medical professionals on a neonatal ward, as well as the referral level of a unit, versus the application of pharmacological and non-pharmacological methods.

METHODS

A descriptive and quantitative study conducted in 2019 among Polish nurses/midwives working at neonatal intensive care units.

RESULTS

The analysis of the material reflected the deficit of knowledge and the insufficient daily use of recommended pain-relief measures among the respondents.

CONCLUSIONS

The interpretation of data indicates that despite the clear and easily available recommendations of scientific societies concerning the mode of conduct in particular medical procedures, medical personnel do not apply those recommendations in their everyday practice. It is necessary to plan and implement education strategies for nurses/midwives on standard pain-management interventions during painful medical procedures.

Nurses’ experiences of caring for preterm infants in pain: A meta-ethnography

Objective

Preterm infants are subjected to numerous painful procedures during their neonatal intensive care unit (NICU) hospitalization. Despite advancements in pain alleviation, nurses remain challenged to provide timely and effective pain management for preterm infants. Greater understanding of the lived experience of nurses caring for preterm infants in pain could provide novel insights to improve pain management for this vulnerable population. The aim of this meta-ethnography was to synthesize and interpret qualitative findings of nurses’ experiences of taking care of preterm infants in pain.

Methods

An extensive literature search in PubMed, CINAHL, PsycINFO, Scopus, BIOSIS and ProQuest Dissertation and Theses Database was conducted, including studies within the past 10 years. Two nursing researchers conducted data extraction and analysis independently. Inclusion criteria were applied to search for qualitative studies of nurse participants who worked in the NICU taking care of preterm infants. Studies published in a language other than English, articles that did not include qualitative data and qualitative data that could not be extracted from the findings or did not discuss nurses’ experiences were excluded. Critical Appraisal Skills Programme was used for literature quality evaluation.

Results

Eight studies remained after further screening according to inclusion and exclusion criteria. These eight studies were conducted from 2013 to 2018 and totally enrolled 205 nurses from Iran, Canada, the United States, Finland, Sweden, Switzerland, and Australia. Five themes emerged on the nurses’ perspectives of taking care of preterm infants in pain: 1) They sense the neonatal pain; 2) Adverse consequences of unrelieved pain; 3) Barriers of managing pain; 4) Concerns of available approaches for pain relief; 5) Failure to work with parents.

Conclusions

This meta-ethnography identified nurses’ understanding of pain in preterm infants that can be assessed, and they acknowledged that unrelieved pain could cause developmental deficits in infants. The barriers are lack of training and support on pain assessment and intervention in preterm infants. Optimizing workload and environment, developing age-specified pain assessment and intervention, receiving emotional support and training, and building up a rapport with parents are urgent needs for nurses to provide better care to infants having pain.

Amygdalar Functional Connectivity Differences Associated With Reduced Pain Intensity in Pediatric Peripheral Neuropathic Pain

Background

There is evidence of altered corticolimbic circuitry in adults with chronic pain, but relatively little is known of functional brain mechanisms in adolescents with neuropathic pain (NeuP). Pediatric NeuP is etiologically and phenotypically different from NeuP in adults, highlighting the need for pediatric-focused research. The amygdala is a key limbic region with important roles in the emotional-affective dimension of pain and in pain modulation.

Objective

To investigate amygdalar resting state functional connectivity (rsFC) in adolescents with NeuP.

Methods

This cross-sectional observational cohort study compared resting state functional MRI scans in adolescents aged 11–18 years with clinical features of chronic peripheral NeuP (n = 17), recruited from a tertiary clinic, relative to healthy adolescents (n = 17). We performed seed-to-voxel whole-brain rsFC analysis of the bilateral amygdalae. Next, we performed post hoc exploratory correlations with clinical variables to further explain rsFC differences.

Results

Adolescents with NeuP had stronger negative rsFC between right amygdala and right dorsolateral prefrontal cortex (dlPFC) and stronger positive rsFC between right amygdala and left angular gyrus (AG), compared to controls (P_FDR<0.025). Furthermore, lower pain intensity correlated with stronger negative amygdala-dlPFC rsFC in males (r = 0.67, P = 0.034, n = 10), and with stronger positive amygdala-AG rsFC in females (r = −0.90, P = 0.006, n = 7). These amygdalar rsFC differences may thus be pain inhibitory.

Conclusions

Consistent with the considerable affective and cognitive factors reported in a larger cohort, there are rsFC differences in limbic pain modulatory circuits in adolescents with NeuP. Findings also highlight the need for assessing sex-dependent brain mechanisms in future studies, where possible.

The development of descending serotonergic modulation of the spinal nociceptive network: a life span perspective

The nociceptive network, responsible for transmission of nociceptive signals that generate the pain experience, is not fully developed at birth. Descending serotonergic modulation of spinal nociception, an important part of the pain network, undergoes substantial postnatal maturation and is suggested to be involved in the altered pain response observed in human newborns. This review summarizes preclinical data of the development of descending serotonergic modulation of the spinal nociceptive network across the life span, providing a comprehensive background to understand human newborn pain experience and treatment. Sprouting of descending serotonergic axons, originating from the rostroventral medulla, as well as changes in receptor function and expression take place in the first postnatal weeks of rodents, corresponding to human neonates in early infancy. Descending serotonergic modulation switches from facilitation in early life to bimodal control in adulthood, masking an already functional 5-HT inhibitory system at early ages. Specifically the 5-HT₃ and 5-HT₇ receptors seem distinctly important for pain facilitation at neonatal and early infancy, while the 5-HT_1a, 5-HT_1b, and 5-HT₂ receptors mediate inhibitory effects at all ages. Analgesic therapy that considers the neurodevelopmental phase is likely to result in a more targeted treatment of neonatal pain and may improve both short- and long-term effects. IMPACT: The descending serotonergic system undergoes anatomical changes from birth to early infancy, as its sprouts and descending projections increase and the dorsal horn innervation pattern changes. Descending serotonergic modulation from the rostral ventral medulla switches from facilitation in early life via the 5-HT₃ and 5-HT₇ receptors to bimodal control in adulthood. A functional inhibitory serotonergic system mainly via 5-HT_1a, 5-HT_1b, and 5-HT_2a receptors at the spinal level exists already at the neonatal phase but is masked by descending facilitation.

Assessing Neonatal Pain with NIPS and COMFORT-B: Evaluation of NICU’s Staff Competences

Background

Pain is considered “the 5th vital sign” that should be regularly assessed in the neonatal intensive care setting. Although over 40 pain assessment tools have been developed for neonates, their implementation in everyday practice is challenging. Epidemiological studies demonstrate that pain is still underassessed and undertreated in European NICUs.

Purpose

To evaluate the interrater and intrarater reliability of the NIPS and COMFORT-B scales among the tertiary NICU's staff members 4 years after their implementation in local pain guidelines with no prior dedicated training.

Methods

Physicians and nurses were invited to evaluate 5 video recordings of infants hospitalized in the intensive care settings, using the NIPS and COMFORT-B scales. The assessment took part twice at a 3-month interval. Interrater reliability was calculated for both scales using Kendall's W coefficient of concordance and Krippendorff's alpha coefficient. Cohen's kappa was used to assess intrarater reliability.

Results

17 physicians and 19 nurses took part in the study. Interrater agreement for the COMFORT-B scale was above 0.8 for Kendall's W coefficient (p < .01) and above 0.667 for Krippendorff's alpha coefficient. Kendall's W coefficient for the NIPS scores ranged between 0.7 and 0.8 (p < .01). Krippendorff's alpha was above 0.667. Intrarater agreement for both the COMFORT-B and NIPS scales was 0.693 and 0.724, respectively.

Conclusions

Overall, the agreement between our staff members was moderately good for both scales. This is not enough to avoid inadequate pain assessment. More training is needed to improve NICU's staff competences in using pain scales.

What brain abnormalities can magnetic resonance imaging detect in foetal and early neonatal spina bifida: a systematic review

PURPOSE

Open spina bifida (OSB) encompasses a wide spectrum of intracranial abnormalities. With foetal surgery as a new treatment option, robust intracranial imaging is important for comprehensive preoperative evaluation and prognostication. We aimed to determine the incidence of infratentorial and supratentorial findings detected by magnetic resonance imaging (MRI) alone and MRI compared to ultrasound.

METHODS

Two systematic reviews comparing MRI to ultrasound and MRI alone were conducted on MEDLINE, EMBASE, and Cochrane databases identifying studies of foetal OSB from 2000 to 2020. Intracranial imaging findings were analysed at ≤ 26 or > 26 weeks gestation and neonates (≤ 28 days). Data was independently extracted by two reviewers and meta-analysis was performed where possible.

RESULTS

Thirty-six studies reported brain abnormalities detected by MRI alone in patients who previously had an ultrasound. Callosal dysgenesis was identified in 4/29 cases (2 foetuses ≤ 26 weeks, 1 foetus under any gestation, and 1 neonate ≤ 28 days) (15.1%, CI:5.7-34.3%). Heterotopia was identified in 7/40 foetuses ≤ 26 weeks (19.8%, CI:7.7-42.2%), 9/36 foetuses > 26 weeks (25.3%, CI:13.7-41.9%), and 64/250 neonates ≤ 28 days (26.9%, CI:15.3-42.8%). Additional abnormalities included aberrant cortical folding and other Chiari II malformation findings such as lower cervicomedullary kink level, tectal beaking, and hypoplastic tentorium. Eight studies compared MRI directly to ultrasound, but due to reporting inconsistencies, it was not possible to meta-analyse.

CONCLUSION

MRI is able to detect anomalies hitherto underestimated in foetal OSB which may be important for case selection. In view of increasing prenatal OSB surgery, further studies are required to assess developmental consequences of these findings.

Functional Ophthalmic Factors Associated With Extreme Prematurity in Young Adults

IMPORTANCE

Children born preterm (<37 weeks' gestation) have a higher risk of visual impairment and ocular morbidities compared peers born at full term. However, the long-term ocular sequelae in adulthood for those born extremely preterm (EP), who have the highest risk of neonatal retinopathy, are unknown.

OBJECTIVE

To evaluate visual function and ocular morbidity in young adults born EP compared with controls born full term.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study of a geographically based birth cohort in the UK and Ireland born from March 1 through December 31, 1995, included 128 participants aged 19 years (born at 22-25 weeks' gestation) and 65 age-matched controls born at full term. Statistical analysis was performed from March 1, 2020, to November 26, 2021.

EXPOSURES

Participants underwent eye examinations as part of a comprehensive outcome evaluation.

MAIN OUTCOMES AND MEASURES

Best-corrected visual acuity, refractive status, contrast sensitivity, color vision, prevalence of strabismus and nystagmus, and patient-reported visual function, measured using the Health Utilities Index Mark 3.

RESULTS

The study comprised 128 participants (256 eyes; 68 female participants [53%]; mean [SD] age, 19.3 [0.5] years) and 65 age-matched controls born at full term (130 eyes; 40 female participants [62%]; mean [SD] age, 19.2 [0.5] years). Compared with control eyes, the mean (SD) best-corrected visual acuity among eyes in the EP group was significantly worse (monocular vision: -0.06 [0.14] logMAR in the control group vs 0.14 [0.38] logMAR in the EP group; P < .001; binocular vision: -0.14 [0.15] logMAR in the control group vs 0.06 [0.37] logMAR in the EP group; P < .001). Participants in the EP group had a significantly higher prevalence of strabismus (36% [46 of 127] vs 0%; P < .001), abnormal ocular motility (15% [19 of 125] vs 0%; P < .001), and nystagmus (13% [16 of 127] vs 0%; P < .001) than the control group. No significant differences between participants in the EP group and controls were observed for refractive error, contrast sensitivity, color vision, or patient-reported visual function. Among the participants in the EP group, 48% of eyes (120 of 250) had no retinopathy of prematurity (ROP), 39% (98 of 250) had ROP not requiring neonatal treatment, and 13% (32 of 250) received cryotherapy or laser ablation for ROP. Within the EP group, there was no significant difference in binocular visual function parameters, prevalence of ocular morbidity, and patient-reported visual function by neonatal ROP status.

CONCLUSIONS AND RELEVANCE

Extreme prematurity is associated with an increased prevalence of visual and ocular deficits in young adulthood; this study suggests that, for individuals born EP, visual and ocular deficits appear to be partially independent of ROP status in the neonatal period but reports similar overall visual function.

Developmental Mechanisms of CPSP: Clinical Observations and Translational Laboratory Evaluations

Understanding mechanisms that underly the transition from acute to chronic pain and identifying potential targets for preventing or minimizing this progression have specific relevance for chronic postsurgical pain (CPSP). Though it is clear that multiple psychosocial, family, and environmental factors may influence CPSP, this review will focus on parallels between clinical observations and translational laboratory studies investigating the acute and long-term effects of surgical injury on nociceptive pathways. This includes data related to alterations in sensitivity at different points along nociceptive pathways from the periphery to the brain; age- and sex-dependent mechanisms underlying the transition from acute to persistent pain; potential targets for preventive interventions; and the impact of prior surgical injury. Ongoing preclinical studies evaluating age- and sex-dependent mechanisms will also inform comparative efficacy and preclinical safety assessments of potential preventive pharmacological interventions aimed at reducing the risk of CPSP. In future clinical studies, more detailed and longitudinal peri-operative phenotyping with patient- and parent-reported chronic pain core outcomes, alongside more specialized evaluations of somatosensory function, modulation, and circuitry, may enhance understanding of individual variability in postsurgical pain trajectories and improve recognition and management of CPSP.

Refining the prediction of multisite pain in 13-year-old boys and girls by using parent-reported pain experiences in the first decade of life

Background

We evaluated different pain profiles as prospective predictors of multisite pain in 13‐year‐old adolescents (1300 girls and 1457 boys) enrolled in Generation XXI, a birth cohort study in Portugal.

Methods

Pain history was queried using the Luebeck Pain Questionnaire through parent proxy‐ (ages 7 and 10) and adolescent (age 13) self‐reports. We estimated the risk of multisite pain (2 or more pain sites) at age 13, according to previous pain experiences, including accumulation and timing. We defined five profiles that combined adverse features at ages 7 and 10 (recurrence, multisite, frequency, duration, intensity, triggers, activity restrictions, passive coping, and family history) and estimated their relative risks (RR) and likelihood ratios (LR) for adolescent multisite pain.

Results

At age 13, 39.2% of girls and 27.2% of boys reported multisite pain in the previous three months. The risk was higher among girls with multisite and recurrent pain at ages 7 and 10 than in girls without those adverse features, especially if psychosocial triggers were also present (RR 1.87; 95% confidence interval 1.36, 2.36 and LR 3.49; 1.53, 7.96). Boys with recurrent pain of higher frequency and causing activity restrictions at ages 7 and 10 had a higher risk of multisite pain at 13 (RR 2.05; 1.03, 3.05 and LR 3.06; 1.12, 8.39). Earlier adverse experiences were more predictive of future pain in girls than in boys.

Conclusions

Different profiles were useful to rule in future multisite pain in boys and girls. This provides clues for early stratification of chronic pain risk.

Significance

We identified sex‐specific pain features that can be collected by practitioners in the first decade of life to improve the stratification of children in terms of their future risk of a maladaptive pain experience in adolescence. Using a prospective population‐based cohort design, we show that early multisite pain and psychosocial triggers are relevant predictors of future multisite pain in girls, whereas repeated reports of high‐frequency pain leading to activity restrictions are predictive of adolescent multisite pain in boys.

Neonatal procedural pain affects state, but not trait anxiety behavior in adult rats

The influence of neonatal experiences upon later-life affective behavior is increasingly recognized, but the reported effects on anxiety are often contradictory. The observed effect may depend upon the type of anxiety (state or trait) affected. The current study aims to investigate whether neonatal repetitive needle pricking alters anxiety behavior in adulthood, by assessing both state and trait anxiety in rats. Sprague-Dawley rat pups received four unilateral needle pricks per day, while controls received four tactile stimuli or were left completely undisturbed during the first postnatal week. Mechanical sensitivity was assessed in the neonatal phase and throughout the development. State anxiety was assessed in the open field test and trait anxiety in the elevated zero maze. The results show that repetitive needle pricking leads to acute mechanical hypersensitivity, but does not affect baseline mechanical sensitivity throughout development. In adulthood, animals previously exposed to neonatal procedural pain (including repetitive handling and removal from litter) showed lower state anxiety but did not differ in trait anxiety, as compared with the undisturbed controls. These findings indicate that early-life procedural pain decreases state but not trait anxiety behavior in later life in a rodent model of repetitive needle pricking.

Event-related potentials evoked by skin puncture reflect activation of Aβ fibers: comparison with intraepidermal and transcutaneous electrical stimulations

Background

Recently, event-related potentials (ERPs) evoked by skin puncture, commonly used for blood sampling, have received attention as a pain assessment tool in neonates. However, their latency appears to be far shorter than the latency of ERPs evoked by intraepidermal electrical stimulation (IES), which selectively activates nociceptive Aδ and C fibers. To clarify this important issue, we examined whether ERPs evoked by skin puncture appropriately reflect central nociceptive processing, as is the case with IES.

Methods

In Experiment 1, we recorded evoked potentials to the click sound produced by a lance device (click-only), lance stimulation with the click sound (click+lance), or lance stimulation with white noise (WN+lance) in eight healthy adults to investigate the effect of the click sound on the ERP evoked by skin puncture. In Experiment 2, we tested 18 heathy adults and recorded evoked potentials to shallow lance stimulation (SL) with a blade that did not reach the dermis (0.1 mm insertion depth); normal lance stimulation (CL) (1 mm depth); transcutaneous electrical stimulation (ES), which mainly activates Aβ fibers; and IES, which selectively activates Aδ fibers when low stimulation current intensities are applied. White noise was continuously presented during the experiments. The stimulations were applied to the hand dorsum. In the SL, the lance device did not touch the skin and the blade was inserted to a depth of 0.1 mm into the epidermis, where the free nerve endings of Aδ fibers are located, which minimized the tactile sensation caused by the device touching the skin and the activation of Aβ fibers by the blade reaching the dermis. In the CL, as in clinical use, the lance device touched the skin and the blade reached a depth of 1 mm from the skin surface, i.e., the depth of the dermis at which the Aβ fibers are located.

Results

The ERP N2 latencies for click-only (122 ± 2.9 ms) and click+lance (121 ± 6.5 ms) were significantly shorter than that for WN+lance (154 ± 7.1 ms). The ERP P2 latency for click-only (191 ± 11.3 ms) was significantly shorter than those for click+lance (249 ± 18.6 ms) and WN+lance (253 ± 11.2 ms). This suggests that the click sound shortens the N2 latency of the ERP evoked by skin puncture. The ERP N2 latencies for SL, CL, ES, and IES were 146 ± 8.3, 149 ± 9.9, 148 ± 13.1, and 197 ± 21.2 ms, respectively. The ERP P2 latencies were 250 ± 18.2, 251 ± 14.1, 237 ± 26.3, and 294 ± 30.0 ms, respectively. The ERP latency for SL was significantly shorter than that for IES and was similar to that for ES. This suggests that the penetration force generated by the blade of the lance device activates the Aβ fibers, consequently shortening the ERP latency.

Conclusions

Lance ERP may reflect the activation of Aβ fibers rather than Aδ fibers. A pain index that correctly and reliably reflects nociceptive processing must be developed to improve pain assessment and management in neonates.

Pain in Preterm Infants: Different Perspectives

In the last decades, there has been a tremendous change in approaching and managing neonates' pain. These changes began with rebutting the previous misconception about neonates' , particularly preterm infants' , pain. The development in neuroimaging has revealed that by 24 weeks of gestation the peripheral nervous system is mature and function fully. Researchers now know that neonates experience pain and premature infants have even lower pain thresholds. Since that time, a mounting amount of literature has addressed the issue of neonatal pain. Many pharmacological and non pharmacological pain reduction strategies have been investigated for their safety and analgesic effectiveness. Many interventions such as nonnutritive sucking (NNS), skin-to-skin contact (SSC), and facilitated tucking are effective in controlling neonates pain.

Maternal separation with neonatal pain influences later-life fear conditioning and somatosenation in male and female rats

Early life adversity, including that which occurs in a medical setting, has been increasingly shown to have lasting consequences on both physical and mental health. In order to understand the lasting effects of early-life adversity, such as that might occur in the neonatal intensive care unit (NICU), several rodent models have been developed including maternal separation, neonatal handling, and repeated needle prick pain. However, in the clinical scenario, these stressors are often combined. Thus, the current study seeks to observe the lasting impacts of both neonatal pain and maternal separation in a rodent model. Rats were separated from their dam for 6 h per day during the first 7 days of life, during which they were subjected to repeated needle prick pain or handling. A separate group was left undisturbed. All rats were subsequently tested for threat processing using a 3-day Pavlovian fear conditioning model and for somatosensation using measures of mechanical and thermal thresholds. Results indicated that rats subjected to maternal separation and pain had enhanced fear conditioning in adolescence as well as displaying a modest age-independent tactile hypersensitivity compared to undisturbed controls. These data show that experiencing combined neonatal pain and maternal separation may create a latent vulnerability to subsequent stressors.

What Facial Features Does the Pediatrician Look to Decide That a Newborn Is Feeling Pain?

OBJECTIVE

 The study aimed to analyze the gaze fixation of pediatricians during the decision process regarding the presence/absence of pain in pictures of newborn infants.

STUDY DESIGN

 Experimental study, involving 38 pediatricians (92% females, 34.6 ± 9.0 years, 22 neonatologists) who evaluated 20 pictures (two pictures of each newborn: one at rest and one during a painful procedure), presented in random order for each participant. The Tobii-TX300 equipment tracked eye movements in four areas of interest of each picture (AOI): mouth, eyes, forehead, and nasolabial furrow. Pediatricians evaluated the intensity of pain with a verbal analogue score from 0 to 10 (0 = no pain; 10 = maximum pain). The number of pictures in which pediatricians fixed their gaze, the number of gaze fixations, and the total and average time of gaze fixations were compared among the AOI by analysis of variance (ANOVA). The visual-tracking parameters of the pictures' evaluations were also compared by ANOVA according to the pediatricians' perception of pain presence: moderate/severe (score = 6-10), mild (score = 3-5), and absent (score = 0-2). The association between the total time of gaze fixations in the AOI and pain perception was assessed by logistic regression.

RESULTS

 In the 20 newborn pictures, the mean number of gaze fixations was greater in the mouth, eyes, and forehead than in the nasolabial furrow. Also, the average total time of gaze fixations was greater in the mouth and forehead than in the nasolabial furrow. Controlling for the time of gaze fixation in the AOI, each additional second in the time of gaze fixation in the mouth (odds ratio [OR]: 1.26; 95% confidence interval [CI]: 1.08-1.46) and forehead (OR: 1.16; 95% CI: 1.02-1.33) was associated with an increase in the chance of moderate/severe pain presence in the neonatal facial picture.

CONCLUSION

 When challenged to say whether pain is present in pictures of newborn infants' faces, pediatricians fix their gaze preferably in the mouth. The longer duration of gaze fixation in the mouth and forehead is associated with an increase perception that moderate/severe pain is present.

KEY POINTS

· Neonatal pain assessment is intrinsically subjective.. · Visual tracking identifies the focus of attention of individuals.. · Adults' gaze in neonates' mouth and forehead is associated with pain perception..

Self‐reported sensitivity to pain in early and moderately‐late preterm‐born adolescents: A community‐based cohort study

We aimed to compare ratings of self‐reported and parent‐reported pain sensitivity between early preterm (EP), moderately‐late preterm (MLP), and full‐term (FT) adolescents. For EP adolescents, we aimed to determine whether pain sensitivity was associated with early‐life events. EP (n = 68, response rate 47.4%), MLP (n = 128, response rate 33.0%), and FT (n = 78, response rate 31.1%) adolescents and their parents (n = 277) answered an author‐generated question on pain sensitivity at 14‐15 years of age within a community‐based cohort study. Differences between groups were determined using the chi‐square test for trends. For EP adolescents, we assessed associations of treatment modalities (inotrope treatment, mechanical ventilation, and C‐section) and neonatal morbidities (sepsis/necrotizing enterocolitis, small‐for‐gestational age status, asphyxia, and cerebral pathologies) with adolescent pain sensitivity using logistic regression analyses. Increased pain sensitivity was reported by 18% of EP adolescents, compared with 12% of MLP adolescents, and 7% of FT adolescents (P = 0.033). Parent‐reported pain sensitivity did not differ by gestational age group. For EP adolescents, inotrope treatment was associated with increased pain sensitivity (odds ratio, 5.00, 95% confidence interval, 1.23‐20.4, P = 0.025). No other neonatal treatment modalities or morbidities were associated with pain sensitivity in adolescence. In conclusion, we observed higher proportions of increased pain sensitivity for EP and MLP adolescents. Physicians treating preterm adolescents should be aware of altered pain sensitivity.

Phenotyping peripheral neuropathic pain in male and female adolescents: pain descriptors, somatosensory profiles, conditioned pain modulation, and child-parent reported disability

ABSTRACT

Neuropathic pain (NeuP) can be difficult to diagnose and manage in children. Data regarding prevalence and sex-dependent differences are limited, and more detailed phenotyping is needed. This observational cohort study recruited adolescents (10-17 years) with NeuP or complex regional pain syndrome (CRPS). After pain history and NeuP questionnaires, quantitative sensory testing was performed. Individual z-score plots were calculated with body-region control measures and matched to mechanism-related sensory profiles (sensory loss, thermal hyperalgesia, and mechanical hyperalgesia). Conditioned pain modulation was assessed with pressure pain threshold and a contralateral cold conditioning stimulus, and meaningful conditioned pain modulation defined as twice the standard error of measurement. Patients and parents completed validated questionnaires for child quality of life (QoL), pain catastrophizing, and self-reported anxiety/depression. Males (n = 23) and females (n = 43) with NeuP (n = 52) or CRPS (n = 14) reported moderate-severe pain with neuropathic sensory descriptors. Mixed patterns of sensory gain/loss at pain sites were not sex-dependent. Thermal hyperalgesia was common in both NeuP and CRPS, whereas sensory loss occurred only with NeuP and in a smaller proportion than adult cohorts. Conditioned pain modulation was inhibitory in 54%, facilitatory in 14%, and nonresponders had variable cold conditioning sensitivity. Males and females reported marked impairment of QoL, increased emotional distress, and pain catastrophising. Child-parent QoL scores correlated, but catastrophizing scores were discordant when parents or adolescents reported higher anxiety/depression. NeuP in adolescents is associated with significant pain, physical impairment, and psychosocial impairment. Quantifying alterations in somatosensory profiles, descending modulation, child and parent psychological function will inform individualized therapy and stratification for future clinical trials.

The burden of early life stress on the nociceptive system development and pain responses

For a long time, the capacity of the newborn infant to feel pain was denied. Today it is clear that the nociceptive system, even if still immature, is functional enough in the newborn infant to elicit pain responses. Unfortunately, pain is often present in the neonatal period, in particular in the case of premature infants which are subjected to a high number of painful procedures during care. These are accompanied by a variety of environmental stressors, which could impact the maturation of the nociceptive system. Therefore, the question of the long-term consequences of early life stress is a critical question. Early stressful experience, both painful and non-painful, can imprint the nociceptive system and induce long-term alteration in brain function and nociceptive behavior, often leading to an increase sensitivity and higher susceptibility to chronic pain. Different animal models have been developed to understand the mechanisms underlying the long-term effects of different early life stressful procedures, including pain and maternal separation. This review will focus on the clinical and preclinical data about early life stress and its consequence on the nociceptive system.

Can Event-Related Potentials Evoked by Heel Lance Assess Pain Processing in Neonates? A Systematic Review

To clarify the possibility of event-related potential (ERP) evoked by heel lance in neonates as an index of pain assessment, knowledge acquired by and problems of the methods used in studies on ERP evoked by heel lance in neonates were systematically reviewed, including knowledge about Aδ and C fibers responding to noxious stimuli and Aβ fibers responding to non-noxious stimuli. Of the 863 reports searched, 19 were selected for the final analysis. The following points were identified as problems for ERP evoked by heel lance in neonates to serve as a pain assessment index: (1) It is possible that the ERP evoked by heel lance reflected the activation of Aβ fibers responding to non-noxious stimuli and not the activation of Aδ or C fibers responding to noxious stimulation; (2) Sample size calculation was presented in few studies, and the number of stimulation trials to obtain an averaged ERP was small. Accordingly, to establish ERP evoked by heel lance as a pain assessment in neonates, it is necessary to perform a study to clarify ERP evoked by Aδ- and C-fiber stimulations accompanied by heel lance in neonates.

The Role of Affectionate Caregiver Touch in Early Neurodevelopment and Parent-Infant Interactional Synchrony

Though rarely included in studies of parent–infant interactions, affectionate touch plays a unique and vital role in infant development. Previous studies in human and rodent models have established that early and consistent affectionate touch from a caregiver confers wide-ranging and holistic benefits for infant psychosocial and neurophysiological development. We begin with an introduction to the neurophysiological pathways for the positive effects of touch. Then, we provide a brief review of how affectionate touch tunes the development of infant somatosensory, autonomic (stress regulation), and immune systems. Affective touch also plays a foundational role in the establishment of social affiliative bonds and early psychosocial behavior. These touch-related bonding effects are known to be mediated primarily by the oxytocin system, but touch also activates mesocorticolimbic dopamine and endogenous opioid systems which aid the development of social cognitive processes such as social learning and reward processing. We conclude by proposing a unique role for affectionate touch as an essential pathway to establishing and maintaining parent-infant interactional synchrony at behavioral and neural levels. The limitations of the current understanding of affectionate touch in infant development point to fruitful avenues for future research.

Early Life Health in Women with Provoked Vestibulodynia and/or Vaginismus

Background: The lifetime prevalence of prolonged vulvar pain ranges from 3% to 28% among premenopausal women. Provoked vestibulodynia (PVD), often accompanied with various degrees of vaginismus, is the predominant cause. We explored the association between birth-related events and the risk of developing PVD/vaginismus during adulthood. Materials and Methods: We identified all women born in Sweden between 1973 and 2001 and categorized those with and without a diagnosis of PVD/vaginismus between 2001 and 2016 (during ages 15-43 years). Nationwide registry data were used to estimate the association between health during infancy (preterm birth, low birth weight, small for gestational age [SGA], Appearance, Pulse, Grimace, Activity and Respiration [APGAR] scores <7, and pain exposure during infancy) and the onset of PVD/vaginismus later in life using an event probability model. Results: Of the 1,359,315 women born in Sweden during 1973-2001, 9,247 were diagnosed with PVD (n = 6,648), vaginismus (n = 3,567), or both (n = 969). Preterm delivery <37 weeks (adjusted odds ratios [aOR]: 1.15, 95% confidence interval [CI]: 1.05-1.26), low birth weight <2,500 g (aOR: 1.24, 95% CI: 1.12-1.36), extremely low birth weight <1,500 g (aOR 1.41, 95% CI: 1.10-1.82), and SGA (aOR 1.20, 95% CI: 1.08-1.34) were factors associated with developing PVD/vaginismus. APGAR scores <7 or pain exposure during birth or infancy was not associated with PVD/vaginismus. Advanced maternal age, higher educational attainment, and being born in Sweden were associated with having a female offspring diagnosed with PVD/vaginismus. Conclusions: In a population of Swedish women 15-43 years of age, adverse health at birth was associated with developing PVD/vaginismus later on in life.

Neuropathic pain in children: Steps towards improved recognition and management

Neuropathic pain in children can be severe and persistent, difficult to recognise and manage, and associated with significant pain-related disability. Recognition based on clinical history and sensory descriptors is challenging in young children, and screening tools require further validation at older ages. Confirmatory tests can identify the disease or lesion of the somatosensory nervous system resulting in neuropathic pain, but feasibility and interpretation may be influenced by age- and sex-dependent changes throughout development. Quantitative sensory testing identifies specific mechanism-related sensory profiles; brain imaging is a potential biomarker of alterations in central processing and modulation of both sensory and affective components of pain; and genetic analysis can reveal known and new causes of neuropathic pain. Alongside existing patient- and parent-reported outcome measures, somatosensory system research methodologies and validation of mechanism-based standardised end-points may inform individualised therapy and stratification for clinical trials that will improve evidence-based management of neuropathic pain in children.

A systematic review of outcomes reported inpediatric perioperative research: A report from the Pediatric Perioperative Outcomes Group

The Pediatric Perioperative Outcomes Group (PPOG) is an international collaborative of clinical investigators and clinicians within the subspecialty of pediatric anesthesiology and perioperative care which aims to use COMET (Core Outcomes Measures in Effectiveness Trials) methodology to develop core outcome setsfor infants, children and young people that are tailored to the priorities of the pediatric surgical population.Focusing on four age-dependent patient subpopulations determined a priori for core outcome set development: i) neonates and former preterm infants (up to 60 weeks postmenstrual age); ii) infants (>60 weeks postmenstrual age - <1 year); iii) toddlers and school age children (>1-<13 years); and iv) adolescents (>13-<18 years), we conducted a systematic review of outcomes reported in perioperative studies that include participants within age-dependent pediatric subpopulations. Our review of pediatric perioperative controlled trials published from 2008 to 2018 identified 724 articles reporting 3192 outcome measures. The proportion of published trials and the most frequently reported outcomes varied across pre-determined age groups. Outcomes related to patient comfort, particularly pain and analgesic requirement, were the most frequent domain for infants, children and adolescents. Clinical indicators, particularly cardiorespiratory or medication-related adverse events, were the most common outcomes for neonates and infants < 60 weeks and were the second most frequent domain at all other ages. Neonates and infants <60 weeks of age were significantly under-represented in perioperative trials. Patient-centered outcomes, heath care utilization, and bleeding/transfusion related outcomes were less often reported. In most studies, outcomes were measured in the immediate perioperative period, with the duration often restricted to the post-anesthesia care unit or the first 24 postoperative hours. The outcomes identified with this systematic review will be combined with patient centered outcomes identified through a subsequent stakeholder engagement study to arrive at a core outcome set for each age-specific group.

New techniques, new challenges—The dilemma of pain management for less invasive surfactant administration?

Recent years have seen the increasing use of noninvasive respiratory support in preterm infants with the aim of minimizing the risk of mechanical ventilation and subsequent bronchopulmonary dysplasia. Respiratory distress syndrome is the most common respiratory diagnosis in preterm infants, and is best treated by administration of surfactant. Until recently, this has been performed via an endotracheal tube using premedication, which has often included opiate analgesia; subsequently, the infant has been ventilated. Avoidance of mechanical ventilation, however, does not negate the need for surfactant therapy. Less invasive surfactant administration (LISA) in spontaneously breathing infants is increasing in popularity, and appears to have beneficial effects. However, laryngoscopy is necessary, which carries adverse effects and is painful for the infant. Conventional methods of premedication for intubation tend to reduce respiratory drive, which increases the likelihood of ventilation being required. This has led to intense debate about the best strategy for providing appropriate treatment, taking into account both the respiratory needs of the infant and the need to alleviate procedural pain. Currently, clinical practice varies considerably and there is no consensus with respect to optimal management. This review seeks to summarize the benefits, risks, and challenges associated with this new approach.