Early pain experience, child and family factors, as precursors of somatization: a prospective study of extremely premature and fullterm children

Prolonged pain in premature neonates hospitalised in neonatal intensive care units: A scoping review

BACKGROUND

Exposure to repetitive pain during the neonatal period has been shown to have important short and long-term effects on the neurodevelopment of the premature neonate and can contribute to experienced prolonged pain. A uniform taxonomy of neonatal prolonged pain is still lacking to this day which contributes to suboptimal prolonged pain management in neonatal intensive care units. Accordingly, a scoping review exploring the state of knowledge about prolonged pain in preterm neonates hospitalised in the neonatal intensive care unit will contribute to the developing field of neonatal prolonged pain and provide recommendations for clinical prolonged pain management.

OBJECTIVE

To determine the scope, extent, and nature of the available literature on prolonged pain in premature neonates hospitalised in neonatal intensive care units.

DESIGN

Scoping review.

METHODS

An electronic search was conducted from inception to November 2023 in the databases of CINAHL, PubMed, Medline, Web of Science, GeryLit.org and Grey Source Index. Included studies discussed concepts related to neonatal prolonged pain such as definitions of prolonged pain, indicators of prolonged pain, contexts that result in prolonged pain, prolonged pain evaluation tools, consequences of prolonged pain and interventions for prolonged pain management.

RESULTS

Key concepts of neonatal prolonged pain were identified in the 86 included articles of this scoping review such as definitions (n = 26), indicators (n = 39), contexts (n = 49), scales (n = 56), consequences of prolonged pain (n = 30) and possible interventions for prolonged pain management (n = 22). Whilst a consensus on a definition has yet to be achieved, no proximate event was shown to cause prolonged pain and a time criterion was identified by authors as being relevant in defining prolonged pain. Interestingly, the context of hospitalisation was identified as being the most indicative of prolonged pain in premature neonates and should guide its evaluation and management, whilst only limited pain management interventions and consequences were discussed.

CONCLUSION

The findings of this scoping review contribute to the foundation of growing knowledge in neonatal prolonged pain and shed light on the ambiguity that currently exists on this topic in the scientific literature. This review summarises knowledge of key concepts necessary for a better understanding of prolonged pain and stresses the importance of considering contexts of hospitalisation for prolonged pain evaluation and management in neonatal intensive care units, with the objective of improving developmental outcomes of premature neonates.

TWEETABLE ABSTRACT

A scoping review reveals that the contexts of prolonged pain in premature neonates hospitalised in the neonatal intensive care unit are essential in guiding its evaluation and management.

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.

Neurodevelopmental, Mental Health, and Parenting Issues in Preterm Infants

The World Health Organization in its recommendations for the care of preterm infants has drawn attention to the need to address issues related to family involvement and support, including education, counseling, discharge preparation, and peer support. A failure to address these issues may translate into poor outcomes that extend across the lifespan. In this paper, we review the often far-reaching impact of preterm birth on the health and wellbeing of the parents and highlight the ways in which psychological stress may have a negative long-term impact on the parent-child interaction, attachment, and the styles of parenting. This paper addresses the following topics: (1) neurodevelopmental outcomes in preterm infants, including cognitive, sensory, and motor difficulties, (2) long-term mental health issues in premature infants that include elevated rates of anxiety and depressive disorders, autism, and somatization, which may affect social relationships and quality of life, (3) adverse mental health outcomes for parents that include elevated rates of depression, anxiety, and symptoms of post-traumatic stress, as well as increased rates of substance abuse, and relationship strain, (4) negative impacts on the parent-infant relationship, potentially mediated by maternal sensitivity, parent child-interactions, and attachment, and (5) impact on the parenting behaviors, including patterns of overprotective parenting, and development of Vulnerable Child Syndrome. Greater awareness of these issues has led to the development of programs in neonatal mental health and developmental care with some data suggesting benefits in terms of shorter lengths of stay and decreased health care costs.

Body size and brain volumetry in the rat following prolonged morphine administration in infancy and adulthood

Background

Prolonged morphine treatment in infancy is associated with a high incidence of opioid tolerance and dependence, but our knowledge of the long-term consequences of this treatment is sparse. Using a rodent model, we examined the (1) short- and (2) long-term effects of prolonged morphine administration in infancy on body weight and brain volume, and (3) we evaluated if subsequent dosing in adulthood poses an increased brain vulnerability.

Methods

Newborn rats received subcutaneous injections of either morphine or equal volume of saline twice daily for the first two weeks of life. In adulthood, animals received an additional two weeks of saline or morphine injections before undergoing structural brain MRI. After completion of treatment, structural T2-weigthed MRI images were acquired on a 7 T preclinical scanner (Bruker) using a RARE FSE sequence. Total and regional brain volumes were manually extracted from the MRI images using ITK-SNAP (v.3.6). Regions of interest included the brainstem, the cerebellum, as well as the forebrain and its components: the cerebral cortex, hippocampus, and deep gray matter (including basal ganglia, thalamus, hypothalamus, ventral tegmental area). Absolute (cm³) and normalized (as % total brain volume) values were compared using a one-way ANOVA with Tukey HSD post-hoc test.

Results

Prolonged morphine administration in infancy was associated with lower body weight and globally smaller brain volumes, which was not different between the sexes. In adulthood, females had lower body weights than males, but no difference was observed in brain volumes between treatment groups. Our results are suggestive of no long-term effect of prolonged morphine treatment in infancy with respect to body weight and brain size in either sex. Interestingly, prolonged morphine administration in adulthood was associated with smaller brain volumes that differed by sex only in case of previous exposure to morphine in infancy. Specifically, we report significantly smaller total brain volume of female rats on account of decreased volumes of forebrain and cortex.

Conclusions

Our study provides insight into the short- and long-term consequences of prolonged morphine administration in an infant rat model and suggests brain vulnerability to subsequent exposure in adulthood that might differ with sex.

Efficacy of Distraction for Reducing Pain and Distress Associated With Venipuncture in the Pediatric Posttransplant Population: A Randomized Controlled Trial

OBJECTIVE

Distraction can reduce pain and distress associated with painful procedures but has never been studied in children with solid organ transplants. We aimed to determine whether there is a difference in pain and distress associated with venipuncture in pediatric posttransplant patients who receive distraction compared with those who do not.

METHODS

Randomized controlled trial of children aged 4 to 17 years with solid organ transplants undergoing venipuncture in the outpatient setting. Patients were randomized to receive distraction or no distraction. The primary outcome was the Faces Pain Scale-Revised. Secondary outcomes were the Observational Scale of Behavioral Distress-Revised; Faces, Leg, Activity, Cry, Consolability; and Children's Hospital of Eastern Ontario Pain Scale. Exploratory outcomes included the number of venipuncture attempts, time to successful venipuncture, and satisfaction of phlebotomists and parents.

RESULTS

Median age of the 40 children enrolled was 11.5 years. Type of transplants included the heart (67.5%), kidney (22.5%), liver (7.5%), and more than 1 organ (2.5%). There was no difference between the Faces Pain Scale-Revised scores in distraction and no distraction groups (1.4; 95% confidence interval, 0.9-1.9; and 1.3, 95% confidence interval, 0.5-2.1, respectively). There was also no difference in the Observational Scale of Behavioral Distress-Revised; Faces, Leg, Activity, Cry, Consolability; and Children's Hospital of Eastern Ontario Pain Scale scores, number of venipuncture attempts, or time to successful venipuncture. Phlebotomists were more satisfied with the venipuncture when distraction was implemented.

CONCLUSIONS

In children with solid organ transplants, there was no difference in pain and distress associated with venipuncture between those who did and did not receive distraction. There was also no difference in other procedure-related outcomes except for greater phlebotomist satisfaction when distraction was implemented.

Understanding early-life pain and its effects on adult human and animal emotionality: Translational lessons from rodent and zebrafish models

Critical for organismal survival, pain evokes strong physiological and behavioral responses in various sentient species. Clinical and preclinical (animal) studies markedly increase our understanding of biological consequences of developmental (early-life) adversity, as well as acute and chronic pain. However, the long-term effects of early-life pain exposure on human and animal emotional responses remain poorly understood. Here, we discuss experimental models of nociception in rodents and zebrafish, and summarize mounting evidence of the role of early-life pain in shaping emotional traits later in life. We also call for further development of animal models to probe the impact of early-life pain exposure on behavioral traits, brain disorders and novel therapeutic treatments.

Available Instruments to Assess Pain in Infants

Pain assessment in newborns and infants is challenging for clinicians. Although behavioral and behavioral-physiological scales are validated pain assessment instruments, their use in this age group has significant limitations. In this review, we summarize the methods currently available for assessing pain in neonates and infants. It is possible that these pain detection methods are also useful for assessing the quality of anesthesia and analgosedation in these populations. Further research should be aimed at confirming the usefulness of these tools in infants and identifying additional pain assessment options for clinical practice.

Effect on Pain of an Oral Sucrose Solution vs. Placebo in Children 1 to 3 Months Old Needing Nasopharyngeal Aspiration: A Randomized Controlled Trial

BACKGROUND

Oral sweet solutions have been proposed as effective pain-reducing agents for procedures.

OBJECTIVES

To compare the efficacy of an oral sucrose solution vs. placebo in alleviating pain in children (1-3 months) during nasopharyngeal aspiration (NPA).

METHODS

A randomized, double-blind, controlled clinical trial was conducted in a pediatric hospital emergency department. Participants (aged 1-3 months) requiring NPA were randomly allocated to receive 2 mL of 88% sucrose (SUC) or 2 mL of a placebo (PLA) 2 min prior to the procedure. The primary outcome was the mean difference in pain scores at 1 min post NPA as assessed by the Face, Legs, Activity, Cry and Consolability (FLACC) Pain Scale.

RESULTS

Seventy-two participants completed the study, 37 receiving SUC and 35 PLA. The mean difference in FLACC scores compared with baseline was 3.3 (2.5-4.1) for SUC vs. 3.2 (2.3-4.1) for PLA (p = .094) at 1 min and -1.2 (-1.7-0.7) for SUC vs. -0.8 (-1.5 to -0.1) for PLA (p = 0.66) at 3 min after NPA. For the Neonatal Infant Pain Scale scores, it was 2.3 (1.6-3.0) (SUC) vs. 2.5 (1.8-3.2) (PLA) (p = .086) at 1 min and -1.2 (-1.6 to -0.8) (SUC) vs. -0.8 (-1.3 to 0.2) (PLA) (p = 0.59) 3 min after NPA. There was no difference in the mean crying time, 114 (98-130) s, SUC vs. 109 (92-126) s, PLA (p = 0.81). No significant difference was found in participants' heart rate at 1 min 174 (154-194) beats/min in SUC vs. 179 (160-198) beats/min in PLA (p = 0.32).

CONCLUSIONS

In infants (1-3 months) undergoing NPA, administration of an oral sweet solution did not statistically decrease pain scores.

Psychosocial Factors Affecting Parental Report of Symptoms in Children: A Systematic Review

OBJECTIVE

Parents make important treatment decisions for their children based on symptoms they perceive their child to be experiencing. Multiple psychological factors are associated with subjective symptom perception, but factors affecting perception of symptoms in others have been explored less. We systematically reviewed the literature to identify parent and child psychological factors associated with parental report of physical symptoms in their child.

METHODS

We searched Embase, Ovid, PsycINFO, and Scopus for studies that investigated associations between psychological factors and parental report of symptoms in their child.

RESULTS

Thirty-six citations reporting on 34 studies that assessed the association between parent or child psychological factors and parental report of physical symptoms in the child were included in the review. Three main factors were identified as being associated with parental symptom report. First, there was evidence for an association between parental symptom report and affect, in particular parent and child anxiety. Second, child behavioral and conduct problems, and temperament-related challenges (problems with feeding and sleeping) were associated with parental symptom report. Third, parental expectations and beliefs that symptoms would occur were associated with parental symptom report, although few studies investigated these associations.

CONCLUSIONS

Parent and child affect, and parental expectations and beliefs may influence parents' cognition, causing them to pay more attention to their child, interpret their child's behavior as symptomatic, and recall symptoms in the child. Given the importance of parental perception of symptoms in driving decisions around care, additional research in this field is needed.

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.

Quantitative MRI study of infant regional brain size following surgery for long-gap esophageal atresia requiring prolonged critical care

INTRODUCTION

Little is known regarding the impact of concurrent critical illness and thoracic noncardiac perioperative critical care on postnatal brain development. Previously, we reported smaller total brain volumes in both critically ill full-term and premature patients following complex perioperative critical care for long-gap esophageal atresia (LGEA). Our current report assessed trends in regional brain sizes during infancy, and probed for any group differences.

METHODS

Full-term (n = 13) and preterm (n = 13) patients without any previously known neurological concerns, and control infants (n = 16), underwent non-sedated 3 T MRI in infancy (<1 year old). T2-weighted images underwent semi-automated brain segmentation using Morphologically Adaptive Neonatal Tissue Segmentation (MANTiS). Regional tissue volumes of the forebrain, deep gray matter (DGM), cerebellum, and brainstem are presented as absolute (cm3) and normalized (% total brain volume (%TBV)) values. Group differences were assessed using a general linear model univariate analysis with corrected age at scan as a covariate.

RESULTS

Absolute volumes of regions analyzed increased with advancing age, paralleling total brain size, but were significantly smaller in both full-term and premature patients compared to controls. Normalized volumes (%TBV) of forebrain, DGM, and cerebellum were not different between subject groups analyzed. Normalized brainstem volumes showed group differences that warrant future studies to confirm the same finding.

DISCUSSION

Both full-term and premature critically ill infants undergoing life-saving surgery for LGEA are at risk of smaller total and regional brain sizes. Normalized volumes support globally delayed or diminished brain growth in patients. Future research should look into neurodevelopmental outcomes of infants born with LGEA.

Early Pain Exposure Influences Functional Brain Connectivity in Very Preterm Neonates

Background

Early exposure to nociceptive events may cause brain structural alterations in preterm neonates, with long-lasting consequences on neurodevelopmental outcome. Little is known on the extent to which early pain may affect brain connectivity. We aim to evaluate brain functional connectivity changes in preterm neonate that underwent multiple invasive procedures during the postnatal period, and to correlate them with the neurodevelopmental outcome at 24 months.

Methods

In this prospective case-control study, we collected information about exposure to painful events during the early postnatal period and resting-state BOLD-fMRI data at term equivalent age from two groups of preterm neonate: 33 subjected to painful procedures during the neonatal intensive care (mean gestational age 27.9 ± 1.8 weeks) and 13 who did not require invasive procedures (average gestational age 31.2 ± 2.1 weeks). A data-driven principal-component-based multivariate pattern analysis (MVPA) was used to investigate the effect of early pain exposure on brain functional connectivity, and the relationship between connectivity changes and neurodevelopmental outcome at 24 months, assessed with Griffiths, Developmental Scale-Revised: 0-2.

Results

Early pain was associated with decreased functional connectivity between thalami and bilateral somatosensory cortex, and between the right insular cortex and ipsilateral amygdala and hippocampal regions, with a more evident effect in preterm neonate undergoing more invasive procedures. Functional connectivity of the right thalamocortical pathway was related to neuromotor outcome at 24 months (P = 0.003).

Conclusion

Early exposure to pain is associated with abnormal functional connectivity of developing networks involved in the modulation of noxious stimuli in preterm neonate, contributing to the neurodevelopmental consequence of preterm birth.

Non-pharmacological pain management in the neonatal intensive care unit: Managing neonatal pain without drugs

Premature infants hospitalized after birth are exposed to repeated painful procedures as part of their routine medical care. Early neonatal exposure to unmanaged pain has been linked to numerous negative long-term outcomes, such as the development of pain hypersensitivity, detrimental psychological symptomology, and altered neurodevelopment. These findings emphasize the crucial role of pain management in neonatal care. The aim of this article is to give an overview of evidence-based non-pharmacological pain management techniques for hospitalized neonates. Research supporting the effectiveness of various proximal, distal, and procedural pain management methods in neonates will be presented. Additionally, understanding the larger biopsychosocial context of the infant that underpins the mechanisms of these pain management methods is essential. Therefore, two important models that inform non-pharmacological approaches to infant pain management (DIAPR-R [The Development of Infant Acute Pain Responding-Revised], Attachment Theory) will be discussed.

Are perinatal factors associated with musculoskeletal pain across the lifespan? A systematic review with meta-analysis

BACKGROUND

Musculoskeletal conditions are common health issues with great impact on individuals. Although many factors have been associated with the development of musculoskeletal pain, such as perinatal factors, its aetiology is still poorly understood.

OBJECTIVE

To systematically investigate whether perinatal factors can increase the risk of having musculoskeletal pain across the lifespan.

METHODS

MEDLINE, CINAHL, Scopus, Web of Science and EMBASE databases were searched from their inception to December 2017. Descriptors used in our search strategy were related to "perinatal factors" and "musculoskeletal pain". There were no language, age, sex or date restrictions. Meta-analysis was used to pool the estimates of association between perinatal factors and musculoskeletal pain.

RESULTS

Among the six articles included in this systematic review, three were extracted for the meta-analysis. The pooled of three and two studies showed no association between chronic musculoskeletal pain and low birth weight (OR 1.8, 95% CI 0.9-3.8, I² = 0; n = 157) or pre-term birth (OR 0.5, 95% CI 0.0-4.5; I² = 78%; n = 374) in adults, respectively. Overall, the quality of evidence after applying the GRADE approach was very low across all the studies.

CONCLUSION

In adults, our meta-analysis showed no association between birth weight or pre-term birth and musculoskeletal pain, and the quality of the evidence was very low. Thus, the very low quality of evidence and limited number of studies do not suggest a direct clear association. Further high-quality longitudinal studies accounting for more relevant confounders are needed to better understand the complex mechanism that may operate between perinatal factors and musculoskeletal pain.

Infant Brain Structural MRI Analysis in the Context of Thoracic Non-cardiac Surgery and Critical Care

Objective: To determine brain magnetic resonance imaging (MRI) measures of cerebrospinal fluid (CSF) and whole brain volume of full-term and premature infants following surgical treatment for thoracic non-cardiac congenital anomalies requiring critical care. Methods: Full-term (n = 13) and pre-term (n = 13) patients with long-gap esophageal atresia, and full-term naïve controls (n = 19) < 1 year corrected age, underwent non-sedated brain MRI following completion of thoracic non-cardiac surgery and critical care treatment. Qualitative MRI findings were reviewed and reported by a pediatric neuroradiologist and neurologist. Several linear brain metrics were measured using structural T1-weighted images, while T2-weighted images were required for segmentation of total CSF and whole brain tissue using the Morphologically Adaptive Neonatal Tissue Segmentation (MANTiS) tool. Group differences in absolute (mm, cm³) and normalized (%) data were analyzed using a univariate general linear model with age at scan as a covariate. Mean normalized values were assessed using one-way ANOVA. Results: Qualitative brain findings suggest brain atrophy in both full-term and pre-term patients. Both linear and volumetric MRI analyses confirmed significantly greater total CSF and extra-axial space, and decreased whole brain size in both full-term and pre-term patients compared to naïve controls. Although linear analysis suggests greater ventricular volumes in all patients, volumetric analysis showed that normalized ventricular volumes were higher only in premature patients compared to controls. Discussion: Linear brain metrics paralleled volumetric MRI analysis of total CSF and extra-axial space, but not ventricular size. Full-term infants appear to demonstrate similar brain vulnerability in the context of life-saving thoracic non-cardiac surgery requiring critical care as premature infants.

Factors Associated With Infant Pain Severity Undergoing Immunization Injections

PURPOSE

Factors influencing infants' behavioral and vocal (cry) response to painful stimuli are explored to improve pain management plans for infants undergoing immunizations.

DESIGN AND METHODS

An observational study design was used. Pain responses of 60 to 75 days-old infants (44% male vs 56% female) undergoing two-month immunization injections were videotaped and coded using the Modified Behavioral Pain Scale (MBPS), and duration of total crying time during injection was recorded. The influences of five factors (gender, caregiver attendance, previous experience of nociception (circumcision), mode of delivery), and weight (birth and current) were examined at baseline, during and post-immunization.

RESULTS

Higher birth weight was the most significant factor that reduced pain responses during (p = 0.001) and post-immunization (p = 0.03). A higher birth weight reduced full lung crying (p = 0.04), which reflects crying during injection as compared to total crying time. Vaginal delivery had a significant effect on behavioral pain responses of infants only post-immunization (p = 0.006). Parent's presence in the immunization room significantly reduced total crying time (p = 0.03). Uncircumcised male infants had a significant reduction in behavioral pain responses during immunization (p = 0.01) compared to circumcised infants.

CONCLUSIONS

The literature well supports the acknowledgement of early pain experience and its psychological consequences. Knowing and controlling for each of mentioned factors early in life during every painful procedure could improve coping mechanisms of infants for any painful procedures later in life.

PRACTICE IMPLICATIONS

Control of certain factors during early life experiences can modify pain of immunization.

The Influence of Early Life Experience on Visceral Pain

Pain is the most reported and troublesome symptom of nearly all functional disorders affecting the genitourinary and gastrointestinal organs. Patients with irritable bowel syndrome (IBS), interstitial cystitis/painful bladder syndrome (IC/PBS), vulvodynia, and/or chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS; collectively termed chronic pelvic pain syndromes) report pain severe enough to impact quality of life and often suffer from symptoms of or are diagnosed with more than one of these syndromes. This increased comorbidity between chronic pelvic pain syndromes, and with pain disorders of disparate body regions, as well as with mood disorders, can be influenced by disruptions in the hypothalamic-pituitary-adrenal (HPA) axis, which regulates the response to stress and influences the perception of pain. Experiencing trauma, neglect, or abuse in early life can permanently affect the functioning of the HPA axis. As such, a significant proportion of patients suffering from comorbid chronic pelvic pain syndromes report a history of early life stress or trauma. Here we will report on how these early life experiences influence chronic pelvic pain in patients. We will also discuss various rodent models that have been developed to study this phenomenon to understand the mechanisms underlying HPA axis dysfunction, as well as potential underlying mechanisms connecting these syndromes to one another.

Early Procedural Pain Is Associated with Regionally-Specific Alterations in Thalamic Development in Preterm Neonates

Very preterm human neonates are exposed to numerous invasive procedures as part of life-saving care. Evidence suggests that repetitive neonatal procedural pain precedes long-term alterations in brain development. However, to date the link between pain and brain development has limited temporal and anatomic specificity. We hypothesized that early exposure to painful stimuli during a period of rapid brain development, before pain modulatory systems reach maturity, will predict pronounced changes in thalamic development, and thereby cognitive and motor function. In a prospective cohort study, 155 very preterm neonates (82 males, 73 females) born 24-32 weeks' gestation underwent two MRIs at median postmenstrual ages 32 and 40 weeks that included structural, metabolic, and diffusion imaging. Detailed day-by-day clinical data were collected. Cognitive and motor abilities were assessed at 3 years, corrected age. The association of early (skin breaks, birth-Scan 1) and late pain (skin breaks, Scans 1-2) with thalamic volumes and N-acetylaspartate (NAA)/choline (Cho), and fractional anisotropy of white-matter pathways was assessed. Early pain was associated with slower thalamic macrostructural growth, most pronounced in extremely premature neonates. Deformation-based morphometry analyses confirmed early pain-related volume losses were localized to somatosensory regions. In extremely preterm neonates early pain was associated with decreased thalamic NAA/Cho and microstructural alterations in thalamocortical pathways. Thalamic growth was in turn related to cognitive and motor outcomes. We observed regionally-specific alterations in the lateral thalamus and thalamocortical pathways in extremely preterm neonates exposed to more procedural pain. Findings suggest a sensitive period leading to lasting alterations in somatosensory-system development.SIGNIFICANCE STATEMENT Early exposure to repetitive procedural pain in very preterm neonates may disrupt the development of regions involved in somatosensory processing, leading to poor functional outcomes. We demonstrate that early pain is associated with thalamic volume loss in the territory of the somatosensory thalamus and is accompanied by disruptions thalamic metabolic growth and thalamocortical pathway maturation, particularly in extremely preterm neonates. Thalamic growth was associated with cognitive and motor outcome at 3 years corrected age. Findings provide evidence for a developmentally sensitive period whereby subcortical structures in young neonates may be most vulnerable to procedural pain. Furthermore, results suggest that the thalamus may play a key role underlying the association between neonatal pain and poor neurodevelopmental outcomes in these high-risk neonates.

Analgesic Efficacy of Oral Dextrose and Breast Milk during Nasopharyngeal Suctioning of Preterm Infants on CPAP: A Blinded Randomized Controlled Trial

Continuous positive airway pressure (CPAP) requires nasopharyngeal suctioning for airway patency, which is painful. Other procedures have used breast milk and 25% dextrose as analgesics. We aimed to compare their analgesic efficacy during nasopharyngeal suctioning in preterm neonates on CPAP. In this blinded randomized controlled trial, babies received 25% dextrose or breast milk orally. Pain before, during and after was assessed using the Premature Infant Pain Profile (PIPP) score. Analysis was done for 40 babies. The mean PIPP score in the 25% dextrose group during the procedure was 11.25 ± 2.73 and 13.2 ± 2.55 (p = 0.02) with the intervention and without. In the breast milk group the PIPP score during the procedure was 11.35 ± 3.05 and 13.45 ± 3.27 (p = 0.04); this difference persisted even after the procedure. There was no significant difference between the interventions. Both interventions significantly reduce pain. The analgesic effect of breast milk was sustained.

Neonatal bladder inflammation induces long-term visceral pain and altered responses of spinal neurons in adult rats

Painful events early in life have been shown to increase the incidence of interstitial cystitis/painful bladder syndrome in adulthood. However, the intrinsic mechanism is not well studied. We previously reported that neonatal bladder inflammation causes chronic visceral hypersensitivity along with molecular disruption of spinal GABAergic system in rats. The present study investigates whether these molecular changes affect the integrative function and responses of bladder-sensitive primary afferent and spinal neurons. Neonatal bladder inflammation was induced by intravesicular injection of zymosan during postnatal (P) days 14-16. In adulthood (P60), the viscero-motor response (VMR) to visceral stimuli was significantly inhibited by intrathecal (i.t) HZ166 (GABA_Aα-2 agonist) only in neonatally saline-treated, but not in neonatally zymosan-treated rats. HZ166 significantly inhibited the responses of bladder-responsive lumbosacral (LS) spinal neurons to urinary bladder distension (UBD) and slow infusion (SI) in neonatally saline-treated rats. Similar results were also observed in naïve adult rats where HZ166 produced significant inhibition of bladder-responsive spinal neurons. However, HZ166 did not inhibit responses of UBD-responsive spinal neurons from neonatally zymosan-treated rats. The drug did not attenuate the responses of UBD-sensitive pelvic nerve afferent (PNA) fibers to UBD and SI in either group of rats tested. Immunohistochemical studies showed a significantly lower level of GABA_Aα-2 receptor expression in the LS spinal cord of neonatally zymosan-treated rats compared to saline-treated rats. These findings indicate that neonatal bladder inflammation leads to functional and molecular alteration of spinal GABA_Aα-2 receptor subtypes, which may result in chronic visceral hyperalgesia in adulthood.

A Broad Consideration of Risk Factors in Pediatric Chronic Pain: Where to Go from Here?

Pediatric chronic pain is a significant problem associated with substantial functional impairment. A variety of risk factors have been found to be associated with chronic pain in youth. The greatest amount of evidence appears to support that temperament, anxiety, depression, subjective experience of stress, passive coping strategies, sleep problems, other somatic-related problems, and parent and/or family factors are important variables. However, a great deal of this research focuses on a single risk factor or on multiple risk factors in isolation. Much of the literature utilizes older diagnostic criteria and would benefit from replication, larger sample sizes, and comparison across pain disorders. Problems also exist with disagreement across definitions, resulting in inconsistency or unclear use of terms. Furthermore, recent consideration has suggested that outcome measures should include functional disability in addition to pain. A second generation of research is needed to shed light on the complex interactions that likely play a role in the transition from acute to chronic pain. Building on recent calls for changes in research in this area, we propose the next steps for this research, which involve consideration of both biopsychosocial and developmental contexts.

The Future of Neonatal Advanced Practice Registered Nurse Practice: White Paper

In recent years, the National Association of Neonatal Nurses and the National Association of Neonatal Nurse Practitioners have been monitoring aspects of neonatal advanced practice nursing and providing leadership and advocacy to address concerns related to workforce, education, competency, fatigue, safety, and scope of practice. This white paper discusses current barriers within neonatal advanced practice registered nurse practice as well as strategies to promote the longevity of the neonatal advanced practice registered nurse roles.

Long-term behavioral effects in a rat model of prolonged postnatal morphine exposure

Prolonged morphine treatment in neonatal pediatric populations is associated with a high incidence of opioid tolerance and dependence. Despite the clinical relevance of this problem, our knowledge of long-term consequences is sparse. The main objective of this study was to investigate whether prolonged morphine administration in a neonatal rat is associated with long-term behavioral changes in adulthood. Newborn animals received either morphine (10 mg/kg) or equal volume of saline subcutaneously twice daily for the first 2 weeks of life. Morphine-treated animals underwent 10 days of morphine weaning to reduce the potential for observable physical signs of withdrawal. Animals were subjected to nonstressful testing (locomotor activity recording and a novel-object recognition test) at a young age (Postnatal Days [PDs] 27-31) or later in adulthood (PDs 55-56), as well as stressful testing (calibrated forceps test, hot plate test, and forced swim test) only in adulthood. Analysis revealed that prolonged neonatal morphine exposure resulted in decreased thermal but not mechanical threshold. Importantly, no differences were found for total locomotor activity (proxy of drug reward/reinforcement behavior), individual forced swim test behaviors (proxy of affective processing), or novel-object recognition test. Performance on the novel-object recognition test was compromised in the morphine-treated group at the young age, but the effect disappeared in adulthood. These novel results provide insight into the long-term consequences of opioid treatment during an early developmental period and suggest long-term neuroplastic differences in sensory processing related to thermal stimuli.

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.

The long-term impact of early life pain on adult responses to anxiety and stress: Historical perspectives and empirical evidence

Approximately 1 in 6 infants are born prematurely each year. Typically, these infants spend 25 days in the Neonatal Intensive Care Unit (NICU) where they experience 10-18 painful and inflammatory procedures each day. Remarkably, pre-emptive analgesics and/or anesthesia are administered less than 25% of the time. Unalleviated pain during the perinatal period is associated with permanent decreases in pain sensitivity, blunted cortisol responses and high rates of neuropsychiatric disorders. To date, the mechanism(s) by which these long-term changes in stress and pain behavior occur, and whether such alterations can be prevented by appropriate analgesia at the time of insult, remains unclear. Work in our lab using a rodent model of early life pain suggests that inflammatory pain experienced on the day of birth blunts adult responses to stress- and pain-provoking stimuli, and dysregulates the hypothalamic pituitary adrenal (HPA) axis in part through a permanent upregulation in central endogenous opioid tone. This review focuses on the long-term impact of neonatal inflammatory pain on adult anxiety- and stress-related responses, and underlying neuroanatomical changes in the context of endogenous pain control and the HPA axis. These two systems are in a state of exaggerated developmental plasticity early in postnatal life, and work in concert to respond to noxious or aversive stimuli. We present empirical evidence from animal and clinical studies, and discuss historical perspectives underlying the lack of analgesia/anesthetic use for early life pain in the modern NICU.

Oral glucose in preterm neonates during oropharyngeal suctioning: a randomized controlled cross-over trial

To investigate whether orally applied glucose reduces pain response during oropharyngeal suctioning in preterm infants with a birth weight >1500 g, we conducted a randomized, double-blind, placebo-controlled cross-over trial on 32 preterm infants undergoing oropharyngeal suctioning while on nasal continuous positive airway pressure (CPAP). The Premature Infant Pain Profile (PIPP) score was assessed and compared in a cross-over design to investigate whether there was a significant difference in the patients' pain response. The mean PIPP score during oropharyngeal suctioning after placebo was 8.6 (KI 7.8-9.4). After glucose administration, the mean PIPP score was 8.0 (KI 7.1-8.9). Comparison of the treatment effects reached no statistic significance (p = 0.23). During the oral study drug administration during nasal CPAP, we observed 47 adverse events, but none necessitated therapeutic intervention and none was classified as serious.

CONCLUSION

In our study, late preterm infants in the first days of life did not benefit significantly from analgesia with glucose during oropharyngeal suctioning. The oral administration of glucose under nasal CPAP led to no serious adverse events.

Fetal Neurology: The Role of Fetal Stress

Fetal development and growth, as well as the timing of birth is influenced by the intrauterine environment. Many environmental factors causing the fetal stress can interfere with fetal development and leave long-term and profound consequences on health. Fetal glucocorticoid overexposure has primarily significant consequences for the development of the central nervous system. In response to an adverse intrauterine conditions, the fetus is able to adapt its physiology to promote survival. However, these adaptations can result in permanent changes in tissue and organ structure and function that directly ‘program’ predisposition to disease. Cardiometabolic disorders, behavioral alterations and neuropsychiatric impairments in adulthood and/ or childhood may have their roots in the fetal period of life. Fetal response to stress and its prenatal and lifelong consequences are discussed in this review.

How to cite this article

Kadić AS. Fetal Neurology: The Role of Fetal Stress. Donald School J Ultrasound Obstet Gynecol 2015;9(1):30-39.

Early repetitive pain in preterm infants in relation to the developing brain

Infants born preterm (<37 weeks of gestation) are particularly vulnerable to procedural stress and pain exposure during neonatal intensive care, at a time of rapid and complex brain development. Concerns regarding effects of neonatal pain on brain development have long been expressed. However, empirical evidence of adverse associations is relatively recent. Thus, many questions remain to be answered. This review discusses the short- and long-term effects of pain-related stress and associated treatments on brain maturation and neurodevelopmental outcomes in children born preterm. The current state of the evidence is presented and future research directions are proposed.

Neonatal pain: What's age got to do with it?

Background:

The neurobiology of neonatal pain processing, especially in preterm infants, differs significantly from older infants, children, adolescence, and adults. Research suggests that strong painful procedures or repeated mild procedures may permanently modify individual pain processing. Acute injuries at critical developmental periods are risk factors for persistent altered neurodevelopment. The purpose of this narrative review is to present the seminal and current literature describing the unique physiological aspects of neonatal pain processing.

Methods:

Articles describing the structures and physiological processes that influence neonatal pain were identified from electronic databases Medline, PubMed, and CINAHL.

Results:

The representation of neonatal pain physiology is described in three processes: Local peripheral nervous system processes, referred to as transduction; spinal cord processing, referred to as transmission and modulation; and supraspinal processing and integration or perception of pain. The consequences of undermanaged pain in preterm infants and neonates are discussed.

Conclusion:

Although the process and pain responses in neonates bear some similarity to processes and pain responses in older infants, children, adolescence, and adults; there are some pain processes and responses that are unique to neonates rendering them at risk for inadequate pain treatment. Moreover, exposure to repeated painful stimuli contributes to adverse long-term physiologic and behavioral sequelae. With the emergence of studies showing that painful experiences are capable of rewiring the adult brain, it is imperative that we treat neonatal pain effectively.

Treatment of chronic pain in children and adolescents

SUMMARY Chronic pain in children is a poorly recognized entity that is challenging to treat and leaves many families frustrated. Often, lack of an identifiable etiology along with the complex biopsychosocial nature of this condition leads to a lengthy diagnostic odyssey and delayed treatment that exacerbates the existing problem. Effective treatment of chronic pain requires a team approach in order to deal with the various aspects of this condition. Combinations of medication along with nonpharmacologic treatments, such as physical therapy, psychological interventions and complementary therapies, are often the most effective ways of treating chronic pain rather than medication alone. Further research is needed to understand the complex biobehavioral processes involved in the development and maintenance of chronic pain. Development of targeted novel therapies as well as comparative studies of existing treatments will help to improve treatment for chronic pain in children.

The neurodevelopmental impact of neonatal morphine administration

Medical management of newborn infants often necessitates recurrent painful procedures, which may alter nociceptive pathways during a critical developmental period and adversely effect neuropsychological outcomes. To mitigate the effects of repeated painful stimuli, opioid administration for peri-procedural analgesia and ICU (intensive care unit) sedation is common in the NICU (neonatal intensive care unit). A growing body of basic and animal evidence suggests potential long-term harm associated with neonatal opioid therapy. Morphine increases apoptosis in human microglial cells, and animal studies demonstrate long-term changes in behavior, brain function, and spatial recognition memory following morphine exposure. This comprehensive review examines existing preclinical and clinical evidence on the long-term impacts of neonatal pain and opioid therapy.

In search of risk factors for chronic pain in adolescents: a case-control study of childhood and parental associations

Objectives

This study was designed to investigate whether an individual and parental history of functional pain syndromes (FPS) is found more often in adolescents suffering from chronic pain than in their pain-free peers.

Methods

Our case–control study involved 101 adolescents aged 10–18 years. Cases were 45 patients of the Chronic Pain Clinic at Sydney Children’s Hospital with diverse chronic pain disorders. Controls consisted of 56 adolescent volunteers who did not have chronic pain. Adolescents and their parents filled out questionnaires assessing demographic data as well as known and potential risk factors for chronic pain. A history of FPS was assessed by questionnaire, including restless legs syndrome (RLS). Chi-squared tests and t-tests were used to investigate univariate associations between chronic pain in adolescents and lifetime prevalence of FPS. Logistic regression was used to test multivariate associations, while controlling for possible confounders.

Results

Migraine, non-migraine headaches, recurrent abdominal pain (RAP), and RLS were reported significantly more frequently in cases than controls (P-values of 0.01, <0.001, 0.01, and 0.03, respectively). Parental migraine, RAP, and RLS were also significantly associated with adolescent chronic pain in the multivariate analyses. Individual history of migraine, non-migraine headaches, and RAP, along with parental history of RAP and depression significantly accounted for 36%–49% of variance in chronic pain. Other associations with chronic pain were generally in accordance with previous reports.

Discussion

It may be helpful when assessing a child who has chronic pain or is at risk of chronic pain, to enquire about these associations. Based on the current findings, an individual history of migraine, non-migraine headaches, and RAP, as well as parental migraine, RAP, and RLS are symptoms that are of particular relevance to assess.

Vaginal hypersensitivity and hypothalamic-pituitary-adrenal axis dysfunction as a result of neonatal maternal separation in female mice

Early life stress can permanently alter functioning of the hypothalamic-pituitary-adrenal (HPA) axis, which regulates the stress response and influences the perception of pain. Chronic pelvic pain patients commonly report having experienced childhood neglect or abuse, which increases the likelihood of presenting with comorbid chronic pain and/or mood disorders. Animal models of neonatal stress commonly display enhanced anxiety-like behaviors, colorectal hypersensitivity, and disruption of proper neuro-immune interactions in adulthood. Here, we tested the hypothesis that early life stress impacts vaginal sensitivity by exposing mice to neonatal maternal separation (NMS) for 3h/day during the first two (NMS14) or three (NMS21) postnatal weeks. As adults, female mice underwent vaginal balloon distension (VBD), which was also considered an acute stress. Before or after VBD, mice were assessed for anxiety-like behavior, hindpaw sensitivity, and changes in gene and protein expression related to HPA axis function and regulation. NMS21 mice displayed significantly increased vaginal sensitivity compared to naïve mice, as well as significantly reduced anxiety-like behavior at baseline, which was heightened following VBD. NMS21 mice exhibited significant thermal and mechanical hindpaw hypersensitivity at baseline and following VBD. NMS14 mice displayed no change in anxiety-like behavior and only exhibited significantly increased hindpaw mechanical and thermal sensitivity following VBD. Centrally, a significant decrease in negative regulation of the HPA axis was observed in the hypothalamus and hippocampus of NMS21 mice. Peripherally, NMS and VBD affected the expression of inflammatory mediators in the vagina and bladder. Corticotropin-releasing factor (CRF) receptor and transient receptor potential (TRP) channel protein expression was also significantly, and differentially, affected in vagina, bladder, and colon by both NMS and VBD. Together these data indicate that NMS affects both central and peripheral aspects of the HPA axis, which may drive changes in vaginal sensitivity and the development of comorbid chronic pain and mood disorders.

Acute and chronic pain in children

Pain in neonates and children differs to that in adults. One of the many challenges associated with the diagnosis and management of pain in early life is that neonates are non-verbal and therefore incapable of communicating their pain effectively to their caregivers. Early life pain is characterised by lowered thermal and mechanical thresholds, and exaggerated and often inappropriate behavioural reactions to pain. These differing behavioural reactions are underpinned by increased excitability/decreased inhibition within the spinal dorsal horn. This itself is the result of immaturity in the anatomical expression of key neurotransmitters and neuromodulators within spinal pain circuits, as well as decreased inhibitory input to these circuits from brainstem centres, and an immature relationship between neuronal and non-neuronal cells which affects pain response. These differences between early and adult pain impact upon not just acute reactions to pain, but also the incidence, severity and duration of chronic pain. In this chapter, chronic pain in childhood is discussed, as are the structural and functional differences that underpin differences in acute pain processing between adults and children. The ability of pain that occurs in early life to alter life-long pain responding is also addressed.

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.

Sedation and analgesia to facilitate mechanical ventilation

Regardless of age, health care professionals have a professional and ethical obligation to provide safe and effective analgesia to patients undergoing painful procedures. Historically, newborns, particularly premature and sick infants, have been undertreated for pain. Intubation of the trachea and mechanical ventilation are ubiquitous painful procedures in the neonatal intensive care unit that are poorly assessed and treated. The authors review the use of sedation and analgesia to facilitate endotracheal tube placement and mechanical ventilation. Controversies regarding possible adverse neurodevelopmental outcomes after sedative and anesthetic exposure and in the failure to treat pain is also discussed.

Biological and neurodevelopmental implications of neonatal pain

Nociceptive pathways are functional following birth. In addition to physiological and behavioral responses, neurophysiological measures and neuroimaging evaluate nociceptive pathway function and quantify responses to noxious stimuli in preterm and term neonates. Intensive care and surgery can expose neonates to painful stimuli when the developing nervous system is sensitive to changing input, resulting in persistent impacts into later childhood. Early pain experience has been correlated with increased sensitivity to subsequent painful stimuli, impaired neurodevelopmental outcomes, and structural changes in brain development. Parallel preclinical studies have elucidated underlying mechanisms and evaluate preventive strategies to inform future clinical trials.

A randomized controlled trial of the effectiveness of educating parents about distraction to decrease postoperative pain in children at home after tonsillectomy

Today, parents are more involved with postoperative pain management, because children are discharged as early as possible after surgery. The purpose of this randomized controlled trial was to determine the effectiveness of educating parents to provide distraction in addition to pharmacologic pain management in decreasing postoperative pain at home for children ages 3 to 7 years. Ninety-three children aged 3-7 years having tonsillectomy at Landspitali, The National University Hospital of Iceland, and their parents were randomized to one of two intervention groups. The interventions were pharmacologic pain management education (control group) and pharmacologic pain management education with distraction (experimental group). Pain was measured by parent's report of pain behavior during the evening on postoperative days 1 and 2 and child's report of pain intensity on eight time points on postoperative days 1 and 2. Sixty-nine children had complete data. The results from RM-ANCOVA showed that when adjusting for pain intensity in the morning on postoperative day 1 that educating parents about distraction in addition to educating them about pain medication management decreases mean pain behavior scores (p < .001). There was no difference in pain intensity between the groups using RM-ANCOVA. However, there was association between pain intensity in the morning on postoperative day 1 and follow-up pain intensity (p < .001). The results from this study support the importance of educating parents of children having tonsillectomy about distraction in addition to educating them about pain medication management.

Does neonatal morphine use affect neuropsychological outcomes at 8 to 9 years of age?

Morphine is widely used to treat severe pain in neonatal intensive care unit patients. Animal studies suggest adverse long-term side effects of neonatal morphine, but a follow-up study of 5-year-old children who participated in a morphine-placebo controlled trial as newborns found no such effects on the child's general functioning. This study indicated that morphine may negatively affect response inhibition, a domain of executive functions. Therefore, we performed a second follow-up study in the same population at the age of 8 to 9 years, focused on the child's general functioning in terms of intelligence, visual motor integration, and behavior and on executive functions. Children in the morphine group showed significantly less externalizing problems according to the parents but more internalizing behavior according to the teachers, but only after adjustment for intelligence quotient (IQ), potential confounders using a propensity score, and additional open-label morphine. Morphine-treated children showed significantly fewer problems with executive functions in daily life as rated by parents for the subscales inhibition and organization of materials and for planning/organizing as rated by the teachers. After adjustment for IQ and the propensity score, executive functioning as rated by the parents remained statistically significantly better in the morphine-treated group. The influence of the additional morphine given was not of a significant influence for any of the outcome variables. Overall, the present study demonstrates that continuous morphine infusion of 10 μg/kg/h during the neonatal period does not harm general functioning and may even have a positive influence on executive functions at 8 to 9 years.

Are there long-term consequences of pain in newborn or very young infants?

Physiologic studies indicate that very early pain or stress experiences have more than immediate consequences for infants. Assessment and care of pain are complex subjects made even more complex and challenging when the individual experiencing pain is a very young infant. This review provides evidence that significant and long-lasting physiological consequences may follow painful insults in the very young, including changes in the central nervous system and changes in responsiveness of the neuroendocrine and immune systems to stress at maturity.