Can adverse neonatal experiences alter brain development and subsequent behavior?

Comprehensive pain management protocol reduces children's memory of pain at discharge from the pediatric ED

BACKGROUND

Historically, pain has been poorly managed in the pediatric emergency department (ED) (PED), resulting in measurable psychosocial issues both acute and delayed.

OBJECTIVE

The aim of the study was to measure the impact of protocolized pain management on patients with painful conditions or undergoing painful procedures in the PED.

METHODS

We performed an analysis before and after the implementation of the protocol, dubbed the "Comfort Zone." Validated, age-appropriate pain scales were performed. Validation (using Cronbach α, confirmatory factor analysis) was followed by comparison of responses between the pre- and posttests collected (χ(2) and Wilcoxon rank sum tests). Pain scores were collected at triage and at discharge. At triage, patients were asked to report pain levels. At discharge, they were asked to report their current pain and recall the level of pain during their stay. At triage, parents were asked to report about their perception of the child's pain. At discharge, they were asked to report about their perception of the child's current pain and recall the level of pain during the stay and during procedures, if done.

RESULTS

Five hundred thirty-one patients were enrolled in the preprotocol group; 47% were women with a median age of 5 years (range, 30 days-18 years). Two hundred sixty-three patients were enrolled in the protocol group; 39% were women with a median age of 6 years (range, 30 days-18 years). Patient-recalled pain scores of the ED visit in the protocol group were significantly lower than those of the preprotocol group (Wong-Baker Faces Pain Scale, 5.07-4.01; P < .001); yet parent estimates of pain did not show a significant change at any point. Patient assessment of pain at ED discharge did not show a significant change either (Wong-Baker Faces Pain Scale, 1.99-1.56; P = .09). The Faces scale is not well validated for patients younger than 4, so that group had only parental assessment of pain and, consistent with the larger data set, showed no significant pain scale reduction at any point.

CONCLUSION

Protocolized pain management reduces patients' memory of pain during PED visits but may not affect parental memory of perceived pain or parent- and patient-reported pain at discharge.

The effects of preterm infant massage on brain electrical activity

AIM

Early intervention programmes based on the manipulation of the extra-uterine environment have been used in preterm infants with the aim of improving development and functional outcome. Infant massage, among them, has proved effective for weight gain and reduced length of stay in the neonatal intensive care unit. We have recently shown that infant massage accelerates brain maturation of low-risk preterm infants without brain abnormalities as measured by global parameters of electroencephalography (EEG) activity. In the present study we further analyse the same cohort of preterm infants, testing the hypothesis that massage determines changes in EEG spectral activity, a highly sensitive index of brain maturation.

METHOD

Infants were randomly allocated to a massage or comparison group. Intervention consisted of standard care only (comparison group) or standard care plus infant massage (massage group). Massage was started at around 10 days after birth and was provided for 12 days during a 2-week period. EEG was performed at around 1 and 4 weeks, i.e. before and after intervention. Spectral EEG analysis was performed on 80 seconds of active sleep, applying the fast Fourier transform on the signal obtained from eight monopolar derivations.

RESULTS

The modification in global EEG spectral power between the two assessments was significantly different for the two groups, especially for the delta band activity; the spectral power did not change in massaged infants although, not surprisingly, it decreased significantly in the comparison group, as shown by previous studies.

INTERPRETATION

We propose that massage intervention affects the maturation of brain electrical activity and favours a process more similar to that observed in utero in term infants.

Melamine impairs spatial cognition and hippocampal synaptic plasticity by presynaptic inhibition of glutamatergic transmission in infant rats

The scandal of melamine-contamination has not been quite blown out, since the toxicity of melamine continues to raise concerns for public health. It has been well known that fetus and infant periods play the most important roles in brain development, whereas little has been done on the harmful effects of melamine on the center nervous system (CNS) of children. In the present study, we investigated the effects of melamine on behavioral and electrophysiology alternations in rats, and the effects of melamine on synaptic transmission were examined using whole-cell patch-clamp technique in the hippocampal CA1 neurons of infant rats. Morris water maze (MWM) test showed that learning and memory abilities were impaired significantly by melamine. The long-time potentiation (LTP) test exhibited that the field excitatory postsynaptic potential (fEPSP) slopes were significantly lower in melamine group compared to that in control group. Furthermore, the data of whole-cell patch-clamp experiments showed that melamine decreased the frequencies of both spontaneous EPSCs (sEPSCs) and minitura EPSCs (mEPSCs) to the same extent (about 76% and 78% respectively). However, there were no significant changes in sEPSC or mEPSC amplitude or kinetics after melamine addition, indicating that the effect of melamine on glutamatergic transmission was probably presynaptic. In conclusion, melamine reduced the release of glutamate in presynaptic transmission of hippocampus, which partly resulted in diminished LTP and further damaged the function of learning and memory.

The Newborn Individualized Developmental Care and Assessment Program (NIDCAP) with Kangaroo Mother Care (KMC): Comprehensive Care for Preterm Infants

State-of-the-art Newborn Intensive Care Units (NICUs), instrumental in the survival of high-risk and ever-earlier-born preterm infants, often have costly human repercussions. The developmental sequelae of newborn intensive care are largely misunderstood. Developed countries eager to export their technologies must also transfer the knowledge-base that encompasses all high-risk and preterm infants' personhood as well as the neuro-essential importance of their parents. Without such understanding, the best medical care, while assuring survival jeopardizes infants' long-term potential and deprives parents of their critical role. Exchanging the womb for the NICU environment at a time of rapid brain growth compromises preterm infants' early development, which results in long-term physical and mental health problems and developmental disabilities. The Newborn Individualized Developmental Care and Assessment Program (NIDCAP) aims to prevent the iatrogenic sequelae of intensive care and to maintain the intimate connection between parent and infant, one expression of which is Kangaroo Mother Care. NIDCAP embeds the infant in the natural parent niche, avoids over-stimulation, stress, pain, and isolation while it supports self-regulation, competence, and goal orientation. Research demonstrates that NIDCAP improves brain development, functional competence, health, and life quality. It is cost effective, humane, and ethical, and promises to become the standard for all NICU care.

Ethanol-induced effects on the dopamine and serotonin systems in adult Wistar rats are dependent on early-life experiences

Some individuals control their ethanol consumption throughout life, but others escalate their intake to levels that increase the risk for addiction. The early environment influences the individual response to ethanol and affects the underlying physiological processes that lead to a transition from a voluntary to a compulsive use of ethanol. However, the neurobiological substrates for these processes are not understood. The present study aimed to test the hypothesis that early environmental experiences affect the neurobiological effects that are induced by voluntary ethanol consumption. Rat pups were subjected to three different rearing environments: conventional animal facility rearing or separation from dam and littermates for either 15 or 360min. In adulthood, the rats were exposed to a two-bottle free choice between ethanol and water for seven weeks. Tissue levels of dopamine, 5-hydroxytryptamine (5-HT) and their metabolites were measured in brain areas that have been implicated in reward and addiction processes. Differences in ethanol-induced effects were noted in 5-HT-related measurements in the nucleus accumbens and ventral tegmental area and in dopamine-related measurements in the dorsal raphe nucleus (DRN). These results provided evidence of an early environmental impact on interactive neuronal circuits between the DRN and reward pathways. The amygdala, a key area in addiction processes, was particularly sensitive to early-life conditions. The animals that experienced the longest separation differed from the others; they had low basal 5-HT levels and responded with an increase in 5-HT after ethanol. These altered responses to initial ethanol consumption as a result of early environmental factors may affect the transition from habitual to compulsive drinking and contribute to individual vulnerability or resilience to addiction.

Infant Distress

Infants’ inability to articulate their pain and distress and the diverse range of behavioral responses evoked by painful stimuli may partially explain the challenges associated with the treatment of pain in neonates and infants. To assist nurses in distinguishing nonspecific distress responses from specific pain responses, a concept analysis using Wilson’s method was preformed. An evaluation of published, peer reviewed literature referencing distress in neonates and infants was conducted to extract meaningful information related to distress. This article examines the essential features, antecedents, and consequences of infant distress to generate an evidence-based definition that has relevance for neonatal and pediatric research and clinical practice.

Newly postulated neurodevelopmental risks of pediatric anesthesia

Recent animal and human studies have raised concern that exposure to anesthetic agents in children may cause neuronal damage and be associated with adverse neurodevelopmental outcomes. Exposure of young animals to anesthetic agents above threshold doses and durations during a critical neurodevelopmental window in the absence of concomitant painful stimuli causes widespread neuronal apoptosis and subsequent abnormal behaviors. The relevance of such animal data to humans is unknown. Untreated neonatal pain and stress also are associated with enhanced neuronal death and subsequent maladaptive behaviors, which can be prevented by exposure to these same anesthetic agents. Retrospective observational human studies have suggested a dose-dependent association between multiple anesthetic exposures in early childhood and subsequent learning disability, the causality of which is unknown. Ongoing prospective investigations are underway, the results of which may clarify if and what neurodevelopmental risks are associated with pediatric anesthesia. No change in current practice is yet indicated.

Pain relief for premature infants during ophthalmology assessment

BACKGROUND

The ophthalmological examination of premature infants, which is essential for the detection of retinopathy of prematurity (ROP), can be painful and distressing for the infant. Various researchers have investigated the benefits of topical anesthesia, oral sucrose, and non pharmacological intervention for pain relief. The purpose of this study is to review the current state of knowledge on the effectiveness of these approaches.

METHODS

A literature search was performed with MEDLINE (January 1980 to January 2011) and the Cochrane Central Register of Controlled Trials, Issue 1 of 4 (January 2011), to determine the currently available evidence on methods of pain relief for premature infants undergoing ROP examination.

RESULTS

Most studies supported the use of topical proparacaine, which marginally decreased pain without any side effects. Oral sucrose did not significantly reduce pain scores during ROP examinations, and withholding feeding before the examination was not beneficial. Infants given pacifiers had lower pain scores than those without pacifiers, and infants who were nested experienced less distress during and after the procedure. Conflicting data existed on the benefits of different examination techniques, but the insertion of a lid speculum appeared to be the most uncomfortable aspect of the screening examination.

CONCLUSIONS

Topical anesthetics marginally reduce pain during eye examination in premature infants. Contrary to standard practice, it appears that patients are more comfortable if they are fed before the examination, and there is no benefit of oral sucrose. Nonpharmacological interventions, including sucking on a pacifier and nesting, may also be beneficial.

Preterm birth and childhood psychiatric disorders

Epidemiologic studies have, for many years, identified preterm birth as a significant risk factor for psychiatric disorders. There has been a recent resurgence of interest in neurobehavioral outcomes after preterm birth. In this article, we review clinical cohort studies of the prevalence, etiology, and risk factors for psychiatric sequelae in ex-preterm children. Studies using diagnostic psychiatric evaluations are few in number but typically report a 3- to 4-fold increased risk for disorders in middle childhood. Our review of studies reveals a "preterm behavioral phenotype" characterized by an increased risk for symptoms and disorders associated with inattention, anxiety, and social difficulties. The most contemporary studies have also reported a markedly increased prevalence of autism spectrum disorders (ASD) in preterm populations. Our examination of the correlates and comorbidities of psychiatric disorders is indicative of a different causative pathway that may be associated with altered brain development after preterm birth. Despite the low population attributable risk, the frequency of these symptoms and disorders means that psychiatric screening is likely to be beneficial in this vulnerable population.

An ounce of prevention: decreasing painful interventions in the NICU

Despite a proliferation of literature relative to pain physiology, assessment, and treatment, pain management in NICUs remains inconsistent--most often focused on assessment and treatment rather than prevention. The acceptance of pain as an inevitable part of NICU hospitalization is part of the culture in many NICUs. This article is intended to encourage discussion of pain prevention in the NICU, with a goal of creating a new "minimal-pain" NICU culture. The focus of NICU pain management programs should be on decreasing the number of painful events the NICU patient experiences. Areas for consideration include assessing the performance of procedures by novice versus experienced NICU personnel, reevaluating the role of pediatric residents in the treatment of NICU patients, evaluating the use of umbilical lines and peripherally inserted central catheters to reduce the frequency of peripheral punctures, and evaluating the admission process for ways to reduce neonatal pain and stress. This article discusses the physiology of pain in the neonate, identifies adverse outcomes related to repeated pain, and proposes practice changes that can prevent unnecessary pain in neonatal care.

Psychosocial parental support programs and short-term clinical outcomes in extremely low-birth-weight infants

OBJECTIVE

To describe the association between an individualized psychosocial parental support (PPS) program and short-term clinical outcomes of extremely low-birth-weight (ELBW) infants admitted to the neonatal intensive care unit (NICU).

METHODS

Medical records of ELBW infants (<1000 g) hospitalized in the NICU at Miami Children's Hospital between July 2006 and June 2008 were reviewed. Outborn infants admitted during their first 72 h of life and discharged home were included. Parents were divided in two groups according to their participation status in the PPS program. Neonatal outcomes in both groups were compared.

RESULTS

Forty-one infants were included (n = 41). Mean gestational age was 26.7±2 weeks, and birth weight was 860±125 g. Median length of stay (LOS) was 96 days (quartile range: 76-112 days). PPS was provided to 33.3% of these infants' parents. The median LOS in the PPS group was significantly lower than in control group (86 vs. 99 days; p < 0.05). No other differences in short-term neonatal outcomes were found.

CONCLUSIONS

The addition of individualized psychosocial parent support programs to standard care in the NICU may reduce LOS in surviving infants discharged home. Further larger and randomized prospective studies are needed.

Influence of repeated painful procedures on prefrontal cortical pain responses in newborns

AIM

We examined whether previous experience of repeated skin punctures altered the correlation between prefrontal cortical pain responses and Premature Infant Pain Profile (PIPP) scores, compared with infants who had no experience of skin puncture.

METHODS

Eighty infants at 37-42 weeks of gestational age were observed during clinically required blood sampling: full-term infants with no experience of painful skin-breaking procedures before data collection (controls; n = 30), full-term infants with the experience of painful skin-breaking procedures (n = 20) and preterm infants with the experience of painful skin-breaking procedures (n = 30).

RESULTS

We found no significant differences in PIPP scores among groups. In controls, prefrontal activation in both hemispheres correlated with facial expression score of the PIPP (r = 0.53 for right prefrontal area; r = 0.37 for left prefrontal area) and the total score. In full-term infants with the experience of pain, there was no correlation between cortical activation and clinical pain scores. In preterm infants, prefrontal activation in both hemispheres correlated with the physiological component of the PIPP score (r = 0.36 for right prefrontal area; r = 0.41 for left prefrontal area).

CONCLUSION

Our findings may be useful in considering the effects of cumulative painful experience on emotion and stress in neonates.

Is the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) effective for preterm infants with intrauterine growth restriction?

OBJECTIVE

This study investigates the effectiveness of the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) on neurobehavioral and electrophysiological functioning of preterm infants with severe intrauterine growth restriction (IUGR).

STUDY DESIGN

Thirty IUGR infants, 28 to 33 weeks gestational age, randomized to standard care (control/C=18), or NIDCAP (experimental/E=12), were assessed at 2 weeks corrected age (2wCA) and 9 months corrected age (9mCA) in regard to health, anthropometrics, and neurobehavior, and additionally at 2wCA in regard to electrophysiology (EEG).

RESULT

The two groups were comparable in health and anthropometrics at 2wCA and 9mCA. The E-group at 2wCA showed significantly better autonomic, motor, and self-regulation functioning, improved motility, intensity and response thresholds, and reduced EEG connectivity among several adjacent brain regions. At 9mCA, the E-group showed significantly better mental performance.

CONCLUSION

This is the first study to show NIDCAP effectiveness for IUGR preterm infants.

Pain in children: neglected, unaddressed and mismanaged

Pain is one of the most misunderstood, under diagnosed, and under treated/untreated medical problems, particularly in children. One of the most challenging roles of medical providers serving children is to appropriately assess and treat their pain. New JCAHO regulations regard pain as "the fifth vital sign" and require caregivers to regularly assess and address pain. Pain being a personal experience, many different terms are used to describe different sensations. Assessment of pain in children is linked to their level of development. Children of the same age vary widely in their perception and tolerance of pain.

Systemic G-CSF treatment does not improve long-term outcomes after neonatal hypoxic-ischaemic brain injury

Hypoxia-ischaemia (HI) is a major factor in the pathogenesis of developmental brain injury, leading to cognitive deficits and motor disabilities in preterm infants. The haematopoietic growth factor granulocyte colony-stimulating factor (G-CSF) has been shown to exert a neuroprotective activity in rodent models of ischaemic stroke and is currently subject to phase I/II clinical trials in adults. Results of studies examining the effect of G-CSF in perinatal brain damage have been contradictory. We have previously shown that G-CSF increases NMDAR-mediated excitotoxic brain injury in the neonatal mouse brain. In this study, we evaluated the effect of G-CSF on long-term outcomes after HI. On postnatal day 5, mice pubs were first randomly assigned to a sham operation or HI and then divided into four treatment groups: i) G-CSF; ii) phosphate buffered saline (PBS) 1h after injury; iii) G-CSF and iv) PBS 60 h after injury. G-CSF (200 μg/kg BW) was administered five times within a 24h interval. Neuromotor and cognitive outcomes were assessed by open-field, novel object recognition tests and rotarod tests starting on P90, with subsequent histological analyses of brain injury. G-CSF treatment did not improve either neurobehavioural outcomes or brain injuries. Interestingly, the application of PBS and G-CSF in the acute phase increased brain damage in the hippocampus. We could not confirm the neuroprotective properties of G-CSF in neonatal HI brain damage. The exacerbation of injury by the administration of substances in the acute phase might indicate a heightened state of neurological sensitivity that is specific to mechanisms of secondary neurodegeneration and influenced by unidentified external factors possibly associated with the treatment protocol during the acute phase. This article is part of a Special Issue entitled "Interaction between repair, disease, & inflammation."

Remifentanil in neonatal intensive care and anaesthesia practice

Remifentanil is a relatively new ultrashort action synthetic opioid. Studies on the use of remifentanil in neonatology have emerged demonstrating its effectiveness and safety in neonates. The present study describes the use of remifentanil in both full-term and premature newborns, highlighting the theoretical benefits for this population in terms of both neonatal intensive care and anaesthesia. A Medline search was undertaken of all reviews and reports about the use of remifentanil in neonates published between 1996 and 2009 using MeSH search terms 'remifentanil', 'analgesia', 'anaesthesia', 'newborn' and 'neonate'. The review points that remifentanil has been used with advantages in newborns including preterm neonates and even for foetal anaesthesia. It proved to be a good option to attenuate the hemodynamic/endocrine markers of stress related to surgery. Owing to its unique pharmacokinetic profile, shorter extubation times can be achieved what makes the drug also a good option for short duration invasive procedures in NICUs (InSurE). A concern on its use is that the hemodynamic response (hypotension) may become significant when the drug is associated to other drugs like sevoflurane.

CONCLUSION

Remifentanil seems to be an effective and safely used opioid for neonatal intensive care and anaesthesia practice.

Anesthetic technique and postoperative outcome in preterm infants undergoing PDA closure

OBJECTIVE

To describe the various anesthetic techniques used for surgical closure of PDA in premature infants at the Montreal Children's Hospital and assess their impact on postoperative outcome.

STUDY DESIGN

The charts of all preterms who underwent PDA ligation during a 21-month period were reviewed for preoperative status, intraoperative anesthetic management and postoperative outcome. We determined the associations between independent variables and two postoperative outcome variables: unstable postoperative respiratory course (UPRC) and hypotension.

RESULT

The mean weight at surgery of the 33 infants was 1.031±0.29 kg. All infants, but one, received intraoperative opioids. Eight patients presented UPRC. Mean fentanyl doses were 5.3±2.6 mcg kg(-1) for patients with UPRC vs 22.6±16.6 mcg kg(-1) for patients without UPRC (P=0.004). Applying the receiver-operator characteristic curve (ROC), 10.5 mcg kg(-1) of fentanyl was established as the dose that discriminated and identified patients who experienced UPRC. The postnatal and postmenstrual age of the patient, birthweight, current weight, ventilator settings preoperatively, previous courses of indomethacin, sex and preoperative creatinine, were not correlated with the dose of fentanyl equivalent used. Logistic regression did not show a relationship between any of the previously mentioned factors and receiving a fentanyl equivalent of >10.5 mcg kg(-1). The only factor associated with the total fentanyl equivalent dose (as a continuous variable) or receiving <10.5 mcg kg(-1) (as a dichotomous variable) was the identity of the anesthetist involved, P<0.001.

CONCLUSION

We conclude that the use of at least 10.5 mcg kg(-1) of fentanyl equivalent as a component of the anesthetic regimen for surgical closure of a PDA in premature infants, avoids an unstable postoperative respiratory course.

Relationship between feeding schedules and gastric distress during retinopathy of prematurity screening eye examinations

PURPOSE

To determine whether a relationship exists between the timing of feeding before retinopathy of prematurity (ROP) eye examinations and gastric side effects or distress associated with this examination.

METHODS

A prospective, randomized, single-masked study was conducted involving infants in the neonatal intensive care unit who required an ROP eye examination and who received normal or full enteral feeding over a 1 year period. Infants were randomly assigned to 1 of 2 study arms: feeding 1 hour before examination (arm 1) or feeding schedule adjusted to ensure no feeding within 2 hours before examination (arm 2). Physiological data, including blood pressure and pulse rate, before, during and after examination, crying time during the examination, presence of vomiting and gastric aspirates, and gastric aspirates volume 24 hours after the examination, were recorded.

RESULTS

A total of 34 infants were enrolled, with 57 separate eye examinations conducted. There was 19% less crying (p = 0.016) in arm 1 versus arm 2. Vomiting was 3-fold less in arm 1 versus arm 2 (4.2% vs 12.5%, p = 0.38). Gastric aspirates was less in arm 1 versus arm 2 (p = 0.18). Diastolic blood pressure was lower and respiratory rate greater during the examination in arm 1 (p < 0.05), whereas pulse rate was greater at the start of the examination in arm 1 (p < 0.05).

CONCLUSIONS

Feeding neonatal intensive care unit infants 1 hour before compared with withholding feeding 2 or more hours before ROP examinations may reduce stress during the examination, as measured by percentage crying during the examination, with no increased incidence of vomiting or gastric aspirates.

Individual nurse and organizational context considerations for better Knowledge Use in Pain Care

Nurses are involved in many of the painful procedures performed on hospitalized children. In collaboration with physicians, nurses have an exceptional responsibility to have knowledge to manage the pain; however, the evidence indicates this is not being done. Issues may be twofold: (a) opportunities to improve knowledge of better pain care practices and/or (b) ability to use knowledge. Empirical evidence is available that if used by health care providers can reduce pain in hospitalized children. Theory-guided interventions are necessary to focus resources designated for learning and knowledge translation initiatives in the area of pain care. This article presents the Knowledge Use in Pain Care (KUPC) conceptual model that blends concepts from the fields of knowledge utilization and work life context, which are believed to influence the translation of knowledge to practice. The four main components in the KUPC model include those related to the organization, the individual nurse, the individual patient, and the sociopolitical context. The KUPC model was conceptualized to account for the complex circumstances surrounding nurse's knowledge uptake and use in the context of pain care. The model provides a framework for health care administrators, clinical leaders, and researchers to consider as they decide how to intervene to increase knowledge use to reduce painful experiences of children in the hospital.

Comparison of pain during two methods of urine collection in preterm infants

BACKGROUND

Suprapubic aspiration (SPA) and urine catheterization (UC) are performed frequently in preterm neonates to rule out urinary tract infection; however, a comparison of the pain caused by both procedures has not been made previously.

OBJECTIVE

To compare pain responses in preterm infants who are undergoing urine collection by using SPA versus UC.

METHODS

Prospective, single-blind, randomized clinical trial was conducted in 2 NICUs. Preterm infants who required urine samples for microbiologic analysis were randomly assigned to undergo either SPA or UC. The infants' facial and physiologic responses were videotaped during the procedure and later scored by a research assistant who was blind to the method of urine collection. The primary outcome measure was facial-grimacing during the procedure, which was assessed by measuring the percentage of time the infants displayed brow-bulging. Secondary outcomes included changes in heart rate (beats per minute), oxygen saturation (%), and procedural success rate.

RESULTS

Forty-eight preterm infants participated. Characteristics did not differ (P > .05) between groups. The mean (SD) percent brow-bulging score was higher in the SPA group than in the UC group (67% [34] vs 42% [38]; P = .02). Heart rate and oxygen saturation did not differ (P = .50 and .74, respectively). The procedure-success rate, although lower in the SPA group, was not statistically different (60% vs 78%; P = .17).

CONCLUSIONS

SPA was more painful than UC, as assessed by brow-bulging, and had a tendency to be associated with a higher rate of procedure failure. These findings should be taken into consideration when choosing between these 2 procedures for preterm infants who undergo urine sampling.

Preterm infants' sympathetic arousal and associated behavioral responses to sound stimuli in the neonatal intensive care unit

PURPOSE

To evaluate the utility of skin conductance (SC) as a measure of autonomic arousal to sound stimuli in preterm infants.

DESIGN

A pilot cross-sectional, correlations study.

SUBJECTS

Eleven preterm infants with a mean gestational age of 31.6 weeks without anomalies or conditions associated with neurodevelopmental delay composed the sample.

METHODS

On days 5-7 of life, the following infant responses were simultaneously recorded in response to naturally occurring sound stimuli in the NICU: real-time measurements of heart rate, respiratory rate, and oxygen saturations; sympathetic-mediated sweating via SC; and behavioral responses using the Newborn Individualized Developmental Care and Assessment Program naturalistic observation. Baseline sound levels (BSL, <55 dBA) and high sound levels (HSL, >65 dBA) were measured to index patterns of response during a nonhandling period preceding care.

RESULTS

Mean heart rate during precare was directly associated with higher SC increases to sound stimuli (r[10] = 0.697, P = .017). The SC during HSL was significantly higher than that during BSL (P < .0001). Males demonstrated higher SC increases to sound stimuli than females (P = .030). Changes in SC induced by increases in sound intensity were associated with lower attention responses (r[10] = -0.92, P < .0001) and lower summated behavioral responses (r[10] = -0.59, P = .054).

CONCLUSION

SC provides a noninvasive, sensitive measure of sympathetic arousal that may not be apparent in behavioral cues or states, or determined by standard physiological responses alone.

Opioid Infusions in the Neonatal Intensive Care Unit

OBJECTIVES

The primary objective of this study was to compare the use of opioid infusions to that proposed in guidelines published in an in-house medication handbook. Secondary objectives were to assess the documented use of a standardized neonatal pain assessment tool and to describe the supplemental use of opioids concurrent with an opioid infusion.

METHODS

A retrospective chart review was performed for all patients in the NICU who received opioid infusions between November 1, 2005, and November 30, 2006. Data collected included patient characteristics, opioid infusion dosing and duration, supplemental opioid use, and pain assessment documentation.

RESULTS

Of the110 neonates who received morphine or fentanyl during the study period, 65 patients met inclusion criteria. Reasons for starting an opioid infusion included nonsurgical sedation and/or analgesia (51%), postoperative pain (17%), and procedural pain (1%). No reason was documented for 31% of patients. Thirtyeight percent of neonates received a loading dose of opioid before initiation of the infusion. The median dose was 100 mcg/kg (IQR=48.2) for morphine and and 1 mcg/kg (IQR=0.8) for fentanyl. The mean ± SD starting rates of morphine and fentanyl infusions were 12.3 ± 4.7 mcg/kg/hr and 1.5 ± 1.7 mcg/kg/hr, respectively. Supplemental opioid doses were given to 46% of neonates during the infusion period. Supplemental doses were given for procedures (69%) and pain/agitation/sedation (26%). No reason was documented for 5% of patients. The Neonatal Pain, Agitation and Sedation Scale scores were only documented 9% of the time for each day that the patient received an opioid infusion.

CONCLUSIONS

Dosing of opioids generally was within the recommendations that are described in the in-house medication handbook. A substantial percentage of neonates received supplemental opioid doses while on opioid infusions, mostly for procedural pain management. Documentation of the reason for using opioid infusions and the assessment of neonatal pain was poor.

Staging perspectives in neurodevelopmental aspects of neuropsychiatry: agents, phases and ages at expression

Neurodevelopmental risk factors have assumed a critical role in prevailing notions concerning the etiopathogenesis of neuropsychiatric disorders. Staging, diagnostic elements at which phase of disease is determined, provides a means of conceptualizing the degree and extent of factors affecting brain development trajectories, but is concurrently specified through the particular interactions of genes and environment unique to each individual case. For present purposes, staging perspectives in neurodevelopmental aspects of the disease processes are considered from conditions giving rise to neurodevelopmental staging in affective states, adolescence, dopamine disease states, and autism spectrum disorders. Three major aspects influencing the eventual course of individual developmental trajectories appear to possess an essential determinant influence upon outcome: (i) the type of agent that interferes with brain development, whether chemical, immune system activating or absent (anoxia/hypoxia), (ii) the phase of brain development at which the agent exerts disruption, whether prenatal, postnatal, or adolescent, and (iii) the age of expression of structural and functional abnormalities. Clinical staging may be assumed at any or each developmental phase. The present perspective offers both a challenge to bring further order to diagnosis, intervention, and prognosis and a statement regarding the extreme complexities and interwoven intricacies of epigenetic factors, biomarkers, and neurobehavioral entities that aggravate currents notions of the neuropsychiatric disorders.

Effects of the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) at age 8 years: preliminary data

The current study reports the effects of NIDCAP (Newborn Individualized Developmental Care and Assessment Program) at 8 years of age for a randomized controlled trial of 38 very early born (< or =29 weeks postmenstrual age), high-risk preterm infants. It was hypothesized that the experimental group at school age in comparison with the control group would perform significantly better neuropsychologically and neuroelectrophysiologically. Twenty-two (11 control, 11 experimental) children of the original 38 (18 control, 20 experimental) participants were studied at school age with a detailed neuropsychological battery and with EEG spectral coherence measures. Results indicated significantly better right hemisphere and frontal lobe function in the experimental group than the control group, both neuropsychologically and neurophysiologically. Neurobehavioral and physiological results in the newborn period successfully predicted the beneficial brain function effects at age 8 years. Results support the conclusion that the NIDCAP intervention has lasting effects into school age.

Shaping adult phenotypes through early life environments

A major question in the biology of stress and environmental adaptation concerns the neurobiological basis of how neuroendocrine systems governing physiological regulatory mechanisms essential for life (metabolism, immune response, organ function) become harmful. The current view is that a switch from protection to damage occurs when vulnerable phenotypes are exposed to adverse environmental conditions. In accordance with this theory, sequelae of early life social and environmental stressors, such as childhood abuse, neglect, poverty, and poor nutrition, have been associated with the emergence of mental and physical illness (i.e., anxiety, mood disorders, poor impulse control, psychosis, and drug abuse) and an increased risk of common metabolic and cardiovascular diseases later in life. Evidence from animal and human studies investigating the associations between early life experiences (including parent-infant bonding), hypothalamus-pituitary-adrenal axis activity, brain development, and health outcome provide important clues into the neurobiological mechanisms that mediate the contribution of stressful experiences to personality development and the manifestation of illness. This review summarizes our current molecular understanding of how early environment influences brain development in a manner that persists through life and highlights recent evidence from rodent studies suggesting that maternal care in the first week of postnatal life establishes diverse and stable phenotypes in the offspring through epigenetic modification of genes expressed in the brain that shape neuroendocrine and behavioral stress responsivity throughout life.

Advanced neuroimaging techniques: their role in the development of future fetal and neonatal neuroprotection

Injury to the developing brain is associated with significant risk for potential lifelong, and wide-ranging neurodevelopmental consequences. Despite major advances in neonatal intensive care in recent decades, truly informed brain-oriented care of the critically ill neonate remains lacking. Consequently, this has hindered the development of preventive neuroprotective interventions, which is in large part due to the inherent difficulties in diagnosis, timing, and the severity of insults. Recent advances in understanding the cellular mechanisms of neonatal brain injury, together with the successful application of cutting-edge neuroimaging techniques, have markedly improved our understanding of the timing and evolution of structural injury to the immature brain, and its functional consequences. Triggered by these important advances, there is intense and renewed interest in the development of brain-oriented therapies, including neuroprotective strategies aimed at circumventing the injurious effects of neonatal brain insults. This article will provide an overview of normal and abnormal brain development, and explore the role of advanced neuroimaging techniques in neuroprotective therapies in the neonatal intensive care unit.

Maternal separation alters nerve growth factor and corticosterone levels but not the DNA methylation status of the exon 1(7) glucocorticoid receptor promoter region

Separating rat pups from their mothers during the early stages of life is an animal model commonly used to study the development of psychiatric disorders such as anxiety and depression. The present study investigated how soon after the termination of the maternal separation period behavioural and neuroendocrine abnormalities relevant to above-mentioned illnesses would manifest. Sprague Dawley rat pups were subjected to maternal separation (3 h per day from postnatal day 2 through 14) and their behaviour and HPA axis activity determined 7 d later. We also measured nerve growth factor levels in their hippocampi and assessed the DNA methylation status of the promoter region of exon 1(7) of the glucocorticoid receptor in this brain region. As early as 7 d after the termination of the adverse event, a change in behaviour was observed that was associated with increased plasma corticosterone release and elevated nerve growth factor levels in the hippocampus. No alteration in the methylation status of the exon 1(7) glucocorticoid receptor promoter region was observed. Our data indicate that early life adversity may lead to the rapid development of abnormal behaviours and HPA axis dysregulation though no epigenetic changes to the exon 1(7) glucocorticoid receptor promoter region occurred. We further propose that the observed increased neurotrophin levels reflect compensatory mechanisms that attempt to combat the long-term deleterious effects of maternal separation.

Individualized developmental care for a large sample of very preterm infants: health, neurobehaviour and neurophysiology

AIM

To assess medical and neurodevelopmental effects of Newborn Individualized Developmental Care and Assessment Program (NIDCAP) for a large sample of very early-born infants.

METHODS

One hundred and seven singleton inborn preterm infants, <29 weeks gestational age (GA), <1250 g birth weight, enrolled in three consecutive phases, were randomized within phase to NIDCAP (treatment, E) or standard care (C). Treatment extended from admission to the Newborn Intensive Care Unit to 2 weeks corrected age (wCA). Outcome included medical, neurobehavioural and neurophysiological status at 2 wCA, and growth and neurobehavioural status at 9 months (m) CA.

RESULTS

The C- and E-group within each of the three consecutive phases and across the three phases were comparable in terms of all background measures; they therefore were treated as one sample. The results indicated for the E-group significant reduction in major medical morbidities of prematurity as well as significantly improved neurodevelopmental (behaviour and electrophysiology) functioning at 2 wCA; significantly better neurobehavioural functioning was also found at 9 mCA.

CONCLUSION

The NIDCAP is an effective treatment for very early-born infants. It reduces health morbidities and enhances neurodevelopment, functional competence and life quality for preterm infants at 2 w and 9 mCA.

Heel-lancing in newborns: behavioral and spectral analysis assessment of pain control methods

OBJECTIVE

Pain experience can alter clinical outcome, brain development, and subsequent behavior in newborns, primarily in preterm infants. The aims of this study were (1) to evaluate several simple, commonly used methods for pain control in newborns and (2) to evaluate the concordance between behavioral and autonomic cardiac reactivity to pain in term neonates during heel-lancing.

METHODS

A prospective study was conducted of 180 term newborn infants who were undergoing heel-lancing for routine neonatal screening of phenylketonuria and hypothyroidism. Newborns were assigned to 6 groups: (1) control (no pain relief intervention); (2) nonnutritive sucking; (3) holding by mother; (4) oral glucose solution; (5) oral formula feeding; or (6) breastfeeding. Outcome measures included the Neonatal Facial Coding System score; cry duration; and autonomic variables obtained from spectral analysis of heart rate variability before, during, and after heel-lancing.

RESULTS

Infants with no pain control showed the highest pain manifestation compared with newborns to whom pain control was provided. Infants who breastfed or received an oral formula showed the lowest increase in heart rate (21 and 23 beats per minute, respectively, vs 36; P < .01), lowest neonatal facial score (2.3 and 2.9, respectively, vs 7.1; P < .001), lowest cry duration (5 and 13 seconds, respectively, vs 49; P < .001), and lowest decrease in parasympathetic tone (-2 and -2.4, respectively, vs 1.2; P < .02) compared with the other groups.

CONCLUSIONS

Any method of pain control is better than none. Feeding and breastfeeding during heel-lancing were found to be the most effective methods of pain relief.

Mother-infant synchrony

Synchrony is an essential component of the interaction between a mother and her infant and is characterized by adaptive and reciprocal behaviors that promote a mutually rewarding interaction. It is an antecedent for the emergence of self-regulatory function in infants and influences current and future interactions. Understanding the dynamics of the mother-infant dyad and identifying synchronous patterns are important for promoting a healthy relationship. Approaches to measurement and challenges to model development are described.

The mother-infant feeding tool

OBJECTIVE

To describe the development and evaluation of an observation system to assess the process of mother-infant feeding interaction relevant to infant neuro-behavioral regulation: the Mother-Infant Feeding Tool.

DESIGN

Secondary analysis.

SETTING

Special care nursery just before discharge and in the home at 1 and 4 months postterm age.

PARTICIPANTS

Forty-three mother-infant dyads.

METHODS

Videotaped feeding interactions were examined to assess regulatory processes of mother-infant interaction. Data were collected at three times over the infant's first 4 postterm months: before the infant's discharge from the special care nursery and at 1 and 4 months postterm age in the home.

RESULTS

Across all three data points mothers rarely talked to their infants.

CONCLUSION

Further testing is needed, but the Mother-Infant Feeding Tool shows promise in assessing very early mother-infant feeding interactions.

Early emergence of behavior and social-emotional problems in very preterm infants

OBJECTIVE

Children born very preterm are reported to have an increased frequency of social, emotional, and behavioral problems at school age compared with their peers born at term. The primary aim of this study was to compare social-emotional difficulties and competencies of very preterm and full-term children at 2 years' corrected age. In addition, the relation between perinatal variables and early behavior problems was also examined to help identify those very preterm children most at risk.

METHOD

At 2 years' corrected age, the parents of 188 very preterm (gestational age <30 weeks or birth weight <1,250 g) and 70 full-term (gestational age >or=37 weeks) children completed the Infant Toddler Social and Emotional Assessment to determine externalizing, internalizing, and dysregulation problems and social-emotional competencies. For the very preterm sample, extensive perinatal data were collected including sex, birth weight, gestational age, chronic lung disease, and postnatal steroids, as well as neonatal cerebral white matter abnormalities detected by magnetic resonance imaging.

RESULTS

The very preterm children at 2 years demonstrated significantly higher internalizing and dysregulation scores and lower competence scores than peers born at term. There was no significant difference in externalizing scores between groups. Female sex, lower birth weight z score, white matter abnormalities, and postnatal corticosteroids were significantly associated with lower competence scores in the very preterm group.

CONCLUSIONS

Very preterm children exhibit higher rates of behavior problems early in development, in particular internalizing and dysregulation problems and poorer competence.

Perinatal assessment of infant, parents, and parent-infant relationship: prematurity as an example

This article reviews the stresses for parents, infants, and other caregivers during the period surrounding the birth of the premature infant. Principles of assessment of infant discomfort, parental stress, the parent-infant relationship, and the match of the medical caregiving environment to the individual infant's needs are discussed. Relevant tools to aide in these aspects of assessment are reviewed. The role of early assessment as preventive intervention and the indication for subsequent intervention in complicated cases of premature infants and their parents are further discussed. The article offers detailed clinical examples to illustrate these and other points throughout.

Caregiving behavior and interactions of prenatally depressed mothers (antidepressant-treated and non-antidepressant-treated) during newborn acute pain

This exploratory study aimed to examine time-based measures of the behaviors and interactions of prenatally depressed serotonin reuptake inhibitors (SRI)-medicated mothers to their infant's pain (n = 10) by comparing them with similar measures obtained from prenatally depressed nonmedicated mothers and their infants (n = 10), and nondepressed mothers and their infants (n = 10). During the second trimester of their pregnancy, the 30 study mothers were assessed for depression and anxiety, with no further measures of maternal mood taken. Maternal and infant interactions were continuously videorecorded while the infant underwent a scheduled heel lance for routine blood screening that occurred when study infants were between the ages of 24 and 60 hr. Maternal behavior and infant cry, for all 30 cases, were coded second-by-second for the full duration of each infant's heel lance using a reliable coding system and analyzed using odds ratio and regression analyses. Infants exposed to prenatal SRIs and depressed maternal mood were more likely to have lower Apgar scores and to exhibit weak and absent cry. Even when duration of the heel lance was controlled for, women with depression during the second trimester were more likely to exhibit depressed behavior at 2 days' postpartum despite sustained SRI antidepressant treatment. Both groups of prenatally depressed mothers were more likely to exhibit diminished response to their infants' pain cue although nonmedicated mothers' expressions of depressed behavior were more similar to healthy controls. Comprehensive understanding is essential to optimize the clinical care of mothers and their infants in this complex setting. This study contributes preliminary new findings that warrant prospective and longitudinal studies to clarify further the impacts of prenatal SRI and maternal mental mood (e.g., chronic depression and anxiety) effects on the mother-infant interaction and infant pain and stress reactivity.

Guidelines for procedural pain in the newborn

Despite accumulating evidence that procedural pain experienced by newborn infants may have acute and even long-term detrimental effects on their subsequent behaviour and neurological outcome, pain control and prevention remain controversial issues. Our aim was to develop guidelines based on evidence and clinical practice for preventing and controlling neonatal procedural pain in the light of the evidence-based recommendations contained in the SIGN classification. A panel of expert neonatologists used systematic review, data synthesis and open discussion to reach a consensus on the level of evidence supported by the literature or customs in clinical practice and to describe a global analgesic management, considering pharmacological, non-pharmacological, behavioural and environmental measures for each invasive procedure. There is strong evidence to support some analgesic measures, e.g. sucrose or breast milk for minor invasive procedures, and combinations of drugs for tracheal intubation. Many other pain control measures used during chest tube placement and removal, screening and treatment for ROP, or for postoperative pain, are still based not on evidence, but on good practice or expert opinions.

CONCLUSION

These guidelines should help improving the health care professional's awareness of the need to adequately manage procedural pain in neonates, based on the strongest evidence currently available.

Neonatal handling affects durably bonding and social development

The neonatal period in humans and in most mammals is characterized by intense mother-young interactions favoring pair bonding and the adaptation of neonates to their new environment. However, in many post-delivery procedures, human babies commonly experience combined maternal separation and intense handling for about one hour post-birth. Currently, the effects of such disturbances on later attachment and on the development of newborns are still debated: clearly, further investigations are required. As animals present good models for controlled experimentation, we chose domestic horses to investigate this issue. Horses, like humans, are characterized by single births, long lactating periods and selective mother-infant bonds. Routine postnatal procedures for foals, as for human babies, also involve intense handling and maternal separation. In the present study, we monitored the behavior of foals from early stages of development to "adolescence", in a normal ecological context (social groups with adults and peers). Experimental foals, separated from their mothers and handled for only 1 hour post-birth, were compared to control foals, left undisturbed after birth. Our results revealed short- and long-term effects of this unique neonatal experience on attachment and subsequent social competences. Thus, experimental foals presented patterns of insecure attachment to their mothers (strong dependence on their mothers, little play) and impaired social competences (social withdrawal, aggressiveness) at all ages. We discuss these results in terms of mother-young interactions, timing of interactions and relationships between bonding and subsequent social competences. Our results indicate that this ungulate species could become an interesting animal model. To our knowledge, this is the first clear demonstration that intervention just after birth affects bonding and subsequent social competences (at least until "adolescence"). It opens new research directions for studies on both humans and other animals.

A review of systematic reviews on pain interventions in hospitalized infants

BACKGROUND

Hospitalized infants undergo multiple, repeated painful procedures. Despite continued efforts to prevent procedural pain and improve pain management, clinical guidelines and standards frequently do not reflect the highest quality evidence from systematic reviews.

OBJECTIVE

To critically appraise all systematic reviews on the effectiveness of procedural pain interventions in hospitalized infants.

METHODS

A structured review was conducted on published systematic reviews and meta-analyses of pharmacological and nonpharmacological interventions of acute procedural pain in hospitalized infants. Searches were completed in the Cochrane Database of Systematic Reviews, MEDLINE, EMBASE, CINAHL and PsycINFO. Two reviewers independently selected articles for review and rated the methodological quality of the included reviews using a validated seven-point quality assessment measure. Any discrepancies were resolved by a third reviewer.

RESULTS

Of 1469 potential systematic reviews on interventions for painful procedures in hospitalized infants, 11 high-quality reviews were included in the analysis. Pharmacological interventions supported by research evidence included premedication for intubation, dorsal penile nerve block and EMLA (AstraZeneca Canada, Inc) for circumcision, and sucrose for single painful procedures. Non-nutritive sucking, swaddling, holding, touching, positioning, facilitative tucking, breast feeding and supplemental breast milk were nonpharmacological interventions supported for procedural pain.

CONCLUSION

There is a growing number of high-quality reviews supporting procedural pain management in infants. Ongoing research of single, repeated and combined pharmacological and nonpharmacological interventions is required to provide the highest quality evidence to clinicians for decision-making on optimal pain management.

Factors affecting delivery of evidence-based procedural pain care in hospitalized neonates

OBJECTIVE

To examine the effects of nurse, infant, and organizational factors on delivery of collaborative and evidence-based pain care by nurses.

DESIGN

Cross sectional.

SETTING

Two Level III neonatal intensive care units in 2 large tertiary care centers in Canada.

PARTICIPANTS

A convenience sample of 93 nurses completed survey data on procedures they performed on ill neonates. The 93 nurses performed a total of 170 pain producing procedures on 2 different shifts.

MAIN OUTCOME

Nurse use of evidence-based protocols to manage procedure related pain using a scorecard of nurses' assessment, management, and documentation.

RESULTS

Procedural pain care was more likely to meet evidence-based criteria when nurse participants rated nurse-physician collaboration higher (odds ratio, 1.44; 95% confidence intervals 1.05-1.98), cared for higher care intensity infants (odds ratio, 1.21; 95% confidence intervals, 1.06-1.39), and experienced unexpected increases in work assignments (odds ratio, 1.55; 95% confidence intervals, 1.04-2.30). Nurses' knowledge about the protocols, educational preparation and experience were not significant predictors of evidence-based care for the most common procedures: heel lance and intravenous initiation.

CONCLUSION

Nurse-physician collaboration and nurses' work assignments were more predictive of evidence-based care than infant and nurse factors. Nurses' knowledge regarding evidence-based care was not a predictor of implementation of protocols. In the final statistical modeling, collaboration with physicians, a variable amenable to intervention and further study, emerged as a strong predictor. The results highlight the complex issue of translating knowledge to practice, however, specific findings related to pain assessment and collaboration provide some direction for future practice and research initiatives.

Effects of neonatal stress and morphine on kappa opioid receptor signaling

BACKGROUND

Critically ill neonates experience multiple stressors during hospitalization. Opioids are commonly prescribed to ameliorate their pain and stress. However, the enduring effects of stress and opioids are not understood. The kappa opioid system is important in the mediation of stress in adults, but little is known about its function in neonates.

OBJECTIVES

To characterize kappa opioid receptor (KOR) distribution in the neonatal mouse brain and test whether neonatal exposure to morphine, stress, or both, change KOR signaling.

METHODS

Five groups of wild-type C57BL/6 or prodynorphin (Pdyn) knockout mice were tested: (1) untreated control (dam-reared, no handling), (2) saline-injected control, (3) morphine-injected control, (4) stressed with saline injections and (5) stressed with morphine injections. Mice were treated from postnatal day 5 to postnatal day 9, after which their brains were immunolabeled with a phospho-specific KOR antibody (KOR-P), glial fibrillary acidic protein or glutamic acid decarboxylase.

RESULTS

There were no effects of saline or morphine injection on KOR-P immunoreactivity. Neonatal stress increased KOR-P labeling in wild-type brains (p < 0.05), but not in Pdyn(-/-) animals. Mice exposed to stress and morphine showed region-specific increases in KOR-P immunoreactivity from 38 to 500% (p < 0.05 to p < 0.001), with marked gliosis. In stressed morphine-treated Pdyn(-/-) animals, KOR-P immunoreactivity was absent, but gliosis increased compared to wild-type animals.

CONCLUSIONS

Neonatal stress increases KOR activation via the dynorphin system. Neonatal stress plus morphine treatment further increased this response and also resulted in hippocampal gliosis. Enhanced gliosis noted in Pdyn(-/-) animals suggests that the endogenous dynorphin may play a role in downregulating this inflammatory response.

Mode of delivery modulates physiological and behavioral responses to neonatal pain

OBJECTIVE

To study whether the mode of delivery alters pain expression.

STUDY DESIGN

Full-term infants born by vaginal delivery or elective caesarean section were observed following high- and low-intensity pain stimuli, with recording of electrocardiogram, facial expression and vocalization.

RESULT

Graded physiological and behavioral responses occurred, with greater responses to higher than lower intensity pain stimuli. Elevation in heart rate following both stimuli increased with time after vaginal delivery. Infants delivered by elective caesarean section showed stronger facial expressions and briefer time in vocalizations response to both interventions.

CONCLUSION

Diminished responses following vaginal delivery suggest that physiological events associated with a normal delivery reduce the physiologic and sympathoadrenal activation by nociceptive mechanisms. Pain and stress reactivity appear to be inhibited during fetal life and sensory inputs during vaginal delivery may reverse this inhibition. To minimize neonatal pain, we recommend that postnatal invasive procedures to be performed shortly after vaginal birth.

Neonatal handling and the maternal odor preference in rat pups: involvement of monoamines and cyclic AMP response element-binding protein pathway in the olfactory bulb

Early-life environmental events, such as the handling procedure, can induce long-lasting alterations upon several behavioral and neuroendocrine systems. However, the changes within the pups that could be causally related to the effects in adulthood are still poorly understood. In the present study, we analyzed the effects of neonatal handling on behavioral (maternal odor preference) and biochemical (cyclic AMP response element-binding protein (CREB) phosphorylation, noradrenaline (NA), and serotonin (5-HT) levels in the olfactory bulb (OB)) parameters in 7-day-old male and female rat pups. Repeated handling (RH) abolished preference for the maternal odor in female pups compared with nonhandled (NH) and the single-handled (SH) ones, while in RH males the preference was not different than NH and SH groups. In both male and female pups, RH decreased NA activity in the OB, but 5-HT activity increased only in males. Since preference for the maternal odor involves the synergic action of NA and 5-HT in the OB, the maintenance of the behavior in RH males could be related to the increased 5-HT activity, in spite of reduction in the NA activity in the OB. RH did not alter CREB phosphorylation in the OB of both male and females compared with NH pups. The repeated handling procedure can affect the behavior of rat pups in response to the maternal odor and biochemical parameters related to the olfactory learning mechanism. Sex differences were already detected in 7-day-old pups. Although the responsiveness of the hypothalamic-pituitary-adrenal axis to stressors is reduced in the neonatal period, environmental interventions may impact behavioral and biochemical mechanisms relevant to the animal at that early age.