Neuroimaging, Pain Sensitivity, and Neuropsychological Functioning in School-Age Neonatal Extracorporeal Membrane Oxygenation Survivors Exposed to Opioids and Sedatives

White Matter Integrity Differences in 2-Year-Old Children Treated With ECMO: A Diffusion-Weighted Imaging Study

School-aged and adolescent survivors of neonatal extracorporeal membrane oxygenation (ECMO) treatment still suffer from neurodevelopmental delays such as verbal, visuo-spatial and working memory problems, motor dysfunction and sensorineural hearing loss, respectively, later in life, which is well-documented by neuropsychological testing within follow-up programs. In this study, we demonstrate that diffusion-weighted imaging (DWI) in 2-year-old survivors of neonatal ECMO treatment reveals white matter (WM) alterations in brain regions related to neurodevelopmental outcome seen later in life. From the DWI data of 56 children, fractional anisotropy (FA), first fibre partial volume fraction estimate (F1), radial diffusivity (RD) and mean diffusivity (MD) are calculated and compared using tract-based spatial statistics adapted to a paediatric brain atlas. Significant differences in FA, F1, RD and MD between the no-ECMO and ECMO groups are seen in major WM tracts. Additionally, we examine individual diffusion measures by looking at 50 regions supplied with the paediatric brain atlas. We find the following regions to have significantly different means in the no-ECMO compared with the ECMO group matching reports of neuropsychological delays found in behavioural tests: left anterior corona radiata, left anterior limb of internal capsule, left anterior commissure, left and right corpus callosum (genu, body and splenium), left and right crus of fornix and left tapetum. Analysing diffusion measures at an early stage of life serves as a good tool to detect structural WM changes in survivors of neonatal ECMO treatment. Compared with neuropsychological testing, DWI does not depend on the child's active participation.

Long-Term Neurobehavioral and Functional Outcomes of Pediatric Extracorporeal Membrane Oxygenation Survivors

There are limited reports of neurobehavioral outcomes of children supported on extracorporeal membrane oxygenation (ECMO). This observational study aims to characterize the long-term (≥1 year) neurobehavioral outcomes, identify risk factors associated with neurobehavioral impairment, and evaluate the trajectory of functional status in pediatric ECMO survivors. Pediatric ECMO survivors ≥1-year postdecannulation and ≥3 years of age at follow-up were prospectively enrolled and completed assessments of adaptive behavior (Vineland Adaptive Behavior Scales, Third Edition [Vineland-3]) and functional status (Functional Status Scale [FSS]). Patient characteristics were retrospectively collected. Forty-one ECMO survivors cannulated at 0.0-19.8 years (median: 2.4 [IQR: 0.0, 13.1]) were enrolled at 1.3-12.8 years (median: 5.5 [IQR: 3.3, 6.5]) postdecannulation. ECMO survivors scored significantly lower than the normative population in the Vineland-3 Adaptive Behavior Composite (85 [IQR: 70, 99], P < 0.001) and all domains (Communication, Daily Living, Socialization, Motor). Independent risk factors for lower Vineland-3 composite scores included extracorporeal cardiopulmonary resuscitation, electrographic seizures during ECMO, congenital heart disease, and premorbid developmental delay. Of the 21 patients with impaired function at discharge (FSS ≥8), 86% reported an improved FSS at follow-up. Pediatric ECMO survivors have, on average, mild neurobehavioral impairment related to adaptive functioning years after decannulation. Continued functional recovery after hospital discharge is likely.

The influence of intensive care treatment in infancy on cortisol levels in childhood and adolescence

BACKGROUND

Infants admitted to the intensive care unit experience numerous early-life stressors, which may have long-term effects on hypothalamic-pituitary-adrenal axis functioning.

AIMS

To determine the effects of intensive care treatment and related exposure to stress, pain, and opioids in infancy on cortisol levels in childhood and adolescence.

STUDY DESIGN

Cross-sectional study.

SUBJECTS

Children and adolescents aged 8 to 18 years with a history of intensive care treatment in infancy and healthy controls. The intensive care treatment cohort consisted of four subgroups with varying levels of exposure to stress, pain, and opioids in infancy. They received either mechanical ventilation, extracorporeal membrane oxygenation, major surgery, or excochleation of a giant congenital melanocytic nevus.

OUTCOME MEASURES

Between-group differences in stress reactivity to a study visit consisting of pain threshold testing and an MRI examination and diurnal cortisol levels, as measured in saliva.

RESULTS

After adjustment for age, sex, and gestational age, the diurnal cortisol output (AUCg) in the overall intensive care group (N = 76) was 18 % (approximately 1000 nmol/L) (95 % CI [-31 %, -3 %], P = 0.022) lower than that in the control group (N = 67). Cortisol awakening response, diurnal decline, and stress reactivity neither differed significantly between the overall intensive care group and control group, nor between the intensive care subgroups and control group.

CONCLUSION

Children and adolescents with a history of intensive care treatment in infancy have similar cortisol profiles to those of healthy controls, except for an 18 % lower diurnal cortisol output. The clinical relevance of this reduction is yet to be determined.

Neurocognitive functioning and health-related quality of life of children after pediatric intensive care admission: a systematic review

OBJECTIVE

This study systematically reviewed recent findings on neurocognitive functioning and health-related quality of life (HRQoL) of children after pediatric intensive care unit admission (PICU).

DATA SOURCES

Electronic databases searched included Embase, Medline Ovid, Web of Science, Cochrane CENTRAL, and Google Scholar. The search was limited to studies published in the last five years (2015-2019).

STUDY SELECTION

Original studies assessing neurocognitive functioning or HRQoL in children who were previously admitted to the PICU were included in this systematic review.

DATA EXTRACTION

Of the 3649 identified studies, 299 met the inclusion criteria based on title abstract screening. After full-text screening, 75 articles were included in the qualitative data reviewing: 38 on neurocognitive functioning, 33 on HRQoL, and 4 on both outcomes.

DATA SYNTHESIS

Studies examining neurocognitive functioning found overall worse scores for general intellectual functioning, attention, processing speed, memory, and executive functioning. Studies investigating HRQoL found overall worse scores for both physical and psychosocial HRQoL. On the short term (≤ 12 months), most studies reported HRQoL impairments, whereas in some long-term studies HRQoL normalized. The effectiveness of the few intervention studies during and after PICU admission on long-term outcomes varied.

CONCLUSIONS

PICU survivors have lower scores for neurocognitive functioning and HRQoL than children from the general population. A structured follow-up program after a PICU admission is needed to identify those children and parents who are at risk. However, more research is needed into testing interventions in randomized controlled trials aiming on preventing or improving impairments in critically ill children during and after PICU admission.

Neonatal Pain, Opioid, and Anesthetic Exposure; What Remains in the Human Brain After the Wheels of Time?

OBJECTIVE

To evaluate possible negative long-term effects of neonatal exposure to pain, opioids and anesthetics in children and adolescents.

STUDY DESIGN

We studied five unique groups of children recruited from well-documented neonatal cohorts with a history of neonatal exposure to pain, opioids or anesthetics at different points along the continuum from no pain to intense pain and from no opioid exposure to very high opioid exposure in the presence or absence of anesthetics. We evaluated children who underwent major surgery (group 1 and 2), extracorporeal membrane oxygenation (group 3), preterm birth (group 4) and prenatal opioid exposure (group 5) in comparison to healthy controls. Neuropsychological functioning, thermal detection and pain thresholds and high-resolution structural and task-based functional magnetic resonance imaging during pain were assessed. In total 94 cases were included and compared to their own control groups.

RESULTS

Children and adolescents in groups 3 and 5 showed worse neuropsychological functioning after high opioid exposure. A thicker cortex was found in group 1 (pain, opioid and anesthetic exposure) in only the left rostral-middle-frontal-cortex compared to controls. We found no differences in other brain volumes, pain thresholds or brain activity during pain in pain related brain regions between the other groups and their controls.

CONCLUSIONS

No major effects of neonatal pain, opioid or anesthetic exposure were observed in humans 8-19 years after exposure in early life, apart from neuropsychological effects in the groups with the highest opioid exposure that warrants further investigation. Studies with larger sample sizes are needed to confirm our findings and test for less pronounced differences between exposed and unexposed children.

Analgesics and Sedatives in Critically Ill Newborns and Infants: The Impact on Long-Term Neurodevelopment

Inadequate pain and/or stress management in preterm- and term-born infants has been associated with increased morbidity and even mortality. However, exposure to analgosedatives during early infancy may also be one of the risk factors for subsequent neurodevelopmental impairment, at least in animal studies. Because infants admitted to neonatal or pediatric intensive care units may receive high amounts of these drugs for prolonged periods of time and the majority of these infants nowadays survive to discharge, this is of major concern. A balanced approach that incorporates the assessment and quantification of both wanted effects as well as unwanted side effects is therefore needed. In this article, the optimal dose determination of commonly used analgosedative drugs as well as their potential long-term effects on the developing human brain and neuropsychological functioning are reviewed.

Developmental neurobiology as a guide for pharmacological management of pain in neonates

Pain in newborn children should be prevented due to negative short- and long-term consequences. A good understanding of the development of the nociceptive system in newborns is necessary to enable optimal pain assessment, and most importantly to treat and prevent pain adequately in neonates. So far, preclinical juvenile animal studies have led to a tremendous amount of information regarding the development of the nociceptive system. In addition, they have made clear that the developmental stage of the nociceptive system may influence the mechanism of action of different classes of analgesics. Age specific analgesic therapy, based on post-menstrual age, should therefore be considered by incorporating information on the developmental stages of the nociceptive system in combination with knowledge from pharmacokinetic and -dynamic studies in neonates.

Improving Long-Term Outcomes After Extracorporeal Membrane Oxygenation: From Observational Follow-Up Programs Toward Risk Stratification

Since the introduction of extracorporeal membrane oxygenation (ECMO), more neonates and children with cardiorespiratory failure survive. Interest has therefore shifted from reduction of mortality toward evaluation of long-term outcomes and prevention of morbidity. This review addresses the changes in ECMO population and the ECMO-treatment that may affect long-term outcomes, the diagnostic modalities to evaluate neurological morbidities and their contributions to prognostication of long-term outcomes. Most follow-up data have only become available from observational follow-up programs in neonatal ECMO-survivors. The main topics are discussed in this review. Recommendations for long-term follow up depend on the presence of neurological comorbidity, the nature and extent of the underlying disease, and the indication for ECMO. Follow up should preferably be offered as standard of care, and in an interdisciplinary, structured and standardized way. This permits evaluation of outcome data and effect of interventions. We propose a standardized approach and recommend that multiple domains should be evaluated during long-term follow up of neonates and children who needed extracorporeal life support.

Genetic variants associated with thermal pain sensitivity in a paediatric population

Pain sensitivity is an inherited factor that varies strongly between individuals. We investigated whether genetic polymorphisms in the candidate genes COMT, OPRM1, OPRD1, TAOK3, TRPA1, TRPV1, and SCN9A are contributing to experimental pain variability between children. Our study included 136 children and adolescents (8-18 years). Cold and heat pain thresholds were determined with a Thermal Sensory Analyzer. Women and young children were significantly more sensitive to pain (P < 0.05). After correction for age, gender, reaction time, and correction for multiple testing, OPRM1 118A>G G-allele carriers (AG and GG) rated the hot stimulus as significantly less painful than did OPRM1 118A>G AA genotyped individuals (2[1-5] vs 7 [3-9], respectively; P = 0.00005). Additionally, OPRM1 118G allele carriers reached more frequently the minimum temperature limit (44% vs 17%, respectively; P = 0.003) and maximum temperature limit (52% vs 24%, respectively; P = 0.0052), indicative for lower pain sensitivity. The combined genotype, based on expected pain sensitivity, OPRM1 118AA/COMT 472 GA or AA genotyped children, was associated with lower pain thresholds (ie, higher pain sensitivity) than were the OPRM1 118GA or GG/COMT 472GG genotyped children. This is the first study reporting on genetic variants and experimental thermal pain in children and adolescents. OPRM1 rs1799971 and the combined OPRM1/COMT genotype could serve as biomarkers for pain sensitivity.

The 1-Year Follow-Up Clinic for Neonates and Children After Respiratory Extracorporeal Membrane Oxygenation Support: A 10-Year Single Institution Experience

OBJECTIVES

To establish the effectiveness of a "1-year extracorporeal membrane oxygenation follow-up clinic" and to characterize any neurodevelopmental concerns identified.

DESIGN

Single-center retrospective cohort of respiratory extracorporeal membrane oxygenation survivors over 10 years.

SETTING

Nationally commissioned center for neonatal and pediatric (> 28 d of life) respiratory extracorporeal membrane oxygenation.

PATIENTS

Children attending the follow-up clinic 1 year after receiving respiratory extracorporeal membrane oxygenation between 2003 and 2013.

INTERVENTIONS

Standardized follow-up 1 year after extracorporeal membrane oxygenation.

MEASUREMENTS AND MAIN RESULTS

In 10 years, 290 children received extracorporeal membrane oxygenation, 194 (67%) survived; all were offered 1-year follow-up, and 98 (51%) attended the clinic. Among these, 51 of 98 (52%) had meconium aspiration syndrome, and 74 of 98 (75%) were on veno-arterial extracorporeal membrane oxygenation with a median (interquartile range) duration of 6 days (4-8 d). Neurodevelopmental problems were identified in 30 of 98 (30%). The specific abnormalities noted included neurologic (seizures, motor, or vision abnormalities) (n = 8), hearing with/without language delay (n = 8), and behavioral problems (as reported by parents) (n = 6), with eight of 30 (27%) having difficulties spanning these domains. An acute neurologic event on extracorporeal membrane oxygenation was found to be the only risk factor for neurodevelopmental concerns (p = 0.006 with odds ratio 5.4 [95% CI, 1.63-17.92]). Despite having neither a cardiac arrest nor an acute neurologic event documented, 18 of 74 (24.3%), 95% CI (15.1-35.7), had neurodevelopmental concerns at 1-year follow-up. Among the nonattenders, 30 (15%) had local follow-up, and 66 (34%) were lost to follow-up.

CONCLUSIONS

All extracorporeal membrane oxygenation survivors need follow-up either at the extracorporeal membrane oxygenation center or in their community, as evidenced by the 1-year follow-up data. Our 1-year extracorporeal membrane oxygenation follow-up clinic provides an opportunity to engage with families, identify neurodevelopmental concerns, and signpost to appropriate services. Of concern, one third of survivors are lost to follow-up, some with an acute neurologic event on extracorporeal membrane oxygenation, a significant risk factor. A consensus-based standardized national follow-up program is vital.

Neonatal critical illness and development: white matter and hippocampus alterations in school-age neonatal extracorporeal membrane oxygenation survivors

AIM

To examine the neurobiology of long-term neuropsychological deficits after neonatal extracorporeal membrane oxygenation (ECMO).

METHOD

This cross-sectional study assessed white matter integrity and hippocampal volume of ECMO survivors (8-15y) and healthy children (8-17y) using diffusion tensor imaging (DTI) and structural magnetic resonance imaging (MRI) respectively. Neuropsychological outcome was evaluated in ECMO survivors. Included clinical predictors of white matter integrity: age start ECMO, ECMO duration, highest oxygenation index before ECMO, highest mean airway pressure, and mechanical ventilation duration.

RESULTS

ECMO survivors (n=23) had lower global fractional anisotropy than healthy children (n=54) (patients=0.368; comparison group=0.381; p=0.018), but similar global mean diffusivity (p=0.410). ECMO survivors had lower fractional anisotropy in the left cingulum bundle (ECMO survivors=0.345; comparison group=0.399; p<0.001) and higher mean diffusivity in a region of the left parahippocampal cingulum (patients=0.916; comparison group=0.871; p<0.001). Higher global mean diffusivity predicted worse verbal memory in ECMO survivors (n=17) (β=-0.74, p=0.008). ECMO survivors (n=23) had smaller bilateral hippocampal volume than healthy children (n=43) (left, p<0.001; right, p<0.001) and this was related to worse verbal memory (left, β=0.65, p=0.018; right, β=0.71, p=0.006).

INTERPRETATION

Neonatal ECMO survivors are at risk for long-term brain alterations, which may partly explain long-term neuropsychological impairments. Neuroimaging may contribute to better risk stratification of long-term impairments.

Paracetamol and morphine for infant and neonatal pain; still a long way to go?

INTRODUCTION

Pharmacologic pain management in newborns and infants is often based on limited scientific data. To close the knowledge gap, drug-related research in this population is increasingly supported by the authorities, but remains very challenging. This review summarizes the challenges of analgesic studies in newborns and infants on morphine and paracetamol (acetaminophen). Areas covered: Aspects such as the definition and multimodal character of pain are reflected to newborn infants. Specific problems addressed include defining pharmacodynamic endpoints, performing clinical trials in this population and assessing developmental changes in both pharmacokinetics and pharmacodynamics. Expert commentary: Neonatal and infant pain management research faces two major challenges: lack of clear biomarkers and very heterogeneous pharmacokinetics and pharmacodynamics of analgesics. There is a clear call for integral research addressing the multimodality of pain in this population and further developing population pharmacokinetic models towards physiology-based models.

Sedation in Critically Ill Children with Respiratory Failure

This article discusses the rationale of sedation in respiratory failure, sedation goals, how to assess the need for sedation as well as effectiveness of interventions in critically ill children, with validated observational sedation scales. The drugs and non-pharmacological approaches used for optimal sedation in ventilated children are reviewed, and specifically the rationale for drug selection, including short- and long-term efficacy and safety aspects of the selected drugs. The specific pharmacokinetic and pharmacodynamic aspects of sedative drugs in the critically ill child and consequences for dosing are presented. Furthermore, we discuss different sedation strategies and their adverse events, such as iatrogenic withdrawal syndrome and delirium. These principles can guide clinicians in the choice of sedative drugs in pediatric respiratory failure.