A retrospective cohort study of the association of anesthesia and hernia repair surgery with behavioral and developmental disorders in young children. J Neurosurg Anesthesiol. 2009;21:286-291. [PMID: 19955889 DOI: 10.1097/ana.0b013e3181a71f11]

Developmental outcome at 3 years of age of infants following surgery for infantile hypertrophic pyloric stenosis

PURPOSE

The study compared neurodevelopmental outcome at 3 years of age of infants with infantile hypertrophic pyloric stenosis (IHPS) who underwent pyloromyotomy with healthy control infants in New South Wales, Australia.

METHODS

Infants with IHPS as well as controls were recruited between August 2006 and July 2008. Developmental assessments were performed using the Bayley scales of infant and toddler development (version III) (BSITD-III) at 1 and 3 years of age.

RESULTS

Of the 43 infants originally assessed at 1 year, 39 returned for assessment at 3 years (90%). The majority were term infants (77%). Assessments were also performed on 156 control infants. Infants with IHPS scored significantly lower on four of the five Bayley subsets (cognitive, receptive and expressive language and fine motor) compared to control infants. Analysis of co-variance showed statistically significant results in favour of the control group for these four subsets.

CONCLUSION

Compared with the outcomes at 1 year, infants with IHPS at 3 years of age continue to score below controls in four of the BSITD-III subscales. This suggests they should have developmental follow-up with targeted clinical intervention. There is a need for further studies into functional impact and longer term outcomes.

Neurodevelopmental outcome at 5 years of age after general anaesthesia or awake-regional anaesthesia in infancy (GAS): an international, multicentre, randomised, controlled equivalence trial

BACKGROUND

In laboratory animals, exposure to most general anaesthetics leads to neurotoxicity manifested by neuronal cell death and abnormal behaviour and cognition. Some large human cohort studies have shown an association between general anaesthesia at a young age and subsequent neurodevelopmental deficits, but these studies are prone to bias. Others have found no evidence for an association. We aimed to establish whether general anaesthesia in early infancy affects neurodevelopmental outcomes.

METHODS

In this international, assessor-masked, equivalence, randomised, controlled trial conducted at 28 hospitals in Australia, Italy, the USA, the UK, Canada, the Netherlands, and New Zealand, we recruited infants of less than 60 weeks' postmenstrual age who were born at more than 26 weeks' gestation and were undergoing inguinal herniorrhaphy, without previous exposure to general anaesthesia or risk factors for neurological injury. Patients were randomly assigned (1:1) by use of a web-based randomisation service to receive either awake-regional anaesthetic or sevoflurane-based general anaesthetic. Anaesthetists were aware of group allocation, but individuals administering the neurodevelopmental assessments were not. Parents were informed of their infants group allocation upon request, but were told to mask this information from assessors. The primary outcome measure was full-scale intelligence quotient (FSIQ) on the Wechsler Preschool and Primary Scale of Intelligence, third edition (WPPSI-III), at 5 years of age. The primary analysis was done on a per-protocol basis, adjusted for gestational age at birth and country, with multiple imputation used to account for missing data. An intention-to-treat analysis was also done. A difference in means of 5 points was predefined as the clinical equivalence margin. This completed trial is registered with ANZCTR, number ACTRN12606000441516, and ClinicalTrials.gov, number NCT00756600.

FINDINGS

Between Feb 9, 2007, and Jan 31, 2013, 4023 infants were screened and 722 were randomly allocated: 363 (50%) to the awake-regional anaesthesia group and 359 (50%) to the general anaesthesia group. There were 74 protocol violations in the awake-regional anaesthesia group and two in the general anaesthesia group. Primary outcome data for the per-protocol analysis were obtained from 205 children in the awake-regional anaesthesia group and 242 in the general anaesthesia group. The median duration of general anaesthesia was 54 min (IQR 41-70). The mean FSIQ score was 99·08 (SD 18·35) in the awake-regional anaesthesia group and 98·97 (19·66) in the general anaesthesia group, with a difference in means (awake-regional anaesthesia minus general anaesthesia) of 0·23 (95% CI -2·59 to 3·06), providing strong evidence of equivalence. The results of the intention-to-treat analysis were similar to those of the per-protocol analysis.

INTERPRETATION

Slightly less than 1 h of general anaesthesia in early infancy does not alter neurodevelopmental outcome at age 5 years compared with awake-regional anaesthesia in a predominantly male study population.

FUNDING

US National Institutes of Health, US Food and Drug Administration, Thrasher Research Fund, Australian National Health and Medical Research Council, Health Technologies Assessment-National Institute for Health Research (UK), Australian and New Zealand College of Anaesthetists, Murdoch Children's Research Institute, Canadian Institutes of Health Research, Canadian Anesthesiologists Society, Pfizer Canada, Italian Ministry of Health, Fonds NutsOhra, UK Clinical Research Network, Perth Children's Hospital Foundation, the Stan Perron Charitable Trust, and the Callahan Estate.

Nitric Oxide Donor Prevents Neonatal Isoflurane-induced Impairments in Synaptic Plasticity and Memory

WHAT WE ALREADY KNOW ABOUT THIS TOPIC

Some general anesthetics have been shown to have adverse effects on neuronal development that affect neural function and cognitive behavior.Clinically relevant concentrations of inhalational anesthetics inhibit the postsynaptic density (PSD)-95, discs large homolog, and zona occludens-1 (PDZ) domain-mediated protein-protein interaction between PSD-95 or PSD-93 and N-methyl-D-aspartate receptors or neuronal NO synthase.

WHAT THIS ARTICLE TELLS US THAT IS NEW

Neonatal PSD-95 PDZ2WT peptide treatment mimics the effects of isoflurane (~1 minimum alveolar concentration) by altering dendritic spine morphology, neural plasticity, and memory without inducing detectable increases in apoptosis or changes in synaptic density.These results indicate that a single dose of isoflurane (~1 minimum alveolar concentration) or PSD-95 PDZ2WT peptide alters dendritic spine architecture and functions important for cognition in the developing brain. This impairment can be prevented by administration of the NO donor molsidomine.

BACKGROUND

In humans, multiple early exposures to procedures requiring anesthesia constitute a significant risk factor for development of learning disabilities and disorders of attention. In animal studies, newborns exposed to anesthetics develop long-term deficits in cognition. Previously, our laboratory showed that postsynaptic density (PSD)-95, discs large homolog, and zona occludens-1 (PDZ) domains may serve as a molecular target for inhaled anesthetics. This study investigated a role for PDZ interactions in spine development, plasticity, and memory as a potential mechanism for early anesthetic exposure-produced cognitive impairment.

METHODS

Postnatal day 7 mice were exposed to 1.5% isoflurane for 4 h or injected with 8 mg/kg active PSD-95 PDZ2WT peptide. Apoptosis, hippocampal dendritic spine changes, synapse density, long-term potentiation, and cognition functions were evaluated (n = 4 to 18).

RESULTS

Exposure of postnatal day 7 mice to isoflurane or PSD-95 PDZ2WT peptide causes a reduction in long thin spines (median, interquartile range [IQR]: wild type control [0.54, 0.52 to 0.86] vs. wild type isoflurane [0.31, 0.16 to 0.38], P = 0.034 and PDZ2MUT [0.86, 0.67 to 1.0] vs. PDZ2WT [0.55, 0.53 to 0.59], P = 0.028), impairment in long-term potentiation (median, IQR: wild type control [123, 119 to 147] and wild type isoflurane [101, 96 to 118], P = 0.049 and PDZ2MUT [125, 119 to 131] and PDZ2WT [104, 97 to 107], P = 0.029), and deficits in acute object recognition (median, IQR: wild type control [79, 72 to 88] vs. wild type isoflurane [63, 55 to 72], P = 0.044 and PDZ2MUT [81, 69 to 84] vs. PDZ2WT [67, 57 to 77], P = 0.039) at postnatal day 21 without inducing detectable differences in apoptosis or changes in synaptic density. Impairments in recognition memory and long-term potentiation were preventable by introduction of a NO donor.

CONCLUSIONS

Early disruption of PDZ domain-mediated protein-protein interactions alters spine morphology, synaptic function, and memory. These results support a role for PDZ interactions in early anesthetic exposure-produced cognitive impairment. Prevention of recognition memory and long-term potentiation deficits with a NO donor supports a role for the N-methyl-D-aspartate receptor/PSD-95/neuronal NO synthase pathway in mediating these aspects of isoflurane-induced cognitive impairment.

Sedation and neurodevelopmental outcomes in PICU: Identification of study groups

BACKGROUND/AIMS

As little as 30 minutes of exposure to anesthetic and sedative agents may adversely affect the developing brain. Safe, humane management of critically ill infants requires the use of sedative agents, often for prolonged periods. We sought to identify two comparable groups of critical care patients who did or did not receive sedatives, with the aim of designing a long-term neurodevelopment follow-up study. This feasibility study aimed to determine if two comparable groups could be found.

METHODS

Infants with respiratory diagnoses having noninvasive ventilation without sedation (Group C) or intubation and ventilation with sedation (Group S) were identified by chart review. Charts of patients fulfilling the above inclusion criteria were searched for exclusion criteria including neurological disease, extreme prematurity, congenital cardiac disease, and genetic anomalies. Data were extracted to score pediatric severity of illness scores (PRISM and PELOD) for each patient. These scores were then compared using the absolute scores and by risk strata.

RESULTS

Group S included 33 patients and Group C had 39. The absolute PRISM and PELOD scores were different between groups. Comparing the groups in three risk strata (PRISM greater or less than 5 or 10), there were no significant differences between groups.

CONCLUSION

It is not possible to randomize infants to sedation or no sedation to investigate neurodevelopmental outcomes. This phase of the project aimed to determine the comparability of two groups of PICU patients. These findings indicate that these groups could be enrolled as exposed and control subjects in an outcomes study.

Neonatal exposure to propofol affects interneuron development in the piriform cortex and causes neurobehavioral deficits in adult mice

RATIONALE

Animal studies have shown that early postnatal propofol administration is involved in neurobehavioral alterations in adults. However, the underlying mechanism is not clear.

METHODS

We used c-Fos immunohistochemistry to identify activated neurons in brain regions of neonatal mice under propofol exposure and performed behavioral tests to observe the long-term consequences.

RESULTS

Exposure to propofol (30g or 60 mg/kg) on P7 produced significant c-Fos expression in the deep layers of the piriform cortex on P8. Double immunofluorescence of c-Fos with interneuron markers in the piriform cortex revealed that c-Fos was specifically induced in calbindin (CB)-positive interneurons. Repeated propofol exposure from P7 to P9 induced behavioral deficits in adult mice, such as olfactory function deficit in a buried food test, decreased sociability in a three-chambered choice task, and impaired recognitive ability of learning and memory in novel object recognition tests. However, locomotor activity in the open-field test was not generally affected. Propofol treatment also significantly decreased the number of CB-positive interneurons in the piriform cortex of mice on P21 and adulthood.

CONCLUSIONS

These results suggest that CB-positive interneurons in the piriform cortex are vulnerable to propofol exposure during the neonatal period, and these neurons are involved in the damage effects of propofol on behavior changes. These data provide a new target of propofol neurotoxicity and may elucidate the mechanism of neurobehavioral deficits in adulthood.

LncRNA Riken-201 and Riken-203 modulates neural development by regulating the Sox6 through sequestering miRNAs

Objectives

Long non‐coding RNAs (LncRNAs) play important roles in epigenetic regulatory function during the development processes. In this study, we found that through alternative splicing, LncRNA C130071C03Riken variants Riken‐201 (Riken‐201) and Riken‐203 (Riken‐203) are both expressed highly in brain, and increase gradually during neural differentiation. However, the function of Rik‐201 and Rik‐203 is unknown.

Materials and methods

Embryonic stem cells (ESCs); RNA sequencing; gene expression of mRNAs, LncRNAs and miRNAs; over‐expression and RNA interference of genes; flow cytometry; real‐time quantity PCR; and Western blot were used in the studies. RNA pull‐down assay and PCR were employed to detect any miRNA that attached to Rik‐201 and Rik‐203. The binding of miRNA with mRNA of Sox6 was presented by the luciferase assay.

Results

Repression of Rik‐201 and Rik‐203 inhibited neural differentiation from mouse embryonic stem cells. Moreover, Rik‐201 and Rik‐203 functioned as the competing endogenous RNA (ceRNA) to repress the function of miR‐96 and miR‐467a‐3p, respectively, and modulate the expression of Sox6 to further regulate neural differentiation. Knockout of the Rik‐203 and Rik‐201 induced high ratio of brain developmental retardation. Further we found that C/EBPβ might potentially activated the transcription of Rik‐201 and Rik‐203.

Conclusions

These findings identify the functional role of Rik‐201 and Rik‐203 in facilitating neural differentiation and further brain development, and elucidate the underlying miRNAs‐Sox6‐associated molecular mechanisms.

Neuropsychological and Behavioral Outcomes after Exposure of Young Children to Procedures Requiring General Anesthesia: The Mayo Anesthesia Safety in Kids (MASK) Study

BACKGROUND

Few studies of how exposure of children to anesthesia may affect neurodevelopment employ comprehensive neuropsychological assessments. This study tested the hypothesis that exposure to multiple, but not single, procedures requiring anesthesia before age 3 yr is associated with adverse neurodevelopmental outcomes.

METHODS

Unexposed, singly exposed, and multiply exposed children born in Olmsted County, Minnesota, from 1994 to 2007 were sampled using a propensity-guided approach and underwent neuropsychological testing at ages 8 to 12 or 15 to 20 yr. The primary outcome was the Full-Scale intelligence quotient standard score of the Wechsler Abbreviated Scale of Intelligence. Secondary outcomes included individual domains from a comprehensive neuropsychological assessment and parent reports.

RESULTS

In total, 997 children completed testing (411, 380, and 206 unexposed, singly exposed, and multiply exposed, respectively). The primary outcome of intelligence quotient did not differ significantly according to exposure status; multiply exposed and singly exposed children scoring 1.3 points (95% CI, -3.8 to 1.2; P = 0.32) and 0.5 points (95% CI, -2.8 to 1.9; P = 0.70) lower than unexposed children, respectively. For secondary outcomes, processing speed and fine motor abilities were decreased in multiply but not singly exposed children; other domains did not differ. The parents of multiply exposed children reported increased problems related to executive function, behavior, and reading.

CONCLUSIONS

Anesthesia exposure before age 3 yr was not associated with deficits in the primary outcome of general intelligence. Although secondary outcomes must be interpreted cautiously, they suggest the hypothesis that multiple, but not single, exposures are associated with a pattern of changes in specific neuropsychological domains that is associated with behavioral and learning difficulties.

What do recent human studies tell us about the association between anaesthesia in young children and neurodevelopmental outcomes?

Anaesthetic and sedative drugs transiently disrupt normal neural activity to facilitate healthcare procedures in children, but they can also cause long-term brain injury in experimental animal models. The US Food and Drug Administration (FDA) has recently advised that repeated or lengthy exposures to anaesthetic and sedative drugs prior to 3 yr of age have the potential to harm the development of children's brains and added warnings to these drug labels. Paediatric anaesthesia toxicity could represent a significant public health issue, and concern about this potential injury in children has become an important issue for families, paediatric clinicians and healthcare regulators. Since late 2015, important new data from five major clinical studies have been published. This narrative review aims to provide a brief overview of the preclinical and clinical literature, including a comprehensive review of these recent additions to the human literature. We integrate these new data with prior studies to provide further insights into how these clinical findings can be applied to children.

Duration of general anaesthetic exposure in early childhood and long-term language and cognitive ability

Background

The anaesthetic dose causing neurotoxicity in animals has been evaluated, but the relationship between duration of volatile anaesthetic (VA) exposure and neurodevelopment in children remains unclear.

Methods

Data were obtained from the Western Australian Pregnancy Cohort (Raine) Study, with language (Clinical Evaluation of Language Fundamentals: Receptive [CELF-R] and Expressive [CELF-E] and Total [CELF-T]) and cognition (Coloured Progressive Matrices [CPM]) assessed at age 10 yr. Medical records were reviewed, and children divided into quartiles based on total VA exposure duration before age three yr. The association between test score and exposure duration quartile was evaluated using linear regression, adjusting for patient characteristics and comorbidity.

Results

Of 1622 children with available test scores, 148 had documented VA exposure and were split into the following quartiles: ≤25, >25 to ≤35, >35 to ≤60 and >60 min. Compared with unexposed children, CELF-T scores for children in the first and second quartiles did not differ, but those in the third and fourth quartiles had significantly lower scores ([3 rd quartile - Unexposed] -5.3; 95% confidence interval [CI], (-10.2 - -0.4), [4 th quartile - Unexposed] -6.2; 95% CI, (-11.6 - -0.9). CELF-E showed similar findings, but significant differences were not found in CELF-R or CPM for any quartile.

Conclusions

Children with VA exposures ≤35 min did not differ from unexposed children, but those with exposures >35 min had lower total and expressive language scores. It remains unclear if this is a dose-response relationship, or if children requiring longer exposures for longer surgeries have other clinical reasons for lower scores.

Isoflurane exposure for three hours triggers apoptotic cell death in neonatal macaque brain

Background

Retrospective clinical studies suggest there is a risk for neurodevelopmental impairment following early childhood exposure to anaesthesia. In the developing animal brain, including those of non-human primates (NHPs), anaesthetics induce apoptotic cell death. We previously reported that a 5 h isoflurane (ISO) exposure in infant NHPs increases apoptosis 13-fold compared with control animals. However, the majority of paediatric surgeries requiring anaesthesia are of shorter durations. We examined whether 3 h ISO exposure similarly increases neuroapoptosis in the NHP developing brain.

Methods

Six-day-old NHP infants ( Macaca mulatta ) were exposed to 3 h of a surgical plane of ISO ( n =6) or to room air ( n =5). Following exposure, NHP brains were screened for neuronal and oligodendrocyte apoptosis using activated caspase-3 immunolabelling and unbiased stereology.

Results

ISO treatment increased apoptosis (neurones + oligodendrocyte) to greater than four times that in the control group [mean density of apoptotic profiles: 57 (SD 22) mm -3 vs 14 (SD 5.2) mm -3 , respectively]. Oligodendrocyte apoptosis was evenly distributed throughout the white matter whereas neuroapoptosis occurred primarily in the cortex (all regions), caudate, putamen and thalamus.

Conclusions

A 3 h exposure to ISO is sufficient to induce widespread neurotoxicity in the developing primate brain. These results are relevant for clinical medicine, as many surgical and diagnostic procedures in children require anaesthesia durations similar to those modelled here. Further research is necessary to identify long-term neurobehavioural consequences of 3 h ISO exposure.

Pharmacology related to paediatric anaesthesia

A child is not a mini adult. They differ from adults in terms of weight, shape, anatomical size and major body systems such as cardiovascular and respiratory as well as psychologically. Each organ system is immature in paediatric age group and their growth and development can dramatically affect the pharmacokinetics of different drugs. Children differ in every way from an adult thus mandating to have a basic knowledge of the pharmacokinetic and pharmacodynamic principles in paediatric population to prevent under dosing or toxicity of drugs. This review article aims to simplify the basic principles of pharmacokinetics and pharmacodynamics in paediatric population. It also highlights physiological and pharmacological differences between adults and paediatric age. We performed a PUBMED search for English language articles using keywords including pharmacology, child, paediatric anaesthesia. We also hand searched references from relevant review articles and text book chapters. We have also discussed drug interaction in anaesthesia, pharmacology pertaining to neuromuscular junction and effects of anaesthesia over the developing brain.

Outcomes Research in Vulnerable Pediatric Populations

The Pediatric Anesthesia and Neurodevelopment Assessment (PANDA) study team held its biennial symposium in April 2018 to discuss issues on anesthetic neurotoxicity in the developing brain. One of the sessions invited speakers with different areas of expertise to discuss "Outcomes Research in Vulnerable Pediatric Populations." The vulnerable populations included neonates, children with congenital heart disease, children from low socioeconomic status, and children with incarcerated parents. Each speaker presented some of the ongoing research efforts in these groups as well as the challenges encountered in studying them.

Neurotoxicity of Anesthesia in Children: Prevention and Treatment

PURPOSE OF REVIEW

The purpose of this review is to summarize the current evidence regarding the impact of the exposure to anesthetic and sedative agents on neurodevelopment during the period of rapid brain growth in the first 3 years of life. Though much of the definitive data demonstrating anesthesia-induced neurotoxicity has come from studies in young animals, the focus of this review is on emerging human data.

RECENT FINDINGS

In 2016, the first prospective trials investigating the neurodevelopmental impact of early anesthetic exposure (GAS and PANDA studies) were published, both showing no significant impact on IQ from a single brief anesthetic. More recent population cohort analyses have shown varying, but minimal, impacts from early anesthetic exposure on academic performance and IQ, much smaller than that of maternal education and other environmental factors. Animal and human data document that post-anesthetic neurotoxicity is a genuine phenomenon, but its long-term clinical significance is uncertain. Most experts would agree that a single, brief anesthetic likely has no significant impact on neurodevelopment, but it is yet to be determined whether longer exposures or multiple anesthetics are associated with subsequent learning issues. Future research is aimed at determining the mechanisms of neuronal injury from exposure to anesthetic and sedative agents, adjunctive medications that may prevent or ameliorate this injury, and therapeutic approaches such as early intervention that can enhance recovery. While these studies are underway, it is recommended that exposure to anesthetic and sedative agents be minimized in young children and consideration be given to alternative methods of immobilization for nonpainful procedures such as radiologic imaging.

Multiple surgeries in pediatric otolaryngology patients and associated anesthesia risks

OBJECTIVES

To determine the risk of healthy children undergoing tympanostomy tubes of an additional surgery prior to age three and associated risk factors.

METHODS

A retrospective chart review of pediatric patients at a tertiary metropolitan children's hospital who underwent tympanostomy tube insertion procedure before age of three from January 2010 through March 2015. We determined patient demographics, indication for tympanostomy tube insertion, as well as information about additional procedures requiring general anesthesia before the age of three years. A prospective telephone interview was also performed on a portion of the study population to assess if there were additional surgeries before the age of three that did not occur at our institution.

RESULTS

In our institution there was a 13% risk of getting an additional surgery after tympanostomy tubes in children who are otherwise healthy. The most common second procedure was an otolaryngologic procedure in 77.8% of the cases. Children with a diagnosis of recurrent acute otitis media had a threefold greater chance of getting an additional surgery than those with a diagnosis of chronic otitis media with effusion. Patients that identified as Black or African American were 3.2 times more likely to have additional surgery. With every year increase at age of surgery, the odds of an additional surgery decreased by 77%.

CONCLUSIONS

In healthy children undergoing tympanostomy tube insertion at our institution, the incidence of additional procedures under general anesthesia (GA) is low at 13%. Although there is evidence of possible deleterious effects of anesthesia on the developing brain, it is generally accepted that one short (≤1 h) anesthetic exposure under the age of three has not been associated with adverse neurodevelopmental outcomes. As a specialty that regularly performs procedures on young children, we need to be aware of the possible effects of anesthetic agents on our patients. However, this study shows that the exposure risk is low and should help reassure patient's families.

Design and rationale of the "Sedation strategy and cognitive outcome after critical illness in early childhood" study

There is increasing concern that sedatives commonly used during critical illness may be neurotoxic during the period of early brain development. The Sedation strategy and cognitive outcome after critical illness in early childhood (RESTORE-cognition) study is a prospective cohort study designed to examine the relationships between sedative exposure during pediatric critical illness and long-term neurocognitive outcomes. We assess multiple domains of neurocognitive function 2.5-5 years post-hospital discharge, at a single time point and depending on participant and clinician availability, in up to 500 subjects who had normal baseline cognitive function, were aged 2 weeks to 8 years at pediatric intensive care unit admission, and were enrolled in a cluster randomized controlled trial of a sedation protocol (the RESTORE trial; U01 HL086622 and HL086649). In addition, to provide comparable data on an unexposed group with similar baseline biological characteristics and environment, we are studying matched, healthy siblings of RESTORE patients. Our goal is to increase understanding of the relationships between sedative exposure, critical illness, and long-term neurocognitive outcomes in infants and young children by studying these subjects 2.5 to 5 years after their index hospitalization. This paper highlights the design challenges in conducting comprehensive neurocognitive assessment procedures across a broad age span at multiple testing centers across the United States. Our approach, which includes building interprofessional teams and novel cohort retention strategies, may be of help in future longitudinal trials.

Effects of combined brief etomidate anesthesia and postnatal stress on amygdala expression of Cl- cotransporters and corticotropin-releasing hormone and alcohol intake in adult rats

Early life stressors, including general anesthesia, can have adverse effects on adult neural and behavioral outcomes, such as disruptions in inhibitory signaling, stress responsivity and increased risk of psychiatric disorders. Here we used a rat model to determine the effects of combined exposure to etomidate (ET) neonatal anesthesia and maternal separation on adult amygdala expression of genes for corticotropin-releasing hormone (Crh) and the chloride co-transporters Nkcc1 and Kcc2, as well as ethanol intake. Male and female Sprague-Dawley rats were subjected to 2 h of ET anesthesia on postnatal days (P) 4, 5, or 6 followed by maternal separation for 3 h on P10 (ET + SEP). During the P91-P120 period rats had daily 2 h access to three 0.05% saccharin solutions containing 0%, 5%, or 10% ethanol, followed by gene expression analyses. The ET + SEP group had increased Crh mRNA levels and Nkcc1/Kcc2 mRNA ratios in the amygdala, with greater increases in Nkcc1/Kcc2 mRNA ratios in males. A moderate increase in 5% ethanol intake was evident in the ET + SEP males, but not females, after calculation of the ratio of alcohol intake between the last week and first week of exposure. In contrast, control males tended to decrease alcohol consumption during the same period. A brief exposure to ET combined with a subsequent episode of stress early in life induced significant alterations in expression of amygdala Crh, Nkcc1 and Kcc2 with greater changes in the Cl^- transporter expression in males. The possibility of increased alcohol intake in the exposed males requires further confirmation using different alcohol intake paradigms.

Novel Design and Validation of a Micro Instrument in an Ear Grommet Insertion Device

An automated surgical device, the ventilator tube applicator (VTA), enables a grommet insertion surgery for patients with otitis media with effusion (OME) to be completed in a short time automatically and precisely, eliminating the use of general anesthesia (GA) typically required in such procedure. However, its current design limits the usefulness of the device as it is restricted by the properties of the tympanic membrane (TM), such as angle, thickness, and strength. Therefore, a novel design was conceptualized and the insertion control algorithm was improved to overcome the current challenges of the VTA. This innovative cover-cutter instrument design allows three-dimensional (3D) motion on an oblique surface using a single axis actuator. Experimental results on mock membranes showed great improvements in terms of robustness and success rate. The new design allowed the procedure to be performed on wider range of TM angles and hence increased the effectiveness of VTA. Grommet insertion force was reduced by an average of 66%, and the overall peak force reduced by an average of 14%. Finite element (FE) analysis on a cadaveric TM model further validated the usefulness of the cover-cutter instrument, and showed some interesting insights in the grommet insertion process.

Lycium barbarum polysaccharides attenuates the apoptosis of hippocampal neurons induced by sevoflurane

Following the application of inhalational anesthetics, including sevoflurane, patients may suffer from neural injury. The present study was conducted to explore the mechanism involved in Lycium barbarum polysaccharides (LBP) treatment of sevoflurane injured hippocampal neurons. Primary hippocampal neurons were isolated from Sprague Dawley embryonic rats. The Cell Counting Kit-8 (CCK-8) assay was used to detect cell viability. Furthermore, flow cytometry (FCM) was used to determine cell proliferation and apoptosis rates. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were applied to detect the expression levels of apoptosis-related factors, including activated-Caspase-3, B-cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2 associated X (Bax), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and total ERK1/2. The results showed that LBP promoted cell viability and cell proliferation but inhibited cell apoptosis in neurons injured with 3% sevoflurane, in dose-dependent manners (100, 200 and 400 µg/ml). LBP increased the expression levels of Bcl-2 and p-ERK1/2, and decreased levels of activated-Caspase-3 and Bax in a dose-dependent manner in hippocampal neurons that were injured with sevoflurane. In addition, ERK1/2 inhibitor reversed the above phenomenon in 400 µg/ml LBP and 3% sevoflurane-treated hippocampal neurons. Therefore, the present study indicated that LBP protected hippocampal neurons from sevoflurane injury, including aberrant cell apoptosis, via the ERK1/2 pathway.

Does pediatric anesthesia cause brain damage? - Addressing parental and provider concerns in light of compelling animal studies and seemingly ambivalent human data

Anesthesia facilitates surgery in millions of young children every year. Structural brain abnormalities and functional impairment observed in animals have created substantial concerns among clinicians, parents, and government regulators. Clinical studies seemed ambivalent; it remains unclear whether differential species effects exist towards anesthetic exposure. The current literature search and analysis attempts to unify the available clinical and animal studies, which currently comprise of > 530 in vivo animal studies and > 30 clinical studies. The prevalence of abnormalities was lowest for exposures < 1 hour, in both animals and humans, while studies with injurious findings increased in frequency with exposure time. Importantly, no exposure time, anesthetic technique, or age during exposure was clearly identifiable to be entirely devoid of any adverse outcomes. Moreover, the age dependence of maximum injury clearly identified in animal studies, combined with the heterogeneity in age in most human studies, may impede the discovery of a specific human neurological phenotype. In summary, animal and human research studies identify a growing prevalence of injurious findings with increasing exposure times. However, the existing lack of definitive data regarding safe exposure durations, unaffected ages, and non-injurious anesthetic techniques precludes any evidence-based recommendations for drastically changing current clinical anesthesia management. Animal studies focusing on brain maturational states more applicable to clinical practice, as well as clinical studies focusing on prolonged exposures during distinct developmental windows of vulnerability, are urgently needed to improve the safety of perioperative care for thousands of young children requiring life-saving and quality of life-improving procedures daily.

Influence of nitrous oxide on granule cell migration in the dentate gyrus of the neonatal rat

For several decades, the neurotoxicities of anesthetics to the developing brain have been reported by many researchers focusing on various phenomena such as apoptosis, neurodegeneration, electrophysiological aberrations, and behavioral abnormalities. According to these reports, signals via N-methyl-D-aspartate receptors (NMDA-r) and/or γ-aminobutyric acid type A receptors (GABA_A-r) are implicated in the anesthetic neurotoxicity. On the other hand, during brain development, NMDA-r and GABA_A-r are also recognized to play primary roles in neural cell migration. Therefore, anesthetics exposed in this period may influence the neural cell migration of neonates, and increase the number of hilar ectopic granule cells, which are reported to be a cause of continuous neurological deficits. To examine this hypothesis, we investigated immunohistochemically granule cell distribution in the hippocampal dentate gyrus of Wistar/ST rats after nitrous oxide (N₂O) exposure. At postnatal day (P) 6, 5-bromo-2'-deoxyuridine (BrdU) was administered to label newly generated cells. Then, rats were divided into groups (n = 6 each group), exposed to 50% N₂O at P7, and evaluated at P21. As a result, we found that ectopic ratios (ratio of hilar/total granule cells generated at P6) were decreased in rats at P21 compared with those at P7, and increased in N₂O exposed rats for over 120 min compared with the other groups. These results suggest that 50% N₂O exposure for over 120 min increases the ratios of ectopic granule cells in the rat dentate gyrus.

Simultaneous multi-slice accelerated turbo spin echo of the knee in pediatric patients

PURPOSE

To compare knee MRI performed with the integrated parallel acquisition technique (PAT) and simultaneous multislice (SMS) turbo spin echo (TSE) T2-weighted (T2w) sequences with conventional TSE sequences in pediatric patients.

MATERIALS AND METHODS

This was a retrospective IRB-approved study. Seventy-four subjects (26 male, 48 female, mean age 15.3 years, range 8-20) underwent 3-T MRI of the knee with a T2w TSE pulse sequence prototype with four-fold PAT and SMS acceleration as well as the standard PAT-only accelerated sequences. Images were anonymized and two study folders were created: one examination with only T2w PAT2 images (conventional examination) and one examination with only T2w SMS2/PAT2 sequences (SMS examination). Two readers rated examinations for 15 specific imaging findings and 5 quality metrics. Interreader agreement was measured. Signal to noise (SNR) and contrast to noise (CNR) were measured for SMS and conventional T2w sequences.

RESULTS

Consensus review demonstrated diagnostic quality performance of SMS examinations with respect to all 15 structures. Average area under the curve (AROC) was 0.95 and 0.97 for readers 1 and 2, respectively. The conventional sequence was favored over SMS for four out of five quality metrics (p < 0.001). SNR and CNR were higher for the conventional sequences compared to SMS.

CONCLUSION

SMS accelerated T2w TSE sequences offer a faster alternative for knee imaging in pediatric patients without compromise in diagnostic performance despite diminished SNR. The four-fold acceleration of SMS is beneficial to pediatric patients who often have difficulty staying still for long MRI examinations.

Diagnostic accuracy of low-dose dual-source cardiac computed tomography as compared to surgery in univentricular heart patients

BACKGROUND

To evaluate the ability of low radiation dose dual-source computed tomography (DSCT) to depict the features of morphological univentricular heart and to define accuracy by comparing findings with surgery.

METHODS

Low radiation dose dual-source cardiac computed tomography (CCT) of 33 cases of functional univentricular heart preliminary diagnosis by echocardiography compared with the results of surgery were retrospectively analyzed (aged 1 day to 4 years, median 5 months). The appropriate dose reduction strategies and iterative reconstruction were applied.

RESULTS

Thirty three univentricular heart patients were classified into three types according to Anderson's classification method, including 16 cases (48.5%) univentricular of right ventricular type with rudimentary chamber of left ventricle, 11 cases (33.3%) univentricular of left ventricular type with rudimentary chamber of right ventricle and 6 cases (18.2%) univentricular heart of indeterminate type without rudimentary chamber. The extracardiac malformation such as hypoplastic aortic arch, coronary artery fistula, total anomalous pulmonary venous returns or hypoplastic lung were presented frequently. The overall sensitivity and specification of cardiac CT was 100% compared to the results of surgery. The procedural dose-length product was 18 ± 5 mGy-cm, and unadjusted and adjusted radiation doses were 0.25 and 0.64 mSv, respectively.

CONCLUSION

Cardiac CT can diagnose accurately and be performed with a low radiation exposure in patients with the functional univentricular heart disease. The aorta, pulmonary artery and lung can be evaluated completely and simultaneously as well. Cardiac CT is an effective advanced non-invasive imaging modality to comprehensive evaluation the functional univentricular heart patients, particularly if cardiac MRI poses a high risk or is contraindicated.

The effect of regional anaesthesia versus general anaesthesia on behavioural functions in children

PURPOSE

The primary objective was to assess the effect of general anaesthesia versus regional anaesthesia in a single exposure before the age of 2 years on the development of long-term behavioural changes in children.

METHODS

The study was conducted between January 2014 and March 2015. Medical records of eligible children were reviewed. Then, parents of children who were included in the study were contacted and asked to visit the Outpatient Department to fill the Eyberg Child Behaviour Inventory questionnaire to measure behavioural changes in children. Children who were exposed to regional or general anaesthesia for surgery between January 2002 and December 2006 were included. Data collected were age and weight at the time of the first anaesthesia exposure and surgery duration. Chi-square test, t-test and multivariate analysis were used.

RESULTS

In total, 394 children were exposed to anaesthesia before the age of 2 years. Among the 168 patients who were exposed to general anaesthesia, 44 children (26.2%) developed behavioural abnormalities compared to 12 out of 226 patients (5.3%) who were exposed to regional anaesthesia (P-value<0.0001). Exposure to anaesthesia before age of 2 years increases the risk of developing behavioural disorder when surgery is accompanied by general anaesthesia, younger age at time of exposure, and longer surgery duration (P-value<0.0001, 0.001, 0.038 respectively).

CONCLUSION

Regional anaesthesia showed much lesser effect on children's behaviour compared to general anaesthesia. The incidence of behavioural disorder is increased with the use of general anaesthesia, younger age of the patient at time of exposure, and longer surgery duration.

Clinical Evidence for Any Effect of Anesthesia on the Developing Brain

A recent U.S. Food and Drug Administration warning advised that prolonged or repeated exposure to general anesthetics may affect neurodevelopment in children. This warning is based on a wealth of preclinical animal studies and relatively few human studies. The human studies include a variety of different populations with several different outcome measures. Interpreting the results requires consideration of the outcome used, the power of the study, the length of exposure and the efforts to reduce the confounding effects of comorbidity and surgery. Most, but not all, of the large population-based studies find evidence for associations between surgery in early childhood and slightly worse subsequent academic achievement or increased risk for later diagnosis of a behavioral disability. In several studies, the amount of added risk is very small; however, there is some evidence for a greater association with multiple exposures. These results may be consistent with the preclinical data, but the possibility of confounding means the positive associations can only be regarded as weak evidence for causation. Finally, there is strong evidence that brief exposure is not associated with any long term risk in humans.

Observed Length Increases of Magnetically Controlled Growing Rods are Lower Than Programmed

BACKGROUND

Magnetically controlled growing rods (MCGRs) are increasingly used in the treatment of early onset scoliosis (EOS). Few studies have reported whether desired lengthening can reliably be achieved, or if prior spine instrumentation and large tissue depths affect lengthening. In this clinical study of EOS patients, it was hypothesized that increases in rod length would equal programmed increases, patients with prior spine instrumentation would lengthen less than patients without prior surgery, and larger tissue depths would decrease lengthening success.

METHODS

A retrospective chart review was conducted on EOS patients with single and dual MCGRs placed between April 2014 to September 2015 and distracted at a single institution. Rod distraction was measured at each visit using ultrasound. Differences between programmed and actual distraction for each patient, and between groups with and without prior spine instrumentation, were determined by 2-tailed t tests. Regression and correlation were used to determine the relationship between tissue depth and length increases.

RESULTS

Thirty-one patients were included, 18 males, 13 females, age 8.1 (±2.5) years, with major curves measuring 60 (±14.6) degrees at time of MCGR insertion. In the 12 patients with prior instrumentation, time from initial growing rod placement to MCGR insertion was 23.1 (±10.6) months. The number of surgical procedures before MCGR insertion was 2.8 (±2.0). Total length increase relative to the programmed distraction was 86% (±21) (P<0.001). Length increases for patients with and without prior surgery were 87% (±23) and 86% (±19), respectively (P>0.9). Total lengthening was inversely proportional to tissue depth (r=0.38, P<0.01); the decrease in lengthening achieved was 2.1%/mm of tissue depth.

CONCLUSIONS

Increases in rod length were 14% lower than the programmed distraction. Prior instrumentation did not impact the amount of rod distraction. Greater distance between the rod and the skin surface negatively affected the magnitude of distraction.

Reducing the Number of Anesthetic Exposures in the Early Years of Life: Circumcision and Myringotomy as an Example

Evidence suggests multiple anesthetics in early childhood may increase risk for neurodevelopmental injury. We evaluated proportions of children undergoing circumcision and myringotomy, concomitantly with or prior to circumcision, and compared costs between groups. The Pediatric Health Information System was queried for males aged 6 to 36 months who underwent circumcision in 2009-2014. Relative to circumcision, the proportion who underwent myringotomy previously, concomitantly, or both, was calculated. Of 29  789 patients who underwent circumcision, 822 also underwent myringotomy; 342 (41.6%) underwent myringotomy on a previous day, and 480 (58.4%) underwent myringotomy at time of circumcision. Total hospital costs were lower for concomitant procedures (median $2994 vs $4609, P < .001. In total, 58.4% of patients who underwent circumcision and myringotomy did so concomitantly. Combined procedures resulted in significantly reduced costs and potentially minimized neurocognitive risk. Ideally, both referring pediatricians and surgical specialists should inquire about other surgical needs to optimize the availability of concomitant procedures.

Free-breathing 320-row computed tomographic angiography with low-tube voltage and hybrid iterative reconstruction in infants with complex congenital heart disease

We explored the clinical value of low-tube voltage prospective second-generation ECG-triggered 320-row CT angiography in infants with complex CHD (37 male, 23 female, aged 0-2 years). The diagnostic accuracy of 320-row CT in complex CHD was 99.4% for intracardiac cardiovascular malformations, 99.8% for extracardiac cardiovascular malformations, and 100% for other malformations. The average subjective overall image quality score for cardiac structures was 3.7 ± 0.5 points. Second-generation 320-row CT angiography with low-tube voltage and prospective ECG-triggered volume target scanning allows accurate diagnosis of cardiovascular anomalies in infants with complex CHD.

Role of α7nAChR-NMDAR in sevoflurane-induced memory deficits in the developing rat hippocampus

Detrimental effects of volatile anaesthetics, including sevoflurane, on the structure and function of the developing brain have been reported. The internalization of N-methyl-D-aspartate receptors (NMDARs) contributes to anaesthetic neurotoxicity. Both nicotinic acetylcholine receptors (nAChRs) and NMDAR play a critical role in the development of the nervous system. Moreover, nAChR can interact with NMDAR, and previous studies have demonstrated modulation of NMDAR by nAChR. In our study, we used an α7 nicotinic acetylcholine receptor (α7nAChR) agonist and α7nAChR antagonist to explore the role of α7nAChR and NMDAR in sevoflurane-induced long-term effects on memory and dendritic spine both in vivo and in vitro. The results revealed that the activation of α7nAChR attenuated the development of sevoflurane-induced memory deficit and dendritic spine changes, which might be by regulating NR2B-containing NMDAR trafficking from the intracellular pool to the cell surface pool in the hippocampus. Moreover, we demonstrated that α7nAChR could regulate NR2B-containing NMDAR via Src-family tyrosine kinase (SFK). Thus, our current study indicates that the trafficking of NR2B-containing NMDAR is regulated by α7nAChR via SFK in neonatal rat hippocampus, which may be secondary to sevoflurane-induced cognitive deficits in the developing hippocampus.

Risk of ADHD After Multiple Exposures to General Anesthesia: A Nationwide Retrospective Cohort Study

OBJECTIVE

To study the association between general anesthesia exposure before age 3 years and having a later ADHD diagnosis.

METHOD

In a birth cohort, data were collected from a nationwide population database for children born between 1997 and 1999 who were exposed to general anesthesia before their third birthday. Age- and gender-matched enrollees without general anesthesia exposure were taken as the comparison. Groups were compared to identify the incidence of ADHD after age 4 and anesthesia-related predictive factors.

RESULTS

Among the 1,146 exposed children, 74 ADHD cases were identified, and 158 ADHD cases were identified in 3,438 matched controls. After adjusting for comorbid conditions and possible confounding factors, if exposure on more than one occasion or ≥3 hr, an increased likelihood of having a later ADHD diagnosis was found (HR, 1.71 and 2.43, respectively).

CONCLUSION

Children with multiple or ≥3 hr general anesthesia exposures before age 3 years have an increased likelihood of a later ADHD diagnosis.

Mechanisms of Anesthetic Action and Neurotoxicity: Lessons from Molluscs

Anesthesia is a prerequisite for most surgical procedures in both animals and humans. Significant strides have been made in search of effective and safer compounds that elicit rapid induction and recovery from anesthesia. However, recent studies have highlighted possible negative effects of several anesthetic agents on the developing brain. The precise nature of this cytotoxicity remains to be determined mainly due to the complexity and the intricacies of the mammalian brain. Various invertebrates have contributed significantly toward our understanding of how both local and general anesthetics affect intrinsic membrane and synaptic properties. Moreover, the ability to reconstruct in vitro synapses between individually identifiable pre- and postsynaptic neurons is a unique characteristic of molluscan neurons allowing us to ask fundamental questions vis-à-vis the long-term effects of anesthetics on neuronal viability and synaptic connectivity. Here, we highlight some of the salient aspects of various molluscan organisms and their contributions toward our understanding of the fundamental mechanisms underlying the actions of anesthetic agents as well as their potential detrimental effects on neuronal growth and synaptic connectivity. We also present some novel preliminary data regarding a newer anesthetic agent, dexmedetomidine, and its effects on synaptic transmission between Lymnaea neurons. The findings presented here underscore the importance of invertebrates for research in the field of anesthesiology while highlighting their relevance to both vertebrates and humans.

Pediatric anesthesia and neurotoxicity: what the radiologist needs to know

The use of cross-sectional imaging in the pediatric population continues to rise, particularly the use of MRI. Limiting motion artifact requires cooperative subjects who do not move during imaging, so there has been an increase in the need for pediatric sedation or anesthesia. Over the last decade, concern has increased that exposure to anesthesia might be associated with long-term cognitive deficits. In this review we report current understanding of the effects of anesthesia on the pediatric population, with special focus on long-term developmental and cognitive outcomes, and suggest how radiologists can use new technologies or imaging strategies to mitigate or minimize these potential risks.

Cardiovascular CT for evaluation of single-ventricle heart disease: risks and accuracy compared with interventional findings

OBJECTIVE

We sought to evaluate the risk and image quality from cardiovascular CT in patients across all stages of single-ventricle palliation, and to define accuracy by comparing findings with intervention and surgery.

METHODS

Consecutive CT scans performed in patients with single-ventricle heart disease were retrospectively reviewed at a single institution. Diagnosis, sedation needs, estimated radiation dose, and adverse events were recorded. Anatomical findings, image quality (1-4, 1=optimal), and discrepancy compared with interventional findings were determined. Results are described as medians with their 25th and 75th percentiles.

RESULTS

From January, 2010 to August, 2015, 132 CT scans were performed in single-ventricle patients of whom 20 were neonates, 52 were post-Norwood, 15 were post-Glenn, and 45 were post-Fontan. No sedation was used in 76 patients, 47 were under minimal or moderate sedation, and nine were under general anaesthesia. The median image quality score was 1.2. The procedural dose-length product was 24 mGy-cm, and unadjusted and adjusted radiation doses were 0.34 (0.2, 1.8) and 0.82 (0.55, 1.88) mSv, respectively. There was one adverse event. No major and two minor discrepancies were noted at the time of 79 surgical and 10 catheter-based interventions.

CONCLUSIONS

Cardiovascular CT can be performed with a low radiation exposure in patients with single-ventricle heart disease. Its accuracy compared with that of interventional findings is excellent. CT is an effective advanced imaging modality when a non-invasive pathway is desired, particularly if cardiac MRI poses a high risk or is contraindicated.

Ionizing radiation from computed tomography versus anesthesia for magnetic resonance imaging in infants and children: patient safety considerations

In the context of health care, risk assessment is the identification, evaluation and estimation of risk related to a particular clinical situation or intervention compared to accepted medical practice standards. The goal of risk assessment is to determine an acceptable level of risk for a given clinical treatment or intervention in association with the provided clinical circumstances for a patient or group of patients. In spite of the inherent challenges related to risk assessment in pediatric cross-sectional imaging, the potential risks of ionizing radiation and sedation/anesthesia in the pediatric population are thought to be quite small. Nevertheless both issues continue to be topics of discussion concerning risk and generate significant anxiety and concern for patients, parents and practicing pediatricians. Recent advances in CT technology allow for more rapid imaging with substantially lower radiation exposures, obviating the need for anesthesia for many indications and potentially mitigating concerns related to radiation exposure. In this review, we compare and contrast the potential risks of CT without anesthesia against the potential risks of MRI with anesthesia, and discuss the implications of this analysis on exam selection, providing specific examples related to neuroblastoma surveillance imaging.

Neurocognitive Adverse Effects of Anesthesia in Adults and Children: Gaps in Knowledge

Numerous preclinical and clinical studies investigating the neurodevelopmental and neurocognitive effects of exposure to anesthesia and the combination of anesthesia and surgery have demonstrated histopathological and both temporary and long-term cognitive and behavioral effects at the extremes of the human age spectrum. Increasing coverage in the lay press for both our youngest and oldest patient populations has led to heightened concerns regarding the potential harmful side effects of almost all commonly used anesthetic drug regimens. Although the majority of information regarding anesthetic risks in the developing brain derives from preclinical work in rodents, research involving the aged brain has identified a well-defined postoperative cognitive phenotype in humans. While preclinical and clinical data appear to support some association between anesthesia and surgery and the development of detrimental cognitive changes in both the developing and the aged brain, correlation between anesthesia and surgery and poor neurological outcomes does not imply causation. Given this information, no single anesthetic or group of anesthetics can be recommended over any other in terms of causing or preventing negative neurocognitive outcomes in either population. This review summarizes the growing body of preclinical and clinical literature dedicated to the detrimental effects of anesthesia on both the developing and the aging brain.

Age at Exposure to Surgery and Anesthesia in Children and Association With Mental Disorder Diagnosis

BACKGROUND

Animals exposed to anesthetics during specific age periods of brain development experience neurotoxicity, with neurodevelopmental changes subsequently observed during adulthood. The corresponding vulnerable age in children, however, is unknown.

METHODS

An observational cohort study was performed using a longitudinal dataset constructed by linking individual-level Medicaid claims from Texas and New York from 1999 to 2010. This dataset was evaluated to determine whether the timing of exposure to anesthesia ≤5 years of age for a single common procedure (pyloromyotomy, inguinal hernia, circumcision outside the perinatal period, or tonsillectomy and/or adenoidectomy) is associated with increased subsequent risk of diagnoses for any mental disorder, or specifically developmental delay (DD) such as reading and language disorders, and attention deficit hyperactivity disorder (ADHD). Exposure to anesthesia and surgery was evaluated in 11 separate age at exposure categories: ≤28 days old, >28 days and ≤6 months, >6 months and ≤1 year, and 6-month age intervals between >1 year old and ≤5 years old. For each exposed child, 5 children matched on propensity score calculated using sociodemographic and clinical covariates were selected for comparison. Cox proportional hazards models were used to measure the hazard ratio of a mental disorder diagnosis associated with exposure to surgery and anesthesia.

RESULTS

A total of 38,493 children with a single exposure and 192,465 propensity score-matched children unexposed before 5 years of age were included in the analysis. Increased risk of mental disorder diagnosis was observed at all ages at exposure with an overall hazard ratio of 1.26 (95% confidence interval [CI], 1.22-1.30), which did not vary significantly with the timing of exposure. Analysis of DD and ADHD showed similar results, with elevated hazard ratios distributed evenly across all ages, and overall hazard ratios of 1.26 (95% CI, 1.20-1.32) for DD and 1.31 (95% CI, 1.25-1.37) for ADHD.

CONCLUSIONS

Children who undergo minor surgery requiring anesthesia under age 5 have a small but statistically significant increased risk of mental disorder diagnoses and DD and ADHD diagnoses, but the timing of the surgical procedure does not alter the elevated risks. Based on these findings, there is little support for the concept of delaying a minor procedure to reduce long-term neurodevelopmental risks of anesthesia in children. In evaluating the influence of age at exposure, the types of procedures included may need to be considered, as some procedures are associated with specific comorbid conditions and are only performed at certain ages.

Serial Casting for Infantile Idiopathic Scoliosis: Radiographic Outcomes and Factors Associated With Response to Treatment

BACKGROUND

Serial casting for early-onset scoliosis has been shown to improve curve deformity. Our goal was to define clinical and radiographic features that determine response to treatment.

METHODS

We retrospectively reviewed patients with idiopathic infantile scoliosis with a minimum of 2-year follow-up. Inclusion criteria were: progressive idiopathic infantile scoliosis and initial casting before 6 years of age. Two groups were analyzed and compared: group 1 (≥10-degree improvement in Cobb angle from baseline) and group 2 (no improvement).

RESULTS

Twenty-one patients with an average Cobb angle of 48 degrees (range, 24 to 72 degrees) underwent initial casting at an average age of 2.1 years (range, 0.7 to 5.4 y). Average follow-up was 3.5 years (range, 2 to 6.9 y). Sex, age at initial casting, magnitude of spinal deformity, and curve flexibility (defined as change in Cobb angle from pretreatment to first in-cast radiograph) were not significantly different between groups (P>0.05). Group 1 had a significantly higher body mass index (BMI) than group 2 at the onset of treatment (17.6 vs. 14.8, P<0.05). Univariate analysis of demographic, radiographic, and treatment factors revealed that only BMI was predictive of Cobb improvement (P=0.04; odds ratio=2.38). Group 1 (n=15) had a significantly lower Cobb angle (21 vs. 56 degrees) and rib vertebral angle difference (13 vs. 25 degrees) compared with group 2 at latest follow-up (P<0.05). A significantly larger proportion of children who were casted at less than 1.8 years of age had a Cobb angle <20 degrees at latest follow-up (P=0.03). Group 2 maintained stable clinical and radiograph parameters from pretreatment to most recent follow-up.

CONCLUSIONS

To maintain a homogeneous cohort, we excluded patients with syndromes and developmental delays. We believe that analyzing a homogeneous group provides more meaningful results than if we studied a heterogeneous sample. BMI was significantly associated with outcome such that for each unit increase in BMI, there is a 2.38× increase in the chance of improvement. Curve flexibility was similar between groups, which suggest that the amount of correction obtained at initial casting does not confirm treatment success. Key aspects of treatment that may determine success include age of less than 1.8 years at initiation of casting and derotation of the spine to correct rib vertebral angle difference of <20 degrees.

LEVEL OF EVIDENCE

Level IV-Therapeutic.

Are Anesthesia and Surgery during Infancy Associated with Decreased White Matter Integrity and Volume during Childhood?

Background

Anesthetics have neurotoxic effects in neonatal animals. Relevant human evidence is limited. We sought such evidence in a structural neuroimaging study.

Methods

Two groups of children underwent structural magnetic resonance imaging: patients who, during infancy, had one of four operations commonly performed in otherwise healthy children and comparable, nonexposed control subjects. Total and regional brain tissue composition and volume, as well as regional indicators of white matter integrity (fractional anisotropy and mean diffusivity), were analyzed.

Results

Analyses included 17 patients, without potential confounding central nervous system problems or risk factors, who had general anesthesia and surgery during infancy and 17 control subjects (age ranges, 12.3 to 15.2 yr and 12.6 to 15.1 yr, respectively). Whole brain white matter volume, as a percentage of total intracranial volume, was lower for the exposed than the nonexposed group, 37.3 ± 0.4% and 38.9 ± 0.4% (least squares mean ± SE), respectively, a difference of 1.5 percentage points (95% CI, 0.3 to 2.8; P = 0.016). Corresponding decreases were statistically significant for parietal and occipital lobes, infratentorium, and brainstem separately. White matter integrity was lower for the exposed than the nonexposed group in superior cerebellar peduncle, cerebral peduncle, external capsule, cingulum (cingulate gyrus), and fornix (cres) and/or stria terminalis. The groups did not differ in total intracranial, gray matter, and cerebrospinal fluid volumes.

Conclusions

Children who had anesthesia and surgery during infancy showed broadly distributed, decreased white matter integrity and volume. Although the findings may be related to anesthesia and surgery during infancy, other explanations are possible.

Report on the Fifth PANDA Symposium on "Anesthesia and Neurodevelopment in Children"

On April 16 and 17, 2016, the Pediatric Anesthesia and Neurodevelopment Assessment (PANDA) study held its fifth biennial symposium at the Morgan Stanley Children's Hospital of New York. The PANDA symposium has served as a key forum for clinicians, researchers, and other major stakeholders to gather and review the current state of preclinical and clinical research related to anesthetic neurotoxicity in children. Goals of the meeting included assessing how current knowledge has translated and impacted clinical care of patients who may be at risk, and future directions for research and policy. The program participants represented a diverse group with a shared concern of potential anesthetic neurotoxicity in children. It included clinicians, preclinical and clinical researchers as well as representatives from government organizations (FDA [Food and Drug Administration] and National Institutes of Health). A total of 135 attended the symposium.

Sevoflurane Impairs Growth Cone Motility in Dissociated Murine Neurons

BACKGROUND

Early postnatal exposure to general anesthetic agents causes a lasting impairment in learning and memory in animal models. One hypothesis to explain this finding is that exposure to anesthetic agents during critical points in neural development disrupts the formation of brain circuitry. Here, we explore the effects of sevoflurane on the neuronal growth cone, a specialization at the growing end of axons and dendrites that is responsible for the targeted growth that underlies connectivity between neurons.

METHODS

Dissociated neuronal cultures were prepared from embryonic mouse neocortex. Time-lapse images of live growth cones exposed to anesthetics were taken using differential interference contrast microscopy, and the rate of change of the area of the lamellipodia and the speed of the filopodial tip were quantified as measures of motility. The involvement of the p75 neurotropin receptor (p75NTR) was tested using inhibitors applied to the media and by a coimmunoprecipitation assay.

RESULTS

The rate of lamellipodial area change and filopodial tip velocity in both axonal and dendritic growth cones was significantly reduced with sevoflurane exposure between 2% and 6%. Motility could be substantially restored by treatment with Y27632 and TAT-peptide 5, which are inhibitors of Rho Kinase and p75NTR, respectively. Sevoflurane results in reduced coimmunoprecipitation of Rho-Guanosine-5'-diphosphate dissociation inhibitor after pulldown with p75NTR.

CONCLUSIONS

Sevoflurane interferes with growth cone motility, which is a critical process in brain circuitry formation. Our data suggest that this may occur through an action on the p75NTR, which promotes growth inhibitory signaling by the Rho pathway.

Physical Activity and Cognitive Development: A Meta-Analysis

RESEARCH QUESTION

Is there an association between regular exercise, defined as a structured program of increased physical activity at least 1 month in duration, and improvements in measures of executive functions compared with children who engage in their normal daily activities?

CONTEXT

The association between increased physical activity and changes in performance on tasks of executive functions have not been well elucidated in children. Executive functioning is important to intellectual development and academic success in children, and inexpensive, nonpharmacological methods for the treatment of executive dysfunction represent an attractive interventional target.

OBJECTIVE

To estimate the effect of a structured regular exercise program on neuropsychological domains of executive function in children ages 7 to 12.

DATA SOURCES

We performed a systematic review of English and non-English articles using Cochrane Library, EBSCO CINAHL, Ovid MEDLINE, PSYCInfo, Pubmed, and Web of Science, including all years allowed by each individual search engine. The search string used was "(exercise OR phys*) AND (cognit* OR executive) AND (child* OR preadolesc*)." The authors of the studies selected for review were contacted for any unpublished data.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials, which enrolled children between the ages of 7 and 12, with randomization to either normal activity or a structured physical activity intervention consisting of scheduled aerobic exercise, at least once per week, for a period of at least 1 month. Eligible studies must have included a neuropsychological battery of tests that measured at least 1 executive function both before and after the intervention was completed.

STUDY APPRAISAL

Two independent reviewers examined the screened studies in detail for potential inclusion. The results of the individual examinations were compared; if any discrepancies were present, a third party analyzed the study to determine if it should be included in the meta-analysis.

RESULTS

A total of 18 studies were identified by abstract as candidates for inclusion. From these 18 studies, 8 were independently selected by 2 authors for inclusion in the final analysis; there were no selection discrepancies between authors with regard to the studies to be included. In all, 770 subjects were included, 339 in the control group and 431 in the intervention group. All 8 studies contained a measure of inhibitory control; no other domain of executive function was measured frequently enough to perform meta-analysis, so only measures of inhibitory control were pooled and analyzed. A Cohen d effect size was calculated for each measure using the method of Morris for controlled pre-post control measurement studies. The studies were then combined in a random effects model using Comprehensive Meta Analysis software (Biostat, Englewood, NJ) for Windows (Microsoft, Redmond, WA). All studies showed a positive effect of regular exercise with improvements in measures of inhibitory control, but none were statistically significant for this measure. When pooled, the model revealed a combined Cohen d effect size of 0.2 (95% confidence interval, 0.03-0.37; P=0.021), indicating a small improvement of inhibitory control with long-term physical activity. Heterogeneity was very low (I=0).

LIMITATIONS

Many studies used different neuropsychological tests to assess inhibitory control, which may have introduced unforeseen confounders. Other domains of executive functions were not measured frequently enough to perform meta-analysis. Despite attempts to gather unpublished data, positive results were observed in all of the included studies, raising the possibility of publication bias.

CONCLUSIONS AND IMPLICATIONS

Increased regular physical activity is associated with a small and measurable, improvement in neuropsychological tests of executive functions, specifically inhibitory control. Executive functions play an important role in complex behavior, and may contribute to academic and career achievement as well as success in social interaction. This finding provides support for the important interaction between exercise and cognitive functioning.

Molecular Mechanisms of Anesthetic Neurotoxicity: A Review of the Current Literature

Data from epidemiologic studies and animal models have raised a concern that exposure to anesthetic agents during early postnatal life may cause lasting impairments in cognitive function. It is hypothesized that this is due to disruptions in brain development, but the mechanism underlying this toxic effect remains unknown. Ongoing research, particularly in rodents, has begun to address this question. In this review we examine currently postulated molecular mechanisms of anesthetic toxicity in the developing brain, including effects on cell death pathways, growth factor signaling systems, NMDA and GABA receptors, mitochondria, and epigenetic factors. The level of evidence for each putative mechanism is critically evaluated, and we attempt to draw connections between them where it is possible to do so. Although there are many promising avenues of research, at this time no consensus can be reached as to a definitive mechanism of injury.

Association between Exposure of Young Children to Procedures Requiring General Anesthesia and Learning and Behavioral Outcomes in a Population-based Birth Cohort

BACKGROUND

Exposure of young animals to general anesthesia causes neurodegeneration and lasting behavioral abnormalities; whether these findings translate to children remains unclear. This study used a population-based birth cohort to test the hypothesis that multiple, but not single, exposures to procedures requiring general anesthesia before age 3 yr are associated with adverse neurodevelopmental outcomes.

METHODS

A retrospective study cohort was assembled from children born in Olmsted County, Minnesota, from 1996 to 2000 (inclusive). Propensity matching selected children exposed and not exposed to general anesthesia before age 3 yr. Outcomes ascertained via medical and school records included learning disabilities, attention-deficit/hyperactivity disorder, and group-administered ability and achievement tests. Analysis methods included proportional hazard regression models and mixed linear models.

RESULTS

For the 116 multiply exposed, 457 singly exposed, and 463 unexposed children analyzed, multiple, but not single, exposures were associated with an increased frequency of both learning disabilities and attention-deficit/hyperactivity disorder (hazard ratio for learning disabilities = 2.17 [95% CI, 1.32 to 3.59], unexposed as reference). Multiple exposures were associated with decreases in both cognitive ability and academic achievement. Single exposures were associated with modest decreases in reading and language achievement but not cognitive ability.

CONCLUSIONS

These findings in children anesthetized with modern techniques largely confirm those found in an older birth cohort and provide additional evidence that children with multiple exposures are more likely to develop adverse outcomes related to learning and attention. Although a robust association was observed, these data do not determine whether anesthesia per se is causal.