Association between Exposure of Young Children to Procedures Requiring General Anesthesia and Learning and Behavioral Outcomes in a Population-based Birth Cohort. Anesthesiology. 2017;127:227-240. [PMID: 28609302 DOI: 10.1097/aln.0000000000001735]

Repeated Neonatal Isoflurane Exposure is Associated with Higher Susceptibility to Chronic Variable Stress-induced Behavioural and Neuro-inflammatory Alterations

Numerous studies have reported that prolonged or multiple exposures to anaesthetics in early life lead to detrimental effects on brain function, most having focused on neurocognitive function, and relatively few on long term neuropsychiatric performance. The present study investigated the impact of repeated neonatal isoflurane exposure on chronic variable stress (CVS)-induced psychiatric and behavioural outcomes together with CVS-related neuronal activity and neuro-inflammatory reactivity in relevant brain circuits. In the present study, C57BL/6J mice received either three exposures to isoflurane at postnatal days 7, 8, and 9 or a control exposure. From postnatal day 45, mice were exposed to a mild, 3-week, CVS paradigm or none and the CVS-related neuropsychiatric performance was evaluated using a series of behavioural tests. The neuronal activity in relevant brain regions was measured by ΔFosB immunopositivity and CVS-related neuroinflammation was assessed by analysing levels of pro-inflammatory cytokines IL-1α, IL-1β, IL-6, and TNF-α. In mice experiencing serial neonatal isoflurane exposure, we detected a significant enhancement in anxiety levels following CVS procedures, together with enhanced neuronal activity, and exacerbated neuroinflammation in the basolateral amygdaloid nuclei (BLA) and hippocampal dentate gyrus (DG) regions. No such change was found in control mice. These results indicate an association between early multiple isoflurane exposures in infant mice and susceptibility to a CVS-evoked anxious phenotype accompanied by enhanced neuronal activity in BLA and DG regions and high inflammatory reactivity in response to CVS.

The effects of early anesthesia on neurodevelopment: A systematic review

BACKGROUND

There is growing concern regarding the impact of general anesthesia on neurodevelopment in children. Pre-clinical animal studies have linked anesthetic exposure to abnormal central nervous system development, but it is unclear whether these results translate into humans. The purpose of this systematic review from the American Pediatric Surgical Association (APSA) Outcomes and Evidence-Based Practice (OEBP) Committee was to review, summarize, and evaluate the evidence regarding the neurodevelopmental impact of general anesthesia on children and identify factors that may affect the risk of neurotoxicity.

METHODS

Medline, Cochrane, Embase, Web of Science, and Scopus databases were queried for articles published up to and including December 2017 using the search terms "general anesthesia and neurodevelopment" as well as specific anesthetic agents. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to screen manuscripts for inclusion in the review. A consensus statement of recommendations in response to each study question was synthesized based upon the best available evidence.

RESULTS

In total, 493 titles were initially identified, with 56 articles selected for full analysis and 44 included for review. Based on currently available developmental assessment tools, a single exposure to general anesthesia does not appear to have a significant effect on general neurodevelopment, although prolonged or multiple anesthetic exposures may have some adverse effects. Exposure to general anesthesia may affect different domains of development at different ages. Regional anesthetic techniques with the addition of dexmedetomidine and/or some intravenous agents may mitigate the risks of neurotoxicity. This approach may be performed safely in some patients and can be considered as an option in selected short procedures.

CONCLUSION

There is no conclusive evidence that a single short anesthetic in infancy has a detectable neurodevelopmental effect. Data do not support waiting until later in childhood to perform general anesthesia for single short procedures. With the complexities and nuances of different anesthetic methods, patients and procedures, the planning and execution of anesthesia for the pediatric patient is generally best accomplished by an anesthesiologist, ideally a pediatric anesthesiologist.

TYPE OF STUDY

Systematic review of level 1-4 studies.

LEVEL OF EVIDENCE

Level 1-4 (mainly level 3-4).

Long-term medical imaging use in children with central nervous system tumors

BACKGROUND

Children with central nervous system (CNS) tumors undergo frequent imaging for diagnosis and follow-up, but few studies have characterized longitudinal imaging patterns. We described medical imaging in children before and after malignant CNS tumor diagnosis.

PROCEDURE

We conducted a retrospective cohort study of children aged 0-20 years diagnosed with CNS tumors between 1996-2016 at six U.S. integrated healthcare systems and Ontario, Canada. We collected computed topography (CT), magnetic resonance imaging (MRI), radiography, ultrasound, nuclear medicine examinations from 12 months before through 10 years after CNS diagnosis censoring six months before death or a subsequent cancer diagnosis, disenrollment from the health system, age 21 years, or December 31, 2016. We calculated imaging rates per child per month stratified by modality, country, diagnosis age, calendar year, time since diagnosis, and tumor grade.

RESULTS

We observed 1,879 children with median four years follow-up post-diagnosis in the U.S. and seven years in Ontario, Canada. During the diagnosis period (±15 days of diagnosis), children averaged 1.10 CTs (95% confidence interval [CI] 1.09-1.13) and 2.14 MRIs (95%CI 2.12-2.16) in the U.S., and 1.67 CTs (95%CI 1.65-1.68) and 1.86 MRIs (95%CI 1.85-1.88) in Ontario. Within one year after diagnosis, 19% of children had ≥5 CTs and 45% had ≥5 MRIs. By nine years after diagnosis, children averaged one MRI and one radiograph per year with little use of other imaging modalities.

CONCLUSIONS

MRI and CT are commonly used for CNS tumor diagnosis, whereas MRI is the primary modality used during surveillance of children with CNS tumors.

The effect of sevoflurane anesthesia for dental procedure on neurocognition in children: a prospective, equivalence, controlled trial

BACKGROUND

Dental procedures under general anesthesia (DGA) was found to improve the oral health-related quality of children's life. However, some parents and pediatricians expressed concern about the neurotoxicity of general anesthesia. The purpose of this trial was to whether DGA in children has an adverse effect on neurocognition.

METHODS

In this prospective, assessor-masked, controlled, equivalence trial, we recruited 340 children younger than 7 years who were undergoing caries treatment between Feb 1, 2019, and Aug 31, 2019, without factors affecting neurodevelopment. They received either sevoflurane-based general anesthesia or awake-local anesthesia. The Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition was used to evaluate the neurocognitive function of children at 6 months after surgery, and the Full-Scale IQ (FSIQ) was selected as the primary outcome. The predefined clinical equivalence margin was 5 (1/3 SD of FSIQ score). If the 95% CI of the difference between the average FSIQ score of the two groups is within - 5 to + 5, then the two groups are equivalent.

RESULTS

The outcome data were obtained from 129 children in the general anesthesia group and 144 in the local anesthesia group. The median length of general anesthesia was 130 min (IQR 110-160). The mean FSIQ score in the general anesthesia group was 103·12 (SD 8.94), and the mean of the local anesthesia group was 103·58 (SD 8.40). There was equivalence in means of FSIQ score between the two groups (local minus general anesthesia 0.46, 95% CI - 2.35 to 1.61). There was no significant difference in FSIQ scores between different age groups and different anesthesia durations. Only the mother's education could affect the primary outcome.

CONCLUSIONS

In this trial, prolonged DGA with a sevoflurane-only anesthetic in preschool children, does not adversely affect neurocognitive function at 6 months after surgery compared with awake-local anesthesia.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1800015216 . Registered Mar 15 2018.

[Inhalational anesthetics]

Inhalational anesthetics have been used for induction and maintenance of general anesthesia for more than 150 years. All of the currently used inhalational anesthetics are chlorinated and fluorinated derivatives of ether. Dosing is carried out using the minimal alveolar concentration (MAC) concept. The pharmacokinetic properties of the various inhalational anesthetics are governed by the specific distribution coefficients. Mechanisms of action include specific modulations of various receptors of the central nervous system as well as an unspecific interaction with the cell membrane. Organ toxicity of modern inhalational anesthetics is considered to be minimal. The role of inhalational anesthetics in the context of postoperative nausea and vomiting (PONV) has been reassessed in recent years. The superiority of inhalational anesthetics over intravenous hypnotics with respect to intraoperative awareness is undisputed. The organ protective mechanism of preconditioning is an exclusive property of inhalational anesthetics among all the currently available hypnotics.

Singular and short-term anesthesia exposure in the developing brain induces persistent neuronal changes consistent with chronic neurodegenerative disease

The potential adverse impact of inhalational anesthetics on the developing brain was highlighted by the addition of a medication warning by the U.S. Food and Drug Administration for their use in the pediatric population. To investigate mechanisms by which early life anesthesia exposure could induce long-term neuronal dysfunction, we exposed rats to 1 minimum alveolar concentration sevoflurane at 7 days of life. The animals were raised normally until adulthood (P300) prior to sacrifice and analysis of cortical tissue structure (TEM), mitochondrial quality control and biogenesis pathways (Western blot, ELISA, ADP/ATP content), and markers of oxidative stress, proteotoxicity and inflammation (Western blot, ELISA). We found that early life anesthesia exposure led to adverse changes in mitochondrial quality maintenance pathways, autophagy and mitochondrial biogenesis. Although there was an escalation of oxidative stress markers and an increase in the nuclear localization of stress-related transcription factors, cellular redox compensatory responses were blunted, and oxidative phosphorylation was reduced. We found upregulation of mitochondrial stress and proteotoxicity markers, but a significant reduction of mitochondrial unfolded protein response end-effectors, contributing to an increase in inflammation. Contrary to acute exposure, we did not find an increase in apoptosis. Our findings suggest that a limited, early exposure to anesthesia may produce lasting cellular dysfunction through the induction of a sustained energy deficient state, resulting in persistent neuroinflammation and altered proteostasis/toxicity, mimicking aspects of chronic neurodegenerative diseases.

Preventing the Long-term Effects of General Anesthesia on the Developing Brain: How Translational Research can Contribute

In 2017, the Food and Drug Administration published a safety recommendation to limit the exposure to general anesthesia as much as possible below the age of three. Indeed, several preclinical and clinical studies have questioned the possible toxicity of general anesthesia on the developing brain. Since then, recent clinical studies tried to mitigate this alarming issue. What is true, what is false? Contrary to some perceptions, the debate is not over yet. Only stronger translational research will allow scientists to provide concrete answers to this public health issue. In this review, we will provide and discuss the more recent data in this field, including the point of view of preclinical researchers, neuropsychologists and pediatric anesthesiologists. Through translational research, preclinical researchers have more than ever a role to play to better understand and identify long-term effects of general anesthesia for pediatric surgery on brain development in order to minimize it.

Anesthesia and the Developing Brain: A Review of Sevoflurane-induced Neurotoxicity in Pediatric Populations

PURPOSE

For over 150 years of anesthetic practice, it was believed that the effects of general anesthetics were temporary and not adverse. A growing number of studies over the past 2 decades, however, have identified structural and cognitive abnormalities, especially in the developing brain. Despite the growing evidence of anesthetic-induced neurotoxicity in animal studies, the evidence to date in humans has been inconsistent and unclear. Sevoflurane, a commonly used inhalational agent in pediatric anesthesia, is an agent of choice for inhalational induction due to its rapid activity and low blood-gas solubility. With evaluation of the current literature, improved considerations can be made regarding the widespread use of sevoflurane as an anesthetic.

METHODS

PubMed database was searched for article published between 1969 through 2020. The reference lists of identified articles were searched manually for additional papers eligible for inclusion. This review addressed the tolerability of sevoflurane in specific populations, particularly pediatrics, and is divided into 3 parts: (1) the history of sevoflurane use in anesthetic practice and the pharmacokinetic properties that make it advantageous in pediatric populations; (2) proposed mechanisms of anesthesia-induced neurotoxicity; and (3) considerations due to potential adverse effects of sevoflurane in both short and long procedures.

FINDINGS

There is reason for concern regarding the neurotoxic effects of sevoflurane in both the pediatric and elderly populations, as spatial memory loss, developmental deficits, and an enhanced risk for Alzheimer disease have been linked with the use of this popular inhalational agent.

IMPLICATIONS

The duration and dose of sevoflurane may need to be altered, especially in longer procedures in pediatric populations. This may change how sevoflurane is administered, thus indicating a greater demand for an understanding of its limitations as an anesthetic agent.

Hypotension and adverse neurodevelopmental outcomes among children with multiple exposures to general anesthesia: Subanalysis of the Mayo Anesthesia Safety in Kids (MASK) Study

BACKGROUND

The potential adverse effects of exposures to general anesthesia on the developing human brain remain controversial. It has been hypothesized that hypotension accompanying anesthesia could be contributory. We hypothesized that among children exposed to multiple anesthetics prior to age 3, children developing adverse neurodevelopmental outcomes would be more likely to have intraoperative hypotension.

METHODS

Two previously published study cohorts were utilized for analysis: the retrospective and prospective Mayo Anesthesia Safety in Kids cohorts. The two lowest consecutive systolic blood pressure measurements were abstracted and standardized by calculating a z-score for noninvasive blood pressure reference ranges for children. The lowest systolic blood pressure z-score (continuous variable) and intraoperative hypotension (lowest systolic blood pressure z-score <-1.0) were used to assess the association of intraoperative hypotension with the incidence of learning disabilities or attention-deficit/hyperactivity disorder(retrospective cohort) and factor scores/cluster membership (prospective cohort).

RESULTS

One hunderd and sixteen and 206 children with multiple exposures to general anesthesia were analyzed in the retrospective and prospective cohorts with mean lowest systolic blood pressure z-scores -0.26 (SD 1.02) and -0.62 (SD 1.10), respectively. There was no overall association of the lowest z-score or hypotension with learning disabilities or attention-deficit/hyperactivity disorder in the retrospective cohort. In the prospective cohort, there was no overall association of the lowest systolic blood pressure or hypotension with factor scores or cluster membership.

CONCLUSIONS

We did not find evidence to support the hypothesis that, among children exposed to multiple anesthetics prior to age 3, children developing adverse neurodevelopmental outcomes would be more likely to have intraoperative hypotension compared with those who did not.

[Effect of Long-time Postnatal Exposure to Sevoflurane on Causing Attention-deficit/Hyperactivity Disorder in Rats]

OBJECTIVE

To investigate whether long-term exposure to inhaled sevoflurane, a volatile anesthetic, causes abnormal activities and memory impairment related to attention-deficit/hyperactivity disorder (ADHD) in neonatal rats.

METHODS

On postnatal day 5 (P5), Sprague-Dawley rats were randomly assigned to two sevoflurane subgroups and two control subgroups and underwent experimental intervention. The two sevoflurane (SEVO) subgroups were exposed to 3% sevoflurane for 2 h and 4 h respectively, while the two control subgroups were given pure oxygen for the same amount and duration. Behavioral tests, including open-field test (OFT), five-choice serial reaction time task (5-CSRTT), fear-conditioning (FC) and Morris water maze (MWM), were applied to evaluate changes in cognition, memory, anxiety and ADHD-related behavioral changes in the rats in adolescence (-P25) and in adulthood (-P65).

RESULTS

In OFT, the SEVO 2 h and SEVO 4 h subgroups displayed activity level and exploratory behaviors similar to those of the control subgroups on P21 and P61, with no statistically significant difference identified in the data. 5-CSRTT results on P25 and P65 indicated no statistically significant difference between the SEVO subgroups and the control subgroups in regard to ADHD-related abnormal behaviors, including number of immature reaction, rate of correct response and omission rate. In the FC experiment, SEVO 4 h group had a shorter freezing period and longer period of freezing latency ( P=0.029) in comparison to the control groups. The results of the MWM test showed that the escape latency period of rats in the SEVO 4 h group was significantly prolonged on the second day and the third day, compared to the control groups ( P<0.05). The average swimming speed of SEVO groups did no exhibit any statistically significant difference on P69 or P76. The time the SEVO 4 h group spent in the target quadrant was significantly shorter than that of the control group ( P=0.039) and percentage of distance traveled in the target quadrant was significantly reduced compared to that the control group ( P=0.048).

CONCLUSION

The findings suggest that four hours of inhaled sevoflurane exposure in neonate rats may cause memory impairment, but does no increase risks for ADHD-related abnormal activities.

Effects of Maternal Abdominal Surgery on Fetal Brain Development in the Rabbit Model

INTRODUCTION

Anesthesia during pregnancy can impair fetal neurodevelopment, but effects of surgery remain unknown. The aim is to investigate effects of abdominal surgery on fetal brain development. Hypothesis is that surgery impairs outcome.

METHODS

Pregnant rabbits were randomized at 28 days of gestation to 2 h of general anesthesia (sevoflurane group, n = 6) or to anesthesia plus laparoscopic appendectomy (surgery group, n = 13). On postnatal day 1, neurobehavior of pups was assessed and brains harvested. Primary outcome was neuron density in the frontal cortex, and secondary outcomes included neurobehavioral assessment and other histological parameters.

RESULTS

Fetal survival was lower in the surgery group: 54 versus 100% litters alive at birth (p = 0.0442). In alive litters, pup survival until harvesting was 50 versus 69% (p = 0.0352). No differences were observed for primary outcome (p = 0.5114) for surviving pups. Neuron densities were significantly lower in the surgery group in the caudate nucleus (p = 0.0180), but not different in other regions. No differences were observed for secondary outcomes. Conclusions did not change after adjustment for mortality.

CONCLUSION

Abdominal surgery in pregnant rabbits at a gestational age corresponding to the end of human second trimester results in limited neurohistological changes but not in neurobehavioral impairments. High intrauterine mortality limits translation to clinical scenario, where fetal mortality is close to zero.

Prospectively assessed neurodevelopmental outcomes in studies of anaesthetic neurotoxicity in children: a systematic review and meta-analysis

BACKGROUND

Whether exposure to a single general anaesthetic (GA) in early childhood causes long-term neurodevelopmental problems remains unclear.

METHODS

PubMed/MEDLINE, Embase, CINAHL, Web of Science, and the Cochrane Library were searched from inception to October 2019. Studies evaluating neurodevelopmental outcomes and prospectively enrolling children exposed to a single GA procedure compared with unexposed children were identified. Outcomes common to at least three studies were evaluated using random-effects meta-analyses.

RESULTS

Full-scale intelligence quotient (FSIQ); the parentally reported Child Behavior Checklist (CBCL) total, externalising, and internalising problems scores; and Behavior Rating Inventory of Executive Function (BRIEF) scores were assessed. Of 1644 children identified, 841 who had a single exposure to GA were evaluated. The CBCL problem scores were significantly higher (i.e. worse) in exposed children: mean score difference (CBCL total: 2.3 [95% confidence interval {CI}: 1.0-3.7], P=0.001; CBCL externalising: 1.9 [95% CI: 0.7-3.1], P=0.003; and CBCL internalising problems: 2.2 [95% CI: 0.9-3.5], P=0.001). Differences in BRIEF were not significant after multiple comparison adjustment. Full-scale intelligence quotient was not affected by GA exposure. Secondary analyses evaluating the risk of these scores exceeding predetermined clinical thresholds found that GA exposure was associated with increased risk of CBCL internalising behavioural deficit (risk ratio [RR]: 1.47; 95% CI: 1.08-2.02; P=0.016) and impaired BRIEF executive function (RR: 1.68; 95% CI: 1.23-2.30; P=0.001).

CONCLUSIONS

Combining results of studies utilising prospectively collected outcomes showed that a single GA exposure was associated with statistically significant increases in parent reports of behavioural problems with no difference in general intelligence.

Does Exposure to General Anesthesia Increase Risk of ADHD for Children Before Age of Three?

Objective: The objective of the study was to evaluate the relationship between frequency of exposure to general anesthesia before the age of 3 and subsequent risk of diagnosis for attention-deficit hyperactivity disorder (ADHD). Method: We searched PubMed, Embase, Web of Science, and Cochrane Library database for eligible inclusion in the meta-analysis. The indicated outcomes were extracted from the included studies, and the combined effects were calculated using the RevMan software 5.3. Results: Compared with no exposure to general anesthesia, single exposure to general anesthesia did not increase the risk of ADHD for children before the age of 3 [hazard ratio (HR): 1.14, 95%; confidence intervals (CI): 0.97-1.35; p = 0.11; I ² = 0%], while multiple exposures to general anesthesia did increase the risk of ADHD (HR: 1.83; 95% CIs: 1.00-3.32; p = 0.05; I ² = 81%). Conclusion: Multiple, but not single, exposures to general anesthesia in children before age of 3 increased the risk of ADHD.

Surveillance endoscopy in pediatric tracheostomy: A systematic review

OBJECTIVES

To systematically review the literature on the yield of surveillance airway endoscopy in pediatric patients with tracheostomies.

METHODS

A systematic search was performed according to PRISMA guidelines of the MEDLINE/Pubmed and Embase databases. Data were collected on the following outcomes of interest: abnormal airway findings in surveillance endoscopy performed in pediatric tracheostomy patients, frequency and nature of interventions performed during endoscopy, and predictive factors associated with abnormal airway findings.

RESULTS

Seven studies were included in the review. The timing of endoscopy post-tracheostomy placement was variable and ranged from 1 to 24 months. All studies reported abnormal airway findings on initial endoscopic examination, with rates varying from 20 to 87%. Airway granulomas/granulation tissue was the most common finding, followed by airway stenosis and suprastomal collapse. Interventions performed to improve airway safety occurred in 18%-64% of patients undergoing surveillance endoscopy. The most commonly reported interventions were debridement of granulation tissue and dilation of subglottic stenosis. No endoscopy-related complications were reported across the studies. The presence of tracheostomy-related symptoms was the most consistently reported predictor of abnormal airway findings and airway interventions.

CONCLUSION

Pediatric tracheostomy patients undergoing surveillance airway endoscopy have a high rate of abnormal airway findings and interventions. However, additional studies are needed before routine endoscopy can be recommended in asymptomatic patients.

ED50 of Intranasal Dexmedetomidine Sedation for Transthoracic Echocardiography in Children with or without a History of Cardiac Surgery for Cyanotic Congenital Heart Disease

Methods

This prospective single-blinded clinical trial included 72 ASA I-II stage children aged 1-36 months with cCHD who were scheduled to undergo TTE under sedation. Children were assigned to group A (n = 37) with a previous history of cardiac surgery and group B (n = 35) with no history of cardiac surgery. Doses of intranasal DEX were analyzed by up-down sequential allocation at an initial dose of 2.3 μg/kg and an increase in steps of 0.2 μg/kg. Intranasal DEXED50 values were analyzed by the up-and-down method of Dixon-Massey and probit regression to determine ED50 and 95% confidence interval (CI) for sedation. The time to effective sedation, time to regaining consciousness, vital signs, oxygen saturation, time of performing TTE, clinical adverse effects, and characteristics of regaining consciousness were compared between the two groups.

Results

ED50 of intranasal DEX sedation was 2.530 μg/kg (95% CI, 1.657-4.156) in group A and 2.500 μg/kg (95% CI, 1.987-3.013) in group B. There was no significant difference in sedation onset time and time to regaining consciousness between the two groups. Additionally, no significant adverse hemodynamic or hypoxemic effect was observed. There was no significant difference in sedation-onset time and wake-up time between the two groups (15 ± 4 min vs.16 ± 5 min; 50 ± 11 min vs.48 ± 10 min). This trial is registered with the China Clinical Trials Registry (ChiCTR-IOR-1800015038).

Conclusions

ED50 of intranasal DEX sedation for TTE is similar in children with and without a history of cardiac surgery for cCHD.

Attention deficit hyperactivity disorder and educational level in adolescent and adult individuals after anesthesia and abdominal surgery during infancy

AIM

Several studies in animal models have found that exposure to anesthetics in early life can cause cognitive dysfunction. Human studies show conflicting results and studies of cognitive function after anesthesia and neonatal surgery are scarce. The aim of this study was to investigate whether exposure to anesthesia and abdominal surgery during infancy was associated with cognitive dysfunction from the perspective of educational level, disposable income and attention deficit hyperactivity disorders (ADHD) in adolescent and adult individuals.

METHODS

A cohort study with patients born 1976 to 2002 that underwent abdominal surgery during infancy at a pediatric surgical center were matched by age, sex, and gestational age to ten randomly selected individuals from the Swedish Medical Birth Register. Individuals with chromosomal aberrations were excluded. Data on highest level of education and annual disposable income were attained from Statistics Sweden and the diagnosis of ADHD were retrieved from the Swedish National Patient Register.

RESULTS

485 individuals and 4835 controls were included. Median gestational age was 38 weeks (24-44) and median age at surgery was seven days (0-365). Three hundred sixty-six individuals (70.0%) underwent surgery during the neonatal period (< 44 gestational weeks). Median operating time was 80 minutes (10-430). The mean age at follow-up was 28 years. Fisher's exact test for highest level of education for the exposed and unexposed groups were respectively: university 35% and 33%, upper secondary 44% and 47%, compulsory 21% and 20% (p = 0.6718). The median disposable income was 177.7 versus 180.9 TSEK respectively (p = 0.7532). Exposed individuals had a prevalence of ADHD of 5.2% and unexposed 4.4% (p = 0.4191).

CONCLUSIONS

This study shows that exposure to anesthesia and abdominal surgery during infancy is not associated with cognitive dysfunction from the perspective of educational level, disposable income and ADHD in adolescent and adult individuals. Further studies in larger cohorts at earlier gestational ages are needed to verify these findings.

Safety of anesthetic exposure on the developing brain - Do we have the answer yet?

During the past two decades, a vast number of studies done on rodents and nonhuman primates have implicated general anesthetic exposure of developing brains in producing neurotoxicity leading to various structural and functional neurological abnormalities with cognitive and behavioral deficits later in life. However, it is still unclear whether these findings translate to children and whether single exposure to anesthesia in childhood can have long-term neuro-developmental risks. Considering the fact that a large number of healthy young children are undergoing elective surgery under general anesthesia globally, any such potential neurocognitive risk of pediatric anesthesia is a serious public health issue and is therefore important to understand. This review aims to assess the current preclinical and clinical evidence related to anesthetic neurotoxicity.

Diverse approaches to scoliosis in young children

Management of scoliosis in young children needs a comprehensive approach because of its complexity. There are many debatable points; however, only serial casting, growing rods (including traditional and magnetically controlled) and anterior vertebral body tethering will be discussed in this article.Serial casting is a time-gaining method for postponing surgical interventions in early onset scoliosis, despite the fact that it has some adverse effects which should be considered and discussed with the family beforehand.Use of growing rods is a growth-friendly surgical technique for the treatment of early onset spine deformity which allows chest growth and lung development. Magnetically controlled growing rods are effective in selected cases although they sometimes have a high number of unplanned revisions.Anterior vertebral body tethering seems to be a promising novel technique for the treatment of idiopathic scoliosis in immature cases. It provides substantial correction and continuous curve control while maintaining mobility between spinal segments. However, long-term results, adverse effects and their prevention should be clarified by future studies. Cite this article: EFORT Open Rev 2020;5:753-762. DOI: 10.1302/2058-5241.5.190087.

Exposure to Surgery and Anesthesia in Early Childhood and Subsequent Use of Attention Deficit Hyperactivity Disorder Medications

BACKGROUND

Some recent clinical studies have found that early childhood exposure to anesthesia is associated with increased risks of behavioral deficits and clinical diagnoses of attention deficit hyperactivity disorder (ADHD). While diagnoses in claims data may be subject to inaccuracies, pharmacy claims are highly accurate in reflecting medication use. This study examines the association between exposure to surgery and anesthesia and subsequent ADHD medication use.

METHODS

Longitudinal data for children enrolled in Texas and New York Medicaid from 1999 to 2010 were used. We assessed the association between a single exposure to anesthesia before age 5 years for 1 of 4 common pediatric surgical procedures (pyloromyotomy, inguinal hernia repair, circumcisions outside the perinatal period, and tonsillectomy and/or adenoidectomy) and persistent ADHD medication use (event defined as the initial ADHD medication prescription, and persistent use defined as filling 2 or more ≥30-day prescriptions between 6 months following surgery until censoring). Exposed children (n = 42,687) were matched on propensity score (ie, the probability of receiving surgery) estimated in logistic regression including sociodemographic and clinical covariates, to children without anesthesia exposure before age 5 years (n = 213,435). Cox proportional hazards models were used to evaluate the hazard ratio (HR) of ADHD medication use following exposure. Nonpsychotropic medications served as negative controls to determine if exposed children simply had higher overall medication use.

RESULTS

Children with a single exposure to surgery and anesthesia were 37% more likely than unexposed children to persistently use ADHD medication (HR, 1.37; 95% confidence interval [CI], 1.30-1.44). The estimated HRs for common nonpsychotropic medication use following a single anesthetic exposure were 1.06 (95% CI, 1.04-1.07) for amoxicillin, 1.10 (95% CI, 1.08-1.12) for azithromycin, and 1.08 (95% CI, 1.05-1.11) for diphenhydramine. In comparison, the risk of using other psychotropic medication to treat conditions besides ADHD was also significantly higher, with HRs of 1.37 (95% CI, 1.24-1.51) for sedative/anxiolytics, 1.40 (95% CI, 1.25-1.58) for antidepressants, 1.31 (95% CI, 1.20-1.44) for antipsychotics, and 1.24 (95% CI, 1.10-1.40) for mood stabilizers.

CONCLUSIONS

Medicaid-enrolled children receiving anesthesia for a single common pediatric surgical procedure under age 5 years were 37% more likely to require subsequent persistent use of ADHD medications than unexposed children. Because the increased use of ADHD medication is disproportionately higher than that of nonpsychotropic medications, unmeasured confounding may not account for all of the increase in ADHD medication use. By evaluating Medicaid data, this study assesses children who may be particularly vulnerable to neurotoxic exposures.

LncRNA Rik-203 Contributes to Sevoflurane Induced Neurotoxicity?

Background: The anesthetics inhibit neural differentiation, induce neuron loss and cognitive impairment in young animals. However, the underlying mechanisms of anesthesia on neural differentiation are unknown. Methods: Embryonic stem cells (ESCs) and mice received sevoflurane anesthesia. 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-203. The binding of miRNA with mRNA of BDNF was presented by the luciferase assay. Results: Here we found that LncRNA Riken-203(Rik-203) was highly expressed in mice brain and was upregulated during neural differentiation. Sevoflurane decreased the amount of Rik-203 in mice brain. Knockdown of Rik-203 repressed the neural differentiation derived from mouse embryonic stem cell and downregulated the neural progenitor cells markers Sox1 and Nestin. RNA pull-down showed that miR-466l-3p was highly bound to Rik-203. Inhibition of miR-466l-3p restored the neural differentiation repressed by Rik-203 knockdown. Brain derived neurotrophic factor (BDNF), which was downregulated by sevoflurane, was also directly targeted by miR-466l-3p. Overexpression of BDNF restored the neural differentiation repressed by miR-466l-3p and Rik-203 knockdown. Conclusion: Our study suggested that sevoflurane related LncRNARik-203 facilitates neural differentiation by inhibiting miR-466l-3p's ability to reduce BDNF levels.

Development: Epidemiology and management of postoperative apnoea in premature and term newborns

Postoperative apnoea (PA) is defined as a respiratory pause of more than 15seconds or as a respiratory pause associated with bradycardia < 120/min, desaturation (Sat02<90%), cyanosis or hypotonia. This is a relatively frequent phenomenon that affects 10% of infants under 60 weeks of post-conceptual age, born prematurely or not, and occurs during the first 12-48h postoperatively. The population exposed to PA is heterogeneous and it is necessary to standardise the management both during the intra- and postoperative period, and to adapt this management according to the risk factors for PA and the status as prematurely born infants or not, based on recent data from the literature.

Is Anesthesia Bad for the Brain? Current Knowledge on the Impact of Anesthetics on the Developing Brain

There are compelling preclinical data that common general anesthetics cause increased neuroapoptosis in juvenile animals. Retrospective studies demonstrate that young children exposed to anesthesia have school difficulties, which could be caused by anesthetic neurotoxicity, perioperative hemodynamic and homeostatic instability, underlying morbidity, or the neuroinflammatory effects of surgical trauma. Unnecessary procedures should be avoided. Baseline measures of blood pressure are important in determining perioperative blood pressure goals. Inadvertent hypocapnia or moderate hypercapnia and hyperoxia or hypoxia should be avoided. Pediatric patients should be maintained in a normothermic, euglycemic state with neutral positioning. Improving outcomes of infants and children requires the collaboration of anesthesiologists, surgeons, pediatricians and neonatologists.

Neonatal exposure to sevoflurane expands the window of vulnerability to adverse effects of subsequent exposure to sevoflurane and alters hippocampal morphology via decitabine-sensitive mechanisms

BACKGROUND

Deficiencies in neurocognitive function have been found in late childhood or adolescence in patients who had prolonged and/or repeated early-life general anesthesia. Animal studies suggest that anesthetic-induced impairment in the neuron-specific K⁺-2Cl^- (Kcc2) Cl^- exporter expression, which regulates developmental maturation of GABA type A receptor (GABA_AR) signaling from excitatory to inhibitory, may play a mediating role. We tested whether the DNA methyltransferase (DNMT) inhibitor decitabine ameliorates the anesthetic's adverse effects.

METHODS

Sprague-Dawley male rats were injected with vehicle or decitabine 30 min before 2.1 % sevoflurane exposure for 5 h on postnatal day 5 (P5). On P19, P20, or P21, electroencephalography-detectable seizures were measured during 1 h of sevoflurane exposure, followed by collection of the trunk blood and brain tissue samples. Other rats were evaluated for changes in hippocampal CA1 dendrite morphology and gene expressions on ≥ P120.

RESULTS

Rats in the vehicle plus sevoflurane group responded to sevoflurane exposure on P19, P20 or P21 with electroencephalography-detectable seizures and stress-like corticosterone secretion and had altered hippocampal dendrite morphology in adulthood. These rats had expressions of Kcc2 and Dnmt genes downregulated and upregulated, respectively, in the P19 - P21 cortex and hypothalamus and the ≥ P120 hippocampus. All measured parameters in the sevoflurane-exposed rats that were pretreated with decitabine were not different from those in the control group.

CONCLUSIONS

Neonatal exposure to sevoflurane sensitizes rats to adverse effects of repeated exposure to the anesthetic. The anesthetic-caused changes in the decitabine-sensitive mechanisms may play a mediating role in the developmental effects of early-life anesthesia.

General anesthesia affecting on developing brain: evidence from animal to clinical research

As the recent update of General anaesthesia compared to spinal anaesthesia (GAS) studies has been published in 2019, together with other clinical evidence, the human studies provided an overwhelming mixed evidence of an association between anaesthesia exposure in early childhood and later neurodevelopment changes in children. Pre-clinical studies in animals provided strong evidence on how anaesthetic and sedative agents (ASAs) causing neurotoxicity in developing brain and deficits in long-term cognitive functions. However pre-clinical results cannot translate to clinical practice directly. Three well designed large population-based human studies strongly indicated that a single brief exposure to general anesthesia (GAs) is not associated with any long-term neurodevelopment deficits in children's brain. Multiple exposure might cause decrease in processing speed and motor skills of children. However, the association between GAs and neurodevelopment in children is still inconclusive. More clinical studies with larger scale observations, randomized trials with longer duration exposure of GAs and follow-ups, more sensitive outcome measurements, and strict confounder controls are needed in the future to provide more conclusive and informative data. New research area has been developed to contribute in finding solutions for clinical practice as attenuating the neurotoxic effect of ASAs. Xenon and Dexmedetomidine are already used in clinical setting as neuroprotection and anaesthetic sparing-effect, but more research is still needed.

Neonatal sevoflurane exposure induces impulsive behavioral deficit through disrupting excitatory neurons in the medial prefrontal cortex in mice

Sevoflurane, in particular multiple exposures, has been reported to cause the abnormal neurological development including attention-deficit/hyperactivity disorder (ADHD). This study is to investigate ADHD-like impulsivity in adult mice after repeated sevoflurane exposures at the neonatal stage. Six-day-old pups were exposed to 60% oxygen in the presence or absence of 3% sevoflurane for 2 h and the treatment was administrated once daily for three consecutive days. To assess the impulsivity, the cliff avoidance reaction (CAR) was carried out at the 8th week. Our results showed that repeated sevoflurane treatment increased the number of jumps and shortened the jumping latency in the CAR test. The cortices were harvested for immunostaining to detect c-Fos and calmodulin-dependent protein kinase IIα (CaMKIIα) expression in the medial prefrontal cortex (mPFC). We found that mPFC neurons, especially excitatory neurons, were highly activated and related to impulsive behavior. The activation viruses (AAV-CaMKIIα-hM3Dq) were injected to evaluate the effects of specific activation of mPFC excitatory neurons on impulsive behavior in the presence of clozapine-N-oxide (CNO). Likewise, the inhibitory viruses (AAV-CaMKIIα-hM4Di) were injected in the sevoflurane group to explore whether the mPFC excitatory neuronal inhibition reduced the impulsivity. Our results revealed that chemogenetic activation of mPFC excitatory neurons induced impulsive behavior whereas inhibition of mPFC excitatory neurons partially rescued the deficit. These results indicate that repeated sevoflurane exposures at the critical time induce impulsive behavior accompanied with overactivation of mPFC excitatory neurons in adult stages. This work may further extend to understand the ADHD-like impulsive behavior of the anesthetic neurotoxicity.

Anesthetic neurotoxicity in the pediatric population: a systematic review of the clinical evidence

Background: Exposure to general anesthesia (GA) in early life is known to be neurotoxic to animals. Objectives: To evaluate the risk of GA inducing long-term neurodevelopmental deficits in human children. Design: Systematic review. Methods: We included observational and randomized studies that compared the long-term neurodevelopment of postnatal children exposed to GA to the long-term neurodevelopment of children not exposed to GA. We searched MEDLINE, Embase and Web of Science for relevant studies published in the year 2000 or later. We screened all the identified studies on predetermined inclusion and exclusion criteria. A risk of bias assessment was made for each included study. We identified 9 neurodevelopmental domains for which a sub-analysis was made: intelligence; memory; learning; language/speech; motor function; visuospatial skills; development/emotions/behavior; ADHD/attention; autistic disorder. Results: We included 26 studies involving 605.391 participants. Based on AHRQ-standards 11 studies were of poor quality, 7 studies were of fair quality and 8 studies were of good quality. The major causes of potential bias were selection and comparability bias. On 2 neurodevelopmental domains (visuospatial skills and autistic disorder), the available evidence showed no association with exposure to GA. On 7 other neurodevelopmental domains, the available evidence showed mixed results. The 4 studies that used a randomized or sibling-controlled design showed no association between GA and neurodevelopmental deficits in their primary endpoints. Limitations: The absence of a meta-analysis and funnel plot. Conclusions: Based on observational studies, we found an association between GA in childhood and neuro-developmental deficits in later life. Randomized and sibling-matched observational studies failed to show the same association and therefore no evidence of a causal relationship exists at present. Since GA seems to be a marker, but not a cause of worse neurodevelopment, we argue against delaying or avoiding interventional or diagnostic procedures requiring GA in childhood based on the argument of GA-induced neurotoxicity.

Voltage dependent allosteric modulation of IPSCs by benzodiazepines

GABA_A receptors (GABA_AR) are inhibitory ion channels ubiquitously expressed in the central nervous system and play critical roles in brain development and function. Benzodiazepines are positive allosteric modulators of GABA_AR, enhancing channel opening frequency when GABA is bound to the receptor. Midazolam is a commonly used benzodiazepine. It is frequently used for premature infants, but the long-term consequences of its use in this patient population are not well established. Here, we studied the acute effects of midazolam on immature synapses. Using a rodent organotypic hippocampal slice preparation, we evaluated how midazolam affects inhibitory synaptic transmission onto CA1 pyramidal neurons. We found that 1 μM midazolam enhances evoked inhibitory post synaptic currents (eIPSCs) at a holding potential of -60 mV. Similarly, 1 μM midazolam enhances miniature IPSCs (mIPSCs) in CA1 pyramidal neurons at holding potentials of -60 mV and -30 mV. At depolarized holding potentials, however, midazolam no longer enhances mIPSCs. Depolarization of the postsynaptic cell by itself increases mIPSC decay, which occludes the allosteric effects of midazolam. These results provide insight into how a benzodiazepine and membrane voltage may modulate GABA_AR function in developing circuits.

Neonatal Exposure to Anesthesia Leads to Cognitive Deficits in Old Age: Prevention with Intranasal Administration of Insulin in Mice

Recent pre-clinical and clinical studies suggest that general anesthesia in infants and children may increase the risk of learning disabilities. Currently, there is no treatment for preventing anesthesia-induced neurotoxicity and potential long-term functional impairment. Animal studies have shown that neonatal exposure to anesthesia can induce acute neurotoxicity and long-term behavioral changes that can be detected a few months later. It is currently unknown whether neonatal exposure, especially repeated exposures, to general anesthesia can induce or increase the risk for cognitive impairment during aging. Here, we report that repeated exposures of neonatal mice (P7-9 days old) to anesthesia with sevoflurane (3 h/day for 3 days) led to cognitive impairment that was detectable at the age of 18-19 months, as assessed by using novel object recognition, Morris water maze, and fear conditioning tests. The repeated neonatal exposures to anesthesia did not result in detectable alterations in neurobehavioral development, in tau phosphorylation, or in the levels of synaptic proteins in the aged mouse brains. Importantly, we found that treatment with intranasal insulin prior to anesthesia exposure can prevent mice from anesthesia-induced cognitive impairment. These results suggest that neonatal exposure to general anesthesia could increase the risk for cognitive impairment during aging. This study also supports pre-treatment with intranasal administration of insulin to be a simple, effective approach to prevent infants and children from the increased risk for age-related cognitive impairment induced by neonatal exposure to general anesthesia.

Neuroendocrine, epigenetic, and intergenerational effects of general anesthetics

The progress of modern medicine would be impossible without the use of general anesthetics (GAs). Despite advancements in refining anesthesia approaches, the effects of GAs are not fully reversible upon GA withdrawal. Neurocognitive deficiencies attributed to GA exposure may persist in neonates or endure for weeks to years in the elderly. Human studies on the mechanisms of the long-term adverse effects of GAs are needed to improve the safety of general anesthesia but they are hampered not only by ethical limitations specific to human research, but also by a lack of specific biological markers that can be used in human studies to safely and objectively study such effects. The latter can primarily be attributed to an insufficient understanding of the full range of the biological effects induced by GAs and the molecular mechanisms mediating such effects even in rodents, which are far more extensively studied than any other species. Our most recent experimental findings in rodents suggest that GAs may adversely affect many more people than is currently anticipated. Specifically, we have shown that anesthesia with the commonly used GA sevoflurane induces in exposed animals not only neuroendocrine abnormalities (somatic effects), but also epigenetic reprogramming of germ cells (germ cell effects). The latter may pass the neurobehavioral effects of parental sevoflurane exposure to the offspring, who may be affected even at levels of anesthesia that are not harmful to the exposed parents. The large number of patients who require general anesthesia, the even larger number of their future unexposed offspring whose health may be affected, and a growing number of neurodevelopmental disorders of unknown etiology underscore the translational importance of investigating the intergenerational effects of GAs. In this mini review, we discuss emerging experimental findings on neuroendocrine, epigenetic, and intergenerational effects of GAs.

Acetyl-l-carnitine does not prevent neurodegeneration in a rodent model of prolonged neonatal anesthesia

Many studies have shown that prolonged or repeated use of general anesthesia early in life can cause an increase in neurodegeneration and lasting changes in behavior. While short periods of general anesthesia appear to be safe, there is a concern about the neurotoxic potential of prolonged or repeated general anesthesia in young children. Unfortunately, the use of general anesthesia in children cannot be avoided. It would be a great benefit to develop a strategy to reduce or reverse anesthesia mitigated neurotoxicity. The mechanisms behind anesthesia related neurotoxicity are unknown, but evidence suggests that mitochondrial dysfunction and abnormal energy utilization are involved. Recent research suggests that a class of compounds known as carnitines may be effective at preventing anesthesia related neurotoxicity by influencing fatty acid metabolism in the mitochondria. However, it is unknown if carnitines can provide protection against changes in behavior associated with early life exposure to anesthesia. Accordingly, we evaluated the neuroprotective potential of acetyl-l-carnitine in 7-day old rats. Rat pups were exposed to 6 h of general anesthesia with sevoflurane or a control condition, with and without acetyl-l-carnitine. The oxygenation level of animals was continuously monitored during sevoflurane exposure, and any animal showing signs of hypoxia was removed from the study. Animals exposed to sevoflurane showed clear signs of neurodegeneration 2 h after sevoflurane exposure. The hippocampus, cortex, thalamus, and caudate putamen all had elevated levels of Fluoro-Jade C staining. Despite the elevated levels of Fluoro-Jade C, few behavioral changes were observed in an independent cohort of animals treated with sevoflurane. Furthermore, acetyl-l-carnitine had little impact on levels of Fluoro-Jade C staining in animals treated with sevoflurane. These data suggest that acetyl-l-carnitine may offer little protection again anesthesia related neurotoxicity in fully oxygenated animals.

Shockwave lithotripsy for kidney stones as a first-line therapy in children younger than 2 years

BACKGROUND

The incidence of urolithiasis in children has risen worldwide over the last decades with geographical varieties. As pediatric patients begin forming stones earlier in life, they have high risk of recurrence. Extracorporeal shockwave lithotripsy (SWL) is a non-invasive treatment modality that is preferred in the management of pediatric stones. Reports about the safety and efficacy of SWL in patients younger than 24 months are scarce in the literature.

OBJECTIVE

The aim of the study was to evaluate the effectiveness and safety of SWL in patients younger than 24 months. The authors also aimed to assess the validity of the Dogan nomogram in predicting stone-free rates.

STUDY DESIGN

Between January 2009 and March 2019, data of 247 patients younger than 24 months at the time of SWL were retrospectively collected. Analysis was performed on 260 renal units. Success was considered in patients who were completely free of stones after the first session.

RESULTS AND DISCUSSION

The female/male ratio was 103/157, with a median age of 15 (5-24) months, a median stone size of 8 (3-30) mm and a median follow-up period of 7 (3-20) months. Multiple stones and lower calyx stones were observed in 19.6% (51/260) and 23.4% (61/260) of patients, respectively. Complications were detected in 5.8% (15/260) of patients (9 with steinstrasse, 3 with UTI, 2 with vomiting, 1 with hematuria). After the first session, 56.9% (148/260) of patients were stone-free. Forty-six of the failed 112 first sessions underwent second session. A total of 5 patients had a third session. The efficacy quotient was 57%. On univariate analysis, younger age (≤16 months), single stone, small stone size (<10 mm), and non-lower pole location were significant predictors of stone clearance. On multivariate analysis, younger age (=<16 months) and single stone remained significant. The Dogan nomogram score lower than 150 was found to be a good cutoff point to predict better stone clearance (Table).

CONCLUSION

Shockwave lithotripsy is a safe and effective treatment modality in patients younger than 24 months and could be the first option in this particular age-group in whom the other endourological modalities are not always applicable. The Dogan nomogram is reliable in predicting the stone-free rate in this age-group.

Safety of anesthetic exposure on the developing brain - Do we have the answer yet?

During the past two decades, a vast number of studies done on rodents and nonhuman primates have implicated general anesthetic exposure of developing brains in producing neurotoxicity leading to various structural and functional neurological abnormalities with cognitive and behavioral deficits later in life. However, it is still unclear whether these findings translate to children and whether single exposure to anesthesia in childhood can have long-term neuro-developmental risks. Considering the fact that a large number of healthy young children are undergoing elective surgery under general anesthesia globally, any such potential neurocognitive risk of pediatric anesthesia is a serious public health issue and is therefore important to understand. This review aims to assess the current preclinical and clinical evidence related to anesthetic neurotoxicity.

Multiple sevoflurane exposures don't disturb the T-cell receptor repertoire in infant rhesus monkeys' thymus

AIMS

Multiple surgical procedures and anesthesia increase the risk of the development in children. However, the influence of such exposures on the developing childhood immunity organs is rarely reported.

MATERIALS AND METHODS

High-throughput sequencing of T-cell receptor (TCR) repertoires (TCRseq) from rhesus monkeys' thymus was performed to investigate whether anesthetics could induce de novo antigen recognition via TCR or TCR development impairments.

KEY FINDINGS

No significant difference between sevoflurane and control groups regarding VJ gene combinations and diversity of V and J gene was seen, nor was there an obvious change in similar average number of Complementarity Determining Region 3 (CDR3) aa clonotypes. Our analysis of Rank abundance, Gini coefficient, Simpson index, Normalized Shannon Diversity Entropy (NSDE), Morisita-Horn Similarity Index (MHSI) and Bhattacharyya Distance (BD) indicated there is no difference in TCR diversity and similarity.

SIGNIFICANCE

These results suggest early events in thymic T cell development and repertoire generation are not abnormality after multiple sevoflurane exposure during childhood. The stabilization of the immune repertoires suggested the safety of sevoflurane in host immune response in children.

General anesthesia, germ cells and the missing heritability of autism: an urgent need for research

Agents of general anesthesia (GA) are commonly employed in surgical, dental and diagnostic procedures to effectuate global suppression of the nervous system, but in addition to somatic targets, the subject's germ cells-from the embryonic primordial stage to the mature gametes-may likewise be exposed. Although GA is generally considered safe for most patients, evidence has accumulated that various compounds, in particular the synthetic volatile anesthetic gases (SVAGs) such as sevoflurane, can exert neurotoxic, genotoxic and epigenotoxic effects, with adverse consequences for cellular and genomic function in both somatic and germline cells. The purpose of this paper is to review the evidence demonstrating that GA, and in particular, SVAGs, may in some circumstances adversely impact the molecular program of germ cells, resulting in brain and behavioral pathology in the progeny born of the exposed cells. Further, we exhort the medical and scientific communities to undertake comprehensive experimental and epidemiological research programs to address this critical gap in risk assessment.

Assessing Long-term Neurodevelopmental Outcome Following General Anesthesia in Early Childhood: Challenges and Opportunities

Neurodegeneration has been reported in young animals after exposure to all commonly used general anesthetic agents. The brain may be particularly vulnerable to anesthetic toxicity during peak synaptogenesis (in gestation and infancy). Human studies of long-term neurodevelopmental outcome following general anesthesia in early childhood report contradictory findings. This review assesses the strengths and deficiencies in human research methodologies to inform future studies. We identified 76 studies, published between 1990 and 2017, of long-term neurodevelopmental outcome following early childhood or in utero general anesthesia exposure: 49 retrospective, 9 ambidirectional, 17 prospective cohort studies, and 1 randomized controlled trial. Forty-nine studies were explicitly concerned with anesthetic-induced neurotoxicity. Full texts were appraised for methodological challenges and possible solutions. Major challenges identified included delineating effects of anesthesia from surgery, defining the timing and duration of exposure, selection of a surgical cohort and intervention, addressing multiple confounding life course factors, detecting modest neurotoxic effects with small sample sizes (median, 131 children; interquartile range, 50–372), selection of sensitive neurodevelopmental outcomes at appropriate ages for different developmental domains, insufficient length of follow-up (median age, 6 years; interquartile range, 2–12 years), and sample attrition. We discuss potential solutions to these challenges. Further adequately powered, multicenter, prospective randomized controlled trials of anesthetic-induced neurotoxicity in children are required. However, we believe that the inherent methodological challenges of studying anesthetic-induced neurotoxicity necessitate the parallel use of well-designed observational cohort studies.

Does general anesthesia affect neurodevelopment in infants and children?

General anesthesia has been unequivocally linked to abnormal development of the central nervous system, leading to neurocognitive impairments in laboratory models. In vitro and in vivo studies have consistently shown that exposure to GABA agonists (eg, volatile anesthetics, midazolam, and propofol) or NMDA antagonists (eg, ketamine, isoflurane, and nitrous oxide) produces dose dependent and developmental age dependent effects on various neuronal transmission systems. Exposure to these drugs increases neuronal cell death in juvenile animals including rats, mice, and non-human primates. The possibility of anesthetic induced neurotoxicity occurring in children has led to concerns about the safety of pediatric anesthesia. A spectrum of behavioral changes has been documented after general anesthetic exposure in young children, including emergence delirium, which may be evidence of toxicity. Most clinical studies are retrospective; specifics about medications or monitoring are unavailable and many of the outcomes may not be sensitive to detect small neurocognitive deficits. Some of these retrospective studies have shown an association between anesthesia exposure at a young age and neurocognitive deficits, but others have not. Practitioners and families should be reassured that although general anesthetics have the potential to induce neurotoxicity, very little clinical evidence exists to support this.

Human Studies of Anesthesia-Related Neurotoxicity in Children: A Narrative Review of Recent Additions to the Clinical Literature

In 2017, the US Food and Drug Administration warned that exposure to anesthetic medicines for lengthy periods of time or over multiple surgeries may affect brain development in children aged less than 3 years. Since then, the clinical literature continues to find mixed evidence of pediatric anesthesia-related neurotoxicity. However, several new human studies provide strong evidence that a single short exposure to general anesthesia in young children does not cause detectable neurocognitive injury by neuropsychological testing. These newer findings are reassuring, but cannot be extrapolated to children who are deemed to be at highest risk of neurologic injury after anesthesia.

General anesthetic neurotoxicity in the young: Mechanism and prevention

General anesthesia (GA) is usually considered to safely induce a reversible unconscious state allowing surgery to be performed without pain. A growing number of studies, in particular pre-clinical studies, however, demonstrate that general anesthetics can cause neuronal death and even long-term neurological deficits. Herein, we report our literature review and meta-analysis data of the neurological outcomes after anesthesia in the young. We also review available mechanistic and epigenetic data of GA exposure related to cognitive impairment per se and the potential preventive strategies including natural herbal compounds to attenuate those side effects. In summary, anesthetic-induced neurotoxicity may be treatable and natural herbal compounds and other medications may have great potential for such use but warrants further study before clinical applications can be initiated.

Astroglial dysfunctions drive aberrant synaptogenesis and social behavioral deficits in mice with neonatal exposure to lengthy general anesthesia

Lengthy use of general anesthetics (GAs) causes neurobehavioral deficits in the developing brain, which has raised significant clinical concerns such that the United States Food and Drug Administration (FDA) is warning on the use of GAs in children younger than 3 years. However, the molecular and cellular mechanisms for GAs-induced neurotoxicity remain largely unknown. Here, we report that sevoflurane (Sevo), a commonly used GA in pediatrics, caused compromised astrocyte morphogenesis spatiotemporally correlated to synaptic overgrowth, with reduced synaptic function in developing cortex in a regional-, exposure-length-, and age-specific manner. Sevo disrupted astrocyte Ca²⁺ homeostasis both acutely and chronically, which led to the down-regulation of Ezrin, an actin-binding membrane-bound protein, which we found was critically involved in astrocyte morphogenesis in vivo. Importantly, overexpression of astrocyte Ezrin rescued astrocytic and neuronal dysfunctions and fully corrected deficits in social behaviors in developing mice with lengthy Sevo exposure. Our data uncover that, in addition to neurons, astrocytes may represent important targets for GAs to exert toxic effects and that astrocyte morphological integrity is crucial for synaptogenesis and neurological behaviors.

The extended use of general anesthetics can cause neurobehavioral deficits in the developing brain, leading to clinical concerns regarding their use in children younger than 3 years. This study shows that general anesthetics target glial cells to disrupt neural circuit formation in the developing brain, an effect that may underlie the observed learning, cognitive, or emotional deficits.

Pro-Con Debate: Nitrous Oxide for Labor Analgesia

This Pro-Con debate will provide the practitioner with an evidence-based knowledge approach to assist the clinician in determining whether to employ (Pro) or not to employ (Con) this technique in the obstetrical suite for labor analgesia. Nitrous oxide has been used safely in dentistry and medicine for many centuries. However, accumulating preclinical and clinical evidence increasingly suggests previously unrecognized adverse maternal and fetal effects of nitrous oxide, which warrants reconsideration of its use in pregnant women and a more detailed informed consent. Nitrous oxide is associated with metabolic, oxidative, genotoxic, and transgenerational epigenetic effects in animals and humans that may warrant limiting its usefulness in labor. This debate will discuss and review the clinical uses, advantages, and disadvantages of nitrous oxide on occupational effects of nitrous oxide exposure, neuroapoptosis, FDA warning on inhalational anesthetics and the developing brain, research limitations, occupational exposure safety limits, effects on global warming, and potential for diversion.

Neurodevelopmental and Academic Outcomes in Children With Orofacial Clefts: A Systematic Review

CONTEXT

Children with orofacial clefts (OFCs) are reported to have worse neurodevelopmental outcomes than unaffected peers, although study methodologies and findings are highly variable and trends in outcomes by age remain unexplored.

OBJECTIVE

To examine the strength of the evidence and explore trends in neurodevelopment by age.

DATA SOURCES

A systematic review was conducted of studies published from January 1, 1980, through November 3, 2017.

STUDY SELECTION

Studies were independently screened by the authors and included in the review if they met predetermined eligibility criteria: (1) children and/or youth (<25 years) with OFCs were studied, and (2) neurodevelopmental or academic outcomes were included.

DATA EXTRACTION

The authors independently evaluated study quality and extracted outcome data.

RESULTS

Thirty-one studies involving 10 143 patients with OFCs and 2 017 360 controls met eligibility criteria. Although the quality of the studies varied, patients with OFCs consistently performed worse than their peers on neurodevelopmental and academic measures. In infancy, differences were observed on multiple developmental outcomes (eg, cognition, motor skills, and language), and in later childhood and adolescence, differences were manifest on several indicators of academic achievement (eg, use of special education services, grades, and scores on standardized measures).

LIMITATIONS

Heterogeneity in study designs, methods, and outcomes prevented statistical pooling and modeling for meta-analysis.

CONCLUSIONS

Children with OFCs exhibit neurodevelopmental and academic deficits compared with their unaffected peers. Although the nature of these deficits changes with development, differences are observed from infancy through adolescence. Clinicians should monitor neurodevelopment in children with OFCs and support them appropriately.

Sedation and the Food and Drug Administration Warning: What a Pediatric Gastroenterologist, Hepatologist, and Pancreatologist Should Know

Pediatric gastroenterologists recommend and perform a range of procedures requiring sedation and anesthesia in young children. A recent warning from the US Food and Drug Administration (FDA) states that "repeated or lengthy use of general anesthetics and sedation drugs during surgeries or procedures in children younger than 3 years or in pregnant women during their third trimester may affect the development of children's brains." 1 As it relates to time, the FDA warning details risks of "procedures lasting longer than 3 hours or if multiple procedures are required." Pediatric gastroenterologists and related specialists should be aware of the warning and its relevance to their patients.

Developmental neurotoxicity in the context of multiple sevoflurane exposures: Potential role of histone deacetylase 6

Animal studies have demonstrated that multiple exposures to sevoflurane during the postnatal period lead to impaired synaptogenesis and cognitive deficits in adulthood. However, the underlying mechanisms remain unclear. Histone deacetylase 6 (HDAC6), a unique isoform of class II histone deacetylases (HDACs), mediates diverse cellular processes such as cell survival, inflammation, intracellular trafficking and protein degradation. Varieties of literature suggest the importance of HDAC6 in memory formation and abnormal neurodegenerative diseases. The aim of this study was to investigate potential roles of HDAC6 in sevoflurane-induced developmental neurotoxicity. Postnatal day 7 (P7) rat pups were randomly assigned to control group and sevoflurane group (n = 6 for each group). They were exposed to 60% oxygen and 40% nitrogen with or without 3% sevoflurane for 2 h daily for three consecutive days (P7, P8 and P9). Immediately after the last exposure, both hippocampi were harvested for detection of HDAC6 expression and activity. Next, P7 rat pups were divided into control group, sevoflurane group, sevoflurane + Tubastatin A, and Tubastatin A groups (n = 6 for each group in molecular experiments; n = 16 for each group in behavioral testing). A dose of 25 mg/kg body weight of Tubastatin A (a selective HDAC6 inhibitor) were administrated intraperitoneally 30 min prior to each sevoflurane exposure. After treatments, expression levels of synaptophysin and postsynaptic density 95 protein (PSD95) were quantified using Western blot, and synaptic ultrastructure was evaluated by transmission electron microscopy. Additional pups were raised until P49 to measure cognitive performance using the Morris water maze test. Our results demonstrated that multiple sevoflurane exposures enhanced HDAC6 expression and activity in hippocampi of the developing brain. Tubastatin A ameliorated sevoflurane-induced decreases in synaptophysin and PSD95 expression during development, as well as synaptic ultrastructural damage and cognitive deficits in adulthood. In conclusion, HDAC6 is involved in the developmental neurotoxicity caused by multiple sevoflurane exposures and its inhibition may prevent related damage.

Anesthetics: from modes of action to unconsciousness and neurotoxicity

Modern anesthetic compounds and advanced monitoring tools have revolutionized the field of medicine, allowing for complex surgical procedures to occur safely and effectively. Faster induction times and quicker recovery periods of current anesthetic agents have also helped reduce health care costs significantly. Moreover, extensive research has allowed for a better understanding of anesthetic modes of action, thus facilitating the development of more effective and safer compounds. Notwithstanding the realization that anesthetics are a prerequisite to all surgical procedures, evidence is emerging to support the notion that exposure of the developing brain to certain anesthetics may impact future brain development and function. Whereas the data in support of this postulate from human studies is equivocal, the vast majority of animal research strongly suggests that anesthetics are indeed cytotoxic at multiple brain structure and function levels. In this review, we first highlight various modes of anesthetic action and then debate the evidence of harm from both basic science and clinical studies perspectives. We present evidence from animal and human studies vis-à-vis the possible detrimental effects of anesthetic agents on both the young developing and the elderly aging brain while discussing potential ways to mitigate these effects. We hope that this review will, on the one hand, invoke debate vis-à-vis the evidence of anesthetic harm in young children and the elderly, and on the other hand, incentivize the search for better and less toxic anesthetic compounds.

17β-Estradiol Treatment Attenuates Neurogenesis Damage and Improves Behavior Performance After Ketamine Exposure in Neonatal Rats

Ketamine exposure disturbed normal neurogenesis in the developing brain and resulted in subsequent neurocognitive deficits. 17β-estradiol provides robust neuroprotection in a variety of brain injury models in animals of both sexes and attenuates neurodegeneration induced by anesthesia agents. In the present study, we aimed to investigate whether 17β-estradiol could attenuate neonatal ketamine exposure-disturbed neurogenesis and behavioral performance. We treated 7-day-old (Postnatal day 7, PND 7) Sprague-Dawley rats and neural stem cells (NSCs) with either normal saline, ketamine, or 17β-estradiol before/after ketamine exposure, respectively. At PND 14, the rats were decapitated to detect neurogenesis in the subventricular zone (SVZ) and subgranular zone (SGZ) of the hippocampus by immunofluorescence staining. The proliferation, neuronal differentiation, and apoptosis of NSCs were assessed by immunohistochemistry method and TUNEL assay, respectively. The protein levels of cleaved caspase-3 in vivo in addition to GSK-3β and p-GSK-3β in vitro were examined by western blotting. Spatial learning and memory abilities were assessed by Morris water maze (MWM) test at PND 42–47. Ketamine exposure decreased cell proliferation in the SVZ and SGZ, inhibited NSC proliferation and neuronal differentiation, promoted NSC apoptosis and led to adult cognitive deficits. Furthermore, ketamine increased cleaved caspase-3 in vivo and decreased the expression of p-GSK-3β in vitro. Treatment with 17β-estradiol could attenuate ketamine-induced changes both in vivo and in vitro. For the first time we showed that 17β-estradiol alleviated ketamine-induced neurogenesis inhibition and cognitive dysfunction in the developing rat brain. Moreover, the protection of 17β-estradiol was associated with GSK-3β.

Spinal Anesthesia for Pediatric Laparoscopic Hernia Repair: A Case Report

Spinal anesthesia is practical and safe in infants and toddlers and prevents perioperative complications including cardiorespiratory instability and apnea. Other perioperative advantages include reduced time from surgery completion to operating room exit and first feed. This article presents the case of an ex-premature infant who underwent laparoscopic inguinal hernia repair under spinal anesthesia. The infant remained calm and stable throughout the uneventful procedure and postoperative period. Spinal anesthesia may be feasible for laparoscopic herniotomy when pneumoperitoneum pressure and operative time are restricted to 8 mm Hg and 60 minutes, respectively, with sensory level at T10 or higher.

Disrupted folate metabolism with anesthesia leads to myelination deficits mediated by epigenetic regulation of ERMN

Background

Exposure to anesthetics during early life may impair cognitive functions. However, the underlying mechanisms remain largely unknown. We set out to determine effects of sevoflurane anesthesia on folate metabolism and myelination in young non-human primates, mice and children.

Methods

Young rhesus macaque and mice received 2.5 to 3% sevoflurane daily for three days. DNA and RNA sequencing and immunohistochemistry among others were used in the studies. We performed unbiased transcriptome profiling in prefrontal cortex of rhesus macaques and mice after the sevoflurane anesthesia. We constructed a brain blood barrier-crossing AAV-PHP.EB vector to harbor ERMN expression in rescue studies. We measured blood folate levels in children after anesthesia and surgery.

Findings

We found that thymidylate synthase (TYMS) gene was downregulated after the sevoflurane anesthesia in both rhesus macaque and mice. There was a reduction in blood folate levels in children after the anesthesia and surgery. Combined with transcriptome and genome-wide DNA methylation analysis, we identified that ERMN was the primary target of the disrupted folate metabolism. Myelination was compromised by the anesthesia in the young mice, which was rescued by systematic administration of folic acid or expression of ERMN in the brain through brain-specific delivery of the adeno-associated virus. Moreover, folic acid and expression of ERMN alleviated the cognitive impairment caused by the sevoflurane anesthesia in the mice.

Interpretation

General anesthesia leads to disrupted folate metabolism and subsequently defects in myelination in the developmental brain, and ERMN is the important target affected by the anesthesia via epigenetic mechanisms.