Anesthesia and cognitive performance in children: no evidence for a causal relationship

Effects of Cohabitation on Neurodevelopmental Outcomes in Rats Discordant for Neonatal Exposure to Sevoflurane

Background

Having a sibling with autism spectrum disorder is a risk factor for autism spectrum disorder. We used a rat model in which the general anesthetic sevoflurane (SEVO) induces autism spectrum disorder-like neurodevelopmental abnormalities to test whether they can be transmitted via cohabitation.

Methods

Male rat pups from several litters were mixed and randomized to 3 new litter types: SEVO-exposed (SEVO), SEVO-unexposed (control), and equal numbers of SEVO-exposed and SEVO-unexposed (MIXED). After weaning, rats in experiment 1 were housed with littermates in SEVO, control, and MIXED (MIXED-exposed and MIXED-unexposed) pairs. In experiment 2, MIXED-exposed and MIXED-unexposed rats were paired with an unfamiliar naïve cagemate. Corticosterone levels, gene expression, central inflammatory markers (experiment 1), and behavior and corticosterone levels (experiment 2) were assessed in adulthood.

Results

In experiment 1, compared with control rats, SEVO rats exhibited abnormalities in the hypothalamic-pituitary-adrenal axis, inflammatory markers, oxytocin, arginine vasopressin, and DNA methylation systems. Almost all these measures in MIXED-exposed and MIXED-unexposed rats were statistically indistinguishable from and similar to those in SEVO or control rats, with most measures in MIXED rats being similar to those in SEVO rats. Experiment 2 showed that pairing with unfamiliar, naïve rats after weaning caused MIXED-unexposed and MIXED-exposed rats' behavior to be no different from that of control and SEVO rats, respectively; however, the 2 groups of MIXED rats also did not differ from each other.

Conclusions

These findings suggest that neurodevelopmental abnormalities can be transmitted to otherwise healthy individuals through interactions during cohabitation; however, subsequent pairing with unfamiliar, naïve cohabitants may weaken this interaction effect.

Current anesthesia practice for preterm infants undergoing surgery for necrotizing enterocolitis: A European survey

STUDY OBJECTIVE

Necrotizing enterocolitis (NEC) is a life-threatening intestinal illness mostly affecting preterm infants, which commonly requires surgery. Anesthetic care for these patients is challenging, due to their prematurity and critical illness with hemodynamic instability. Currently, there are no guidelines for anesthetic care for these vulnerable patients. Therefore, this study aimed to describe current anesthesia practices across Europe for infants undergoing surgery for NEC.

DESIGN

Cross-sectional survey study.

PARTICIPANTS

Anesthesiologists working in centers where surgery for NEC is performed across Europe.

MEASUREMENTS

A 46-item questionnaire assessing protocols for anesthesia practice, preoperative care, intraoperative care, postoperative care, and the respondent's opinion on the adequacy of anesthetic care for patients with NEC in their center.

MAIN RESULTS

Out of the 173 responding anesthesiologists from 31 countries, approximately a third had a written standard protocol for anesthetic care in infants. Three quarters of the respondents screened all patients with NEC preoperatively, and a third structurally performed preoperative multidisciplinary consultation. For induction of general anesthesia, most respondents opted for intravenous anesthesia (n = 73, 43%) or a combination of intravenous and inhalation anesthesia (n = 57, 33%). For intravenous induction, they mostly used propofol (n = 58, 44%), followed by midazolam (n = 43, 33%) and esketamine (n = 42, 32%). For maintenance of anesthesia, inhalation anesthetic agents were more commonly used (solely: n = 71, 41%; in combination: n = 37, 22%), almost exclusively with sevoflurane. Postoperative analgesics mainly included paracetamol and/or morphine. Sixty percent of the respondents (n = 104) considered their anesthetic care for patients with NEC adequate. Suggestions for further improvement mainly revolved around monitoring, protocols, and collaboration.

CONCLUSIONS

Anesthesia practice for infants undergoing surgery for NEC was highly variable. Most respondents considered the provided anesthetic care for patients with NEC adequate, but also recognized opportunities for further improvement, especially with regards to monitoring, protocols, and interdisciplinary collaboration.

Early Findings of a Preterm Twin Cohort Study Examining the Effect of General Anesthesia on Developmental Outcomes

PURPOSE

The premature infant brain may be particularly vulnerable to anesthesia effects, but there is conflicting evidence on the association between anesthesia exposure and developmental outcomes. Twin studies can control for confounding factors. A twin cohort of premature twins provides internal control of difficulty to measure confounders and delivers added power to a study examining the effects of anesthesia on neurodevelopmental outcomes.

METHODS

We conducted a retrospective cohort study of sets of premature twins and multiples born at an academic medical center, in which 1 member of the set was exposed to general anesthesia. The primary outcome was the composite scores using Bayley Scale of Infant and Toddler Development III performed at age 6 months to 18 months. Unpaired and paired analyses were performed with linear regression models, Wilcoxon signed rank test, and Mann-Whitney U test.

RESULTS

We identified 81 children born at less than 32 weeks gestation within 39 sets of twins and 1 set of triplets for a total of 18 paired observations. All of the exposed infants had a single exposure to general anesthesia. There was no significant association between anesthesia exposure and a diagnosis of developmental delay (OR = 0.8; 95% confidence interval, 0.2-3.2; p = 0.99). Regression models demonstrated no association between anesthesia exposure and cognitive (96.67 vs 97.50; p = 0.74), language (98.33 vs 98.61; p = 0.94), or motor (96.25 vs 96.44; p = 0.91) composite Bayley scores. There was no association between duration of anesthesia and the 3 composite Bayley scores ( p = 0.33; p = 0.40; p = 0.74).

CONCLUSION

Using a premature twin cohort with discordant exposure to anesthesia, our data did not demonstrate any association between anesthesia exposure and developmental delay in this vulnerable population of premature infants.

The Role of Intravenous Anesthetics for Neuro: Protection or Toxicity?

The primary intravenous anesthetics employed in clinical practice encompass dexmedetomidine (Dex), propofol, ketamine, etomidate, midazolam, and remimazolam. Apart from their established sedative, analgesic, and anxiolytic properties, an increasing body of research has uncovered neuroprotective effects of intravenous anesthetics in various animal and cellular models, as well as in clinical studies. However, there also exists conflicting evidence pointing to the potential neurotoxic effects of these intravenous anesthetics. The role of intravenous anesthetics for neuro on both sides of protection or toxicity has been rarely summarized. Considering the mentioned above, this work aims to offer a comprehensive understanding of the underlying mechanisms involved both in the central nerve system (CNS) and the peripheral nerve system (PNS) and provide valuable insights into the potential safety and risk associated with the clinical use of intravenous anesthetics.

A systematic review on safety and surgical and anesthetic risks of elective abdominal laparoscopic surgery in infants to guide laparoscopic ovarian tissue harvest for fertility preservation for infants facing gonadotoxic treatment

Background

Infertility is an important late effect of childhood cancer treatment. Ovarian tissue cryopreservation (OTC) is established as a safe procedure to preserve gonadal tissue in (pre)pubertal girls with cancer at high risk for infertility. However, it is unclear whether elective laparoscopic OTC can also be performed safely in infants <1 year with cancer. This systematic review aims to evaluate the reported risks in infants undergoing elective laparoscopy regarding mortality, and/or critical events (including resuscitation, circulatory, respiratory, neurotoxic, other) during and shortly after surgery.

Methods

This systematic review followed the Preferred reporting Items for Systematic Review and Meta-Analyses (PRISMA) reporting guideline. A systematic literature search in the databases Pubmed and EMbase was performed and updated on February 15th, 2023. Search terms included 'infants', 'intubation', 'laparoscopy', 'mortality', 'critical events', 'comorbidities' and their synonyms. Papers published in English since 2000 and describing at least 50 patients under the age of 1 year undergoing laparoscopic surgery were included. Articles were excluded when the majority of patients had congenital abnormalities. Quality of the studies was assessed using the QUIPS risk of bias tool.

Results

The Pubmed and Embase databases yielded a total of 12,401 unique articles, which after screening on title and abstract resulted in 471 articles to be selected for full text screening. Ten articles met the inclusion criteria for this systematic review, which included 1778 infants <1 years undergoing elective laparoscopic surgery. Mortality occurred once (death not surgery-related), resuscitation in none and critical events in 53/1778 of the procedures.

Conclusion

The results from this review illustrate that morbidity and mortality in infants without extensive comorbidities during and just after elective laparoscopic procedures seem limited, indicating that the advantages of performing elective laparoscopic OTC for infants with cancer at high risk of gonadal damage may outweigh the anesthetic and surgical risks of laparoscopic surgery in this age group.

Readability, Content, and Quality of Online Patient Education Materials on Anesthesia and Neurotoxicity in the Pediatric Population

OBJECTIVE

Internet-based patient education materials (PEMs) are often above the recommended sixth grade reading level recommended by the U.S. Department of Health and Human Services. In 2016 the U.S. Food and Drug Administration (FDA) released a warning statement against use of general anesthetic drugs in children and pregnant women due to concerns about neurotoxicity. The aim of this study is to evaluate readability, content, and quality of Internet-based PEMs on anesthesia in the pediatric population and neurotoxicity.

STUDY DESIGN

The websites of U.S. medical centers with pediatric anesthesiology fellowship programs were searched for PEMs pertaining to pediatric anesthesia and neurotoxicity. Readability was assessed. PEM content was evaluated using matrices specific to pediatric anesthesia and neurotoxicity. PEM quality was assessed with the Patient Education Material Assessment Tool for Print. A one-sample t-test was used to compare the readability of the PEMs to the recommended sixth grade reading level.

RESULTS

We identified 27 PEMs pertaining to pediatric anesthesia and eight to neurotoxicity. Mean readability of all PEMs was greater than a sixth grade reading (p <0.001). While only 13% of PEMs on anesthesia for pediatric patient mentioned the FDA warning, 100% of the neurotoxicity materials did. PEMs had good understandability (83%) and poor actionability (60%).

CONCLUSION

The readability, content, and quality of PEMs are poor and should be improved to help parents and guardians make informed decisions about their children's health care.

KEY POINTS

· The FDA issued a warning statement against the use of general anesthetic drugs in children and pregnant women.. · Readability, content, and quality of Internet-based patient education materials on the topic of neurotoxicity are poor.. · Improving the readability, content, and quality of PEMs could aid parents in making important health care decisions..

Comparison of Morphometric Outcomes following Open Posterior Expansion versus Endoscopic Strip Craniectomy for Sagittal Synostosis

BACKGROUND

Open middle and posterior cranial vault expansion (OPVE) or endoscopic (ES) strip craniectomy are two surgical techniques for normalization of head shape in isolated sagittal synostosis. This study aims to compare 2-year cranial morphometrics after these two approaches.

METHODS

The authors performed morphometric analysis on preoperative [time (T) 0], immediately postoperative (T1), and 2-year (T2) postoperative computed tomographic scans of patients who underwent OPVE or ES before 4 months of age. Perioperative data and morphometrics were compared between the two groups and age-matched controls.

RESULTS

Nineteen patients were included in the ES cohort, 19 age-matched patients were included in the OPVE cohort, and 57 were included as controls. Median surgery time and blood transfusion volume were less for the ES approach (118 minutes and 0 cc, respectively) compared with OPVE (204 minutes and 250 cc, respectively). Anthropometric measurements after OPVE were closer in normal controls at T1 compared with ES, but the skull shapes were comparable at T2. In the midsagittal plane, anterior vault was higher after OPVE at T2 compared with both ES and controls, but the posterior length was shorter and closer to controls than in the ES cohort. Cranial volumes were like controls for both cohorts at T2. There was no difference in complication rate.

CONCLUSIONS

Both OPVE and ES techniques result in normalization of cranial shape in patients with isolated sagittal synostosis after 2 years with minimal morphometric differences. Family decision-making between the two approaches should be based on age at presentation, avoidance of blood transfusion, scar pattern, and availability of helmet molding and not on expected outcome.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

A Scoping Review of the Mechanisms Underlying Developmental Anesthetic Neurotoxicity

Although anesthesia makes painful or uncomfortable diagnostic and interventional health care procedures tolerable, it may also disrupt key cellular processes in neurons and glia, harm the developing brain, and thereby impair cognition and behavior in children. Many years of studies using in vitro, animal behavioral, retrospective database studies in humans, and several prospective clinical trials in humans have been invaluable in discerning the potential toxicity of anesthetics. The objective of this scoping review was to synthetize the evidence from preclinical studies for various mechanisms of toxicity across diverse experimental designs and relate their findings to those of recent clinical trials in real-world settings.

General Surgery During Pregnancy and Gynecologic Emergencies

Nonobstetrical surgical emergencies can occur throughout pregnancy but are often difficult to diagnose due to the physiologic and anatomical changes that occur during pregnancy. Medical providers should have insight into these changes and be familiar with options for the diagnosis and management of common nonobstetrical surgical emergencies, such as appendicitis, cholecystitis, and small bowel obstruction. Surgeons should also be aware of obstetrical emergencies, such as ectopic pregnancy and severe vaginal bleeding, which may be life threatening to mother and the fetus. Intraoperatively, surgeons should be familiar with minimally invasive approaches for surgical diseases and special anesthetic considerations for pregnant patients.

Spinal versus general anesthesia: Comparing outcomes in pediatric patients undergoing urologic procedures

INTRODUCTION

Available literature comparing spinal anesthesia (SA) to general anesthesia (GA) in the pediatric population describes multiple benefits in appropriately selected patients including cost reduction, lower incidence of complications, and shorter operative times. In patients undergoing urologic procedures, data are sparse.

OBJECTIVE

Our goal was to expand on the paucity of existing urologic literature as SA appears to be uniquely suited for a substantial number of its common pediatric procedures.

METHODS

Within a single institution, patients who had a urologic procedure performed under SA between May 2019 and July 2021 and were less than 18 months old were compared with a matched cohort of patients who had GA. The SA and GA groups were compared by two-sample t-tests, chi-square test for independence, and Fisher's exact test.

RESULTS

There were a total of 184 SA and 202 GA patients. There was no significant difference in the demographics except that SA patients were younger and weighed less than GA patients. The patients in the SA group needed less opioids both during the surgery (0% vs 26.1% p N/A) and in the immediate postoperative period when compared with GA patients (0% vs 18.2% p N/A). The patients who had SA had fewer complications necessitating PICU admission, or cancellation of surgery (0% vs 6.8% p = 0.03). Total anesthesia and emergence time were lower for SA patients (41 vs 50.2 p = 0.001 & 3.4 vs 6.1 p = 0.001). Both surgery and total OR time were not different between the groups (37.6 vs 35.5 p = 0.35 and 56.3 vs 54.4 p = 0.49). Overall, raw material cost was also found to be lower per procedure in the SA group vs the GA group ($8.90 vs $38.8: 77% reduction). Adjusted total mean costs for the surgery were not different between groups. The reduction in opioid use postoperatively also suggests reduced cost in the management of postoperative pain in the SA group.

DISCUSSION

Total anesthesia time, opioid use, and serious complications were all significantly lower in the SA group. We did not find significant difference in total surgery cost between two groups. However, patients who had SA had better pain control and needed less rescue analgesics in the immediate postoperative period. No patients in either group were sent home with opioids.

CONCLUSION

Spinal anesthesia was found to be an equally effective and appropriate alternative to GA with many proposed benefits for common pediatric urologic procedures. With further research, SA may prove to be a safer alternative in patients at risk for complications related to GA general anesthesia while also offering a cost benefit.

Effects of anesthesia exposure on postnatal maturation of white matter in rhesus monkeys

There is increasing concern about the potential effects of anesthesia exposure on the developing brain. The effects of relatively brief anesthesia exposures used repeatedly to acquire serial magnetic resonance imaging scans could be examined prospectively in rhesus macaques. We analyzed magnetic resonance diffusion tensor imaging (DTI) of 32 rhesus macaques (14 females, 18 males) aged 2 weeks to 36 months to assess postnatal white matter (WM) maturation. We investigated the longitudinal relationships between each DTI property and anesthesia exposure, taking age, sex, and weight of the monkeys into consideration. Quantification of anesthesia exposure was normalized to account for variation in exposures. Segmented linear regression with two knots provided the best model for quantifying WM DTI properties across brain development as well as the summative effect of anesthesia exposure. The resulting model revealed statistically significant age and anesthesia effects in most WM tracts. Our analysis indicated there were major effects on WM associated with low levels of anesthesia even when repeated as few as three times. Fractional anisotropy values were reduced across several WM tracts in the brain, indicating that anesthesia exposure may delay WM maturation, and highlight the potential clinical concerns with even a few exposures in young children.

Eye-related quality of life and activities of daily living in pediatric retinoblastoma patients: A single-center, non-controlled, cross-sectional analysis

INTRODUCTION

Childhood retinoblastoma (RB) survivors are known to experience long-term morbidity; however, eye-related quality of life (QoL), which may significantly impact activities of daily living (ADL), has not been extensively studied in this population. The purpose of this cross-sectional study was to assess QoL and ADL morbidity among school-age RB survivors.

METHODS

The Pediatric Eye Questionnaire (PedEyeQ) and Roll Evaluation Activities of Life (REAL) were administered to childhood RB survivors between ages 5 and 17 followed at St. Louis Children's Hospital. Visual outcomes and demographic predictors of ADL and QoL were examined.

RESULTS

Total 23 patients (mean age 9.6 years) consented for participation in this study. All children experienced at least one domain on the PedEyeQ ≤ 80%. Subjects and parents marked functional vision to be the most impacted domain with a median score of 82.5 and 83.4, respectively. Only 10.5% of participants scored above 75% on the ADL percentile rank. On multivariable analysis, decreased visual acuity (VA) was associated with worse "Child Functional" (odds ratio [OR] -59.2, p = .004) and "Parent Worry Function" (OR -66.5, p = .03) metrics. Decreased contrast sensitivity was associated with worse "Parent Impact" (OR 21.0, p = .02) and "Parent Worry Function" (OR 3.70, p = .04) metrics. Longer saccade horizontal latency was associated with a worse "Parent Worry Function" metric (OR 43.0, p = .009). On multivariable analysis, no variable was significantly associated with ADL.

CONCLUSION

RB survivors have impaired QoL and ADL. Screening for such difficulties should strongly be considered for all RB patients. Additional studies may help predict morbidity based on visual metrics and demographic data.

Long-term neurocognitive outcomes after pediatric intensive care: exploring the role of drug exposure

BACKGROUND

Concerns exist regarding the impact of widely used clinical drugs on brain development. This study investigates long-term neurocognitive functioning in relation to frequently used drug exposure at the Pediatric Intensive Care Unit (PICU).

METHODS

This study compared children aged 6-12 years with previous PICU admission (age ≤1 year) for bronchiolitis requiring mechanical ventilation (patient group, n = 65) to a demographically comparable control group (n = 76) on a broad range of neurocognitive outcomes. The patient group was selected because bronchiolitis seldom manifests neurologically and is therefore not expected to affect neurocognitive functioning in itself. The relation between exposure to sedatives, analgesics and anesthetics and neurocognitive outcomes was assessed by regression analyses.

RESULTS

The patient group had lower intelligence than the control group (p < 0.001, d = -0.59) and poorer performance in neurocognitive functions; i.e., speed and attention (p = 0.03, d = -0.41) and verbal memory (p < 0.001, d = -0.60). Exposure to sedatives, analgesics and anesthetics was not related to neurocognitive outcomes.

CONCLUSIONS

Children with PICU admission for bronchiolitis requiring mechanical ventilation are at risk of adverse neurocognitive outcomes. This study found no evidence for a role of exposure to sedatives, analgesics or anesthetics. Findings underline the importance of long-term follow-up after PICU admission, even in the absence of disease with neurological manifestation.

IMPACT

Animal studies have indicated that exposing the maturing brain to clinical drugs may cause neurodegeneration. Clinical studies show mixed evidence regarding the association between clinical drugs and neurocognitive outcomes. This study provides evidence for considerably lower neurocognitive functioning among children with a history of PICU admission for bronchiolitis compared to healthy peers. Bronchiolitis seldom manifests neurologically and is therefore not expected to affect neurocognitive functioning in itself. We found no evidence supporting a relation between drug exposure (i.e., sedatives, analgesics and anesthetics) and long-term neurocognitive outcomes. Findings underline the importance of structured follow-up after PICU admission.

General anesthesia in early childhood and possible association with autism: a population-based matched cohort study

BACKGROUND

In experimental animal studies, exposure to general anesthesia in early childhood may results in changes in infant brain morphology and behavior, potentially leading to the development of autistic behaviors in the long-term. However, in clinical studies the role of exposure to general anesthesia in early childhood and the risk of autism is unknown.

METHODS

This is a population-based cohort study including all children aged 0-5 years of age exposed to general anesthesia between 2001 and 2014 and a corresponding matched population without such an exposure. Propensity score calculation was based on 49 variables (including age of parents, malformations, APGAR Score, and family income, among others). Quasi-Poisson regression was used to estimate risk ratios (RRs) with 95% confidence intervals (CIs) for the association between exposure to general anesthesia and autism or autism spectrum disorder.

RESULTS

In total, 401,750 children exposed to general anesthesia were compared with 1,187,796 unexposed individuals. Autism or autism spectrum disorder were more common in the children exposed to general anesthesia as compared to unexposed children (1.65% and 0.98%, respectively, P<0.01). There was a statistically significant higher risk of autism or autism spectrum disorder in children exposed to general anesthesia as compared to unexposed children also after propensity score adjustment (RR 1.62, 95% CI: 1.57-1.67).

CONCLUSIONS

Exposure to general anesthesia in early childhood was associated with an increased risk of autism or autism spectrum disorder. Future studies are needed to asses if general anesthesia may cause autism or if the association is due to other factors.

The risk of autism spectrum disorder and intellectual disability but not attention deficit/hyperactivity disorder is increased in individuals with esophageal atresia

Knowledge of neurodevelopmental disorders such as attention deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASD) and intellectual disability (ID) in patients with esophageal atresia (EA) is scarce. The aims of this study were to investigate the prevalence and risk of ADHD, ASD and ID in individuals with EA. Data were obtained from four longitudinal population-based registries in Sweden and analyzed using Cox proportional hazards regression. Patients with EA born in Sweden in 1973-2018 were included together with five controls for each individual with the exposure matched on sex, gestational age at birth, birth year and birth county. Individuals with chromosomal aberrations and syndromes were excluded. In total, 735 individuals with EA and 3675 controls were included. Median age at time of the study was 20 years (3-48). ASD was found in 24 (3.9%), ADHD in 34 (5.5%) and ID in 28 (4.6%) individuals with EA. Patients with EA had a 1.66 times higher risk of ASD (95% confidence interval [CI], 1.05-2.64) and a 3.62 times higher risk of ID (95% CI, 2.23-5.89) compared with controls. The risk of ADHD was not significantly increased. ADHD medication had been prescribed to 88.2% of patients with EA and ADHD and to 84.5% of controls with ADHD. Individuals with EA have a higher risk of ASD and ID than individuals without the exposure. These results are important when establishing follow-up programs for children with EA to allow timely detection and consequentially an earlier treatment and support especially before school start.

Quantity and duration of exposure to general anesthesia for pediatric patients with retinoblastoma

PURPOSE

To quantify the duration of anesthesia required for optimal management of retinoblastoma (Rb), stratified by clinical factors.

METHODS

The medical records of Rb patients treated at Phoenix Children's Hospital between January 2011 and January 2022 were reviewed retrospectively. Demographic, tumor, and treatment data were collected. Anesthesia time was recorded for procedures requiring general anesthesia, including intra-arterial chemotherapy (IAC), enucleation, brainstem auditory evoked response testing (BAER), port placement, magnetic resonance imaging (MRI), and examination under anesthesia (EUA). Descriptive statistics were used to summarize patient and clinical characteristics.

RESULTS

Total anesthesia time was 48,991 minutes for 610 procedures in 43 patients. The median follow-up time was 36 months (range, 12-114 months). Average anesthetic durations per exposure were 274, 152, 81.8, 62.5, 60.7, and 45 minutes for IAC, enucleation, BAER, port placement, MRI, and EUA, respectively. Patients with bilateral Rb underwent a median of 1,659 minutes of total anesthesia, compared with 397 minutes for those with unilateral disease. In patients with unilateral Rb, median total anesthesia time was 2,651, 1681, 312, 397 minutes for International Classification of Retinoblastoma grades B, C, D, and E tumors, respectively. Patients who received IAC as their primary treatment had the highest median anesthesia duration (2,100 minutes), followed by systemic chemo (654 minutes) and enucleation (289 minutes).

CONCLUSIONS

Treatment of Rb requires prolonged and repeated exposure to general anesthesia. Future studies are required to determine the potential effects of these childhood anesthetic exposures.

General anesthesia in children and long-term neurodevelopmental deficits: A systematic review

Background

Millions of children experienced surgery procedures requiring general anesthesia (GA). Any potential neurodevelopmental risks of pediatric anesthesia can be a serious public health issue. Various animal studies have provided evidence that commonly used GA induced a variety of morphofunctional alterations in the developing brain of juvenile animals.

Methods

We conducted a systematic review to provide a brief overview of preclinical studies and summarize the existing clinical studies. Comprehensive literature searches of PubMed, EMBASE, CINAHL, OVID Medline, Web of Science, and the Cochrane Library were conducted using the relevant search terms “general anesthesia,” “neurocognitive outcome,” and “children.” We included studies investigating children who were exposed to single or multiple GA before 18, with long-term neurodevelopment outcomes evaluated after the exposure(s).

Results

Seventy-two clinical studies originating from 18 different countries published from 2000 to 2022 are included in this review, most of which are retrospective studies (n = 58). Two-thirds of studies (n = 48) provide evidence of negative neurocognitive effects after GA exposure in children. Neurodevelopmental outcomes are categorized into six domains: academics/achievement, cognition, development/behavior, diagnosis, brain studies, and others. Most studies focusing on children &lt;7 years detected adverse neurocognitive effects following GA exposure, but not all studies consistently supported the prevailing view that younger children were at greater risk than senior ones. More times and longer duration of exposures to GA, and major surgeries may indicate a higher risk of negative outcomes.

Conclusion

Based on current studies, it is necessary to endeavor to limit the duration and numbers of anesthesia and the dose of anesthetic agents. For future studies, we require cohort studies with rich sources of data and appropriate outcome measures, and carefully designed and adequately powered clinical trials testing plausible interventions in relevant patient populations.

Long-term cognitive and behavioral outcomes following early exposure to general anesthetics

PURPOSE OF REVIEW

Nearly 100 clinical studies have been published evaluating neurodevelopmental outcomes in children following surgery and anesthesia. These studies have reported mixed results, likely attributable at least in part to significant heterogeneity in their study designs, types and numbers of exposures, patient populations evaluated, and most importantly, the outcomes that were assessed. This review aims to summarize the results from clinical studies evaluating behavioral outcomes in children exposed to surgery and anesthesia.

RECENT FINDINGS

Children with early exposure to surgery and anesthesia were found to have limited to no differences in intelligence when compared with unexposed children. However, several studies have reported more behavioral problems in children exposed to general anesthesia. An increased incidence of attention-deficit hyperactivity disorder has also been reported in anesthetic exposed children, particularly after multiple exposures.

SUMMARY

Nearly all clinical studies of anesthetic neurotoxicity are observational in nature, so the associations between anesthetic exposure and behavioral deficits cannot yet be directly attributed to the anesthetic medication. However, the finding of deficits in some neurodevelopmental domains and not others will help guide the selection of appropriate outcomes in future studies of anesthetic neurotoxicity that can further evaluate whether anesthetic medications have an impact on neurodevelopment in children.

Safety of general anaesthetics on the developing brain: are we there yet?

Thirty years ago, neurotoxicity induced by general anaesthetics in the developing brain of rodents was observed. In both laboratory-based and clinical studies, many conflicting results have been published over the years, with initial data confirming both histopathological and neurodevelopmental deleterious effects after exposure to general anaesthetics. In more recent years, animal studies using non-human primates and new human cohorts have identified some specific deleterious effects on neurocognition. A clearer pattern of neurotoxicity seems connected to exposure to repeated general anaesthesia. The biochemistry involved in this neurotoxicity has been explored, showing differential effects of anaesthetic drugs between the developing and developed brains. In this narrative review, we start with a comprehensive description of the initial concerning results that led to recommend that any non-essential surgery should be postponed after the age of 3 yr and that research into this subject should be stepped up. We then focus on the neurophysiology of the developing brain under general anaesthesia, explore the biochemistry of the observed neurotoxicity, before summarising the main scientific and clinical reports investigating this issue. We finally discuss the GAS trial, the importance of its results, and some potential limitations that should not undermine their clinical relevance. We finally suggest some key points that could be shared with parents, and a potential research path to investigate the biochemical effects of general anaesthesia, opening up perspectives to understand the neurocognitive effects of repetitive exposures, especially in at-risk children.

Anesthetic Exposure During Childhood and Neurodevelopmental Outcomes: A Systematic Review and Meta-analysis

Importance

Clinical studies of neurodevelopmental outcomes after anesthetic exposure have evaluated a range of outcomes with mixed results.

Objective

To examine via meta-analyses the associations between exposure to general anesthesia and domain-specific neurodevelopmental outcomes in children.

Data Sources

PubMed/MEDLINE, Embase, CINAHL, Web of Science and the Cochrane Library were searched from inception to August 31, 2021.

Study Selection

Inclusion criteria were exposures to procedures requiring general anesthesia at younger than 18 years and evaluation of long-term neurodevelopmental function after exposure. Studies lacking unexposed controls or focused on children with major underlying comorbidities were excluded.

Data Extraction and Synthesis

Extracted variables included effect size; hazard, risk, or odds ratio; number of exposures; procedure type; major comorbidities; age of exposure and assessment; presence of unexposed controls; and study design. Studies were independently reviewed by 2 coders, and review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data were pooled using a random-effects model.

Main Outcomes and Measures

The main outcomes were standardized mean differences (SMD) for scores in the neurodevelopmental domains of academics, behavioral problems, cognition, executive function, general development, language, motor function, nonverbal reasoning, social cognition, and hazard and risk of neurodevelopmental disorder diagnoses.

Results

A total of 31 studies contributed data for meta-analysis. For each of the assessed neurodevelopmental domains, the numbers of children evaluated ranged from 571 to 63 315 exposed and 802 to 311 610 unexposed. Children with any exposure (single or multiple) had significantly worse behavioral problems scores, indicating more behavioral problems (SMD, -0.10; 95% CI, -0.18 to -0.02; P = .02), and worse scores in academics (SMD, -0.07; 95% CI -0.12 to -0.01; P = .02), cognition (SMD, -0.03; 95% CI, -0.05 to 0.00; P = .03), executive function (SMD, -0.20; 95% CI, -0.32 to -0.09; P < .001), general development (SMD, -0.08; 95% CI, -0.13 to -0.02; P = .01), language (SMD, -0.08; 95% CI, -0.14 to -0.02; P = .01), motor function (SMD, -0.11; 95% CI, -0.21 to -0.02; P = .02), and nonverbal reasoning (SMD, -0.15; 95% CI, -0.27 to -0.02; P = .02). Higher incidences of neurodevelopmental disorder diagnoses were also reported (hazard ratio, 1.19; 95% CI, 1.09 to 1.30; P < .001; risk ratio, 1.81; 95% CI, 1.25 to 2.61; P = .002).

Conclusions and Relevance

These findings support the hypothesis that associations between anesthetic exposure during childhood and subsequent neurodevelopmental deficits differ based on neurodevelopmental domain.

Percutaneous Closure of Patent Ductus Arteriosus

Percutaneous-based patent ductus arteriosus closure is technically feasible among infants less than 1.5 kg. However, marked heterogeneity in the type and nature of adverse events obscures current safety profile assessments. Although data on the risks of postdevice closure syndrome remain promising, a lack of comparative trials of surgical ductal ligation and inconsistent surveillance across published studies obscure confidence in present estimates of safety and efficacy. To minimize risk and yield the greatest benefits, clinical studies of patent ductus arteriosus treatment should consider incorporating more robust assessments to ensure that infants at greatest risk for adverse ductal consequences are included.

Testosterone attenuates sevoflurane-induced tau phosphorylation and cognitive impairment in neonatal male mice

BACKGROUND

Sevoflurane anaesthesia induces phosphorylation of the microtubule-associated protein tau and cognitive impairment in neonatal, but not adult, mice. The underlying mechanisms remain largely to be determined. Sex hormones can be neuroprotective, but little is known about the influence of testosterone on age-dependent anaesthesia effects.

METHODS

Six- and 60-day-old male mice received anaesthesia with sevoflurane 3% for 2 h daily for 3 days. Morris water maze, immunoassay, immunoblotting, co-immunoprecipitation, nanobeam technology, and electrophysiology were used to assess cognition; testosterone concentrations; tau phosphorylation; glycogen synthase kinase-3β (GSK3β) activation; binding or interaction between tau and GSK3β; and neuronal activation in mice, cells, and neurones.

RESULTS

Compared with 60-day-old male mice, 6-day-old male mice had lower testosterone concentrations (3.03 [0.29] vs 0.44 [0.12] ng ml^-1; P<0.01), higher sevoflurane-induced tau phosphorylation in brain (133 [20]% vs 100 [6]% in 6-day-old mice, P<0.01; 103 [8]% vs 100 [13]% in 60-day-old mice, P=0.77), and sevoflurane-induced cognitive impairment. Testosterone treatment increased brain testosterone concentrations (1.76 [0.10] vs 0.39 [0.05] ng ml^-1; P<0.01) and attenuated the sevoflurane-induced tau phosphorylation and cognitive impairment in neonatal male mice. Testosterone inhibited the interaction between tau and GSK3β, and attenuated sevoflurane-induced inhibition of excitatory postsynaptic currents in hippocampal neurones.

CONCLUSIONS

Lower brain testosterone concentrations in neonatal compared with adult male mice contributed to age-dependent tau phosphorylation and cognitive impairment after sevoflurane anaesthesia. Testosterone might attenuate the sevoflurane-induced tau phosphorylation and cognitive impairment by inhibiting the interaction between tau and GSK3β.

Update on the safety of anesthesia in young children presenting for adenotonsillectomy

Tonsillectomy with and without adenoidectomy is a frequently performed surgical procedure in children. Although a common procedure, it is not without significant risk. It is critical for anesthesiologists to consider preoperative, intraoperative, and postoperative patient factors and events to optimize safety, especially in young children. In the majority of cases, the indication for adenotonsillectomy in young children is obstructive breathing. Preoperative evaluation for patient comorbidities, especially obstructive sleep apnea, risk factors for a difficult airway, and history of recent illness are crucial to prepare the patient for surgery and develop an anesthetic plan. Communication and collaboration with the otolaryngologist is key to prevent and treat intraoperative events such as airway fires or hemorrhage. Postoperative analgesia planning is critical for safe pain control especially for those patients with a history of obstructive sleep apnea and opioid sensitivity. In young children, it is important to also consider the impact of anesthetic medications on the developing brain. This is an area of continuing research but needs to be weighed when planning for surgical treatment and when discussing risks and benefits with patients' families.

Effects of general anesthetics on synaptic transmission and plasticity

General anesthetics depress excitatory and/or enhance inhibitory synaptic transmission principally by modulating the function of glutamatergic or GABAergic synapses, respectively, with relative anesthetic agent-specific mechanisms. Synaptic signaling proteins, including ligand- and voltage-gated ion channels, are targeted by general anesthetics to modulate various synaptic mechanisms, including presynaptic neurotransmitter release, postsynaptic receptor signaling, and dendritic spine dynamics to produce their characteristic acute neurophysiological effects. As synaptic structure and plasticity mediate higher-order functions such as learning and memory, long-term synaptic dysfunction following anesthesia may lead to undesirable neurocognitive consequences depending on the specific anesthetic agent and the vulnerability of the population. Here we review the cellular and molecular mechanisms of transient and persistent general anesthetic alterations of synaptic transmission and plasticity.

Necrotizing Enterocolitis in Neonates: Has the Brain Taken a Hit 10 Years Later?

Background:

The neonate with necrotizing enterocolitis (NEC) is at risk of developing poor neurodevelopmental outcomes. There is a dearth of long-term follow-up studies in this field, with a majority of studies reporting a follow-up duration of 2 years. The aim of this study was to assess neurodevelopment of babies diagnosed with NEC more than a decade ago. This study was carried out in a tertiary hospital with neonatal surgery and intensive care units.

Materials and Methods:

Retrospective review of notes and telephone interviews with parents of babies diagnosed with NEC between January 2007 and December 2008 was conducted. Evidence of motor, cognitive, and sensory impairment was recorded. Fisher’s exact, χ², and unpaired t-tests were used. P-values <0.05 were considered significant.

Results:

Overall mortality in this cohort was 31%. Eighteen patients were followed up to an average age of 11.2 years. Of the 18 patients, 11 (61%) had a neurological impairment. Of the 15 surgically managed patients, 10 (67%) had an impairment and, of the 3 medically managed patients, 1 (33%) had an impairment. Cognitive impairment was the most common (10/18, 56%), followed by motor (6/18, 33%). Ten of 18 (56%) had special education needs, 9 of 18 (50%) had learning difficulties, 6 of 18 (33%) had speaking difficulties, and 4 of 18 (22%) had cerebral palsy. Patients also had behavioral conditions (3/18, 17%), visual impairment (2/18, 11%), and seizures (2/18, 11%).

Conclusion:

In the field of NEC, there is a hidden neurological burden that neonatal surgeons bequeath to the community. Sixty-one percent of patients are neurologically impaired, affecting the quality of life and function in the long-term. There should be appropriate parent counseling at the point of diagnosis and regular development checks for children with NEC.

Anesthetic Exposure in Staged Versus Single-Stage Cleft Lip and Palate Repair: Can We Reduce Risk of Anesthesia-Induced Developmental Neurotoxicity?

ABSTRACT

Cleft lip and palate (CLP) repair is typically performed in a staged fashion, which requires multiple instances of anesthetic exposure during a critical period of infant neurodevelopment. One solution to this concern includes the implementation of a single-stage CLP repair performed between 6 and 12 months of age. This study aimed to compare total anesthetic exposure between single-stage and staged CLP repairs. A retrospective review of unilateral CLP repairs between 2013 and 2018 conducted at a single institution was performed. Patients underwent either traditional, staged lip and palate repair, or single-stage complete cleft repair, where palate, lip, alveolus, and nasal repair was performed simultaneously. Primary endpoints included: total surgical time and total anesthetic exposure. Secondary endpoints included: excess anesthesia time, recovery room time, length of stay, and type of anesthetic administered. Two hundred twenty-five (n = 225) unilateral CLP repairs were conducted at the Loma Linda University. Detailed anesthetic data for eighty-six (n = 86) single-stage and twenty-eight (n = 28) staged operations were available. There was a statistically significant decrease in anesthetic exposure in single-stage versus staged repairs (316 minutes versus 345 minutes, P = 0.017), despite similar procedure times (260 minutes versus 246 minutes, P = 0.224). This resulted in near double excess anesthetic exposure time in the staged group (98 minutes versus 56 minutes, P < 0.001), primarily occurring during induction. This analysis suggests that single-stage CLP repair can reduce wasted time under general anesthesia and potentially reduce harmful neuronal toxicity in the developmental period in this at-risk population.

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).

Longitudinal associations between exposure to anesthesia and neurocognitive functioning in pediatric medulloblastoma

AIM

To examine whether anesthesia exposure is associated with neurocognitive decline in pediatric medulloblastoma.

METHODS

Patients were treated at St. Jude Children's Research Hospital and completed ≥2 protocol-directed neurocognitive assessments (n = 107) as part of a multisite clinical trial for pediatric medulloblastoma (NCT00085202). Patients received risk-adapted craniospinal photon irradiation, followed by four cycles of high-dose chemotherapy and stem cell rescue. Neurocognitive testing was completed at study baseline (after surgery and <2 weeks of starting radiation therapy) and annually for 5 years. Data on anesthesia exposure during treatment was abstracted from medical records.

RESULTS

Patients were 10.2 years at diagnosis on average (SD = 4.5; 37% female, 73% average-risk). Mean cumulative anesthesia duration was 20.4 h (SD = 15.2; range 0.7-55.6 h). In the overall group, longer anesthesia duration was associated with greater declines in IQ (Estimate = -0.08, P < 0.001), attention (Estimate = -0.10, P < .001) and processing speed (Estimate = -0.13, P < 0.001). Similar results were shown in subgroups of patients who were <7 years at diagnosis (IQ = -0.14, P = 0.027; Attention = -0.25: P = 0.011), ≥7 years at diagnosis (Attention = -0.07, P = 0.039; Processing Speed = -0.08, P = 0.022), treated for high-risk disease (IQ = -0.09, P = 0.024; Attention = -0.11, P = 0.034; Processing Speed = -0.13, P = 0.001), or treated for average-risk disease (IQ = -0.05, P = .022; Attention = -0.08, P = 0.011; Processing Speed = -0.10, P < 0.001).

CONCLUSION

Greater anesthesia exposure is a risk factor for clinically significant neurocognitive decline, in addition to factors of age at diagnosis and treatment risk arm. This result is notable as there are evidence-based strategies that can limit the need for anesthesia. Limiting anesthesia exposure, as feasible, may mitigate neurocognitive late effects, and thus, improve quality of life for survivors.

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.

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.

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.

Anesthesia Exposure during Therapy Predicts Neurocognitive Outcomes in Survivors of Childhood Medulloblastoma

OBJECTIVE

To examine the contribution of anesthesia exposure during treatment for childhood medulloblastoma to neurocognitive outcomes 3 years after tumor diagnosis.

STUDY DESIGN

In this retrospective study, anesthesia data were abstracted from medical records for 111 patients treated with risk-adapted protocol therapy at St Jude Children's Research Hospital. Neurocognitive testing data were obtained for 90.9% of patients.

RESULTS

For the 101 patients (62.4% male) who completed testing, mean age at diagnosis was 10.1 years, and 74.3% were staged to have average-risk disease. Anesthesia exposure during treatment ranged from 1 to 52 events (mean = 19.9); mean cumulative duration per patient was 21.1 hours (range 0.7-59.7). Compared with normative expectations (16%), the group had a significantly greater frequency of at-risk scores (<1 SD) on measures of intelligence (28.7%), attention (35.2%), working memory (26.6%), processing speed (46.7%), and reading (25.8%). Including anesthesia exposure duration to linear regression models accounting for age at diagnosis, treatment intensity, and baseline IQ significantly increased the predicted variance for intelligence (r² = 0.59), attention (r² = 0.29), working memory (r² = 0.31), processing speed (r² = 0.44), and reading (r² = 0.25; all P values <.001).

CONCLUSIONS

In survivors of childhood medulloblastoma, a neurodevelopmentally vulnerable population, greater exposure to anesthesia significantly and independently predicts deficits in neurocognitive and academic functioning. When feasible, anesthesia exposure during treatment should be reduced.

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.

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.

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.

Risk of Attention Deficit Hyper Activity Disorder After Early Exposure to General Anesthesia; A Case Control Study

Background: Over the past decade, following the discovery that developing brain of immature animals was affected by anesthetic agents, the safety of general anesthesia (GA) in early life has been questioned. Objectives: We investigated the association between anesthesia exposure in children and ADHD development. Methods: This case-control study was conducted at pediatric psychology clinic of our institution and a pediatric neurology private clinic during 2019. Firstly the responsible resident of anesthesiology separated new ADHD cases. Then a questionnaire was filled out through an almost 10 minute’s telephone interview. Finally, frequency distribution of GA was compared between ADHD cases and controls. Results: Finally, the data from 210 children were analyzed. Among 105 ADHD cases, 19% had a history of a procedure requiring GA while it was 3.8% in control group. Comparing the two groups a significant difference was observed regarding the age of receiving GA (P = 0.004), gender (P < 0.001), the history of receiving GA (P = 0.001) and the number of anesthesia exposures (P = 0.001). According to logistic regression analysis, male gender (P = 0.001) OR 3.11 (95CI = 1.63 - 5.93) and age (P = 0.003) OR 0.92 (95CI = 0.87 - 0.97) were significant predictors of early exposure to GA and ADHD development. Conclusions: It was revealed that early exposure to GA might be a risk factor for later developing ADHD. Boys might be more sensitive to the long term adverse effects of anesthetic agents than girls. Further prospective well-planned studies are needed to confirm these findings.

Association between surgical procedures under general anesthesia in infancy and developmental outcomes at 1 year: the Japan Environment and Children's Study

BACKGROUND

The neurotoxicity of general anesthesia to the developing human brains is controversial. We assessed the associations between surgery under general anesthesia in infancy and development at age 1 year using the Japan Environment and Children's Study (JECS), a large-scale birth cohort study.

METHODS

In the JECS, 103,062 pregnancies and 104,065 fetuses were enrolled between January 2011 and March 2014. Of the 100,144 registered live births, we excluded preterm or post-term infants, multiple births, and infants with chromosomal anomalies and/or anomalies of the head or brain. Data on surgical procedures under general anesthesia in infancy were collected from self-administered questionnaires by parents at the 1-year follow-up. Developmental delay at age 1 year was assessed using the Japanese translation of the Ages and Stages Questionnaires, Third Edition (J-ASQ-3), comprising five developmental domains.

RESULTS

Among the 64,141 infants included, 746 infants had surgery under general anesthesia once, 90 twice, and 71 three or more times. The percentage of developmental delay in the five domains of the J-ASQ-3 significantly increased with the number of surgical procedures. After adjusting for potential confounding factors, the risk of developmental delays in all five domains was significantly increased in infants who had surgery under general anesthesia three times or more (adjusted odds ratios: for communication domain 3.32; gross motor domain 4.69; fine motor domain 2.99; problem solving domain 2.47; personal-social domain 2.55).

CONCLUSIONS

Surgery under general anesthesia in infancy was associated with an increased likelihood of developmental delay in all five domains of the J-ASQ-3, especially the gross motor domain at age 1 year. The neurodevelopment with the growth should be further evaluated among the children who had surgery under general anesthesia.

TRIAL REGISTRATION

UMIN Clinical Trials Registry (number: UMIN000030786 ).

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.

Anesthesia Neurotoxicity in the Developing Brain: Basic Studies Relevant for Neonatal or Perinatal Medicine

Diagnostic and invasive procedures in premature infants may require general anesthesia. General anesthetics interfere with the development of the immature animal brain. Accelerated apoptosis, disturbed synaptogenesis, and cytoarchitecture are among the mechanisms suspected to underlie this phenomenon. The implications for humans are unknown. This article presents current suspected mechanisms of anesthesia-induced neurotoxicity and elaborates on the difficulties in translating results from animal research to human. Ethical considerations limit the conduct of such experiments in human neonates, but the use of animal models is still considered feasible. Vulnerable periods in brain development need further identification as do neurotoxic and neuroprotective interventions.