Performance on the Operant Test Battery in young children exposed to procedures requiring general anaesthesia: the MASK study

Impact of Propofol Exposure on Neurocognitive Outcomes in Children With High-Risk B ALL: A Children's Oncology Group Study

PURPOSE

Many children treated for ALL develop long-term neurocognitive impairments. Increased risk of these impairments is associated with treatment and demographic factors. Exposure to anesthesia is an additional possible risk factor. This study evaluated the impact of cumulative exposure to anesthesia on neurocognitive outcomes among a multicenter cohort of children with ALL.

METHODS

This study was embedded in AALL1131, a Children's Oncology Group phase III trial for patients with high-risk B-ALL. In consenting patients age 6-12 years, prospective uniform assessments of neurocognitive function were performed during and at 1 year after completion of therapy. Exposure to all episodes of anesthetic agents was abstracted. Multivariable linear regression models determined associations of cumulative anesthetic agents with the primary neurocognitive outcome reaction time/processing speed (age-normed) at 1 year off therapy, adjusting for baseline neurocognitive score, age, sex, race/ethnicity, insurance status (as a proxy for socioeconomic status), and leukemia risk group.

RESULTS

One hundred and forty-four children, 76 (52.8%) males, mean age of 9.1 (min-max, 6.0-12.0) years at diagnosis, underwent a median of 27 anesthetic episodes (min-max, 1-37). Almost all patients were exposed to propofol (140/144, 97.2%), with a mean cumulative dose of 112.3 mg/kg. One year after therapy, the proportion of children with impairment (Z-score ≤-1.5) was significantly higher compared with a normative sample. In covariate-adjusted multivariable analysis, cumulative exposure to propofol was associated with a 0.05 Z-score decrease in reaction time/processing speed per each 10 mg/kg propofol exposure (P = .03).

CONCLUSION

In a multicenter and uniformly treated cohort of children with B-ALL, cumulative exposure to propofol was an independent risk factor for impairment in reaction time/processing speed 1 year after therapy. Anesthesia exposure is a modifiable risk, and opportunities to minimize propofol use should be considered.

Pediatric Anesthesia Exposure: Decoding Its Neurodevelopmental Implications and Navigating the Nuances

General anesthesia is fundamental in pediatric medical interventions, but its potential neurodevelopmental impact on children has raised concerns, necessitating a thorough investigation. This systematic review aimed to assess the association between pediatric anesthesia exposure and neurodevelopmental outcomes, focusing on dosage effects and identifying high-risk groups. The study involved an extensive literature search across PubMed, Medline, and Google Scholar, selecting 40 relevant studies from an initial pool of 2,000, based on inclusion criteria that focused on children under 18 years exposed to anesthesia, excluding those with major comorbidities or perioperative physiological insults. It was observed that while a single exposure to anesthesia had minimal impact on general neurodevelopment, repeated or prolonged exposures posed greater concerns. Despite these findings, the study identified gaps in certain areas like adaptive behavior and sensory cognition due to limited data. The conclusion drawn is that although the evidence on anesthesia-induced neurotoxicity in children remains inconclusive, the implications of pediatric anesthesia exposure are significant enough to warrant careful consideration by healthcare professionals, who should balance the procedural benefits against the risks. This study also calls for future research to standardize methodologies and employ consistent, validated neurodevelopmental measurement tools.

Neurobehavioral effects of general anesthesia and cochlear implantation on hearing-impaired infants: A prospective observational cohort study

INTRODUCTION

The potential adverse effects of prolonged exposure to anesthetics in pediatric patients with severe-to-profound sensorineural hearing loss remain unclear. This study aimed to examine whether early bilateral cochlear implantation involving long-duration anesthetic exposure caused greater developmental impairment than that with unilateral cochlear implantation.

METHODS

This prospective observational study included normally developing infants with bilateral severe-to-profound sensorineural hearing loss aged 6 months to 2 years who were candidates for unilateral/bilateral cochlear implantation surgery. Baseline (T0), 6-month (T1), and 1-year (T2) Gesell Scale scores were measured. The outcomes included fine motor, adaptability, gross motor, language, and social skills scale 6 and 12 months postoperatively.

RESULT

The 90 enrolled children with bilateral severe-to-profound sensorineural hearing loss (unilateral n = 43; bilateral n = 47) had a younger bilateral group (11.00 ± 3.66 vs. 15.63 ± 6.99 months, p < .001). Anesthesia duration was longer in the bilateral group (271.57 ± 36.09 vs. 148.81 ± 25.60 min, p < .001). Gross motor, fine motor, adaptability, and language scores improved in both groups, and no significant between-group differences occurred in the fine motor scale at T1 and T2. Language developmental quotients improved significantly in the bilateral group compared with the unilateral group at T1 (mean differences: 25.07 ± 4.37 vs. 10.88 ± 4.61, p < .001) and T2 (mean differences: 34.98 ± 5.94 vs. 15.28 ± 6.55, p < .001). Stepwise regression revealed that gross motor, adaptability, language, and social skill developmental quotients at T1 were positively correlated with those at T0. Gross motor, fine motor, and social skill developmental quotients at T2 were negatively correlated with age at operation. Language developmental quotients were positively correlated with T0 values (p < .001) and in the bilateral group (p < .001) at T1 and T2.

CONCLUSIONS

When evaluating young children with bilateral severe-to-profound sensorineural hearing loss, despite longer exposures to general anesthesia, bilateral cochlear implantations were associated with more improvement in language scores and no differences in other skills compared with those with only unilateral implantation.

Sevoflurane Induces a Cyclophilin D-Dependent Decrease of Neural Progenitor Cells Migration

Clinical studies have suggested that repeated exposure to anesthesia and surgery at a young age may increase the risk of cognitive impairment. Our previous research has shown that sevoflurane can affect neurogenesis and cognitive function in young animals by altering cyclophilin D (CypD) levels and mitochondrial function. Neural progenitor cells (NPCs) migration is associated with cognitive function in developing brains. However, it is unclear whether sevoflurane can regulate NPCs migration via changes in CypD. To address this question, we treated NPCs harvested from wild-type (WT) and CypD knockout (KO) mice and young WT and CypD KO mice with sevoflurane. We used immunofluorescence staining, wound healing assay, transwell assay, mass spectrometry, and Western blot to assess the effects of sevoflurane on CypD, reactive oxygen species (ROS), doublecortin levels, and NPCs migration. We showed that sevoflurane increased levels of CypD and ROS, decreased levels of doublecortin, and reduced migration of NPCs harvested from WT mice in vitro and in WT young mice. KO of CypD attenuated these effects, suggesting that a sevoflurane-induced decrease in NPCs migration is dependent on CypD. Our findings have established a system for future studies aimed at exploring the impacts of sevoflurane anesthesia on the impairment of NPCs migration.

Pediatric Neuroanesthesia — a Review of the Recent Literature

Purpose of Review

Pediatric neuroanesthesia is a growing and still challenging subspecialty. The purpose of this review is to summarize the available knowledge and highlight the most recent findings of the literature on non-traumatic pediatric neuroanesthesia care.

Recent Findings

Several human studies have confirmed the negative effects of early life anesthetic exposure. According to non-human studies, volatile anesthetics and opioids contribute to tumor progression. Tranexamic acid effectively reduces perioperative blood loss; it is used in several different doses without standard guidelines on optimal dosing. The widespread use of neuromonitoring has necessitated the development of anesthetic methods that do not affect neuromuscular transmission.

Summary

Pediatric anesthetic neurotoxicity, management of intraoperative bleeding, and the effect of anesthesia on tumor growth are among the most debated and researched topics in pediatric neuroanesthesia. The lack of evidence and clinical guidelines underlines the need for further large prospective studies in this subspecialty.

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.

Anesthesia and neurotoxicity study design, execution, and reporting in the nonhuman primate: A systematic review

BACKGROUND

Concern for a role of anesthesia in neurotoxicity in children originated from neonatal rodent and nonhuman primate (NHP) models, yet prospective clinical studies have largely not supported this concern. The goal of this study was to conduct an objective assessment of published NHP study rigor in design, execution, and reporting.

METHODS

A MEDLINE search from 2005 to December 2021 was performed. Inclusion criteria included full-length original studies published in English under peer-reviewed journals. We documented experimental parameters on anesthetic dosing, monitoring, vitals, and experimental outcomes.

RESULTS

Twenty-three manuscripts were included. Critical issues identified in study design included: lack of blinding in data acquisition (57%) and analysis (100%), supratherapeutic (4-12 fold) maintenance dosing in 22% of studies, lack of sample size justification (91%) resulting in a mean (SD) sample size of 6 (3) animals per group. Critical items identified in the conduct and reporting of studies included: documentation of anesthesia provider (0%), electrocardiogram monitoring (35%), arterial monitoring (4%), spontaneous ventilation employed (35%), failed intubations resulting in comingling ventilated and unventilated animals in data analysis, inaccurate reporting of failed intubation, and only 50% reporting on survival. Inconsistencies were noted in drug-related induction of neuroapoptosis and region of occurrence. Further, 67%-100% of behavior outcomes were not significantly different from controls.

CONCLUSIONS

Important deficits in study design, execution, and reporting were identified in neonatal NHP studies. These results raise concern for the validity and reliability of these studies and may explain in part the divergence from results obtained in human neonates.

Anesthesia and Developing Brains: Unanswered Questions and Proposed Paths Forward

Anesthetic agents disrupt neurodevelopment in animal models, but evidence in humans is mixed. The morphologic and behavioral changes observed across many species predicted that deficits should be seen in humans, but identifying a phenotype of injury in children has been challenging. It is increasingly clear that in children, a brief or single early anesthetic exposure is not associated with deficits in a range of neurodevelopmental outcomes including broad measures of intelligence. Deficits in other domains including behavior, however, are more consistently reported in humans and also reflect findings from nonhuman primates. The possibility that behavioral deficits are a phenotype, as well as the entire concept of anesthetic neurotoxicity in children, remains a source of intense debate. The purpose of this report is to describe consensus and disagreement among experts, summarize preclinical and clinical evidence, suggest pathways for future clinical research, and compare studies of anesthetic agents to other suspected neurotoxins.

General Anesthesia in the First 36 Months of Life–a Study of Cognitive Performance in Children Aged 7-11 Years (ANFOLKI-36)

BACKGROUND

Experimental data have shown that the developing brain is especially vulnerable to exogenous noxious substances. The potential effects of anesthetic drugs on brain growth and development are a matter of concern. Clinical studies of children who underwent general anesthesia in their earliest years can make a major contribution to our understanding of the effects of anesthetic drugs on infants and toddlers (i.e., children under age 5).

METHODS

Children born at term during the years 2007-2011 who were exposed to general anesthesia before their third birthday were included in the study. Data on general anesthesia were retrospectively evaluated, and the overall intelligence quotient (IQ) was determined prospectively as the primary target parameter. Children who had not been exposed to general anesthesia were recruited as a control group. The non-inferiority threshold was set at a difference of 5 IQ points out of a consideration of clinical relevance.

RESULTS

430 complete data sets were available from exposed children and 67 from members of the control group. The exposed group achieved a mean IQ score of 108.2, with a 95% confidence interval of [107; 109.4]; the corresponding values in the control group were 113 [110; 116.1]. Both groups achieved a mean score that was higher than the expected 100 points. After adjustment for age, socioeconomic status, and sex, the difference between the two groups was 2.9 points [0.2; 5.6], indicating a significantly better outcome in the control group than in the exposed group. The non-inferiority threshold of 5 IQ points was within the confidence interval; thus, non-inferiority was not demonstrated.

CONCLUSION

The fact that both groups achieved a higher IQ score than the expected 100 points may be attributable, at least in part, to the restriction of the study to children born at term. The results indicate that general anesthesia in early childhood is not associated with markedly reduced intelligence in later years, although non-inferiority could not be demonstrated.

Perioperative sedation requirements of infants aged 0 to 3 months subjected to lower-body surgery under caudal blockade: a randomized controlled trial

BACKGROUND

It remains unclear how much sedation is required for subumbilical surgery under caudal blockade, and sedatives may carry a poorly understood risk of late sequelae in infants. We designed a randomized controlled study to evaluate total propofol consumption and perioperative sedation quality with the avoidance of continuous perioperative sedation in infants undergoing surgery under caudal anesthesia.

METHODS

Thirty-two infants (age: 0-3 months) were randomized to one of two groups in which perioperative administration of propofol was provided either "as needed" or by continuous infusion (5 mg kg-1 h-1). After induction of anesthesia via a facemask with sevoflurane, a venous access was established and 1 ml kg-1 of ropivacaine 0.35% was injected for caudal anesthesia. Intraoperative stress was assessed by repeated recording Comfort Behavioral Scale scores and heart rates.

RESULTS

Significantly (p = 0.0001) less propofol was administered in the as-needed group (0.7 ± 1.4 mg/kg) than in the continuous-infusion group (3.0 ± 1.6 mg/kg). This difference was not reflected in different requirements of additional intraoperative sedation (0.5 ± 0.8 mg/kg in 5 versus 0.6 ± 1.0 mg/kg in 4 cases; p = 0.76).

CONCLUSIONS

As needed propofol administration offers no disadvantage in terms of intraoperative sedation, but significant dose reductions can be achieved by avoiding continuous propofol infusion.

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.

Infant isoflurane exposure affects social behaviours, but does not impair specific cognitive domains in juvenile non-human primates

BACKGROUND

Clinical studies show that children exposed to anaesthetics for short times at young age perform normally on intelligence tests, but display altered social behaviours. In non-human primates (NHPs), infant anaesthesia exposure for several hours causes neurobehavioural impairments, including delayed motor reflex development and increased anxiety-related behaviours assessed by provoked response testing. However, the effects of anaesthesia on spontaneous social behaviours in juvenile NHPs have not been investigated. We hypothesised that multiple, but not single, 5 h isoflurane exposures in infant NHPs are associated with impairments in specific cognitive domains and altered social behaviours at juvenile age.

METHODS

Eight Rhesus macaques per group were anaesthetised for 5 h using isoflurane one (1×) or three (3×) times between postnatal days 6 and 12 or were exposed to room air (control). Cognitive testing, behavioural assessments in the home environment, and provoked response testing were performed during the first 2 yr of life.

RESULTS

The cognitive functions tested did not differ amongst groups. However, compared to controls, NHPs in the 3× group showed less close social behaviour (P=0.016), and NHPs in the 1× group displayed increased anxiety-related behaviours (P=0.038) and were more inhibited towards novel objects (P<0.001).

CONCLUSIONS

5 h exposures of NHPs to isoflurane during infancy are associated with decreased close social behaviour after multiple exposures and more anxiety-related behaviours and increased behavioural inhibition after single exposure, but they do not affect the cognitive domains tested. Our findings are consistent with behavioural alterations in social settings reported in clinical studies, which may guide future research.

Early Childhood General Anesthesia and Neurodevelopmental Outcomes in the Avon Longitudinal Study of Parents and Children Birth Cohort

Background

Most common anesthetic agents have been implicated in causing neurodegeneration in the developing animal brain, leading to warnings regarding their use in children. The hypothesis of this study was that exposure to general anesthesia and surgery before 4 yr would associate with adverse neurodevelopmental outcomes at age 7 to 16 yr.

Methods

This cohort study comprised 13,433 children enrolled in the Avon Longitudinal Study of Parents and Children, a prospective, population-based birth cohort born between 1991 and 1993 in southwest England. Children were grouped by none, single, or multiple exposures to general anesthesia and surgery by 4 yr. Motor, cognitive, linguistic, educational, social, and behavioral developmental outcomes were evaluated at 7 to 16 yr using school examination results, validated parent/teacher questionnaires, or clinic assessments. Continuous outcomes were z-scored. P-value thresholds were corrected using false discovery rate procedures.

Results

This study compared 46 neurodevelopmental outcomes in 13,433 children: 8.3% (1,110) exposed singly and 1.6% (212) exposed multiply to general anesthesia and surgery. Of these, the following reached predefined levels of statistical significance (corrected P &lt; 0.00652): dynamic balance scores were 0.3 SD (95% CI, 0.1, 0.5; P &lt; 0.001) lower in multiply exposed children; manual dexterity performance was 0.1 SD (95% CI, 0.0, 0.2; P = 0.006) lower in singly and 0.3 SD (95% CI, 0.1, 0.4; P &lt; 0.001) lower in multiply exposed children; and social communication scores were 0.1 SD (95% CI, 0.0, 0.2; P = 0.001) and 0.4 SD (95% CI, 0.3, 0.5; P &lt; 0.001) lower in singly and multiply exposed children, respectively. General anesthesia and surgery were not associated with impairments in the remaining neurodevelopmental measures including: general cognitive ability; attention; working memory; reading, spelling, verbal comprehension and expression; behavioral difficulties; or national English, mathematics, and science assessments (all ≤0.1 SD; corrected P ≥ 0.00652).

Conclusions

Early childhood general anesthesia and surgery were not associated with a global picture of clinically and statistically significant neurodegenerative effects, providing reassurance about the neurotoxic potential of general anesthesia. Exposure to anesthesia and surgery was associated with significantly lower motor and social linguistic performance.

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

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.

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.

Sedation practices in pediatric patients with acute lymphoblastic leukemia

BACKGROUND

The 5-year survival for pediatric acute lymphoblastic leukemia (ALL) is greater than 90%. One late effect of pediatric ALL associated with numerous long-term difficulties is neurocognitive deficits. The experience at our institution, as well as conversations with oncologists at other institutions, suggests an increase in the use of sedation during lumbar punctures (LPs) for treatment of pediatric ALL. Among the most common Children's Oncology Group (COG) ALL protocols, approximately 30 LPs are performed over 2-3 years. Studies in animals reveal that sedation drugs may harm the developing brain. Gaps in knowledge exist regarding their use in children, particularly repeated exposures. The purpose of this study is to summarize sedation practices for LPs related to the treatment of ALL at COG institutions.

METHODS

Responsible Individuals (RIs) of the Cancer Control Committee of COG were invited to complete an internet-based survey about sedation practices at their institutions.

RESULTS

Surveys were sent to 103 RIs with a 62% response rate (N = 64). A combined 2018 new patients with ALL were seen each year (mean = 31.5, range = 3-110) at the participating institutions. The majority (96%) of children with ALL received sedation for LPs. While there was considerable variability across institutions in the type of sedation given, the most common was propofol alone (n = 36, 56%).

CONCLUSIONS

A substantial number of children with ALL receive sedation for LPs; however, there is variation in the medication used. Better understanding of sedation practices in children with ALL may inform future research to investigate which methods are the safest, with an emphasis on long-term neurocognitive late effects.

Neuroanesthesiology Update

This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.

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.

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.

Pharmacology related to paediatric anaesthesia

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