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

Repeated high-dose esketamine in early postnatal rats leads to behavioural deficits with long-term modifications in white matter microstructural integrity

Esketamine is commonly used for sedation or general anaesthesia in infants and young children. However, repeated esketamine administration during periods of rapid brain growth and development may result in various pathophysiological and cognitive changes. Therefore, this study aimed to investigate the influence of recurrent esketamine exposure on long-term behavioural and white matter consequences. Seven-day-old (P7) male rats were allocated to control, high-, and low-dose groups. Behavioural paradigm assessment was conducted at P25-29. Diffusion tensor imaging revealed long-term effects on water diffusivity in the splenium and cingulum white matter of the corpus callosum at P30. Subsequent two-dimensional structure-tensor analysis of brain tissue sections stained with Luxol fast blue (LFB) showed marked changes in the white matter microstructure in rats after multiple exposures to varying esketamine doses. High-dose esketamine significantly reduced activity time and total distance in the open-field experiment. High-dose esketamine exposure might lead to impaired short-term memory in rats. Additionally, the high-dose group showed prolonged immobility time during the forced swimming test. On the balance beam, the high-dose group displayed more right turns and right-foot slips and lower time spent on the rotating bar, indicating motor defects, than did the other groups. Diffusion tensor imaging demonstrated a decreased water molecule diffusion ability in the corpus callosum in the high-dose group. LFB staining indicated microstructural differences in the white matter of animals in the high-dose group. These findings suggest that behavioural deficits in high-dose esketamine-treated rats are at least partially attributed to changes in the white matter microstructure.

Morphometric analysis of the female reproductive tract: influence of long-term inhalation of trace amounts of sevoflurane

Sevoflurane is extensively employed as an inhalation anesthetic in medical practices, due to its promising pharmacokinetics. Conversely, the data regarding effects of prolonged exposure to trace amounts of sevoflurane on the female reproductive system is obscure. Therefore, this study aimed to investigate the reproductive toxicity and underlying mechanism of long-term sevoflurane inhalation in female rats. A total 60 SPF grade SD female rats were randomly alienated into four equal groups as control group (A), 50 ppm sevoflurane group (B), 150 ppm sevoflurane group (C), and 300 ppm sevoflurane groups (D). Ovaries and uterine organs were collected for gross as well as histopathological analysis, western blotting, and immuno-histochemistry evaluation. Results revealed that pregnancy rate, number of fetuses (fetal mice) and general body weight of group B, C, and D were substantially lower (P < 0.05), while were compared with control. On the contrary, estrous period in groups B, C, D was shortened noticeably (P < 0.05), and estrus interval and cycle were significantly longer (P < 0.05). In fact, the ovarian and uterine coefficients of group B, C and D were significantly reduced as compared with control. However, ovarian and uterine histomorphology remained normal in control group, while obvious pathological alterations were detected in groups B, C, and D. Although, the expression of SOD protein in the ovarian and uterine tissues of groups B, C, and D was significantly reduced (P < 0.05), in contrast to group A. However, the MDA protein expression increased significantly (P < 0.05) as compared with group A. While expression of apoptosis-related genes (Bcl2 and Bax) and humoral immunity related genes (IL-6, IL-10 and TNF-α) showed highest elevation in groups exposure with sevoflurane (p < 0.001) in comparison to control. Conclusively, long-term inhalation of trace amounts of sevoflurane is toxic to female reproductive system and can severely affect reproductive organs and fertility by induction of oxidative stress and apoptosis.

Cerium oxide nanoparticles (nanoceria) pretreatment attenuates cell death in the hippocampus and cognitive dysfunction due to repeated isoflurane anesthesia in newborn rats

General anesthetics exposure, particularly prolonged or repeated exposure, is a crucial cause of neurological injuries. Notably, isoflurane (ISO), used in pediatric anesthesia practice, is toxic to the developing brain. The relatively weak antioxidant system at early ages needs antioxidant support to protect the brain against anesthesia. Cerium oxide nanoparticles (CeO2-NPs, nanoceria) are nano-antioxidants and stand out due to their unique surface chemistry, high stability, and biocompatibility. Although CeO2-NPs have been shown to exhibit neuroprotective and cognitive function-facilitating effects, there are no reports on their protective effects against anesthesia-induced neurotoxicity and cognitive impairments. Herein, Wistar albino rat pups were exposed to ISO (1.5 %, 3-h) at postnatal day (P)7+P9+P11, and the protective properties of CeO2-NP pretreatment (0.5 mg/kg, intraperitoneal route) were investigated for the first time. The control group at P7+9+11 received 50 % O2 (3-h) instead of ISO. Exposure to nanoceria one-hour before ISO protected hippocampal neurons of the developing rat brain against apoptosis [determined by hematoxylin-eosin (HE) staining, immunohistochemistry (IHC) analysis with caspase-3, and immunoblotting with Bax/Bcl2, cleaved caspase-3 and PARP1] oxidative stress, and inflammation [determined by immunoblotting with 4-hydroxynonenal (4HNE), nuclear factor kappa-B (NF-κB), and tumor necrosis factor-alpha (TNF-α)]. CeO2-NP pretreatment also reduced ISO-induced learning (at P28-32) and memory (at P33) deficits evaluated by Morris Water Maze. However, memory deficits and thigmotactic behaviors were detected in the agent-control group; elimination of these harmful effects will be possible with dose studies, thus providing evidence supporting safer use. Overall, our findings support pretreatment with nanoceria application as a simple strategy that might be used for pediatric anesthesia practice to protect infants and children from ISO-induced cell death and learning and memory deficits.

Association between general anesthesia in early childhood and neurodevelopment up to 4 years of age: the Japan Environment and Children's Study

PURPOSE

The effects of general anesthesia on neurodevelopment in children remain controversial. We explored the relationship between general anesthesia and neurodevelopment in children participating in the Japan Environment and Children's Study (JECS).

METHODS

This study enrolled children born between 37 and 41 weeks of pregnancy via single-vaginal delivery to pregnant women registered in the JECS between January 2011 and March 2014. Data were collected from mother-completed questionnaires and medical transcripts. Neurodevelopment in five domains was assessed every 6 months between 12 and 48 months of age, using the Ages and Stages Questionnaires. The associations between general anesthesia exposure during early childhood and neurodevelopment in children were evaluated at each time point. Adjusted odds ratios and 95% confidence intervals were estimated after covariate adjustment using logistic regression models.

RESULTS

Children who received general anesthesia before age 1 year had higher risks of neurodevelopmental delay in all five domains throughout the observational period. The largest risk was for gross motor delay at 18 months (adjusted odds ratio: 3.51; 95% confidence interval: 2.75-4.49). The effects on the incidence of neurodevelopmental delays after age 3 were not observed except for problem solving at 48 months. The risk of neurodevelopmental delay in children who first received general anesthesia after age 1 was considerably small.

CONCLUSIONS

This study suggests that general anesthesia administration before age 1 is associated with neurodevelopmental delay during 1-4 years of age. The risk of general anesthesia after age 1 may be small.

Assessment of Gross Motor Skills in Ponseti-treated Children With Idiopathic Clubfoot at 3 Years Old: Insights from the Peabody Developmental Motor Scale 2

BACKGROUND

Congenital talipes equinovarus, or clubfoot, can lead to lifelong functional impairments, including diminished gross motor skills (GMS), if left untreated. The Ponseti method corrects idiopathic clubfoot through casting and bracing. Given the importance of GMS in childhood development, this technique must be optimized to support childhood and long-term health outcomes. This study examined immediate posttreatment GMS in 3-year-old children treated with Ponseti, hypothesizing that they would perform on par with their nonclubfoot peers.

METHODS

Data from 45 children (33 to 46 mo of age) treated for idiopathic clubfoot were analyzed. The Peabody Developmental Motor Scales, 2nd edition, was used to assess GMS, and logistic regression identified factors influencing Gross Motor Quotient (GMQ) scores.

RESULTS

Approximately half (n=22) of the patients exhibited below-average GMS (11th to 25th percentile), with 11 scoring below the 10th percentile. Initial deformity severity, gender, and cast numbers did not impact GMQ. Repeat percutaneous tenotomy was associated with lower GMQs. Brace compliance significantly reduced odds of low GMQs by up to 80%. Age at testing and additional surgery were also linked to below-average and poor GMQs.

CONCLUSIONS

GMS appeared to be impaired in almost half of the 3-year-old patients treated for idiopathic clubfoot, so our hypothesis was disproven. Repeat percutaneous tenotomy was associated with lower GMS, necessitating future recognition of patients who might be at risk of relapse. Brace noncompliance emerged as a significant risk factor, emphasizing early identification of these patients and education for their parents. This study offers a benchmark for clinicians and parents, but research on long-term outcomes is needed.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Childhood anaesthesia and autism risk: population and murine study

Early childhood exposure to general anaesthesia has been linked to potential changes in infant brain morphology and behaviour in preclinical studies, contributing to long-term behaviours associated with autism spectrum disorder. This study investigates the association between early childhood exposure to general anaesthesia and the risk of autism, using a population-based cohort study with matching for baseline characteristics and evaluates the effect of sevoflurane exposure on autism-like behaviour in mice, using the Taiwan Maternal and Child Health Database. Children aged 0-3 who received at least one exposure to general anaesthesia between 2004 and 2014 were matched 1:1 with children who were not exposed. Risk ratios and confidence intervals were used to assess the relationship between general anaesthesia and the occurrence of autism. Additionally, mice were exposed to sevoflurane for 2 h on postnatal days 5-7, and changes in behaviour related to autism were evaluated. Propensity score matching resulted in 7530 children in each group. The incidence rates (IRs) of autism were 11.26 and 6.05 per 100 000 person-years in the exposed and unexposed groups, respectively. The incidence ratio for autism following exposure to general anaesthesia was 1.86 (95% confidence interval, 1.34-2.59). In mice, sevoflurane exposure induced autism-like behaviours and led to the downregulation of high-risk autism genes, including ARID1B, GABRA5, GABRB3, GRIN2B, SHANK3 and SUV420H1. Early childhood exposure to general anaesthesia is associated with an increased risk of autism. Repeated exposure to sevoflurane in mice induces autism-like behaviours, suggesting a potential link between anaesthesia and the development of autism.

The prevalence of visual axis opacification in the Swedish Pediatric Cataract Register

PURPOSE

To report on the occurrence of postoperative visual axis opacification (VAO) in children younger than 5 years of age operated for cataract in Sweden, and to analyse correlations with age at surgery and surgical method.

METHODS

Data were derived from the Swedish Pediatric Cataract Register (PECARE). All children operated on between 1 January 2007 and 31 December 2020 were included. Follow-ups at 1, 2 and 5 years of age were analysed.

RESULTS

Cataract surgery were performed on 770 eyes belonging to 549 children (n = 282 boys, 51.4%); 327/770 (42.5%) of the children underwent surgery before 3 months of age and 216/770 (28%) before 6 weeks of age. Data on 881 follow-up visits were registered. At the follow up-visits at 1, 2 and 5 years of age, VAO was present in 154/349 (44.1%), 41/323 (12.7%) and 25/208 (12%). The majority of the children with VAO underwent cataract surgery before age 6 months, with a predominance before age 2 months. Primary IOL was implanted in 601/770 (78%) of eyes; 40.8% had an acrylic one-piece lens, 31.8% had a bag-in-the-lens IOL, 21.9% were aphakic and 5.2% had an acrylic three-piece lens. Implantation of a bag-in-the-lens IOL was related to a significantly lower occurrence of VAO compared to other types of IOL, including aphakia (p < 0.0002).

CONCLUSION

Our results are in accordance with the literature. Primary bag-in-the-lens IOL implantation before 2 years of age seems adequate and safe, with a low occurrence of VAO, and can thus be continued as routine in Sweden.

Unraveling the signaling network between dysregulated microRNA and mRNA expression in sevoflurane-induced developmental neurotoxicity in rat

Research has indicated that general anesthesia may cause neuroapoptosis and long-term cognitive dysfunction in developing animals, however, the precise mechanisms orchestrating these outcomes remain inadequately elucidated within scholarly discourse. The purpose of this study was to investigate the impact of sevoflurane on the hippocampus of developing rats by analyzing the changes in microRNA and mRNA and their interactions. Rats were exposed to sevoflurane for 4 h on their seventh day after birth, and the hippocampus was collected for analysis of neuroapoptosis by Western blot and immunohistochemistry. High-throughput sequencing was conducted to analyze the variances in miRNA and mRNA expression levels, and the Morris water maze was employed to assess long-term memory in rats exposed to sevoflurane after 8 weeks. The results showed that sevoflurane exposure led to dysregulation of 5 miRNAs and 306 mRNAs in the hippocampus. Bioinformatic analysis revealed that these dysregulated miRNA-mRNA target pairs were associated with pathological neurodevelopment and developmental disorders, such as regulation of axonogenesis, regulation of neuron projection development, regulation of neuron differentiation, transmission of nerve impulse, and neuronal cell body. Further analysis showed that these miRNAs formed potential network interactions with 44 mRNAs, and two important nodes were identified, miR-130b-5p and miR-449c-5p. Overall, this study suggests that the dysregulation of the miRNA-mRNA signaling network induced by sevoflurane may contribute to neurodevelopmental toxicity in the hippocampus of rats and be associated with long-term cognitive dysfunction.

Postoperative Analgesia With Modified Thoracoabdominal Nerve Block Through Perichondrial Approach in Neonatal and Infantile Abdominal Surgery

Modified thoracoabdominal nerve block through the perichondrial approach (M-TAPA) is a novel strategy for peripheral nerve block in the abdomen. Its usefulness has been highlighted in adults, but no literature is currently available regarding its efficacy in infants. This report describes the cases of a one-day-old neonate in open abdominal surgery and a one-month-old infant in laparoscopic surgery who received M-TAPA. The postoperative condition of the infants was assessed through a neonate pain scale and the Face, Legs, Activity, Cry, and Consolability behavioral scale, respectively; both scales remained at 0 until discharge. Despite the need for special attention, M-TAPA may provide effective analgesia in neonatal and infant abdominal surgery in addition to adult cases, and its indications should be considered.

Intelligent ultrafast total-body PET for sedation-free pediatric [18F]FDG imaging

PURPOSE

This study aims to develop deep learning techniques on total-body PET to bolster the feasibility of sedation-free pediatric PET imaging.

METHODS

A deformable 3D U-Net was developed based on 245 adult subjects with standard total-body PET imaging for the quality enhancement of simulated rapid imaging. The developed method was first tested on 16 children receiving total-body [18F]FDG PET scans with standard 300-s acquisition time with sedation. Sixteen rapid scans (acquisition time about 3 s, 6 s, 15 s, 30 s, and 75 s) were retrospectively simulated by selecting the reconstruction time window. In the end, the developed methodology was prospectively tested on five children without sedation to prove the routine feasibility.

RESULTS

The approach significantly improved the subjective image quality and lesion conspicuity in abdominal and pelvic regions of the generated 6-s data. In the first test set, the proposed method enhanced the objective image quality metrics of 6-s data, such as PSNR (from 29.13 to 37.09, p < 0.01) and SSIM (from 0.906 to 0.921, p < 0.01). Furthermore, the errors of mean standardized uptake values (SUVmean) for lesions between 300-s data and 6-s data were reduced from 12.9 to 4.1% (p < 0.01), and the errors of max SUV (SUVmax) were reduced from 17.4 to 6.2% (p < 0.01). In the prospective test, radiologists reached a high degree of consistency on the clinical feasibility of the enhanced PET images.

CONCLUSION

The proposed method can effectively enhance the image quality of total-body PET scanning with ultrafast acquisition time, leading to meeting clinical diagnostic requirements of lesion detectability and quantification in abdominal and pelvic regions. It has much potential to solve the dilemma of the use of sedation and long acquisition time that influence the health of pediatric patients.

A Prospective Randomized Controlled Trial Using Virtual Reality in Pediatric Pre-intervention Echocardiograms to Decrease Child Anxiety and Fear

Virtual reality (VR) as a distraction tool decreases anxiety and fear in children undergoing procedures, but its use has not been studied during transthoracic echocardiograms (TTEs). We hypothesized that VR in children undergoing pre-intervention TTEs decreases anxiety and fear and increases TTE study comprehensiveness and diagnostic accuracy when compared with standard distractors (television, mobile devices). Patients (6-18 years old) scheduled for pre-intervention TTEs at Lucile Packard Children's Hospital in 2021 and 2022 were prospectively enrolled and randomized to VR and non-VR groups. Patients completed pre- and post-TTE surveys using the Children's Anxiety Meter-State (CAM-S) and Children's Fear Scale (CFS). Patients, parents, and sonographers completed post-TTE experience surveys. TTEs were reviewed by pediatric cardiologists for study comprehensiveness and compared with electronic medical records for diagnostic accuracy. Among 67 enrolled patients, 6 declined VR, 31 randomized to the VR group, and 30 to the non-VR group. Anxiety (average CAM-S difference 0.78 ± 1.80, p = 0.0012) and fear (average CFS difference 0.36 ± 0.74, p = 0.0005) decreased in both groups. There was no difference between groups in the change in anxiety and fear pre- and post-TTE (p = 0.96-1.00). TTE study comprehensiveness and diagnostic accuracy were high in both groups. Procedure time (time in the echocardiography room) was less for the VR group (48.4 ± 18.1 min) than the non-VR group (58.8 ± 24.4 min), but without a statistically significant difference (p = 0.075). VR is similar to standard distractors and may decrease procedure time. Patients, parents, and sonographers rated the VR experience highly and encouraged its use with future procedures.

Let Kids Play: Using Virtual Reality as a Substitute for General Anesthesia for Minor Procedures in Pediatric Population

BACKGROUND

In the pediatric population, virtual reality (VR) has been used as an adjunct to augment analgesia and reduce the need for opioids. In this study, we review our experience using VR in lieu of anesthesia or sedation to enable minor procedures in children.

METHODS

A retrospective chart review study was performed on patients who presented to our institution from 2019 to 2022 for hormone implant placement, exchange, or removal with VR distraction. Demographic and procedure information was recorded. The primary outcome was successful procedure completion without requiring pharmacologic sedation or analgesia.

RESULTS

A total of 111 patients underwent the following minor procedures with VR and without anesthesia or sedation. Fourteen patients had multiple encounters resulting in a total of 126 encounters. The median age was 11 [6] years. 43 patients were female, 23 were female to male, 6 were non-binary, 7 were male, and 32 were male to female. 58 % had private insurance. Most common diagnosis was precocious puberty (54 %) followed by gender dysphoria (46 %). Most common procedure was implant placement (72 %). 69 % of procedures were performed in the clinic and 31 % in the OR. All procedures were completed without requiring the administration of additional sedation or anesthesia. None of the patients required intravenous catheter placement for the procedure. No intra-procedural complications were recorded.

CONCLUSION

VR is a feasible option that can spare children from sedation or general anesthesia for minor procedures. VR may enable minor procedures in children to be successfully performed in clinic setting.

LEVEL OF EVIDENCE: 4

Screening of potential biomarkers in propofol-induced neurotoxicity via bioinformatics prediction and experimental verification

OBJECTIVES

To identify hub genes and biological processes of propofol-induced neurotoxicity and promote the development of pediatric anesthesiology.

METHODS

We downloaded the GSE106799 dataset from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were screened, then Kyoto Encyclopedia of Genes and Genomes, Gene Ontology and Gene Set Enrichment analyses were performed on all DEGs. We identified potential ferroptosis genes in the pathogenesis of propofol-induced neurotoxicity. A key module was obtained after performing weighted gene co-expression network analysis (WGCNA) on the GSE106799 dataset. Hub genes were identified after the least absolute shrinkage and selection operator (LASSO) regression analysis of the intersection of DEGs and genes from the key module. We established a competing endogenous RNA network and predicted potential drugs according to the hub genes. Total RNA and proteins were extracted for real-time quantitative polymerase chain reaction and Western blotting, respectively.

RESULTS

A total of 112 DEGs, including 76 upregulated and 36 downregulated ones were screened out. Propofol-induced neurotoxicity involved processes such as nervous system development, activation of JAK/STAT and MAPK signaling pathways, vascular regeneration, and oxidative stress. The results of WGCNA suggested that the tan module was the most strongly associated with propofol-induced neurotoxicity. We identified 4 hub genes (EGR4, HAO1, ITK and GM14446) after LASSO regression analysis. Animal experiments demonstrated that propofol caused overexpression of the protein levels of HAO1, ITK and inflammatory factors in the brain, as well as the mRNA levels of HAO1, ITK and GM14446. Propofol inhibited expression of EGR4 at mRNA and protein levels.

CONCLUSIONS

Previous studies have demonstrated that EGR4, HAO1, ITK and GM14446 play a role in intellectual development, neuroinflammation and neuronal differentiation. These hub genes may help us to find new preventive and therapeutic targets for propofol-induced neurotoxicity.

Tandem pediatric neurosurgery: treatment of synostosis and intractable epilepsy. Illustrative case

BACKGROUND

Hemispherectomy is a surgical procedure reserved for hemispheric intractable epilepsy. Sagittal craniosynostosis is a congenital disorder treated with open or endoscope-assisted approaches for synostosis correction. These procedures are not commonly performed in the same setting.

OBSERVATIONS

In this report, the authors present a 6-month-old female with sagittal craniosynostosis, hemimegalencephaly, and intractable epilepsy who underwent a left hemispherotomy with open sagittal synostosis correction followed by cranial molding orthosis therapy.

LESSONS

The report highlights the technical nuances of the procedure, but also discusses the possible genetic disorder responsible for both conditions, megalencephaly-capillary malformation syndrome.

Machine Learning Technology for EEG-Forecast of the Blood-Brain Barrier Leakage and the Activation of the Brain's Drainage System during Isoflurane Anesthesia

Anesthesia enables the painless performance of complex surgical procedures. However, the effects of anesthesia on the brain may not be limited only by its duration. Also, anesthetic agents may cause long-lasting changes in the brain. There is growing evidence that anesthesia can disrupt the integrity of the blood-brain barrier (BBB), leading to neuroinflammation and neurotoxicity. However, there are no widely used methods for real-time BBB monitoring during surgery. The development of technologies for an express diagnosis of the opening of the BBB (OBBB) is a challenge for reducing post-surgical/anesthesia consequences. In this study on male rats, we demonstrate a successful application of machine learning technology, such as artificial neural networks (ANNs), to recognize the OBBB induced by isoflurane, which is widely used in surgery. The ANNs were trained on our previously presented data obtained on the sound-induced OBBB with an 85% testing accuracy. Using an optical and nonlinear analysis of the OBBB, we found that 1% isoflurane does not induce any changes in the BBB, while 4% isoflurane caused significant BBB leakage in all tested rats. Both 1% and 4% isoflurane stimulate the brain's drainage system (BDS) in a dose-related manner. We show that ANNs can recognize the OBBB induced by 4% isoflurane in 57% of rats and BDS activation induced by 1% isoflurane in 81% of rats. These results open new perspectives for the development of clinically significant bedside technologies for EEG-monitoring of OBBB and BDS.

Effects of Early Exposure to Isoflurane on Susceptibility to Chronic Pain Are Mediated by Increased Neural Activity Due to Actions of the Mammalian Target of the Rapamycin Pathway

Patients who have undergone surgery in early life may be at elevated risk for suffering neuropathic pain in later life. The risk factors for this susceptibility are not fully understood. Here, we used a mouse chronic pain model to test the hypothesis that early exposure to the general anesthetic (GA) Isoflurane causes cellular and molecular alterations in dorsal spinal cord (DSC) and dorsal root ganglion (DRG) that produces a predisposition to neuropathic pain via an upregulation of the mammalian target of the rapamycin (mTOR) signaling pathway. Mice were exposed to isoflurane at postnatal day 7 (P7) and underwent spared nerve injury at P28 which causes chronic pain. Selected groups were treated with rapamycin, an mTOR inhibitor, for eight weeks. Behavioral tests showed that early isoflurane exposure enhanced susceptibility to chronic pain, and rapamycin treatment improved outcomes. Immunohistochemistry, Western blotting, and q-PCR indicated that isoflurane upregulated mTOR expression and neural activity in DSC and DRG. Accompanying upregulation of mTOR and rapamycin-reversible changes in chronic pain-associated markers, including N-cadherin, cAMP response element-binding protein (CREB), purinergic P2Y12 receptor, glial fibrillary acidic protein (GFAP) in DSC; and connexin 43, phospho-extracellular signal-regulated kinase (p-ERK), GFAP, Iba1 in DRG, were observed. We concluded that early GA exposure, at least with isoflurane, alters the development of pain circuits such that mice are subsequently more vulnerable to chronic neuropathic pain states.

The effects of general anesthetics on mitochondrial structure and function in the developing brain

The use of general anesthetics in modern clinical practice is commonly regarded as safe for healthy individuals, but exposures at the extreme ends of the age spectrum have been linked to chronic cognitive impairments and persistent functional and structural alterations to the nervous system. The accumulation of evidence at both the epidemiological and experimental level prompted the addition of a warning label to inhaled anesthetics by the Food and Drug Administration cautioning their use in children under 3  years of age. Though the mechanism by which anesthetics may induce these detrimental changes remains to be fully elucidated, increasing evidence implicates mitochondria as a potential primary target of anesthetic damage, meditating many of the associated neurotoxic effects. Along with their commonly cited role in energy production via oxidative phosphorylation, mitochondria also play a central role in other critical cellular processes including calcium buffering, cell death pathways, and metabolite synthesis. In addition to meeting their immense energy demands, neurons are particularly dependent on the proper function and spatial organization of mitochondria to mediate specialized functions including neurotransmitter trafficking and release. Mitochondrial dependence is further highlighted in the developing brain, requiring spatiotemporally complex and metabolically expensive processes such as neurogenesis, synaptogenesis, and synaptic pruning, making the consequence of functional alterations potentially impactful. To this end, we explore and summarize the current mechanistic understanding of the effects of anesthetic exposure on mitochondria in the developing nervous system. We will specifically focus on the impact of anesthetic agents on mitochondrial dynamics, apoptosis, bioenergetics, stress pathways, and redox homeostasis. In addition, we will highlight critical knowledge gaps, pertinent challenges, and potential therapeutic targets warranting future exploration to guide mechanistic and outcomes research.

Impact of Repeated Infantile Exposure to Surgery and Anesthesia on Gut Microbiota and Anxiety Behaviors at Age 6-9

(1) Background: Preclinical as well as population studies have connected general anesthesia and surgery with a higher risk of abnormal cognitive development, including emotional development. Gut microbiota dysbiosis in neonatal rodents during the perioperative period has been reported, however, the relevance of this to human children who undergo multiple anesthesia for surgeries is unknown. Given the emerging role of altered gut microbes in propagating anxiety and depression, we sought to study whether repeated infantile exposures to surgery and anesthesia affect gut microbiota and anxiety behaviors later in life. (2) Methods: This is a retrospectively matched cohort study comparing 22 pediatric patients of less than 3 years of age with multiple exposures (≥3) to anesthesia for surgeries and 22 healthy controls with no history of exposure to anesthesia. The parent report version of the Spence Children's Anxiety Scale (SCAS-P) was applied to evaluate anxiety in children aged between 6 and 9 years old. Additionally, the gut microbiota profiles of the two groups were compared using 16S rRNA gene sequencing. (3) Results: In behavioral tests, the p-SCAS score of obsessive compulsive disorder and social phobia were significantly higher in children with repeated anesthesia exposure relative to the controls. There were no significant differences between the two groups with respect to panic attacks and agoraphobia, separation anxiety disorder, physical injury fears, generalized anxiety disorder, and the total SCAS-P scores. In the control group, 3 children out of 22 were found to have moderately elevated scores, but none of them had abnormally elevated scores. In the multiple-exposure group, 5 children out of 22 obtained moderately elevated scores, while 2 scored as abnormally elevated. However, no statistically significant differences were detected in the number of children with elevated and abnormally elevated scores. The data show that repeated anesthesia and surgical exposures in children led to long-lasting severe gut microbiota dysbiosis. (4) Conclusions: In this preliminary study, our findings demonstrated that early repeated exposures to anesthesia and surgical predisposes children to anxiety as well as long-term gut microbiota dysbiosis. We should confirm these findings in a larger data population size and with detailed analysis. However, the authors cannot confirm an association between the dysbiosis and anxiety.

Knocking down Trim47 ameliorated sevoflurane-induced neuronal cell injury and cognitive impairment in rats

Sevoflurane (SEV), usually causing neuronal damage and cognitive dysfunction, is one of the most commonly used anesthetics in clinical practice. However, the function of Trim47 in SEV-induced neuronal impairment remains elusive. The aim of this study was to study the effect of knocking down Trim47 on the nerve injury induced by SEV. Nerve injury was induced in rats by 3% SEV, and H19-7 was used to establish a pathological model, and sh-Trim47 was transfected into H19-7 to study the function of Trim47. The effects of SEV on the expression of Trim47 in the hippocampus and cognitive function of rats were studied by neurological function score and Moris water maze (MWM). The mRNA and protein expression of TNF-α, IL-1β and IL-6 in the cells, along with the neuronal apoptosis in the hippocampus of rats in each group were studied by TUNEL or WB. Flow cytometry was used to study the effect of knockdown of Trim47 on cell apoptosis. CCK-8 was used to detect cell viability of H19-7 cells. Finally, the potential signaling pathway affected by knockdown of Trim47 after abrogation of SEV induction was investigated by WB. The results showed that, knockdown of Trim47 ameliorated SEV-induced neurological damage and cognitive deficits, inflammation and neuronal cell apoptosis in rats, and promoted hippocampal neuronal activity. Knockdown of Trim47 can inhibit the NF-κB signaling pathway and improve neuronal cell damage and cognitive impairment induced by SEV in neonatal rats by regulating NF-κB signaling pathway, alleviating inflammatory response, and inhibiting neuronal apoptosis.

Microureteroscopy in the treatment of upper urinary tract stones in pediatric patients younger than 3 years of age

The aim of this study is to evaluate the usefulness of microureteroscopy (m-URS) in the treatment of renal and ureteral stones in children younger than 3 years of age. A retrospective analysis of pediatric patients aged < 3 years with upper urinary tract calculi who underwent lithotripsy was performed. The children were divided into the m-URS group (4.85 F, n = 41) and the ureteroscopy (URS) group (4.5/6.5 F, n = 42) according to the type of ureteroscope used. The mean age of the patients was 23.5 ± 10.7 months in the m-URS group and 20.6 ± 7.1 months in the URS group (P = 0.212). The success rate of one-stage surgery was 80.5% (33/41) for m-URS and 38.1% (16/42) for URS (P < 0.001). The success rates of m-URS were 60.0%, 69.2%, and 91.3% for stones located in the renal pelvis/calix, upper ureter, and mid-lower ureter, respectively. Eight children in the m-URS group and 26 children in the URS group underwent the second-stage ureteroscopic surgery. The mean operation time was 50 (30-60) min in the m-URS group and 40 (34-60) min in the URS group (P = 0.287). The complication rates were 4.9% and 7.1% in the m-URS and URS groups, respectively (P = 1.000). The stone-free rate at 1 month after lithotripsy was 87.8% in the m-URS group and 83.3% in the URS group (P = 0.563). The mean anesthesia session was 2.1 in the m-URS group and 2.5 in the URS group (P = 0.002). M-URS can effectively reduce the number of anesthesia sessions and is considered an alternative treatment for upper urinary tract calculi in selected pediatric patients younger than 3 years of age.

Bicuculline and Bumetanide Attenuate Sevoflurane-Induced Impairment of Myelination and Cognition in Young Mice

Sevoflurane (Sevo) is one of the most commonly used general anesthetics for infants and young children. We investigated whether Sevo impairs neurological functions, myelination, and cognition via the γ-aminobutyric acid A receptor (GABA_AR) and Na⁺-K⁺-2Cl^- cotransporter (NKCC1) in neonatal mice. On postnatal days 5-7, mice were exposed to 3% Sevo for 2 h. On postnatal day 14, mouse brains were dissected, and oligodendrocyte precursor cell line level lentivirus knockdown of GABRB3, immunofluorescence, and transwell migration assays were performed. Finally, behavioral tests were conducted. Multiple Sevo exposure groups exhibited increased neuronal apoptosis levels and decreased neurofilament protein levels in the mouse cortex compared with the control group. Sevo exposure inhibited the proliferation, differentiation, and migration of the oligodendrocyte precursor cells, thereby affecting their maturation process. Electron microscopy revealed that Sevo exposure reduced myelin sheath thickness. The behavioral tests showed that multiple Sevo exposures induced cognitive impairment. GABA_AR and NKCC1 inhibition provided protection against Sevo-induced neurotoxicity and cognitive dysfunction. Thus, bicuculline and bumetanide can protect against Sevo-induced neuronal injury, myelination impairment, and cognitive dysfunction in neonatal mice. Furthermore, GABA_AR and NKCC1 may be mediators of Sevo-induced myelination impairment and cognitive dysfunction.

The Management of Postoperative Cognitive Dysfunction in Cirrhotic Patients: An Overview of the Literature

Background and objectives: Postoperative cognitive dysfunction (POCD) represents a decreased cognitive performance in patients undergoing general anesthesia for major surgery. Since liver cirrhosis is associated with high mortality and morbidity rates, cirrhotic patients also assemble many risk factors for POCD. Therefore, preserving cognition after major surgery is a priority, especially in this group of patients. The purpose of this review is to summarize the current knowledge regarding the effectiveness of perioperative therapeutic strategies in terms of cognitive dysfunction reduction. Data Collection: Using medical search engines such as PubMed, Google Scholar, and Cochrane library, we analyzed articles on topics such as: POCD, perioperative management in patients with cirrhosis, hepatic encephalopathy, general anesthesia in patients with liver cirrhosis, depth of anesthesia, virtual reality in perioperative settings. We included 115 relevant original articles, reviews and meta-analyses, and other article types such as case reports, guidelines, editorials, and medical books. Results: According to the reviewed literature, the predictive capacity of the common clinical tools used to quantify cognitive dysfunction in cirrhotic settings is reduced in perioperative settings; however, novel neuropsychological tools could manage to better identify the subclinical forms of perioperative cognitive impairments in cirrhotic patients. Moreover, patients with preoperative hepatic encephalopathy could benefit from specific preventive strategies aimed to reduce the risk of further neurocognitive deterioration. Intraoperatively, the adequate monitoring of the anesthesia depth, appropriate anesthetics use, and an opioid-sparing technique have shown favorable results in terms of POCD. Early recovery after surgery (ERAS) protocols should be implemented in the postoperative setting. Other pharmacological strategies provided conflicting results in reducing POCD in cirrhotic patients. Conclusions: The perioperative management of the cognitive function of cirrhotic patients is challenging for anesthesia providers, with specific and targeted therapies for POCD still sparse. Therefore, the implementation of preventive strategies appears to remain the optimal attitude. Further research is needed for a better understanding of POCD, especially in cirrhotic patients.

Solid Xenon Carrier Based on α-Cyclodextrin: Properties, Preparation, and Application

The inert gas xenon (Xe) is increasingly used in medicine as a universal anesthetic, a regulator of cellular metabolism, and a broad-spectrum organoprotector. Commonly utilized Xe inhalation requires expensive equipment that is not universally available. Here we describe the production process and physical characteristics of a solid, highly stable xenon carrier based on α-cyclodextrin (α-CD), developed for oral administration. It was found, that the interaction of α-CD with Xe in an aqueous solution and elevated pressure leads to precipitation of the α-CD-Xe complex. We have discovered three new properties of the resulting complex that promote long-term storage and oral delivery of Xe. (i) At temperatures below 0 °C, the precipitated α-CD-Xe complex containing water is so stable that it allows the removal of water by vacuum freeze-drying (lyophilization). (ii). Lyophilized α-CD-Xe remains stable for months at room temperature. (iii) Upon contact with water, α-CD-Xe rapidly releases gaseous Xe. As revealed in the forced swim test, after oral administration of lyophilized α-CD-Xe to rats, the duration of swimming was significantly increased. The obtained data open up prospects for the development of drugs based on the lyophilized α-CD-Xe complex suitable for storage, transportation, and medical use, including outside the hospital.

Effects of lncRNA HOXA11-AS on Sevoflurane-Induced Neuronal Apoptosis and Inflammatory Responses by Regulating miR-98-5p/EphA4

Objective

To explore the molecular mechanism of sevoflurane-induced neurotoxicity and to determine whether lncRNA HOXA11-AS affects sevoflurane-induced neuronal apoptosis and inflammation by regulating miR-98-5p/EphA4.

Methods

Morris water maze (MWM) test was used to detect the learning and memory ability of rats, HE staining was used to observe hippocampal pathology, TUNEL staining was used to detect the level of neuronal apoptosis, and RT-qPCR was used to detect the expression of HOXA11-AS, miR-98-5p, IL-6, IL-1β, and TNF-α. At the same time, the contents of IL-6, IL-1β, and TNF-α in serum were detected by ELISA. The expressions of apoptosis-related proteins EphA4, Bax, Cleaved caspase 3, and Bcl-2 were detected by Western blot. The dual-luciferase gene reporter verified the targeting relationship between HOXA11-AS and miR-98-5p and the targeting relationship between miR-98-5p and EphA4.

Results

The expression of HOXA11-AS was observed in sevoflurane-treated rats or cells and promoted neuronal apoptosis and inflammation. HOXA11-AS was knocked out alone, or miR-98-5p was overexpressed which attenuates neuronal apoptosis and inflammatory inflammation after sevoflurane treatment. Furthermore, knockdown of HOXA11-AS alone was partially restored by knockdown of miR-98-5p or overexpression of EphA4.

Conclusion

Inhibition of lncRNA HOXA11-AS attenuates sevoflurane-induced neuronal apoptosis and inflammatory responses via miR-98-5p/EphA4.

Safety of Cochlear Implantation in Children 12 Months or Younger: Systematic Review and Meta-analysis

OBJECTIVE

To systematically review the literature to determine safety of cochlear implantation in pediatric patients 12 months and younger.

DATA SOURCE

Ovid MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched from inception to March 20, 2021.

REVIEW METHODS

Studies that involved patients 12 months and younger with report of intraoperative or postoperative complication outcomes were included. Studies selected were reviewed for complications, explants, readmissions, and prolonged hospitalizations. Two independent reviewers screened all studies that were selected for the systematic review and meta-analysis. All studies included were assessed for quality and risk of bias.

RESULTS

The literature search yielded 269 studies, of which 53 studies underwent full-text screening, and 18 studies were selected for the systematic review and meta-analysis. A total of 449 patients and 625 cochlear implants were assessed. Across all included studies, major complications were noted in 3.1% of patients (95% CI, 0.8-7.1) and 2.3% of cochlear implantations (95% CI, 0.6-5.2), whereas minor complications were noted in 2.4% of patients (95% CI, 0.4-6.0) and 1.8% of cochlear implantations (95% CI, 0.4-4.3). There were no anesthetic complications reported across all included studies.

CONCLUSION

The results of this systematic review and meta-analysis suggest that cochlear implantation in patients 12 months and younger is safe with similar rates of complications to older cohorts.

The Crosstalk between the Blood–Brain Barrier Dysfunction and Neuroinflammation after General Anaesthesia

As we know, with continuous medical progress, the treatment of many diseases can be conducted via surgery, which often relies on general anaesthesia for its satisfactory performance. With the widespread use of general anaesthetics, people are beginning to question the safety of general anaesthesia and there is a growing interest in central nervous system (CNS) complications associated with anaesthetics. Recently, abundant evidence has suggested that both blood–brain barrier (BBB) dysfunction and neuroinflammation play roles in the development of CNS complications after anaesthesia. Whether there is a crosstalk between BBB dysfunction and neuroinflammation after general anaesthesia, and whether this possible crosstalk could be a therapeutic target for CNS complications after general anaesthesia needs to be clarified by further studies.

Clinical Observation of General Anesthesia Combined with Spinal Anesthesia in Elderly Patients with Chronic Obstructive Pulmonary Disease

Objective

This work is aimed at evaluating the efficacy and safety of general anesthesia (GA) combined with spinal anesthesia (SA) (GA+SA) in elderly patients with chronic obstructive pulmonary disease (COPD). Methods and Material. 50 elderly COPD patients were rolled randomly into a control group (simple GA) and observation group (GA+SA). The differences in operation time, postoperative recovery time (PRT), language expression time (LET), anesthetic dosage (AD), catheter extubation time (CET), respiratory circulation indicators (mean arterial pressure (MAP), heart rate (HR), SaO2, and PaO2), postoperative VRS score, pulmonary function (forced vital capacity (FVC)), forced expiratory volume in 1 s (FEV1)/FVC and forced expiratory flow (FEF 25%~75%), serum inflammatory factors (IL-6, IL-8, and TNF-α), Short Portable Mental Status Questionnaire (SPMSQ) score, and the incidence of respiratory system events were analyzed.

Results

The results showed that the PRT, LET, AD, and CET of the observation group were all shorter (P < 0.05). The postoperative MAP, HR, SaO2, and PaO2 levels of patients who received GA+SA were much higher than those who received simple GA (P < 0.05). The postoperative VRS score of the observation group was better than that of the controls (P < 0.05). The postoperative pulmonary function of patients in the observation group was better compared with that in the control group (P < 0.05). The postoperative serum inflammatory factors in the observation group were lower in contrast to the patients who received simple GA (P < 0.05). The postoperative cognitive function SPMSQ score of patients who received GA+SA was lower compared with the score of patients who received simple GA (P < 0.05). However, the probability of respiratory system events in the observation group was lower (P < 0.05).

Conclusion

In conclusion, GA+SA could significantly shorten the PRT and improve the recovery quality of elderly COPD patients. It can also reduce the postoperative inflammatory response and strengthen the pulmonary function and cognitive function. It also enhances the analgesic which is beneficial to patients' postoperative recovery. Therefore, GA+SA was a highly effective and safe anesthesia method for elderly patients with COPD, and it was worthy of clinical application.

Isoflurane Disrupts Postsynaptic Density-95 Protein Interactions Causing Neuronal Synapse Loss and Cognitive Impairment in Juvenile Mice via Canonical NO-mediated Protein Kinase-G Signaling

BACKGROUND

Inhalational anesthetics are known to disrupt PDZ2 domain-mediated protein-protein interactions of the postsynaptic density (PSD)-95 protein. The aim of this study is to investigate the underlying mechanisms in response to early isoflurane exposure on synaptic PSD-95 PDZ2 domain disruption that altered spine densities and cognitive function. The authors hypothesized that activation of protein kinase-G by the components of nitric oxide (NO) signaling pathway constitutes a mechanism that prevents loss of early dendritic spines and synapse in neurons and cognitive impairment in mice in response to disruption of PDZ2 domain of the PSD-95 protein.

METHODS

Postnatal day 7 mice were exposed to 1.5% isoflurane for 4 h or injected with 8 mg/kg active PSD-95 wild-type PDZ2 peptide or soluble guanylyl cyclase activator YC-1 along with their respective controls. Primary neurons at 7 days in vitro were exposed to isoflurane or PSD-95 wild-type PDZ2 peptide for 4 h. Coimmunoprecipitation, spine density, synapses, cyclic guanosine monophosphate-dependent protein kinase activity, and novel object recognition memory were assessed.

RESULTS

Exposure of isoflurane or PSD-95 wild-type PDZ2 peptide relative to controls causes the following. First, there is a decrease in PSD-95 coimmunoprecipitate relative to N-methyl-d-aspartate receptor subunits NR2A and NR2B precipitate (mean ± SD [in percentage of control]: isoflurane, 54.73 ± 16.52, P = 0.001; and PSD-95 wild-type PDZ2 peptide, 51.32 ± 12.93, P = 0.001). Second, there is a loss in spine density (mean ± SD [spine density per 10 µm]: control, 5.28 ± 0.56 vs. isoflurane, 2.23 ± 0.67, P < 0.0001; and PSD-95 mutant PDZ2 peptide, 4.74 ± 0.94 vs. PSD-95 wild-type PDZ2 peptide, 1.47 ± 0.87, P < 0.001) and a decrease in synaptic puncta (mean ± SD [in percentage of control]: isoflurane, 41.1 ± 14.38, P = 0.001; and PSD-95 wild-type PDZ2 peptide, 50.49 ± 14.31, P < 0.001). NO donor or cyclic guanosine monophosphate analog prevents the spines and synapse loss and decline in the cyclic guanosine monophosphate-dependent protein kinase activity, but this prevention was blocked by soluble guanylyl cyclase or protein kinase-G inhibitors in primary neurons. Third, there were deficits in object recognition at 5 weeks (mean ± SD [recognition index]: male, control, 64.08 ± 10.57 vs. isoflurane, 48.49 ± 13.41, P = 0.001, n = 60; and female, control, 67.13 ± 11.17 vs. isoflurane, 53.76 ± 6.64, P = 0.003, n = 58). Isoflurane-induced impairment in recognition memory was preventable by the introduction of YC-1.

CONCLUSIONS

Activation of soluble guanylyl cyclase or protein kinase-G prevents isoflurane or PSD-95 wild-type PDZ2 peptide-induced loss of dendritic spines and synapse. Prevention of recognition memory with YC-1, a NO-independent activator of guanylyl cyclase, supports a role for the soluble guanylyl cyclase mediated protein kinase-G signaling in countering the effects of isoflurane-induced cognitive impairment.

EDITOR’S PERSPECTIVE

Carnosol alleviates sevoflurane-induced cognitive dysfunction by mediating NF-κB pathway in aged rats

Postoperative Cognitive Dysfunction (POCD) is a neurological disorder of unconsciousness due to cognitive regression after surgical anesthesia. However, the specific mechanism has not yet been clarified. Sevoflurane (SEV) is one of the most commonly used anesthetics in clinical practice, and how SEV mediates the generation of POCD is unclear. Carnosol, a natural ingredient, has been reported to have various beneficial effects such as anti-inflammatory, immune enhancement, and so forth, but how it ameliorates SEV-mediated neurotoxicity remains unclear. This study aimed to induce a POCD model in aged rats by SEV and to elucidate how Carnosol ameliorated SEV-mediated neurotoxicity. The effects of Carnosol on the expression of inflammatory factors in rat hippocampus mediated by SEV were determined by enzyme-linked immunoassay and polymerase chain reaction experiments; the effects of Carnosol on the expressions of Iba-1 and glial fibrillary acidic protein after SEV-mediated activation of rat microglia were clarified by immunofluorescence and Western blotting (WB); The effects of Carnosol on SEV-mediated neuronal apoptosis were studied by terminal deoxynucleotidyl transferase dUTP nick end labeling and WB; the specific signaling pathways regulated by Carnosol were elucidated by WB. The results showed that Carnosol can improve the cognitive dysfunction and reduce neuroinflammation in aged rats induced by SEV; Carnosol can reduce the activation of microglia and inhibit neuronal apoptosis in aged rats induced by SEV; Carnosol can phosphorylate p65 and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha regulates the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. Carnosol can attenuate SEV-induced neuroinflammation, prevent microglial activation and inhibit neuronal apoptosis by modulating the NF-κB pathway.

The Safety of Propofol Versus Sevoflurane for General Anesthesia in Children: A Meta-Analysis of Randomized Controlled Trials

Background

Propofol and sevoflurane are the most used anesthetics for pediatric surgery. Emergence agitation, postoperative nausea and vomiting and postoperative pain are the primary adverse effect of these general anesthetics. Many clinical studies had compared the safety of propofol and sevoflurane in pediatric surgery, but the results were controversial.

Objectives

To evaluate the evidence surrounding the safety of propofol versus sevoflurane for general anesthesia in children.

Methods

Databases including PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang Data and Vip Data were searched to collect relevant articles. Trials were strictly selected according to previously defined inclusion and exclusion criteria. RevMan 5.3 software was used for meta-analyses.

Results

Twenty randomized controlled trials recruiting 1,550 children for general anesthesia were included, with overall low-moderate methodological quality. There was evidence that compared with sevoflurane anesthesia, propofol anesthesia significantly decreased the incidence of emergence agitation (OR = 4.99, 95% CI, 3.67–6.80; P &lt; 0.00001), postoperative nausea and vomiting (OR = 1.91, 95% CI, 1.27–2.87; P  =  0.002) and postoperative pain (OR = 1.72, 95% CI, 1.11–2.64; P = 0.01) in children. However, patients who received sevoflurane tended to have shorter times to eye opening (MD = −2.58, 95% CI, −2.97– −2.19; P &lt; 0.00001) and times to extubation (MD = −1.42, 95% CI, −1.81– −1.02; P &lt; 0.00001).

Conclusions

This review reveals that the children who received propofol anesthesia had the lower risks of emergence agitation, postoperative nausea and vomiting and postoperative pain when compared with sevoflurane anesthesia. But the children who received sevoflurane recovered slightly faster than those received propofol. Considering the limitations of the included studies, better methodological quality and large controlled trials are expected to further quantify the safety of propofol and sevoflurane for general anesthesia in children.

Mechanistic insight into sevoflurane-associated developmental neurotoxicity

With the development of technology, more infants receive general anesthesia for surgery, other interventions, or clinical examination at an early stage after birth. However, whether general anesthetics can affect the function and structure of the developing infant brain remains an important, complex, and controversial issue. Sevoflurane is the most-used anesthetic in infants, but this drug is potentially neurotoxic. Short or single exposure to sevoflurane has a weak effect on cognitive function, while long or repeated exposure to general anesthetics may cause cognitive dysfunction. This review focuses on the mechanisms by which sevoflurane exposure during development may induce long-lasting undesirable effects on the brain. We review neural cell death, neural cell damage, impaired assembly and plasticity of neural circuits, tau phosphorylation, and neuroendocrine effects as important mechanisms for sevoflurane-induced developmental neurotoxicity. More advanced technologies and methods should be applied to determine the underlying mechanism(s) and guide prevention and treatment of sevoflurane-induced neurotoxicity.

1. We discuss the mechanisms underlying sevoflurane-induced developmental neurotoxicity from five perspectives: neural cell death, neural cell damage, assembly and plasticity of neural circuits, tau phosphorylation, and neuroendocrine effects. 2. Tau phosphorylation, IL-6, and mitochondrial dysfunction could interact with each other to cause a nerve damage loop. 3. miRNAs and lncRNAs are associated with sevoflurane-induced neurotoxicity.

Knowledge, Attitude, and Performance of Pregnant Women Regarding General Anesthesia Neurotoxicity in Children under Three: A Report from an Academic Hospital

Background: Recently, concerns about general anesthesia (GA)-related neurotoxicity has been growing in societies. Parents’ information obviously plays an important role to make right decision for elective surgeries on children aged under three years old. Objectives: The aim of this survey was to evaluate the knowledge, attitude, and performance of pregnant women about the GA-related neurotoxicity in children aged under three years old. Methods: This descriptive study was conducted at Alzahra Teaching Hospital in Guilan, Iran, during 2020. The eligible pregnant women admitted to this center were interviewed, and a questionnaire containing 10 items was filled out by the responsible resident of anesthesiology. Results: In this research, a total of 361 pregnant women were enrolled and underwent a face-to-face interview. The mean age of the participants was 31.4 ± 7 years, 64.5% were living in urban areas, 82.5% were housewives, and 65.7% were multipara. Moreover, 83.7% of participants believed that receiving information in this regard was crucial, and 81.7% preferred physicians as the source of information. Only 8% of mothers had received information regarding the issue. A significant correlation was observed between the habitat, employment, the level of education, knowledge, and attitude status, and the source of receiving information. Conclusions: According to our results, the knowledge, attitude, and performance of pregnant women were not optimal and needed to be improved through practical strategies.

Essential Infantile Esotropia: A Course of Treatment From Our Experience

Background: Essential infantile esotropia (EIE) is the most common type of childhood esotropia. Although its classical approach is surgical, less invasive techniques have been proposed as an adjunct or alternative to traditional surgery. Among them, chemodenervation with botulinum toxin (BT) has been investigated, showing variable and sometimes conflicting results. Objectives: To compare the outcomes of bilateral BT injection and traditional surgery in a pediatric population with EIE in order to optimize and standardize the therapeutic approach. Other purposes are to evaluate whether early intervention may prevent the onset of vertical ocular deviation (which is part of the clinical picture of EIE) and/or influence the development of fine stereopsis, and also to assess changes in refractive status over time among the enrolled population. Methods: A retrospective consecutive cohort study was conducted in 86 children aged 0-48 months who underwent correction of EIE. The primary intervention in naïve subjects was either bilateral BT injection (36 subjects, "BT group") or strabismus surgery (50 subjects, "surgery group"). Results: Overall, BT chemodenervation (one or two injections) was effective in 13 (36.1%) subjects. With regard to residual deviation angle, the outcomes at least 5 years after the last intervention were overlapping in children receiving initial treatment with either injection or surgery; however, the success rate of primary intervention in the surgery group was higher, and the average number of interventions necessary to achieve orthotropia was smaller. Both early treatment with chemodenervation and surgery at a later age were not found to prevent the onset of vertical ocular deviation, whereas, surprisingly, the percentage of subjects developing fine stereopsis was higher in the surgery group. Finally, with regard to the change in refractive status over time, most of the subjects increased their initial hyperopia, whereas 10% became myopic. Conclusions: Our data suggest that a single bilateral BT injection by age 2 years should be considered as the first-line treatment of EIE without vertical component; whereas, traditional surgery should be considered as the first-line treatment for all other cases and in subjects unresponsive to primary single BT injection.

Minimally-Invasive Surgical Approach to Congenital Dacryostenosis: Proposal for a New Protocol

Background: Congenital dacryostenosis is one of the most common ophthalmological disorders in infants, with a high spontaneous resolution rate. In patients unresponsive to conservative treatment, the first-line approach is lacrimal drainage system probing, thought there is no clear consensus on optimal timing of surgery. The optimal treatment of patients unresponsive to primary probing is also controversial. Objectives: The aim of this study is to assess the optimal timing of probing in children with congenital dacryostenosis. Other purposes are to evaluate the efficacy of repeated probing and dacryointubation in patients unresponsive to the initial surgery without evident lacrimal outflow dysgenesis, and to determine the epidemiology of these maldevelopments. Methods: A retrospective consecutive cohort study was conducted in 625 eyes of 457 patients aged 7-48 months who underwent surgery for dacryostenosis. Patients were divided into 4 cohorts according to the timing of surgery. Data were analyzed using Fisher's test. Results: The success rate of primary probing was high, without significant differences between cohorts. One-third of recurrences were related to maldevelopments, the other two-thirds were treated with a second probing or dacryointubation, with high success rates, that did not significantly differ between the procedures. All cases unresponsive to the second surgery were resolved with dacryointubation. Conclusions: Probing is highly effective and its outcome is not affected by timing of surgery. Nevertheless, we advocate for early intervention, in order to identify possible maldevelopments, which require more invasive management. In patients unresponsive to primary probing, without evident maldevelopments, repeated probing should still be considered as the first-line approach, since it's less invasive but similarly effective to dacryointubation.