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

Hyperoxia and brain: the link between necessity and injury from a molecular perspective

Oxygen (O2) supplementation is commonly used to treat hypoxia in patients with respiratory failure. However, indiscriminate use can lead to hyperoxia, a condition detrimental to living tissues, particularly the brain. The brain is sensitive to reactive oxygen species (ROS) and inflammation caused by high concentrations of O2, which can result in brain damage and mitochondrial dysfunction, common features of neurodegenerative disorders. Hyperoxia leads to increased production of ROS, causing oxidative stress, an imbalance between oxidants and antioxidants, which can damage tissues. The brain is particularly vulnerable to oxidative stress due to its lipid composition, high O2 consumption rate, and low levels of antioxidant enzymes. Moreover, hyperoxia can cause vasoconstriction and decreased O2 supply to the brain, posing a challenge to redox balance and neurodegenerative processes. Studies have shown that the severity of hyperoxia-induced brain damage varies with inspired O2 concentration and duration of exposure. Therefore, careful evaluation of the balance between benefits and risks of O2 supplementation, especially in clinical settings, is crucial.

Regional Anesthesia for Neonates

Pain management in neonates and infants has many unique and important facets, particularly in former preterm infants. Untreated pain and surgical stress in neonates are associated with myriad negative sequelae, including deleterious inflammatory, autonomic, hormonal, metabolic, and neurologic effects. Meanwhile, opioid side effects are also very impactful and affect multiple systems and pathways, particularly in the neonatal and infant population. Regional anesthesia presents a unique opportunity to provide highly effective analgesia; prevent deleterious signaling cascade pathways within the endocrine, immune, and nervous systems from occurring; and create conditions to facilitate reduced reliance on opioids and other analgesics. In some cases, clinicians can completely avoid general anesthesia and systemic anesthetics. This review will discuss some of the unique aspects of pain management in neonates and infants and provide an overview of the different regional anesthetic options available, namely, spinal anesthesia, epidural anesthesia, and peripheral nerve blocks.

Minimum 5-Year Results of Elongation Derotation Flexion Casting for Early Onset Scoliosis: The Story Is Not Over Until Skeletal Maturity

BACKGROUND

Early conservative treatment for patients with idiopathic infantile scoliosis (IIS) with elongation derotation flexion (EDF) casting and subsequent serial bracing has become widely utilized. However, the long-term outcomes of patients treated with EDF casting are limited.

METHODS

We performed a retrospective chart review of all patients who had undergone serial elongation derotation flexion casting and subsequent bracing for scoliosis presenting at a single large tertiary center. All patients were followed for a minimum of 5 years or until surgical intervention.

RESULTS

Our study included 21 patients diagnosed with IIS and treated with EDF casting. At a mean 7-year follow-up, 13 of the 21 patients were considered successfully treated with a mean final major coronal curvature of 9 degrees compared to a pretreatment coronal curve of 36 degrees. These patients, on average, began casting at 1.3 years old and spent 1 year in a cast. Patients that did not have substantial improvement began casting at mean 4 years old and remained in a cast for 0.8 years. Three patients initially had substantial improvement with the correction to <20 degrees at a mean age of 7; however, their curves worsened in adolescence with poor brace compliance. All 3 patients will require surgical intervention. Of the patients not successfully treated with casting, 7 required surgery at a mean 8.2 years of age, 4.3 years after initiation of casting. A significant predictor of treatment failure was older age of cast initiation (P<0.001).

CONCLUSIONS

EDF casting can be an effective cure for IIS patients if initiated at a young age with 15 of 21 patients successfully treated (76%). However, 3 patients had a recurrence in adolescence resulting in an overall success rate of only 62%. Casting should be initiated early to maximize the likelihood of treatment success and periodic monitoring should be continued through skeletal maturity as recurrence during adolescence can occur.

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

Background

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

Methods

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

Results

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

Conclusion

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

Hyperoxia by short-term promotes oxidative damage and mitochondrial dysfunction in rat brain

Oxygen (O₂) therapy is used as a therapeutic protocol to prevent or treat hypoxia. However, a high inspired fraction of O₂ (FIO₂) promotes hyperoxia, a harmful condition for the central nervous system (CNS). The present study evaluated parameters of oxidative stress and mitochondrial dysfunction in the brain of rats exposed to different FIO₂. Male Wistar rats were exposed to hyperoxia (FIO₂ 40 % and 60 %) compared to the control group (FIO₂ 21 %) for 2 h. Oxidative stress, neutrophilic infiltration, and mitochondrial respiratory chain enzymes were determined in the hippocampus, striatum, cerebellum, cortex, and prefrontal cortex after O₂ exposure. The animals exposed to hyperoxia showed increased lipid peroxidation, formation of carbonyl proteins, N/N concentration, and neutrophilic infiltration in some brain regions, like hippocampus, striatum, and cerebellum being the most affected. Furthermore, CAT activity and activity of mitochondrial enzyme complexes were also altered after exposure to hyperoxia. Rats exposed to hyperoxia showed increase in oxidative stress parameters and mitochondrial dysfunction in brain structures.

The impact of early exposure to general anesthesia on visual and neurocognitive development

Every year millions of children are exposed to general anesthesia while undergoing surgical and diagnostic procedures. In the field of ophthalmology, 44,000 children are exposed to general anesthesia annually for strabismus surgery alone. While it is clear that general anesthesia is necessary for sedation and pain minimization during surgical procedures, the possibility of neurotoxic impairments from its exposure is of concern. In animals there is strong evidence linking early anesthesia exposure to abnormal neural development. but in humans the effects of anesthesia are debated. In humans many aspects of vision develop within the first year of life, making the visual system vulnerable to early adverse experiences and potentially vulnerable to early exposure to general anesthesia. We attempt to address whether the visual system is affected by early postnatal exposure to general anesthesia. We first summarize key mechanisms that could account for the neurotoxic effects of general anesthesia on the developing brain and review existing literature on the effects of early anesthesia exposure on the visual system in both animals and humans and on neurocognitive development in humans. Finally, we conclude by proposing future directions for research that could address unanswered questions regarding the impact of general anesthesia on visual development.

After nectarine: how should we provide anesthesia for neonates?

PURPOSE OF REVIEW

Neonates have a high risk of perioperative morbidity and mortality. The NEonate and Children audiT of Anaesthesia pRactice IN Europe (NECTARINE) investigated the anesthesia practice, complications and perioperative morbidity and mortality in neonates and infants <60 weeks post menstrual age requiring anesthesia across 165 European hospitals. The goal of this review is to highlight recent publications in the context of the NECTARINE findings and subsequent changes in clinical practice.

RECENT FINDINGS

A perioperative triad of hypoxia, anemia, and hypotension is associated with an increased overall mortality at 30 days. Hypoxia is frequent at induction and during maintenance of anesthesia and is commonly addressed once oxygen saturation fall below 85%.Blood transfusion practices vary widely variable among anesthesiologists and blood pressure is only a poor surrogate of tissue perfusion. Newer technologies, whereas acknowledging important limitations, may represent the currently best tools available to monitor tissue perfusion. Harmonization of pediatric anesthesia education and training, development of evidence-based practice guidelines, and provision of centralized care appear to be paramount as well as pediatric center referrals and international data collection networks.

SUMMARY

The NECTARINE provided new insights into European neonatal anesthesia practice and subsequent morbidity and mortality.Maintenance of physiological homeostasis, optimization of oxygen delivery by avoiding the triad of hypotension, hypoxia, and anemia are the main factors to reduce morbidity and mortality. Underlying and preexisting conditions such as prematurity, congenital abnormalities carry high risk of morbidity and mortality and require specialist care in pediatric referral centers.

Percutaneous Closure of Patent Ductus Arteriosus

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

Pediatric eosinophilic esophagitis: a review for the clinician

Eosinophilic esophagitis (EoE) is a chronic clinical-pathologic disease characterized by eosinophilic infiltration of the esophageal epithelium with esophageal dysfunction symptoms.EoE can occur at any age and has different clinical manifestations depending on the age onset.To date, esophago-gastroduodenal endoscopy (EGD) with biopsy is the gold-standard for EoE diagnosis.According to the recent consensus guidelines, proton pump inhibitors, corticosteroids and elimination diets could be a first-line therapy option. The aim of the treatment is clinical and histological remission for preventing long-lasting untreatable fibrosis.A multidisciplinary approach (allergist, gastroenterology, dietitian, and pathologist) is recommended for managing patients affected by EoE, given the complexity of its treatment.This review will provide a practical guide to assist pediatricians treating children with EoE.Moreover, it highlights the unmet needs in diagnosis and treatment that require urgent attention from the scientific community in the aim of improving the management of patients with EoE.

The outcome of laparoscopic assisted orchidopexy in very young children: A single hospital experience

INTRODUCTION

Early orchidopexy has been linked to improved long term outcomes of fertility and reduced malignancy rates. However, the optimal age of intervention has been subject to change over the years.

OBJECTIVE

This study aims to study males aged 6 months or less who undergo laparoscopic assisted orchidopexy for intraabdominal testes to establish the safety, efficacy, and benefit in the defined age group.

STUDY DESIGN

We prospectively assessed 19 boys at or below 6 months of age, who had laparoscopic assisted orchidopexy for intraabdominal undescended testes at Salmaniya Medical Complex in Bahrain between January 2014 and December 2018. We examined: demographics, laterality, testicular locations, testicular volumes, operative time, complications, and durations of hospitalization and follow-up. Ultrasound-derived testicular volumes were assessed before and after orchidopexy. They were calculated using the Hansen formula (Testicular volume = 0.52 × length [L] × width [W]² [1]. They were then compared with reference ranges from a Dutch cohort study of 769 healthy boys. Successful outcomes were correct intrascrotal position with minimal complications and normal testicular volumes.

RESULTS

A total of 19 males were operated at a mean age of 5.6 months and followed for a mean of 2.35 years. Of these, 7 had left-sided and 12 had right-sided cryptorchidism. Testicular locations were noted intra-operatively; 10 were above the internal ring, 5 near the iliac vessels, and 4 close to the kidney. The mean operative time was 59.58 minutes. Only 2 minor complications occurred and no cases of testicular atrophy. None of the patients required hospital-stay beyond 24 hours. The success rate was 89.46% in achieving correct scrotal position. Testicular volumes were normal before and after orchidopexy. They significantly increased after orchidopexy (P ≤ 0.05). The testicular growth rate after 24 months was slightly higher than normal.

DISCUSSION

In line with previous studies we were 89.46% successful in re-positioning testes [2]. In contrast to studies intervening at older ages which associated intra-abdominal testes with greater risks of complications, we found few minor complications and no testicular atrophy [3,4]. Testicular volumes in the affected testes were normal, contrary to decreased volumes found by other researchers [5]. Limitations of this study are the small number of patients and short follow-up which limits assessment of long-term outcomes.

CONCLUSION

Early orchiopexy is safe and effective. Laparoscopic assisted orchidopexy at an early age was beneficial and resulted in normal testicular volumes before and after surgery.