Long-term differences in language and cognitive function after childhood exposure to anesthesia

General Anesthesia-Related Neurotoxicity in the Developing Brain and Current Knowledge and Practice of Physicians at Guilan Academic Hospitals

Background

Recent articles about the topic of the anesthetic agents-related neurotoxicity have currently attracted the attention to the issue in the anesthesiology community. However, specialists in other fields should also be aware of this potential risk.

Objectives

This study aimed to evaluate the knowledge and practice of physicians at Guilan academic hospitals regarding general anesthesia-related neurotoxicity.

Methods

Firstly, the responsible anesthesia resident explained the purpose of this work to Guilan faculty and residents and if they agreed to participate a questionnaire containing 12 items was filled via a face to face interview.

Results

A response rate of 100% was achieved (271 responders from 271 eligible study responders). Also, 89 (33.1%) responders were attending, 180 (66.9%) were residents, 112 (41.6%) were female, and 157 (58.4%) were male. The mean years of experience was 8.8 ± 4.82 (2 - 28 years). According to the achieved data, the majority of the precipitants did not believe in GA toxicity.

Conclusions

This paper revealed that the current curriculum does not sufficiently address the anesthesia-related neurotoxicity problem. Indeed, the need for training and communication with non-anesthesia medical colleagues was highlighted.

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

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

Anesthetics disrupt growth cone guidance cue sensing through actions on the GABAA α2 receptor mediated by the immature chloride gradient

BACKGROUND

General anesthetics (GAs) may exert harmful effects on the developing brain by disrupting neuronal circuit formation. Anesthetics that act on γ-aminobutyric acid (GABA) receptors can interfere with axonal growth cone guidance, a critical process in the assembly of neuronal circuitry. Here we investigate the mechanism by which isoflurane prevents sensing of the repulsive guidance cue, Semaphorin 3A (Sema3A).

METHODS

Growth cone sensing was assayed by measuring growth cone collapse in dissociated neocortical cultures exposed to recombinant Sema3A in the presence or absence of isoflurane and/or a panel of reagents with specific actions on components of the GABA receptor and chloride ion systems.

RESULTS

Isoflurane exposure prevents Sema3A induced growth cone collapse. A GABA_A α2 specific agonist replicates this effect (36.83 ± 3.417% vs 70.82 ± 2.941%, in the Sema3A induced control group, p < 0.0001), but an α1-specific agonist does not. Both a Na-K-Cl cotransporter 1 antagonism (bumetanide, BUM) and a chloride ionophore (IONO) prevent isoflurane from disrupting growth cone sensing of Sema3A. (65.67 ± 3.775% in Iso + BUM group vs 67.45 ± 3.624% in Sema3A induced control group, 65.34 ± 1.678% in Iso + IONO group vs 68.71 ± 2.071% in Sema3A induced control group, no significant difference) (n = 96 growth cones per group).

CONCLUSION

Our data suggest that the effects of isoflurane on growth cone sensing are mediated by the α2 subunit of the GABA_A receptor and also that they are dependent on the developmental chloride gradient, in which Cl^- exhibits a depolarizing effect. These findings provide a rationale for why immature neurons are particularly susceptible to anesthetic toxicity.

Anesthetics: from modes of action to unconsciousness and neurotoxicity

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

Both GSK-3β/CRMP2 and CDK5/CRMP2 pathways participate in the protection of dexmedetomidine against propofol-induced learning and memory impairment in neonatal rats

Dexmedetomidine has been reported to ameliorate propofol-induced neurotoxicity in neonatal animals. However, the underlying mechanism is still undetermined. Glycogen synthase kinase-3β (GSK-3β), cycline dependent kinase-5 (CDK5) and Rho-kinase (RhoA) pathways play critical roles in neuronal development. The present study is to investigate whether GSK-3β, CDK5 and RhoA pathways are involved in the neuroprotection of dexmedetomidine. Seven-day-old (P7) Sprague-Dawley rats were anesthetized with propofol for 6 h. Dexmedetomidine at various concentrations were administered before propofol exposure. Neuroapoptosis, the neuronal proliferation and the level of neurotransmitter in the hippocampus were evaluated. The effects of GSK-3β inhibitor SB415286, CDK5 inhibitor roscovitine or RhoA inhibitor Y276321 on propofol-induced neurotoxicity were assessed. Propofol induced apoptosis in the hippocampal neurons and astrocytes, inhibited neuronal proliferation in the DG region, down-regulated the level of γ-aminobutyric acid (GABA) and glutamate in the hippocampus, and impaired long-term cognitive function. These harmful effects were reduced by pretreatment with 50 μg·kg-1 dexmedetomidine. Moreover, propofol activated GSK-3β and CDK5 pathways, but not RhoA pathway, by reducing the phosphorylation of GSK-3β (ser 9), increasing the expression of CDK5 activator P25 and increasing the phosphorylation of their target sites on CRMP2 shortly after exposure. These effects were reversed by pretreatment with 50 μg·kg-1 dexmedetomidine. Furthermore, SB415286 and roscovitine, not Y276321, attenuated the propofol-induced neuroapoptosis, brain cell proliferation inhibition, GABA and glutamate downregulation, and learning and memory dysfunction. Our results indicate that dexmedetomidine reduces propofol-induced neurotoxicity and neurocognitive impairment via inhibiting activation of GSK-3β/CRMP2 and CDK5/CRMP2 pathways in the hippocampus of neonatal rats.

Reaching Parents Through an Online Community

Scientific studies in animal models have demonstrated the neurotoxic effects of anesthetic and sedative drugs on the developing brain. Human studies, however, have been limited and less conclusive. The implications for clinical care remain unclear, and there is a critical need for further research on anesthetic toxicity to ensure safe anesthesia practices for infants and children. The sixth PANDA Symposium organized a session on "Engaging Stakeholders to Support Research" to facilitate dialog around improving communication and collaboration among stakeholders and to promote coordinated research efforts. Key stakeholders include patients, families, clinicians, researchers, community organizations, and federal agencies. This article provides an overview of an online platform called the Family Talkboard, a novel method which is destined to enhance patient outreach, engagement, and quality improvement, as well as outcomes research.

Using Neuroimaging to Study the Effects of Pain, Analgesia, and Anesthesia on Brain Development

Neuroimaging has been increasingly used as a modality to study the impact of pain, analgesia, and anesthetics on pediatric neurodevelopment. The sixth biennial Pediatric Anesthesia Neurodevelopmental Assessment (PANDA) Symposium addressed the 2016 US Food and Drug Administration drug safety warning regarding the potential neurotoxic effects of commonly used anesthetic and sedative medications in children, and included a session discussing the use of various neuroimaging techniques, to detect structural, metabolic, and functional brain changes that can occur with exposure to pain and to anesthetic medications. The presenters concluded that advanced multimodal magnetic resonance imaging techniques are useful in detecting the aforementioned changes, which were found to be pain-specific and anesthetic agent-specific.

Early Developmental Exposure to Repetitive Long Duration of Midazolam Sedation Causes Behavioral and Synaptic Alterations in a Rodent Model of Neurodevelopment

There is a large body of preclinical literature suggesting that exposure to general anesthetic agents during early life may have harmful effects on brain development. Patients in intensive care settings are often treated for prolonged periods with sedative medications, many of which have mechanisms of action that are similar to general anesthetics. Using in vivo studies of the mouse hippocampus and an in vitro rat cortical neuron model we asked whether there is evidence that repeated, long duration exposure to midazolam, a commonly used sedative in pediatric intensive care practice, has the potential to cause lasting harm to the developing brain. We found that mice that underwent midazolam sedation in early postnatal life exhibited deficits in the performance on Y-maze and fear-conditioning testing at young adult ages. Labeling with a nucleoside analog revealed a reduction in the rate of adult neurogenesis in the hippocampal dentate gyrus, a brain region that has been shown to be vulnerable to developmental anesthetic neurotoxicity. In addition, using immunohistochemistry for synaptic markers we found that the number of presynaptic terminals in the dentate gyrus was reduced, while the number of excitatory postsynaptic terminals was increased. These findings were replicated in a midazolam sedation exposure model in neurons in culture. We conclude that repeated, long duration exposure to midazolam during early development has the potential to result in persistent alterations in the structure and function of the brain.

A Summary of Preclinical Poster Presentations at the Sixth Biennial Pediatric Anesthesia Neurodevelopment Assessment (PANDA) Symposium

The potential for long-term neurotoxic effects of anesthetics on the developing human brain has led to intensified research in this area. To date, the human evidence has been inconclusive, but a large body of animal evidence continues to demonstrate cause for concern. On April 14 and 15, 2018 the sixth biennial Pediatric Anesthesia and Neurodevelopmental Assessment (PANDA) study symposium was held at Morgan Stanley Children's Hospital of New York. This symposium brought together clinicians and researchers and served as a platform to review preclinical and clinical data related to anesthesia and neurotoxicity in developing brains. The program participants included many active investigators in the field of anesthesia neurotoxicity as well as stakeholders from different backgrounds with the common interest of potential anesthetic neurotoxicity in children. The moderated poster session included presentations of preclinical animal research studies. These studies focused on defining the anesthetic-induced neurotoxicity phenotype, understanding the mechanism of injury and discovering potential inhibitors of neurotoxic effects.

Patterns of neuropsychological changes after general anaesthesia in young children: secondary analysis of the Mayo Anesthesia Safety in Kids study

BACKGROUND

We hypothesised that exposure to multiple, but not single, procedures requiring general anaesthesia before age 3 yr is associated with a specific pattern of deficits in processing speed and fine motor skills.

METHODS

A secondary analysis (using factor and cluster analyses) of data from the Mayo Anesthesia Safety in Kids study was conducted, in which unexposed, singly exposed, and multiply exposed children born in Olmsted County, MN, USA from 1994 to 2007 were sampled using a propensity-guided approach and underwent neuropsychological testing at ages 8-12 or 15-20 yr.

RESULTS

In the factor analysis, the data were well fit to a five factor model. For subjects multiply (but not singly) exposed to anaesthesia, a factor reflecting motor skills, visual-motor integration, and processing speed was significantly lower [standardised difference of -0.35 (95% confidence interval {CI} -0.57 to -0.13)] compared with unexposed subjects. No other factor was associated with exposure. Three groups were identified in the cluster analysis, with 106 subjects (10.6%) in Cluster A (lowest performance in most tests), 557 (55.9%) in Cluster B, and 334 (33.5%) in Cluster C (highest performance in most tests). The odds of multiply exposed children belonging to Cluster A was 2.83 (95% CI: 1.49-5.35; P=0.001) compared with belonging to Cluster B; there was no other significant association between exposure status and cluster membership.

CONCLUSIONS

Multiple, but not single, exposures to procedures requiring general anaesthesia before age 3 yr are associated with a specific pattern of deficits in neuropsychological tests. Factors predicting which children develop the most pronounced deficits remain unknown.

In utero Exposure to Anesthetics Alters Neuronal Migration Pattern in Developing Cerebral Cortex and Causes Postnatal Behavioral Deficits in Rats

During fetal development, cerebral cortical neurons are generated in the proliferative zone along the ventricles and then migrate to their final positions. To examine the impact of in utero exposure to anesthetics on neuronal migration, we injected pregnant rats with bromodeoxyuridine to label fetal neurons generated at embryonic Day (E) 17 and then randomized these rats to 9 different groups receiving 3 different means of anesthesia (oxygen/control, propofol, isoflurane) for 3 exposure durations (20, 50, 120 min). Histological analysis of brains from 54 pups revealed that significant number of neurons in anesthetized animals failed to acquire their correct cortical position and remained dispersed within inappropriate cortical layers and/or adjacent white matter. Behavioral testing of 86 littermates pointed to abnormalities that correspond to the aberrations in the brain areas that are specifically developing during the E17. In the second set of experiments, fetal brains exposed to isoflurane at E16 had diminished expression of the reelin and glutamic acid decarboxylase 67, proteins critical for neuronal migration. Together, these results call for cautious use of anesthetics during the neuronal migration period in pregnancy and more comprehensive investigation of neurodevelopmental consequences for the fetus and possible consequences later in life.

Neurotoxicity of general anesthetics in children: evidence and uncertainties

PURPOSE OF REVIEW

Compelling evidence in animal models that, under some conditions, general anesthetics and sedatives produce changes in the brain and persistent impairments in learning, memory, and behavior. The present review summarizes recent clinical studies investigating whether the use of these agents in children causes similar neurotoxicities.

RECENT FINDINGS

Although the results of retrospective studies are somewhat mixed, multiple exposures to general anesthesia were generally found to confer greater risk than single exposures with regard to learning disability, attention deficit hyperactivity disorder, school readiness, and academic achievement. Recent clinical studies, including a large randomized controlled trial, are consistent in confirming that a single exposure in infancy to general anesthesia lasting less than 1 h is not associated with neurodevelopmental impairments in later childhood. These studies do not, however, clarify the potential impacts of longer exposures or multiple exposures.

SUMMARY

Given that approximately half of the anesthetic exposures in young US children are 1 h or less in duration, the results of the recent clinical studies are reassuring. Because of the clinical necessity of administering general anesthetics and sedatives for longer periods for many surgical, procedural, or diagnostic purposes, the identification of adjuvants that prevent or reduce the potential neurotoxicity of these agents is an area of active research.

Age-dependent outcomes in asymptomatic umbilical hernia repair

PURPOSE

Umbilical hernias are common in young children. Many resolve spontaneously by age four with very low risk of symptoms or incarceration. Complications associated with surgical repair of asymptomatic umbilical hernias have not been well elucidated. We analyzed data from one hospital to test the hypothesis that repair at younger ages is associated with increased complication rates.

METHODS

A retrospective chart review of all umbilical hernia repairs performed during 2007-2015 was conducted at a tertiary care children's hospital. Patients undergoing repairs as a single procedure for asymptomatic hernia were evaluated for post-operative complications by age, demographics, and co-morbidities.

RESULTS

Of 308 umbilical hernia repairs performed, 204 were isolated and asymptomatic. Postoperative complications were more frequent in children < 4 years (12.3%) compared to > 4 years (3.1%, p = 0.034). All respiratory complications (N = 4) and readmissions (N = 1) were in children < 4 years.

CONCLUSIONS

Age of umbilical hernia repair in children varied widely even within a single institution, demonstrating that timing of repair may be a surgeon-dependent decision. Patients < 4 years were more likely to experience post-operative complications. Umbilical hernias often resolve over time and can safely be monitored with watchful waiting. Formal guidelines are needed to support delayed repair and prevent unnecessary, potentially harmful operations.

Microwave ablation of osteoid osteoma: initial experience and efficacy

BACKGROUND

Image-guided percutaneous microwave ablation has been used to treat adult osteoid osteomas but has not been thoroughly evaluated in the pediatric population.

OBJECTIVE

To evaluate the technical feasibility and clinical efficacy of microwave ablation to treat osteoid osteomas in pediatric patients.

MATERIALS AND METHODS

The electronic medical record and imaging archive were reviewed for 24 consecutive patients who had undergone microwave ablation of osteoid osteomas between January 1, 2015, and May 31, 2018, at a single tertiary care pediatric hospital. All patients were diagnosed by clinical and imaging criteria, and referred by a pediatric orthopedic surgeon after failing conservative management with pain medication. The average age of the patients was 13.3 years (range: 3-18 years), and the average size of the osteoid osteoma nidus was 8.8 mm (range: 5-22 mm). Technical success was defined as placement of the microwave antenna at the distal margin of the lesion nidus and achievement of the target ablation temperature. Clinical findings were assessed pre- and post-ablation and clinical success was defined as complete relief of pain without pain medication at 1-month follow-up. The number and severity of complications were also documented.

RESULTS

Clinical success was achieved in 100% of patients (24/24), with all reporting complete cessation of pain medication use 1 week after treatment and 0/10 pain at 1 month. There were 4 minor complications (17%) including access site numbness and a minor soft-tissue infection. There were no major complications.

CONCLUSION

Microwave ablation is a technically feasible and clinically effective treatment for pediatric osteoid osteomas.

Relevance of experimental paradigms of anesthesia induced neurotoxicity in the mouse

Routine general anesthesia is considered to be safe in healthy individuals. However, pre-clinical studies in mice, rats, and monkeys have repeatedly demonstrated that exposure to anesthetic agents during early post-natal periods can lead to acute neurotoxicity. More concerning, later-life defects in cognition, assessed by behavioral assays for learning and memory, have been reported. Although the potential for anesthetics to damage the neonatal brain is well-documented, the clinical significance of the pre-clinical models in which damage is induced remains quite unclear. Here, we systematically evaluate critical physiological parameters in post-natal day 7 neonatal mice exposed to 1.5% isoflurane for 2–4 hours, the most common anesthesia induced neurotoxicity paradigm in this animal model. We find that 2 or more hours of anesthesia exposure results in dramatic respiratory and metabolic changes that may limit interpretation of this paradigm to the clinical situation. Our data indicate that neonatal mouse models of AIN are not necessarily appropriate representations of human exposures.

Techniques for minimizing sedation in pediatric MRI

MRI is used widely in infants and young children. However, in these young cases deep sedation or general anesthesia is often required to minimize motion artifacts during MRI examinations. Although the benefits of MR typically outweigh the potential risks of sedation when delivered by an experienced team, there are increasing concerns regarding the affect of sedation on young children. There continues to be a push to develop various strategies that can minimize the need for sedation. The present review summarizes several technical and clinical approaches that can help decrease the need for sedation in the pediatric patient. Optimization of the MRI environment, the role of child life specialists, feed-and-bundle and distraction techniques, noise-reduction methods, artificial intelligence, and MRI advances to decrease both scan times and motion artifacts will be discussed. Level of Evidence: 5 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019.

Lasting effects of general anesthetics on the brain in the young and elderly: "mixed picture" of neurotoxicity, neuroprotection and cognitive impairment

General anesthetics are commonly used in major surgery. To achieve the depth of anesthesia for surgery, patients are being subjected to a variety of general anesthetics, alone or in combination. It has been long held an illusory concept that the general anesthesia is entirely reversible and that the central nervous system is returned to its pristine state once the anesthetic agent is eliminated from the active site. However, studies indicate that perturbation of the normal functioning of these targets may result in long-lasting desirable or undesirable effects. This review focuses on the impact of general anesthetic exposure to the brain and summarizes the molecular and cellular mechanisms by which general anesthetics may induce long-lasting undesirable effects when exposed at the developing stage of the brain. The vulnerability of aging brain to general anesthetics, specifically in the context of cognitive disorders and Alzheimer’s disease pathogeneses are also discussed. Moreover, we will review emerging evidence regarding the neuroprotective property of xenon and anesthetic adjuvant dexmedetomidine in the immature and mature brains. In conclusion, “mixed picture” effects of general anesthetics should be well acknowledged and should be implemented into daily clinical practice for better patient outcome.

Randomised controlled trial of dexmedetomidine sedation vs general anaesthesia for inguinal hernia surgery on perioperative outcomes in infants

BACKGROUND

Neonates and infants undergoing general anaesthesia for hernia surgery are at risk of perioperative cardiorespiratory adverse events. The use of regional anaesthesia with dexmedetomidine preserves airway tone and may potentially avoid these complications. This study compares the perioperative conditions and adverse events between dexmedetomidine sedation with caudal block and general anaesthesia with caudal block for inguinal hernia surgery in infants.

METHODS

A randomised controlled trial was conducted in a tertiary hospital in Singapore involving 104 infants younger than 3 months, who were randomised to receive either dexmedetomidine sedation (DEX) with caudal block or general sevoflurane anaesthesia with tracheal intubation and caudal block (GA) for inguinal hernia surgery. Perioperative conditions, haemodynamics and adverse events were compared between groups.

RESULTS

Fifty-one infants received DEX and 48 infants received GA. In the DEX group, 46 infants (90.2%) had their operations completed solely under this technique, two (3.9%) were converted to general anaesthesia with intubation, and three (5.9%) required brief administration of nitrous oxide or low-dose sevoflurane. Overall, 96.1% of infants in the DEX group did not require intubation. Perioperative conditions were similar in both groups. The DEX group had significantly lower heart rates and higher mean arterial pressures intraoperatively. Two infants in the DEX group (3.9%) required postoperative intensive care admission compared with six infants (12.5%) in the GA group.

CONCLUSIONS

Dexmedetomidine sedation with caudal block provides a feasible alternative to general anaesthesia in infants undergoing hernia surgery. This technique avoids the need for tracheal intubation, which may be beneficial in neonates.

CLINICAL TRIAL REGISTRATION

NCT02559102.

Practice Variation in Umbilical Hernia Repair Demonstrates a Need for Best Practice Guidelines

OBJECTIVE

To evaluate and better understand variations in practice patterns, we analyzed ambulatory surgery claims data from 3 demographically diverse states to assess the relationship between age at umbilical hernia repair and patient, hospital, and geographic characteristics.

STUDY DESIGN

We performed a cross-sectional descriptive study of uncomplicated hernia repairs performed as a single procedure in 2012-2014, using the State Ambulatory Surgery and Services Database for Wisconsin, New York, and Florida. Age and demographic characteristics of umbilical hernia repair patients are described.

RESULTS

The State Ambulatory Surgery and Services Database analysis included 6551 patients. Across 3 states, 8.2% of hernia repairs were performed in children <2 years, 18.7% in children age 2-3 years, and 73.0% in children age ≥4 years, but there was significant variability (P < .001) in practice patterns by state. In regression analysis, race, Medicaid insurance and rural residence were predictive of early repair, with African American patients less likely to have a repair before age 2 (OR 0.62, P = .046) and rural children (OR 1.53, P = .009) and Medicaid patients (OR 2.01, P < .001) more likely to do so. State of residence predicted early repair even when holding these variables constant.

CONCLUSIONS

The age of pediatric umbilical hernia repair varies widely. As hernias may resolve over time and can be safely monitored with watchful waiting, formal guidelines are needed to support delayed repair and prevent unnecessary operations.

Functional magnetic resonance urography in infants: feasibility of a feed-and-sleep technique

BACKGROUND

Functional magnetic resonance (MR) urography has been well established in the diagnostic workup of congenital anomalies of kidneys and urinary tract, though long acquisition time requires sedation or general anesthesia in infants.

OBJECTIVE

To evaluate the success rate of an optimized functional MR urography protocol in infants carried out in natural sleep.

MATERIALS AND METHODS

We retrospectively evaluated all functional MR urographies performed under general anesthesia or during natural sleep in infants younger than 1 year between 2010 and 2017 and rated image quality in both cohorts using a 3-point Likert scale. We tested the analyzability of functional sequences using a free available software. We also calculated examination time. Finally, we compared examinations in natural sleep and those with general anesthesia using independent t-test for continuous data and Mann-Whitney U test for categorical data.

RESULTS

Functional MR urography could be performed successfully during natural sleep in 38 of 42 (90%) infants younger than 10 months. Four examinations were aborted before contrast medium was administrated. In the same period, 19 functional MR urographies were performed successfully under general anesthesia. Although image quality was significantly better in this group (P<0.0001), image quality was at least diagnostic in all finished examinations in natural sleep, and the functional analyzability was given in all completed examinations. There was a significant saving in examination time during natural sleep (P<0.001).

CONCLUSION

Functional MR urography can be successfully performed in natural sleep in infants younger than 10 months.

Effects of Perinatal Exposure to Ketamine on the Developing Brain

Initially used as an analgesic and anesthetic, ketamine has unfortunately been abused as a popular recreational party drug due to its psychotropic effects. Over the last decade, ketamine has also emerged as an effective rapid-onset anti-depressant. The increasingly widespread use and misuse of the drug in infants and pregnant women has posed a concern about the neurotoxicity of ketamine to the immature brains of developing fetuses and children. In this review, we summarize recent research findings on major possible mechanisms of perinatal ketamine-induced neurotoxicity. We also briefly summarize the neuroprotective effects of ketamine in the presence of noxious stimuli. Future actions include implementation of more drug abuse education and prevention campaigns to raise the public’s awareness of the harmful effects of ketamine abuse; further investigations to justify the clinical use of ketamine as analgesic, anesthetic and anti-depressant; and further studies to develop alternatives to ketamine or treatments that can alleviate the detrimental effects of ketamine use, especially in infants and pregnant women.

Neurodevelopmental outcome at 5 years of age after general anaesthesia or awake-regional anaesthesia in infancy (GAS): an international, multicentre, randomised, controlled equivalence trial

BACKGROUND

In laboratory animals, exposure to most general anaesthetics leads to neurotoxicity manifested by neuronal cell death and abnormal behaviour and cognition. Some large human cohort studies have shown an association between general anaesthesia at a young age and subsequent neurodevelopmental deficits, but these studies are prone to bias. Others have found no evidence for an association. We aimed to establish whether general anaesthesia in early infancy affects neurodevelopmental outcomes.

METHODS

In this international, assessor-masked, equivalence, randomised, controlled trial conducted at 28 hospitals in Australia, Italy, the USA, the UK, Canada, the Netherlands, and New Zealand, we recruited infants of less than 60 weeks' postmenstrual age who were born at more than 26 weeks' gestation and were undergoing inguinal herniorrhaphy, without previous exposure to general anaesthesia or risk factors for neurological injury. Patients were randomly assigned (1:1) by use of a web-based randomisation service to receive either awake-regional anaesthetic or sevoflurane-based general anaesthetic. Anaesthetists were aware of group allocation, but individuals administering the neurodevelopmental assessments were not. Parents were informed of their infants group allocation upon request, but were told to mask this information from assessors. The primary outcome measure was full-scale intelligence quotient (FSIQ) on the Wechsler Preschool and Primary Scale of Intelligence, third edition (WPPSI-III), at 5 years of age. The primary analysis was done on a per-protocol basis, adjusted for gestational age at birth and country, with multiple imputation used to account for missing data. An intention-to-treat analysis was also done. A difference in means of 5 points was predefined as the clinical equivalence margin. This completed trial is registered with ANZCTR, number ACTRN12606000441516, and ClinicalTrials.gov, number NCT00756600.

FINDINGS

Between Feb 9, 2007, and Jan 31, 2013, 4023 infants were screened and 722 were randomly allocated: 363 (50%) to the awake-regional anaesthesia group and 359 (50%) to the general anaesthesia group. There were 74 protocol violations in the awake-regional anaesthesia group and two in the general anaesthesia group. Primary outcome data for the per-protocol analysis were obtained from 205 children in the awake-regional anaesthesia group and 242 in the general anaesthesia group. The median duration of general anaesthesia was 54 min (IQR 41-70). The mean FSIQ score was 99·08 (SD 18·35) in the awake-regional anaesthesia group and 98·97 (19·66) in the general anaesthesia group, with a difference in means (awake-regional anaesthesia minus general anaesthesia) of 0·23 (95% CI -2·59 to 3·06), providing strong evidence of equivalence. The results of the intention-to-treat analysis were similar to those of the per-protocol analysis.

INTERPRETATION

Slightly less than 1 h of general anaesthesia in early infancy does not alter neurodevelopmental outcome at age 5 years compared with awake-regional anaesthesia in a predominantly male study population.

FUNDING

US National Institutes of Health, US Food and Drug Administration, Thrasher Research Fund, Australian National Health and Medical Research Council, Health Technologies Assessment-National Institute for Health Research (UK), Australian and New Zealand College of Anaesthetists, Murdoch Children's Research Institute, Canadian Institutes of Health Research, Canadian Anesthesiologists Society, Pfizer Canada, Italian Ministry of Health, Fonds NutsOhra, UK Clinical Research Network, Perth Children's Hospital Foundation, the Stan Perron Charitable Trust, and the Callahan Estate.

Neonatal Skin-to-Skin Contact: Implications for Learning and Autonomic Nervous System Function in Infants With Congenital Heart Disease

Background:

Infants with complex congenital heart disease (CCHD) often develop neurodevelopmental disabilities. Cognitive abilities are associated with vagally mediated autonomic function. Skin-to-skin contact (SSC) interventions enhance infant neurodevelopment and autonomic function in other high-risk populations.

Aim:

To examine the effects of a neonatal SSC intervention on learning and autonomic function in 3-month-old infants: infants with CCHD who received neonatal SSC ( n = 10), typically developing (TD) infants ( n = 16), and infants with CCHD without SSC ( n = 10).

Methods:

This secondary data analysis measured cognitive function using the mobile paradigm (MP), a classic measure of learning based on operant conditioning. Autonomic function was assessed with heart rate (HR) and HR variability (HRV). Data were analyzed with repeated-measures general linear mixed modeling with α = .10 for this exploratory study.

Results:

Learning rates were TD = 75%, cardiac-SSC = 70%, and cardiac-control = 40%. Learners demonstrated significant reductions in HRV during the MP; nonlearners exhibited no change. TD and cardiac-SSC groups exhibited increases in HR and reductions in HRV during the MP. No significant changes occurred in the cardiac-control group. Nonlinear HRV during the MP differed only in the TD group.

Conclusions:

Findings suggest improvements in cognitive and autonomic development in 3-month-old infants with CCHD who received neonatal SSC. Learning and autonomic function results in infants with CCHD who had not received SSC suggest reduced capacity to muster the physiologic resources to carry out this cognitive task. Findings provide preliminary evidence in support of implementation of SSC with infants with CCHD and support additional research.

Nitric Oxide Donor Prevents Neonatal Isoflurane-induced Impairments in Synaptic Plasticity and Memory

WHAT WE ALREADY KNOW ABOUT THIS TOPIC

Some general anesthetics have been shown to have adverse effects on neuronal development that affect neural function and cognitive behavior.Clinically relevant concentrations of inhalational anesthetics inhibit the postsynaptic density (PSD)-95, discs large homolog, and zona occludens-1 (PDZ) domain-mediated protein-protein interaction between PSD-95 or PSD-93 and N-methyl-D-aspartate receptors or neuronal NO synthase.

WHAT THIS ARTICLE TELLS US THAT IS NEW

Neonatal PSD-95 PDZ2WT peptide treatment mimics the effects of isoflurane (~1 minimum alveolar concentration) by altering dendritic spine morphology, neural plasticity, and memory without inducing detectable increases in apoptosis or changes in synaptic density.These results indicate that a single dose of isoflurane (~1 minimum alveolar concentration) or PSD-95 PDZ2WT peptide alters dendritic spine architecture and functions important for cognition in the developing brain. This impairment can be prevented by administration of the NO donor molsidomine.

BACKGROUND

In humans, multiple early exposures to procedures requiring anesthesia constitute a significant risk factor for development of learning disabilities and disorders of attention. In animal studies, newborns exposed to anesthetics develop long-term deficits in cognition. Previously, our laboratory showed that postsynaptic density (PSD)-95, discs large homolog, and zona occludens-1 (PDZ) domains may serve as a molecular target for inhaled anesthetics. This study investigated a role for PDZ interactions in spine development, plasticity, and memory as a potential mechanism for early anesthetic exposure-produced cognitive impairment.

METHODS

Postnatal day 7 mice were exposed to 1.5% isoflurane for 4 h or injected with 8 mg/kg active PSD-95 PDZ2WT peptide. Apoptosis, hippocampal dendritic spine changes, synapse density, long-term potentiation, and cognition functions were evaluated (n = 4 to 18).

RESULTS

Exposure of postnatal day 7 mice to isoflurane or PSD-95 PDZ2WT peptide causes a reduction in long thin spines (median, interquartile range [IQR]: wild type control [0.54, 0.52 to 0.86] vs. wild type isoflurane [0.31, 0.16 to 0.38], P = 0.034 and PDZ2MUT [0.86, 0.67 to 1.0] vs. PDZ2WT [0.55, 0.53 to 0.59], P = 0.028), impairment in long-term potentiation (median, IQR: wild type control [123, 119 to 147] and wild type isoflurane [101, 96 to 118], P = 0.049 and PDZ2MUT [125, 119 to 131] and PDZ2WT [104, 97 to 107], P = 0.029), and deficits in acute object recognition (median, IQR: wild type control [79, 72 to 88] vs. wild type isoflurane [63, 55 to 72], P = 0.044 and PDZ2MUT [81, 69 to 84] vs. PDZ2WT [67, 57 to 77], P = 0.039) at postnatal day 21 without inducing detectable differences in apoptosis or changes in synaptic density. Impairments in recognition memory and long-term potentiation were preventable by introduction of a NO donor.

CONCLUSIONS

Early disruption of PDZ domain-mediated protein-protein interactions alters spine morphology, synaptic function, and memory. These results support a role for PDZ interactions in early anesthetic exposure-produced cognitive impairment. Prevention of recognition memory and long-term potentiation deficits with a NO donor supports a role for the N-methyl-D-aspartate receptor/PSD-95/neuronal NO synthase pathway in mediating these aspects of isoflurane-induced cognitive impairment.

Red flag findings in children with headaches: Prevalence and association with emergency department neuroimaging

BACKGROUND

Clinicians appear to obtain emergent neuroimaging for children with headaches based on the presence of red flag findings. However, little data exists regarding the prevalence of these findings in emergency department populations, and whether the identification of red flag findings is associated with potentially unnecessary emergency department neuroimaging.

OBJECTIVES

We aimed to determine the prevalence of red flag findings and their association with neuroimaging in otherwise healthy children presenting with headaches to the emergency department. Our secondary aim was to determine the prevalence of emergent intracranial abnormalities in this population.

METHODS

A prospective cohort study of otherwise healthy children 2-17 years of age presenting to an urban pediatric emergency department with non-traumatic headaches was undertaken. Emergency department physicians completed a standardized form to document headache descriptors and characteristics, associated symptoms, and physical and neurological exam findings. Children who did not receive emergency department neuroimaging received 4-month telephone follow-up. Outcomes included emergency department neuroimaging and the presence of emergent intracranial abnormalities.

RESULTS

We enrolled 224 patients; 197 (87.9%) had at least one red flag finding on history. Several red flag findings were reported by more than a third of children, including: Headache waking from sleep (34.8%); headache present with or soon after waking (39.7%); or headaches increasing in frequency, duration and severity (40%, 33.1%, and 46.3%). Thirty-three percent of children received emergency department neuroimaging. The prevalence of emergent intracranial abnormalities was 1% (95% CI 0.1, 3.6). Abnormal neurological exam, extreme pain intensity of presenting headache, vomiting, and positional symptoms were independently associated with emergency department neuroimaging.

CONCLUSIONS

Red flag findings are common in children presenting with headaches to the emergency department. The presence of red flag findings is associated with emergency department neuroimaging, although the risk of emergent intracranial abnormalities is low. Many children with headaches may be receiving unnecessary neuroimaging due to the high prevalence of non-specific red flag findings.

Airway findings in children with tracheostomies: When is diagnostic bronchoscopy and laryngoscopy indicated?

OBJECTIVES

To determine the utility of diagnostic laryngoscopy and bronchoscopy in children with tracheostomies and to describe the incidence of airway findings.

METHODS

Retrospective cohort study examining children with tracheostomies who underwent direct laryngoscopy and bronchoscopy (DLB) at Duke University Hospital between 2008 and 2016.

RESULTS

A total of 81 patients who underwent 114 bronchoscopies met inclusion criteria. The median time between tracheostomy and first DLB was 13 months (IQR 4.25-14.75). Sixty-six patients were diagnosed with findings on DLB (81.5%). Suprastomal granulation tissue was the most common complication (59.0%), followed by increased tracheal secretions (23%), stomal and peristomal granulation (13.2%), tracheal ulcer (3.3%), and suprastomal collapse (1.6%). The proportion of patients with airway findings who underwent endoscopy >6 months post-tracheostomy was higher than those <6 months post-tracheostomy, although this did not reach statistical significance (90.6% vs. 75.5%, p = 0.087). However, when examining tracheostomy-related findings, the proportion of patients with airway findings who underwent DLB >6 months post-tracheostomy (61%) compared to <6 months post-tracheostomy (36%) was significantly different (p = 0.026). Patients who were symptomatic before bronchoscopy were more likely to have positive findings (91.9% vs. 72.7%, p = 0.027) and patients were more likely to be symptomatic if they had DLB >6 months after tracheostomy versus <6 months after tracheostomy (68.8% vs. 30.6%; p < 0.001).

CONCLUSION

The high incidence of airway findings, especially tracheostomy-related findings, noted on DLB supports the continued use of airway endoscopies in children post-tracheostomy. Timing of DLB may play a role in determining utility with evaluation and symptomatic patients should be more closely monitored as they demonstrate higher rates of airway findings.

Neuropsychological and Behavioral Outcomes after Exposure of Young Children to Procedures Requiring General Anesthesia: The Mayo Anesthesia Safety in Kids (MASK) Study

BACKGROUND

Few studies of how exposure of children to anesthesia may affect neurodevelopment employ comprehensive neuropsychological assessments. This study tested the hypothesis that exposure to multiple, but not single, procedures requiring anesthesia before age 3 yr is associated with adverse neurodevelopmental outcomes.

METHODS

Unexposed, singly exposed, and multiply exposed children born in Olmsted County, Minnesota, from 1994 to 2007 were sampled using a propensity-guided approach and underwent neuropsychological testing at ages 8 to 12 or 15 to 20 yr. The primary outcome was the Full-Scale intelligence quotient standard score of the Wechsler Abbreviated Scale of Intelligence. Secondary outcomes included individual domains from a comprehensive neuropsychological assessment and parent reports.

RESULTS

In total, 997 children completed testing (411, 380, and 206 unexposed, singly exposed, and multiply exposed, respectively). The primary outcome of intelligence quotient did not differ significantly according to exposure status; multiply exposed and singly exposed children scoring 1.3 points (95% CI, -3.8 to 1.2; P = 0.32) and 0.5 points (95% CI, -2.8 to 1.9; P = 0.70) lower than unexposed children, respectively. For secondary outcomes, processing speed and fine motor abilities were decreased in multiply but not singly exposed children; other domains did not differ. The parents of multiply exposed children reported increased problems related to executive function, behavior, and reading.

CONCLUSIONS

Anesthesia exposure before age 3 yr was not associated with deficits in the primary outcome of general intelligence. Although secondary outcomes must be interpreted cautiously, they suggest the hypothesis that multiple, but not single, exposures are associated with a pattern of changes in specific neuropsychological domains that is associated with behavioral and learning difficulties.

What do recent human studies tell us about the association between anaesthesia in young children and neurodevelopmental outcomes?

Anaesthetic and sedative drugs transiently disrupt normal neural activity to facilitate healthcare procedures in children, but they can also cause long-term brain injury in experimental animal models. The US Food and Drug Administration (FDA) has recently advised that repeated or lengthy exposures to anaesthetic and sedative drugs prior to 3 yr of age have the potential to harm the development of children's brains and added warnings to these drug labels. Paediatric anaesthesia toxicity could represent a significant public health issue, and concern about this potential injury in children has become an important issue for families, paediatric clinicians and healthcare regulators. Since late 2015, important new data from five major clinical studies have been published. This narrative review aims to provide a brief overview of the preclinical and clinical literature, including a comprehensive review of these recent additions to the human literature. We integrate these new data with prior studies to provide further insights into how these clinical findings can be applied to children.

Duration of general anaesthetic exposure in early childhood and long-term language and cognitive ability

Background

The anaesthetic dose causing neurotoxicity in animals has been evaluated, but the relationship between duration of volatile anaesthetic (VA) exposure and neurodevelopment in children remains unclear.

Methods

Data were obtained from the Western Australian Pregnancy Cohort (Raine) Study, with language (Clinical Evaluation of Language Fundamentals: Receptive [CELF-R] and Expressive [CELF-E] and Total [CELF-T]) and cognition (Coloured Progressive Matrices [CPM]) assessed at age 10 yr. Medical records were reviewed, and children divided into quartiles based on total VA exposure duration before age three yr. The association between test score and exposure duration quartile was evaluated using linear regression, adjusting for patient characteristics and comorbidity.

Results

Of 1622 children with available test scores, 148 had documented VA exposure and were split into the following quartiles: ≤25, >25 to ≤35, >35 to ≤60 and >60 min. Compared with unexposed children, CELF-T scores for children in the first and second quartiles did not differ, but those in the third and fourth quartiles had significantly lower scores ([3 rd quartile - Unexposed] -5.3; 95% confidence interval [CI], (-10.2 - -0.4), [4 th quartile - Unexposed] -6.2; 95% CI, (-11.6 - -0.9). CELF-E showed similar findings, but significant differences were not found in CELF-R or CPM for any quartile.

Conclusions

Children with VA exposures ≤35 min did not differ from unexposed children, but those with exposures >35 min had lower total and expressive language scores. It remains unclear if this is a dose-response relationship, or if children requiring longer exposures for longer surgeries have other clinical reasons for lower scores.

Visual recognition memory is impaired in rhesus monkeys repeatedly exposed to sevoflurane in infancy

Background

Experimental studies in animals have shown that exposure to general anaesthesia in infancy can cause loss of cells in the central nervous system and long-term impairments in neurocognitive function. Some human epidemiological studies have shown increased risk of learning disability after repeated anaesthesia exposure in early childhood. Thus, we investigated in a highly translational rhesus monkey model, whether repeated exposure in infancy to the inhalation anaesthetic sevoflurane is associated with impaired visual recognition memory during the first two yr of life.

Methods

Rhesus monkeys of both sexes were exposed to sevoflurane inhalation anaesthesia on approximately postnatal day 7 and then again 14 and 28 days later, for four h each time. Visual recognition memory was tested using the visual paired comparison task, which measures memory by assessing preference for looking at a new image over a previously-viewed image. Monkeys were tested at 6-10 months of age, again at 12-18 months of age, and again at 24-30 months of age.

Results

No memory impairment was detected at 6-10 months old, but significant impairment (reduced time looking at the novel image) was observed at 12-18 and 24-30 months old.

Conclusions

Repeated exposure of infant rhesus monkeys to sevoflurane results in visual recognition memory impairment that emerges after the first yr of life. This is consistent with epidemiological studies that show increased risk of learning disability after repeated exposure to anaesthesia in infancy/early childhood. Moreover, these deficits may emerge at later developmental stages, even when memory performance is unaffected earlier in development.

Isoflurane exposure for three hours triggers apoptotic cell death in neonatal macaque brain

Background

Retrospective clinical studies suggest there is a risk for neurodevelopmental impairment following early childhood exposure to anaesthesia. In the developing animal brain, including those of non-human primates (NHPs), anaesthetics induce apoptotic cell death. We previously reported that a 5 h isoflurane (ISO) exposure in infant NHPs increases apoptosis 13-fold compared with control animals. However, the majority of paediatric surgeries requiring anaesthesia are of shorter durations. We examined whether 3 h ISO exposure similarly increases neuroapoptosis in the NHP developing brain.

Methods

Six-day-old NHP infants ( Macaca mulatta ) were exposed to 3 h of a surgical plane of ISO ( n =6) or to room air ( n =5). Following exposure, NHP brains were screened for neuronal and oligodendrocyte apoptosis using activated caspase-3 immunolabelling and unbiased stereology.

Results

ISO treatment increased apoptosis (neurones + oligodendrocyte) to greater than four times that in the control group [mean density of apoptotic profiles: 57 (SD 22) mm -3 vs 14 (SD 5.2) mm -3 , respectively]. Oligodendrocyte apoptosis was evenly distributed throughout the white matter whereas neuroapoptosis occurred primarily in the cortex (all regions), caudate, putamen and thalamus.

Conclusions

A 3 h exposure to ISO is sufficient to induce widespread neurotoxicity in the developing primate brain. These results are relevant for clinical medicine, as many surgical and diagnostic procedures in children require anaesthesia durations similar to those modelled here. Further research is necessary to identify long-term neurobehavioural consequences of 3 h ISO exposure.

Fractured pediatric central venous catheters - Repair or replace?

INTRODUCTION

Central venous catheter (CVC) fracture is a common complication. The aim of this study is to examine risk factors resulting in CVC fracture and compare outcomes of children undergoing CVC repair versus replacement.

METHODS

A retrospective chart review was conducted from 2000 to 2016 for children with tunneled CVCs. Children with CVC fractures were compared to those without to identify risk factors resulting in fracture. Children with fractured CVCs were divided into repair or replacement treatment groups and outcomes compared. A logistic regression model determined independent predictors of CVC-associated bloodstream infections (CLABSI) after fracture.

RESULTS

In the 236 children with CVCs, the fracture rate was 29.2%. Fractured CVCs were more common with double lumen CVC (p = 0.040) and children whose indication was total parenteral nutrition (p = 0.003). Given children often underwent multiple repairs or replacements. 98 CVC repairs and 41 replacements were analyzed. CVC replacements had longer durability than repair (181.98 vs. 98.9 days, p = 0.038). There were no differences in CLABSI incidence for repair vs. replacement (OR 0.5 CI 0.05-4.97) after controlling for other factors.

CONCLUSIONS

CVC fracture is a frequent complication in children with tunneled CVCs. CVC repair has no increased incidence of CLABSI but eliminates the intraoperative and anesthetic risks of CVC replacement.

TYPE OF STUDY

Retrospective cohort study.

LEVEL OF EVIDENCE

Level III.

An open label pilot study of a dexmedetomidine-remifentanil-caudal anesthetic for infant lower abdominal/lower extremity surgery: The T REX pilot study

BACKGROUND

Concern over potential neurotoxicity of anesthetics has led to growing interest in prospective clinical trials using potentially less toxic anesthetic regimens, especially for prolonged anesthesia in infants. Preclinical studies suggest that dexmedetomidine may have a reduced neurotoxic profile compared to other conventional anesthetic regimens; however, coadministration with either anesthetic drugs (eg, remifentanil) and/or regional blockade is required to achieve adequate anesthesia for surgery. The feasibility of this pharmacological approach is unknown. The aim of this study was to determine the feasibility of a remifentanil/dexmedetomidine/neuraxial block technique in infants scheduled for surgery lasting longer than 2 hours.

METHODS

Sixty infants (age 1-12 months) were enrolled at seven centers over 18 months. A caudal local anesthetic block was placed after induction of anesthesia with sevoflurane. Next, an infusion of dexmedetomidine and remifentanil commenced, and the sevoflurane was discontinued. Three different protocols with escalating doses of dexmedetomidine and remifentanil were used.

RESULTS

One infant was excluded due to a protocol violation and consent was withdrawn prior to anesthesia in another. The caudal block was unsuccessful in two infants. Of the 56 infants who completed the protocol, 45 (80%) had at least one episode of hypertension (mean arterial pressure >80 mm Hg) and/or movement that required adjusting the anesthesia regimen. In the majority of these cases, the remifentanil and/or dexmedetomidine doses were increased although six infants required rescue 0.3% sevoflurane and one required a propofol bolus. Ten infants had at least one episode of mild hypotension (mean arterial pressure 40-50 mm Hg) and four had at least one episode of moderate hypotension (mean arterial pressure <40 mm Hg).

CONCLUSION

A dexmedetomidine/remifentanil neuraxial anesthetic regimen was effective in 87.5% of infants. These findings can be used as a foundation for designing larger trials that assess alternative anesthetic regimens for anesthetic neurotoxicity in infants.

Effects of repeated exposure to different concentrations of sevoflurane on the neonatal mouse hippocampus

Background and objectives

Developing brain is more vulnerable to environmental risk than is the developed brain. We evaluated the effects of repeated exposure to different concentrations of sevoflurane on the neonatal mouse hippocampus using stereological methods.

Methods

Eighteen neonatal male mice were randomly divided into three groups. Group A, inhaled sevoflurane at a concentration of 1.5%; Group B, inhaled sevoflurane at a concentration of 3%; and Group C (control group), inhaled only 100% oxygen. Treatments were applied for 30 min a day for 7 consecutive days. The hippocampal volume, dendrite length, number of neurons, and number of glial cells were evaluated in each group using stereological estimations.

Results

We identified a ∼2% reduction in the volume of the hippocampus in Group A compared to Group C. Mean hippocampal volume was ∼11% smaller in Group B than it was in Group C. However, these differences in hippocampal volume between the groups were not statistically significant (p > 0.05 for all). As for the number of neurons, we found significantly fewer neurons in Group A (∼29% less) and Group B (∼43% less) than we did in Group C (p < 0.05 for both). The dendrite length was ∼8% shorter in Group A and ∼11% shorter in Group B than it was in Group C.

Conclusions

Repeated exposure to sevoflurane, regardless of the concentration, reduced the volume of the neonatal mouse hippocampus, as well as the number of neurons and dendrite length.

Conscious Sedation for Pediatric Peritonsillar Abscess: Comparison of Anesthetic Approaches

Objective

To compare the efficacy, safety, and cost of incision and drainage (I&D) for pediatric patients with peritonsillar abscesses (PTAs) under conscious sedation (CS) versus unsedated (awake) and general anesthesia (GA).

Study Design

Case series with chart review.

Setting

Tertiary pediatric hospital.

Subjects and Methods

Records for all pediatric patients (<18 years) treated for PTAs in the emergency department from 2005 to 2015 were reviewed and stratified into awake, CS, and GA groups for comparison. The primary outcome measure was procedure tolerance, with secondary measures including return to the emergency department within 15 days, complications, and facility costs associated with treatment.

Results

A total of 188 patients were identified. The median age was 14 years (interquartile range, 9-16). Awake drainage with injected local anesthetic was used in 115 children; 62 underwent CS; and 11 underwent GA. Over 92% of the children tolerated I&D regardless of anesthesia, with no difference among groups ( P = .60). None of those who underwent I&D via CS returned to the emergency department within 15 days of the procedure, as compared with 5.2% for the awake group and 9.1% for the GA group ( P = .06). None in the GA or awake group had a complication associated with the procedure, as opposed to 9.6% in the CS group ( P = .02). Complications included apnea and dental trauma (2 children each) and transient hypotension and desaturation (1 each). Cost was highest in the GA group and lowest for the awake group ( P < .0001).

Conclusion

CS for PTA I&D is a viable treatment option with tolerance and success similar to that of the awake and GA groups. Complications were observed for those who underwent CS, but they were manageable.

Impact on Patient Care of a Multidisciplinary Center Specializing in Colorectal and Pelvic Reconstruction

Aim of the study: Many patients with an anorectal malformation (ARM) or pelvic anomaly have associated urologic or gynecologic problems. We hypothesized that our multidisciplinary center, which integrates pediatric colorectal, urologic, gynecologic and GI motility services, could impact a patient's anesthetic exposures and hospital visits.

Methods: We tabulated during 2015 anesthetic/surgical events, endotracheal intubations, and clinic/hospital visits for all patients having a combined procedure.

Main results: Eighty two patients underwent 132 combined procedures (Table 1). The median age at intervention was 3 years [0.2-17], and length of follow up was 25 months [7-31]. The number of procedures in patients who underwent combined surgery was lower as compared to if they had been done independently [1(1-5) vs. 3(2-7) (p < 0.001)]. Intubations were also lower [1[1-3] vs. 2[1-6]; p < 0.001]. Hospital length of stay was significantly lower for the combined procedures vs. the theoretical individual procedures [8 days [3-20] vs. 10 days [4-16]] p < 0.05. Post-operative clinic visits were fewer when combined visits were coordinated as compared to the theoretical individual clinic visits (urology, gynecology, and colorectal) [1[1-4] vs. 2[1-6]; p = < 0.001].

Conclusions: Patients with anorectal and pelvic malformations are likely to have many medical or surgical interventions during their lifetime. A multidisciplinary approach can reduce surgical interventions, anesthetic procedures, endotracheal intubations, and hospital/outpatient visits.

[Effects of repeated exposure to different concentrations of sevoflurane on the neonatal mouse hippocampus]

BACKGROUND AND OBJECTIVES

Developing brain is more vulnerable to environmental risk than is the developed brain. We evaluated the effects of repeated exposure to different concentrations of sevoflurane on the neonatal mouse hippocampus using stereological methods.

METHODS

Eighteen neonatal male mice were randomly divided into three groups. Group A, inhaled sevoflurane at a concentration of 1.5%; Group B, inhaled sevoflurane at a concentration of 3%; and Group C (control group), inhaled only 100% oxygen. Treatments were applied for 30min a day for 7 consecutive days. The hippocampal volume, dendrite length, number of neurons, and number of glial cells were evaluated in each group using stereological estimations.

RESULTS

We identified a ∼2% reduction in the volume of the hippocampus in Group A compared to Group C. Mean hippocampal volume was ∼11% smaller in Group B than it was in Group C. However, these differences in hippocampal volume between the groups were not statistically significant (p>0.05 for all). As for the number of neurons, we found significantly fewer neurons in Group A (∼29% less) and Group B (∼43% less) than we did in Group C (p<0.05 for both). The dendrite length was ∼8% shorter in Group A and ∼11% shorter in Group B than it was in Group C.

CONCLUSIONS

Repeated exposure to sevoflurane, regardless of the concentration, reduced the volume of the neonatal mouse hippocampus, as well as the number of neurons and dendrite length.

Decreased Protein Quality Control Promotes the Cognitive Dysfunction Associated With Aging and Environmental Insults

Background: Most neurodegenerative diseases are sporadic and develop with age. Degenerative neural tissues often contain intra- and extracellular protein aggregates, suggesting that the proteostasis network that combats protein misfolding could be dysfunctional in the setting of neurodegenerative disease. Binding immunoglobulin protein (BiP) is an endoplasmic reticulum (ER) chaperone that is crucial for protein folding and modulating the adaptive response in early secretory pathways. The interaction between BiP and unfolded proteins is mediated by the substrate-binding domain and nucleotide-binding domain with ATPase activity. The interaction facilitates protein folding and maturation. BiP has a recovery motif at the carboxyl terminus. The aim of this study is to examine cognitive function in model mice with an impaired proteostasis network by expressing a mutant form of BiP lacking the recovery motif. We also investigated if impairments of cognitive function were exacerbated by exposure to environmental insults, such as inhaled anesthetics.

Methods: We examined cognitive function by performing radial maze testing with mutant BiP mice and assessed the additional impact of general anesthesia in the context of proteostasis dysfunction. Testing over 8 days was performed 10 weeks, 6 months, and 1 year after birth.

Results: Age-related cognitive decline occurred in both forms of mice. The mutant BiP and anesthetic exposure promoted cognitive dysfunction prior to the senile period. After senescence, when mice were tested at 6 months of age and at 1 year old, there were no significant differences between the two genotypes in terms of the radial maze testing; furthermore, there was no significant difference when tested with and without anesthetic exposure.

Conclusion: Our data suggest that aging was the predominant factor underlying the impairment of cognitive function in this study. Impairment of the proteostasis network may promote age-related neurodegeneration, and this is exacerbated by external insults.

The importance of calprotectin for differentiating organic inflammatory disease and avoiding unnecessary procedures in paediatrics

BACKGROUND AND OBJECTIVE

The objective of the study was to determine the ability of faecal calprotectin to differentiate functional and organic intestinal diseases in paediatric patients, and to evaluate the correlation between inflammatory parameters and levels of faecal calprotectin.

PATIENTS AND METHODS

This retrospective study involved clinical data from 129 paediatric patients with symptoms of intestinal pathology. Faecal calprotectin was determined by quantitative immunoassay. Patients were classified into three groups: functional (32.8% of patients); organic non-inflammatory bowel disease (IBD, 53.9%); and organic IBD (13.3%).

RESULTS

Calprotectin levels were significantly different among the three groups; between patients with IBD and the others, and also between patients with non-organic IBD and functional. Positive associations were found between high levels of calprotectin and higher erythrocyte sedimentation rate (rho=0.497), C-reactive protein (rho=0.460), and platelet count (rho=0.232). Nevertheless, an inverse correlation was found between high levels of calprotectin and transferrin saturation (rho=-0.310), albumin (rho=-0.412), and haemoglobin levels (rho=-0.309).

DISCUSSION

Determination of faecal calprotectin is a complementary tool in clinical practice for discriminating between functional and organic IBD, avoiding, according to the levels of calprotectin, unnecessary invasive procedures in paediatric patients.

Sevoflurane anesthesia represses neurogenesis of hippocampus neural stem cells via regulating microRNA-183-mediated NR4A2 in newborn rats

Sevoflurane has been commonly utilized in nonobstetric surgeries in pregnant women, and its impacts on fetal brain are still not completely known. Ectopic NR4A2 expression has been reported to be related with familial Parkinson disease, and through dual luciferase we found that NR4A2 is a target gene of microRNA-183 (miR-183). We proposed a hypothesis that miR-183 may participate in the process by targeting NR4A2 in neurons after sevoflurane anesthesia. To verify the effect of sevoflurane on hippocampal neural stem cells (NSCs) proliferation and differentiation, we conducted EdU assay and immunofluorescence staining. Next, for better understanding of the impact of miR-183, we altered the miR-183 expression using mimic and inhibitor. Meanwhile, the targeting relationship between miR-183 and NR4A2 was validated by a bioinformatics website and dual-luciferase reporter gene assay. Finally, expressions of miR-184, NR4A2, SRY (sex-determining region Y)-box 2 (Sox2), and brain-derived neurotrophic factor (BDNF) were determined and evaluated by reverse transcription quantitative polymerase chain reaction and western blot analysis. First, sevoflurane was determined a crucial factor in biological behaviors of hippocampal NSCs. Moreover, upregulated miR-183 expression by mimic inhibited the proliferation and differentiation of NSCs. Sevoflurane negatively regulated NR4A2 and Sox2 expressions but positively regulated miR-183 and BDNF expressions. Our findings revealed the underlying novel mechanism by which sevoflurane inhibits hippocampal NSC proliferation and differentiation through interaction with miR-183 and NR4A2. The study provides reliable reference for safe application of sevoflurane anesthesia in neonates.