Comparative analysis of outcome measures used in examining neurodevelopmental effects of early childhood anesthesia exposure. Anesthesiology. 2014;120:1319-1332. [PMID: 24694922 DOI: 10.1097/aln.0000000000000248]

Clinical Evidence for Any Effect of Anesthesia on the Developing Brain

A recent U.S. Food and Drug Administration warning advised that prolonged or repeated exposure to general anesthetics may affect neurodevelopment in children. This warning is based on a wealth of preclinical animal studies and relatively few human studies. The human studies include a variety of different populations with several different outcome measures. Interpreting the results requires consideration of the outcome used, the power of the study, the length of exposure and the efforts to reduce the confounding effects of comorbidity and surgery. Most, but not all, of the large population-based studies find evidence for associations between surgery in early childhood and slightly worse subsequent academic achievement or increased risk for later diagnosis of a behavioral disability. In several studies, the amount of added risk is very small; however, there is some evidence for a greater association with multiple exposures. These results may be consistent with the preclinical data, but the possibility of confounding means the positive associations can only be regarded as weak evidence for causation. Finally, there is strong evidence that brief exposure is not associated with any long term risk in humans.

Persistent alteration in behavioural reactivity to a mild social stressor in rhesus monkeys repeatedly exposed to sevoflurane in infancy

BACKGROUND

Socio-emotional development is the expression and management of emotions, which in non-human primates can be examined using responses toward increasing levels of threat. Damage to the limbic system alters socio-emotional development in primates. Thus, neuronal and glial cell loss caused by exposure to general anaesthesia early in infancy might also impact socio-emotional development. We recently reported that repeated sevoflurane exposure in the first month of life alters emotional behaviours at 6 months of age and impairs visual recognition memory after the first year of life in rhesus monkeys. The present study evaluated socio-emotional behaviour at 1 and 2 yr of age in those same monkeys to determine the persistence of altered emotional behaviour.

METHODS

Rhesus monkeys of both sexes were exposed to sevoflurane anaesthesia three times for 4 h each time in the first 6 weeks of life. At 1 and 2 yr of age, they were tested on the human intruder task, a well-established mild acute social stressor.

RESULTS

Monkeys exposed to sevoflurane as infants exhibited normal fear and hostile responses, but exaggerated self-directed (displacement) behaviours, a general indicator of stress and anxiety in non-human primates.

CONCLUSIONS

Early repeated sevoflurane exposure in infant non-human primates results in an anxious phenotype that was first detected at 6 months, and persists for at least 2 yr of age. This is the first demonstration of such a prolonged impact of early anaesthesia exposure on emotional reactivity.

Update on developmental anesthesia neurotoxicity

PURPOSE OF REVIEW

Adverse long-term impact of general anesthesia on the developing brain is a widely discussed and controversial issue with potential public health relevance. The goal of this article is to give insights into the most recent experimental and clinical observations aimed to advance our understanding in this field.

RECENT FINDINGS

Recent investigations demonstrate long-term behavioral consequences of early-life anesthesia exposure in nonhuman primates under experimental conditions that are translationally relevant to human clinical practice. Converging evidence from rodent experiments strongly suggest that anesthetics exert developmental stage-dependent and context-dependent impact on developing neuronal circuitry and, therefore, may induce lasting changes in neuronal plasticity. Although three recent population-based human studies found a strong evidence for small increase in risk, the two most robust studies (General Anaesthesia compared to Spinal anaesthesia trial and Pediatric Anesthesia Neurodevelopment Assessment) did not find an association between brief anesthesia exposure and poor neurodevelopmental outcome.

SUMMARY

Experimental data with reasonable translational relevance suggest that early-life exposure to general anesthetics can induce lasting behavioral and cognitive deficits. In contrast, human studies provide, at best, mixed evidence about developmental anesthesia neurotoxicity. Future research, both experimental and human, is needed to clarify this important issue.

Outcomes of intra-articular corticosteroid injections for adolescents with hip pain

Intra-articular injection of corticosteroid and anesthetic (CSI) is a useful diagnostic tool for hip pain secondary to labral tears or femoroacetabular impingement (FAI). However, the effectiveness of CSI as a stand-alone treatment for hip pain in adolescents is unknown. The purpose of this study is to evaluate the use of CSI for the treatment of hip pain and determine factors that may affect outcomes after injection. Retrospective analysis of 18 patients and 19 hips that underwent fluoroscopic guided hip injection for the treatment of pain at a single institution from 2012 to 2015 was carried out in this study. Mean age at the time of injection was 15.1 years (range 13–17) with mean follow-up of 29.4 months. Fifty-two percent (10/19 hips) went on to surgery after the injection. Average time to surgical conversion was 12.8 months after CSI. Cam or pincer morphologies were present in 90% (9/10 hips) of the operative group. Patients with FAI were more likely to need surgery than patients without bony abnormalities (RR= 10, 95% CI 1.6–64.2, P = 0.0001). There was no difference in the presence of labral tears in the operative and non-operative groups (100% versus 89%, P = 0.47). For adolescents without bony abnormalities, 90% improved with CSI alone and did not require further treatment within 2.4 years. Fluoroscopic guided corticosteroid hip injection may have limited efficacy for the treatment of hip pain secondary to FAI in adolescents. However, for patients without osseous deformity, CSI may offer prolonged improvement of symptoms even in the presence of labral tears.

A neurosteroid analogue with T-type calcium channel blocking properties is an effective hypnotic, but is not harmful to neonatal rat brain

BACKGROUND

More than 4 million children are exposed annually to sedatives and general anaesthetics (GAs) in the USA alone. Recent data suggest that common GAs can be detrimental to brain development causing neurodegeneration and long-term cognitive impairments. Challenged by a recent US Food and Drug Administration (FDA) warning about potentially neurotoxic effects of GAs in children, there is an urgent need to develop safer GAs.

METHODS

Postnatal Day 7 (P7) rat pups of both sexes were exposed to six (repeated every 2 h) injections of equipotent hypnotic doses of ketamine or the neuroactive steroid (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3β-OH) for 12 h. Loss of righting reflex was used to assess hypnotic properties and therapeutic index; quantitative caspase-3 immunohistochemistry was used to assess developmental neuroapoptosis; patch-clamp recordings in acute brain slices were used to assess the effects of 3β-OH on neuronal excitability and synaptic transmission. Cognitive abilities of rats exposed to ketamine, 3β-OH, or vehicle at P7 were assessed in young adulthood using the radial arm maze.

RESULTS

The neuroactive steroid 3β-OH has a therapeutic index similar to ketamine, a commonly used clinical GA. We report that 3β-OH is safe and, unlike ketamine, does not cause neuroapoptosis or impair cognitive development when administered to P7 rat pups. Interestingly, 3β-OH blocks T-type calcium channels and presynaptically dampens synaptic transmission at hypnotically-relevant brain concentrations, but it lacks a direct effect on γ-aminobutyric acid A or glutamate-gated ion channels.

CONCLUSIONS

The neurosteroid 3β-OH is a relatively safe hypnotic that warrants further consideration for paediatric anaesthesia.

Unsedated In-office Transgastrostomy Esophagoscopy to Monitor Therapy in Pediatric Esophageal Disease

Monitoring therapy in esophageal inflammatory disorders such as eosinophilic esophagitis and reflux esophagitis often requires frequent endoscopic evaluation. We recently reported the effective use of unsedated in-office transnasal esophagoscopy that significantly decreased costs and anesthetic exposure associated with pediatric esophagoscopy in eosinophilic esophagitis. Here we report a series of pediatric patients with esophagitis with gastrostomy tubes who underwent unsedated transgastrostomy esophagoscopy (TGE) in an office setting. Nine patients (ages 16 months-21 years) tolerated TGE without significant adverse events. Biopsy specimens were adequate for evaluation. This series confirms that unsedated in-office TGE can be used to successfully obtain mucosal biopsies to monitor esophageal inflammatory conditions in children without the use of sedation.

Age at Exposure to Surgery and Anesthesia in Children and Association With Mental Disorder Diagnosis

BACKGROUND

Animals exposed to anesthetics during specific age periods of brain development experience neurotoxicity, with neurodevelopmental changes subsequently observed during adulthood. The corresponding vulnerable age in children, however, is unknown.

METHODS

An observational cohort study was performed using a longitudinal dataset constructed by linking individual-level Medicaid claims from Texas and New York from 1999 to 2010. This dataset was evaluated to determine whether the timing of exposure to anesthesia ≤5 years of age for a single common procedure (pyloromyotomy, inguinal hernia, circumcision outside the perinatal period, or tonsillectomy and/or adenoidectomy) is associated with increased subsequent risk of diagnoses for any mental disorder, or specifically developmental delay (DD) such as reading and language disorders, and attention deficit hyperactivity disorder (ADHD). Exposure to anesthesia and surgery was evaluated in 11 separate age at exposure categories: ≤28 days old, >28 days and ≤6 months, >6 months and ≤1 year, and 6-month age intervals between >1 year old and ≤5 years old. For each exposed child, 5 children matched on propensity score calculated using sociodemographic and clinical covariates were selected for comparison. Cox proportional hazards models were used to measure the hazard ratio of a mental disorder diagnosis associated with exposure to surgery and anesthesia.

RESULTS

A total of 38,493 children with a single exposure and 192,465 propensity score-matched children unexposed before 5 years of age were included in the analysis. Increased risk of mental disorder diagnosis was observed at all ages at exposure with an overall hazard ratio of 1.26 (95% confidence interval [CI], 1.22-1.30), which did not vary significantly with the timing of exposure. Analysis of DD and ADHD showed similar results, with elevated hazard ratios distributed evenly across all ages, and overall hazard ratios of 1.26 (95% CI, 1.20-1.32) for DD and 1.31 (95% CI, 1.25-1.37) for ADHD.

CONCLUSIONS

Children who undergo minor surgery requiring anesthesia under age 5 have a small but statistically significant increased risk of mental disorder diagnoses and DD and ADHD diagnoses, but the timing of the surgical procedure does not alter the elevated risks. Based on these findings, there is little support for the concept of delaying a minor procedure to reduce long-term neurodevelopmental risks of anesthesia in children. In evaluating the influence of age at exposure, the types of procedures included may need to be considered, as some procedures are associated with specific comorbid conditions and are only performed at certain ages.

Subsequent maternal separation exacerbates neurobehavioral abnormalities in rats neonatally exposed to sevoflurane anesthesia

Several recent studies suggest that in the human population, a routine, short anesthetic in otherwise healthy infants is void of neurodevelopmental insult. On the other hand, many human retrospective epidemiological studies report evidence of cognitive abnormalities in children after testing those who had different anesthesia-requiring procedures in early childhood. We tested in a rat model whether post-anesthesia stressful environmental factors can contribute to developmental abnormalities that were initiated by a relatively short exposure to sevoflurane, the most widely used anesthetic in pediatric anesthesia, whose polyvalent actions include enhancement of gamma-aminobutyric acid type A receptor (GABAAR) activity. Postnatal day 6 (P6) male Sprague-Dawley rats were anesthetized with sevoflurane for 60min. To simulate subsequent stress, the animals were subjected to a single maternal separation for 180min at P10. To study the role of GABAAR-mediated depolarization, subgroups of P6 rats received a single injection of the Na+-K+-2Cl- (NKCC1) inhibitor, bumetanide, prior to initiation of anesthesia with sevoflurane. Rats that were exposed to sevoflurane had decreased hypothalamic K+-2Cl- (KCC2) mRNA level (F(2,13)=3.839, P=0.049), increased NKCC1/KCC2 mRNA ratio (F(2,13)=5.043, P=0.024) and increased corticotropin-releasing hormone (CRH) mRNA level (F(2,12)=9.450, P=0.003) at P10, the age at which maternal separation was imposed. Adult rats, neonatally exposed to a combination of sevoflurane and maternal separation, exhibited increases in the escape latencies greater than animals exposed to sevoflurane only (P=0.012), and only rats in the sevoflurane plus maternal separation group spent significantly less time in the target quadrant during the Morris water maze test (F(4,55)=4.856, P=0.002). Bumetanide ameliorated abnormalities induced by sevoflurane and a combination of sevoflurane plus maternal separation. Neonatal exposure to sevoflurane may sensitize to stressors later in life, and post-exposure stress may exacerbate neurodevelopmental abnormalities even after a relatively short exposure to sevoflurane in rodents. The NKCC1 downregulation prior to exposure to the anesthetic may be therapeutic.

Association between Exposure of Young Children to Procedures Requiring General Anesthesia and Learning and Behavioral Outcomes in a Population-based Birth Cohort

BACKGROUND

Exposure of young animals to general anesthesia causes neurodegeneration and lasting behavioral abnormalities; whether these findings translate to children remains unclear. This study used a population-based birth cohort to test the hypothesis that multiple, but not single, exposures to procedures requiring general anesthesia before age 3 yr are associated with adverse neurodevelopmental outcomes.

METHODS

A retrospective study cohort was assembled from children born in Olmsted County, Minnesota, from 1996 to 2000 (inclusive). Propensity matching selected children exposed and not exposed to general anesthesia before age 3 yr. Outcomes ascertained via medical and school records included learning disabilities, attention-deficit/hyperactivity disorder, and group-administered ability and achievement tests. Analysis methods included proportional hazard regression models and mixed linear models.

RESULTS

For the 116 multiply exposed, 457 singly exposed, and 463 unexposed children analyzed, multiple, but not single, exposures were associated with an increased frequency of both learning disabilities and attention-deficit/hyperactivity disorder (hazard ratio for learning disabilities = 2.17 [95% CI, 1.32 to 3.59], unexposed as reference). Multiple exposures were associated with decreases in both cognitive ability and academic achievement. Single exposures were associated with modest decreases in reading and language achievement but not cognitive ability.

CONCLUSIONS

These findings in children anesthetized with modern techniques largely confirm those found in an older birth cohort and provide additional evidence that children with multiple exposures are more likely to develop adverse outcomes related to learning and attention. Although a robust association was observed, these data do not determine whether anesthesia per se is causal.

Scoping review: Awareness of neurotoxicity from anesthesia in children in otolaryngology literature

OBJECTIVE

Review otolaryngology literature for awareness of neurotoxicity from general anesthesia in children. Recently, there has been increasing focus in anesthesia literature on the long-term effects of general anesthesia on neurodevelopment. Multiple animal models have demonstrated evidence of neurotoxicity from both inhalational and intravenous anesthetics. Cohort studies also have revealed modestly increased risk of adverse neurodevelopmental outcomes in children exposed to a single episode of general anesthesia prior to 3 to 4 years of age, with stronger evidence for multiple exposures in this age range. Otolaryngologists may subject children to general anesthesia via procedures or tests, including computed tomography, magnetic resonance imaging, and auditory brainstem response.

DATA SOURCES

PubMed, Embase, Scopus, and Web of Science Review.

METHODS

A scoping review using the above databases was performed limited to January 2005 through December 2015. Articles were screened and reviewed based on predefined inclusion and exclusion criteria.

RESULTS

Initial search generated 3,909 articles. After 72 full text articles were reviewed, only seven articles mentioned neurotoxicity as a risk of general anesthesia in pediatric patients.

CONCLUSION

Despite the high volume of pediatric otolaryngologic procedures performed annually, there remains limited awareness in our literature discussing neurotoxicity as an outcome. Prospective data from anesthesia literature is still pending; therefore, specific recommendations cannot be made at this time. Otolaryngologists should be aware of the concerns and work toward defining elective procedures, combining surgical procedures with other procedures or imaging, and reassessing the timing and frequency of various interventions under general anesthesia in young children. Laryngoscope, 127:1930-1937, 2017.

Latent Class Analysis of Neurodevelopmental Deficit After Exposure to Anesthesia in Early Childhood

INTRODUCTION

Although some studies have reported an association between early exposure to anesthesia and surgery and long-term neurodevelopmental deficit, the clinical phenotype of children exposed to anesthesia is still unknown.

METHODS

Data were obtained from the Western Australian Pregnancy Cohort Study (Raine) with neuropsychological tests at age 10 years measuring language, cognition, motor function, and behavior. Latent class analysis of the tests was used to divide the cohort into mutually exclusive subclasses of neurodevelopmental deficit. Multivariable polytomous logistic regression was used to evaluate the association between exposure to surgery and anesthesia and each latent class, adjusting for demographic and medical covariates.

RESULTS

In our cohort of 1444 children, latent class analysis identified 4 subclasses: (1) Normal: few deficits (n=1135, 78.6%); (2) Language and Cognitive deficits: primarily language, cognitive, and motor deficits (n=96, 6.6%); (3) Behavioral deficits: primarily behavioral deficits, (n=151, 10.5%); and (4) Severe deficits: deficits in all neuropsychological domains (n=62, 4.3%). Language and cognitive deficit group children were more likely to have exposure before age 3 (adjusted odds ratio [aOR], 2.11; 95% confidence interval [CI], 1.17-3.81), whereas a difference in exposure was not found between Behavioral or Severe deficit children (aOR, 1.00; 95% CI, 0.58-1.73, and aOR, 0.85; 95% CI, 0.34-2.15, respectively) and Normal children.

CONCLUSIONS

Our results suggest that in evaluating children exposed to surgery and anesthesia at an early age, the phenotype of interest may be children with deficits primarily in language and cognition, and not children with broad neurodevelopmental delay or primarily behavioral deficits.

Oral Clefts and Academic Performance in Adolescence: The Impact of Anesthesia-Related Neurotoxicity, Timing of Surgery, and Type of Oral Clefts

OBJECTIVE

Early life exposure to anesthesia and surgery is suspected to associate with cognitive impairment later in life. We compared academic achievement among adolescents with cleft lip only (CL), cleft palate only (CP), and cleft lip and cleft palate (CLP) with a noncleft control group to investigate whether outcome depends on timing and number of operations during childhood and/or type of oral cleft.

DESIGN

Nationwide register-based follow-up study.

SETTING

Danish birth cohort 1986 to 1990.

PARTICIPANTS

Five hundred fifty-eight children with isolated CL (n = 171), CLP (n = 222), or CP (n = 195), of which 509 children had been exposed to anesthesia and one or more cleft operation(s), and a 5% sample of the birth cohort (n = 14,677).

MAIN OUTCOME MEASURE(S)

Test score in the Danish standardized ninth-grade exam and proportion of nonattainment, defined as "results for ninth-grade exam unavailable." Data adjusted for sex, birth weight, parental age, and parental level of education.

RESULTS

Compared to controls, children with CL achieved higher scores (mean difference 0.12, 95% CI -0.05; 0.29) and children with CLP presented with lower scores (mean difference -0.06, 95% CI -0.21; 0.09), albeit both statistically insignificant. Children with CP achieved significantly lower scores, mean difference -0.20 (95% CI -0.38; -0.03). Odds ratios for nonattainment at final exam were: CL 0.79 (95% CI 0.46; 1.35), CLP 1.07 (95% CI 0.71; 1.61), CP 2.59 (95% CI 1.78; 3.76).

CONCLUSIONS

Oral cleft type rather than number and timing of anesthesia and operations associate to poorer academic performance. Although a potential neurotoxic effect due to anesthetic agents is not reflected in the data, it cannot be completely excluded.

Isoflurane Anesthesia Has Long-term Consequences on Motor and Behavioral Development in Infant Rhesus Macaques

BACKGROUND

Experimental evidence correlates anesthetic exposure during early development with neuronal and glial injury and death, as well as behavioral and cognitive impairments, in young animals. Several, although not all, retrospective human studies of neurocognitive and behavioral disorders after childhood exposure to anesthesia suggest a similar association. Few studies have specifically investigated the effects of infant anesthesia exposure on subsequent neurobehavioral development. Using a highly translational nonhuman primate model, the authors investigated the potential dose-dependent effects of anesthesia across the first year of development.

METHODS

The authors examined the effects of single or multiple early postnatal isoflurane exposures on subsequent behavioral development in 24 socially reared rhesus macaques. Infants were exposed to 5 h of isoflurane anesthesia once, three times (ISO-3), or not at all (control). The authors assessed reflex development and anxiety using standardized tests. At approximately 1 yr, infants (n = 23) were weaned and housed indoors with 5 to 6 other subjects. The authors recorded their response to this move and reassessed anxiety.

RESULTS

Compared to controls, animals exposed to repeated isoflurane (ISO-3) presented with motor reflex deficits at 1 month (median [range]: ISO-3 = 2 [1 to 5] vs. control = 5 [3 to 7]; P < 0.005) and responded to their new social environment with increased anxiety (median [range]: ISO-3 = 0.4 bouts/min [0.2 to 0.6]; control = 0.25 bouts/min [0.1 to 0.3]; P = 0.05) and affiliative/appeasement behavior (median [range]: ISO-3 = 0.1 [0 to 0.2]; control = 0 bouts/min [0 to 0.1]; P < 0.01) at 12 months. There were no statistically significant behavioral alterations after single isoflurane exposure.

CONCLUSIONS

Neonatal exposure to isoflurane, particularly when repeated, has long-term behavioral consequences affecting both motor and socioemotional aspects of behavior.

Long-term Fate Mapping to Assess the Impact of Postnatal Isoflurane Exposure on Hippocampal Progenitor Cell Productivity

BACKGROUND

Exposure to isoflurane increases apoptosis among postnatally generated hippocampal dentate granule cells. These neurons play important roles in cognition and behavior, so their permanent loss could explain deficits after surgical procedures.

METHODS

To determine whether developmental anesthesia exposure leads to persistent deficits in granule cell numbers, a genetic fate-mapping approach to label a cohort of postnatally generated granule cells in Gli1-CreER::GFP bitransgenic mice was utilized. Green fluorescent protein (GFP) expression was induced on postnatal day 7 (P7) to fate map progenitor cells, and mice were exposed to 6 h of 1.5% isoflurane or room air 2 weeks later (P21). Brain structure was assessed immediately after anesthesia exposure (n = 7 controls and 8 anesthesia-treated mice) or after a 60-day recovery (n = 8 controls and 8 anesthesia-treated mice). A final group of C57BL/6 mice was exposed to isoflurane at P21 and examined using neurogenesis and cell death markers after a 14-day recovery (n = 10 controls and 16 anesthesia-treated mice).

RESULTS

Isoflurane significantly increased apoptosis immediately after exposure, leading to cell death among 11% of GFP-labeled cells. Sixty days after isoflurane exposure, the number of GFP-expressing granule cells in treated animals was indistinguishable from control animals. Rates of neurogenesis were equivalent among groups at both 2 weeks and 2 months after treatment.

CONCLUSIONS

These findings suggest that the dentate gyrus can restore normal neuron numbers after a single, developmental exposure to isoflurane. The authors' results do not preclude the possibility that the affected population may exhibit more subtle structural or functional deficits. Nonetheless, the dentate appears to exhibit greater resiliency relative to nonneurogenic brain regions, which exhibit permanent neuron loss after isoflurane exposure.

Anesthesia, brain changes, and behavior: Insights from neural systems biology

Long-term consequences of anesthetic exposure in humans are not well understood. It is possible that alterations in brain function occur beyond the initial anesthetic administration. Research in children and adults has reported cognitive and/or behavioral changes after surgery and general anesthesia that may be short lived in some patients, while in others, such changes may persist. The changes observed in humans are corroborated by a large body of evidence from animal studies that support a role for alterations in neuronal survival (neuroapoptosis) or structure (altered dendritic and glial morphology) and later behavioral deficits at older age after exposure to various anesthetic agents during fetal or early life. The potential of anesthetics to induce long-term alterations in brain function, particularly in vulnerable populations, warrants investigation. In this review, we critically evaluate the available preclinical and clinical data on the developing and aging brain, and in known vulnerable populations to provide insights into potential changes that may affect the general population of patients in a more, subtle manner. In addition this review summarizes underlying processes of how general anesthetics produce changes in the brain at the cellular and systems level and the current understanding underlying mechanisms of anesthetics agents on brain systems. Finally, we present how neuroimaging techniques currently emerge as promising approaches to evaluate and define changes in brain function resulting from anesthesia, both in the short and the long-term.

Lasting impact of general anaesthesia on the brain: mechanisms and relevance

General anaesthesia is usually considered to safely induce a reversible brain state allowing the performance of surgery under optimal conditions. An increasing number of clinical and experimental observations, however, suggest that anaesthetic drugs, especially when they are administered at the extremes of age, can trigger long-term morphological and functional alterations in the brain. Here, we review available mechanistic data linking general-anaesthesia exposure to impaired cognitive performance in both young and mature nervous systems. We also provide a critical appraisal of the translational value of animal models and highlight the important challenges that need to be addressed to strengthen the link between laboratory work and clinical investigations in the field of anaesthesia-neurotoxicity research.

General Anesthesia Causes Epigenetic Histone Modulation of c-Fos and Brain-derived Neurotrophic Factor, Target Genes Important for Neuronal Development in the Immature Rat Hippocampus

BACKGROUND

Early postnatal exposure to general anesthesia (GA) may be detrimental to brain development, resulting in long-term cognitive impairments. Older literature suggests that in utero exposure of rodents to GA causes cognitive impairments in the first-generation as well as in the second-generation offspring never exposed to GA. Thus, the authors hypothesize that transient exposure to GA during critical stages of synaptogenesis causes epigenetic changes in chromatin with deleterious effects on transcription of target genes crucial for proper synapse formation and cognitive development. They focus on the effects of GA on histone acetyltransferase activity of cAMP-responsive element-binding protein and the histone-3 acetylation status in the promoters of the target genes brain-derived neurotrophic factor and cellular Finkel-Biskis-Jinkins murine sarcoma virus osteosarcoma oncogene (c-Fos) known to regulate the development of neuronal morphology and function.

METHODS

Seven-day-old rat pups were exposed to a sedative dose of midazolam followed by combined nitrous oxide and isoflurane anesthesia for 6 h. Hippocampal neurons and organotypic hippocampal slices were cultured in vitro and exposed to GA for 24 h.

RESULTS

GA caused epigenetic modulations manifested as histone-3 hypoacetylation (decrease of 25 to 30%, n = 7 to 9) and fragmentation of cAMP-responsive element-binding protein (two-fold increase, n = 6) with 25% decrease in its histone acetyltransferase activity, which resulted in down-regulated transcription of brain-derived neurotrophic factor (0.2- to 0.4-fold, n = 7 to 8) and cellular Finkel-Biskis-Jinkins murine sarcoma virus osteosarcoma oncogene (about 0.2-fold, n = 10 to 12). Reversal of histone hypoacetylation with sodium butyrate blocked GA-induced morphological and functional impairments of neuronal development and synaptic communication.

CONCLUSION

Long-term impairments of neuronal development and synaptic communication could be caused by GA-induced epigenetic phenomena.

Gastrojejunostomy tube complications - A single center experience and systematic review

PURPOSE

Gastrojejunostomy tubes (GJTs) enable enteral nutrition in infants/children with feeding intolerance. However, complications may be increased in small infants. We evaluated our single-institution GJT complication rate and systematically reviewed existing literature.

METHODS

With REB approval, a retrospective single-institution analysis of GJT placements between 2009 and 2015 was performed. For the systematic review, MOOSE guidelines were followed.

RESULTS

At our institution, 48 children underwent 154/159 successful insertions primarily for gastroesophageal reflux (n=27; 55%) and aspiration (n=11; 23%). Median age at first GJT insertion was 2.2years (0.2-18). Thirty-five (73%) had an index insertion when ≤10kg. GJTs caused 2 perforations and 1 death. The systematic review assessed 48 articles representing 2726 procedures. Overall perforation rate was estimated as 2.1% (n=36 studies, 23/1092, 95% CI: 1.0-3.2). Perforation rates in children <10kg versus ≥10kg were estimated as 3.1%/procedure (95% CI: 1.1%-5.0%) and 0.1%/procedure (95% CI: 0%-0.3%), respectively. The relative risk of perforation was 9.4 (95% CI: 2.8-31.3). Overall mortality was estimated as 0.9%/patient (n=39 studies; 95% CI: 0.2-1.6%). Most perforations (19/23; 83%) occurred ≤30days of attempted tube placement.

CONCLUSION

Gastrojejunostomy tubes are associated with significant complications and frequently require revision/replacement. Insertion in patients <10kg is associated with increased perforation risk. Caution is warranted in this subgroup.

LEVEL OF EVIDENCE

Level II.

Elamipretide (SS-31) Ameliorates Isoflurane-Induced Long-Term Impairments of Mitochondrial Morphogenesis and Cognition in Developing Rats

Mitochondria are supposed to be involved in the early pathogenesis of general anesthesia (GA)-induced neurotoxicity and long-term cognitive deficits in developing brains. However, effective pharmacologic agents targeted on mitochondria during GA exposure are lacking. This study explores the protective effects of mitochondrion-targeted antioxidant elamipretide (SS-31) on mitochondrial morphogenesis and cognition in developing rats exposed to isoflurane. Rat pups at postnatal day (PND) 7 were exposed to 1.5% isoflurane for 6 h following intraperitoneal administration of elamipretide or vehicle with 30 min interval. The hippocampus was immediately removed for biochemical assays. Histopathological studies were conducted at PND 21, and behavioral tests were performed at PND 40 or 60. We found that early exposure to isoflurane caused remarkable reactive oxygen species (ROS) accumulation, mitochondrial deformation and neuronal apoptosis in hippocampus. The injury occurrence ultimately gave rise to long-term cognitive deficits in developing rats. Interestingly, pretreatment with elamipretide not only provided protective effect against oxidative stress and mitochondrial damages, but also attenuated isoflurane-induced cognitive deficits. Our data support the notion that mitochondrial damage is an early and long lasting event of GA-induced injury and suggest that elamipretide might have clinically therapeutic benefits for pediatric patients undertaking GA.

General Anesthetics and Neurotoxicity: How Much Do We Know?

Over a decade ago, alarming findings were reported that exposure of the very young and very old animals to clinically used general anesthetics could be detrimental to their brains. The evidence presented suggested that the exposure to commonly used gaseous and intravenous general anesthetics induces the biochemical and morphologic changes in the immature and aging neurons ultimately resulting in their demise. More alarming was the demonstration of significant cognitive and behavioral impairments noted long after the initial anesthesia exposure. This article provides an overview of anesthesia-induced developmental neurotoxicity and commentary on the effects of general anesthesia on the aging brain.

Sevoflurane Exposure during the Critical Period Affects Synaptic Transmission and Mitochondrial Respiration but Not Long-term Behavior in Mice

Background

Anesthesia during the synaptogenic period induces dendritic spine formation, which may affect neurodevelopment. The authors, therefore, evaluated whether changes in synaptic transmission after dendritic spine formation induced by sevoflurane were associated with long-term behavioral changes. The effects of sevoflurane on mitochondrial function were also assessed to further understand the mechanism behind spinogenesis.

Methods

Postnatal day 16 to 17 mice were exposed to sevoflurane (2.5% for 2 h), and synaptic transmission was measured in the medial prefrontal cortex 6 h or 5 days later. The expression of postsynaptic proteins and mitochondrial function were measured after anesthesia. Long-term behavioral changes were assessed in adult mice.

Results

Sevoflurane increased the expression of excitatory postsynaptic proteins in male and female mice (n = 3 to 5 per group). Sevoflurane exposure in male mice transiently increased miniature excitatory postsynaptic current frequency (control: 8.53 ± 2.87; sevoflurane: 11.09 ± 2.58) but decreased miniature inhibitory postsynaptic current frequency (control: 10.18 ± 4.66; sevoflurane: 6.88 ± 2.15). Unexpectedly, sevoflurane increased miniature inhibitory postsynaptic current frequency (control: 1.81 ± 1.11; sevoflurane: 3.56 ± 1.74) in female mice (neurons, n = 10 to 21 per group). Sevoflurane also increased mitochondrial respiration in male mice (n = 5 to 8 per group). However, such changes from anesthesia during the critical period did not induce long-term behavioral consequences. Values are presented as mean ± SD.

Conclusions

Sevoflurane exposure during the critical period induces mitochondrial hyperactivity and transient imbalance of excitatory/inhibitory synaptic transmission, without long-lasting behavioral consequences. Further studies are needed to confirm sexual differences and to define the role of mitochondrial activity during anesthesia-induced spine formation.

Neuroprotection and neurotoxicity in the developing brain: an update on the effects of dexmedetomidine and xenon

Growing and consistent preclinical evidence, combined with early clinical epidemiological observations, suggest potentially neurotoxic effects of commonly used anesthetic agents in the developing brain. This has prompted the FDA to issue a safety warning for all sedatives and anesthetics approved for use in children under three years of age. Recent studies have identified dexmedetomidine, the potent α2-adrenoceptor agonist, and xenon, the noble gas, as effective anesthetic adjuvants that are both less neurotoxic to the developing brain, and also possess neuroprotective properties in neonatal and other settings of acute ongoing neurologic injury. Dexmedetomidine and xenon are effective anesthetic adjuvants that appear to be less neurotoxic than other existing agents and have the potential to be neuroprotective in the neonatal and pediatric settings. Although results from recent clinical trials and case reports have indicated the neuroprotective potential of xenon and dexmedetomidine, additional randomized clinical trials corroborating these studies are necessary. By reviewing both the existing preclinical and clinical evidence on the neuroprotective effects of dexmedetomidine and xenon, we hope to provide insight into the potential clinical efficacy of these agents in the management of pediatric surgical patients.

The effect of anaesthesia on the infant brain

Pre-clinical studies have consistently found that most general anaesthetics produce accelerated apoptosis in the developing brain. The effect has been seen in species ranging from the nematode to the non-human primate. A variety of other effects are also seen. There is also some evidence that animals exposed to anaesthesia are at increased risk of deficits in memory and learning. The effects are only seen with prolonged exposure. There are numerous problems in translating these findings to human clinical scenarios. Several human cohort studies have found an association between surgery in infancy and increased risk of poorer neurobehavioural outcome; however the possibility of confounding factors such as co-morbidity and surgery itself make it impossible to determine if these associations are due to anaesthesia toxicity. A recent trial and cohort studies suggest that an exposure of less than an hour does not increase the risk of poor outcome.

Do anesthetics harm the developing human brain? An integrative analysis of animal and human studies

Anesthetics that permit surgical procedures and stressful interventions have been found to cause structural brain abnormalities and functional impairment in immature animals, generating extensive concerns among clinicians, parents, and government regulators regarding the safe use of these drugs in young children. Critically important questions remain, such as the exact age at which the developing brain is most vulnerable to the effects of anesthetic exposure, whether a particular age exists beyond which anesthetics are devoid of long-term effects on the brain, and whether any specific exposure duration exists that does not lead to deleterious effects. Accordingly, the present analysis attempts to put the growing body of animal studies, which we identified to include >440 laboratory studies to date, into a translational context, by integrating the preclinical data on brain structure and function with clinical results attained from human neurocognitive studies, which currently exceed 30 studies. Our analysis demonstrated no clear exposure duration threshold below which no structural injury or subsequent cognitive abnormalities occurred. Animal data did not clearly identify a specific age beyond which anesthetic exposure did not cause any structural or functional abnormalities. Several potential mitigating strategies were found, however, no general anesthetic was identified that consistently lacked neurodegenerative properties and could be recommended over other anesthetics. It therefore is imperative, to expand efforts to devise safer anesthetic techniques and mitigating strategies, even before long-term alterations in brain development are unequivocally confirmed to occur in millions of young children undergoing anesthesia every year.

What Next After GAS and PANDA?

On April 16 and 17, 2016, the Fifth biennial Pediatric Anesthesia & Neurodevelopment Assessment (PANDA) symposium was convened at the Morgan Stanley Children's Hospital of New York at Columbia University Medical Center. During the symposium, experts in the fields of anesthesiology, neuropsychology, and epidemiology were convened in a small group session to determine the level of confidence in the current clinical evidence and the next steps in anesthetic neurotoxicity clinical research. Among the participants in the discussion, there remained a lack of consensus on whether anesthetic exposure causes long-term neurodevelopmental deficits in children based on the current evidence. This causal relationship between anesthesia exposure and neurodevelopmental deficit is difficult to establish using observational data, and current and future clinical trials are critical for answering this question. It was, however, recognized that the continuum of data that is seen in studies of other toxic environmental exposures, such as lead poisoning, has not been established in the anesthetic neurotoxicity literature, specifically regarding the timing of the exposure, the dose effects, contributing perioperative conditions, or vulnerable populations. As a result, these questions may need to be addressed in observational studies to guide future clinical trials.

Early childhood exposure to short periods of sevoflurane is not associated with later, lasting cognitive deficits

BACKGROUND

A detrimental effect of commonly used anesthetics on the neurodevelopmental and behavioral parameters has long been shown in young animals subjected to early childhood anesthesia. Epidemiologic studies suggest the possibility of a modestly elevated risk of adverse neurodevelopmental outcomes in children exposed to anesthesia during early childhood. However, these results are still preliminary and inconclusive.

AIM

To further elucidate the probability of occurrence of such adverse outcomes, we evaluated cognitive performance of children who underwent general anesthesia early in their childhood.

METHOD

One hundred and fifteen children aged 5-16 years with established glaucoma were included in the study. Of these, 68 children had a history of at least one general anesthesia with sevoflurane before age 3. Phonemic and semantic verbal fluency, and forward and backward digit span tests were performed to evaluate cognitive function in the study subjects.

RESULTS

The two-way anova revealed that all these variables showed significant changes in various age groups, but they were comparable among subjects with no, single, or multiple childhood anesthesia.

CONCLUSION

It can be concluded that brief periods of anesthesia with single anesthetic sevoflurane may be safe for children under age 3.

Is a short anesthetic exposure in children safe? Time will tell: a focused commentary of the GAS and PANDA trials

Early life exposure to general anesthesia in preclinical studies has consistently led to permanent cognitive deficits later in life. However, the extent to which this finding is translatable to humans is the subject of much debate as the results from clinical studies have been mixed. Recently two well-designed clinical trials have attempted to add clarity to our murky understanding. The General Anesthesia compared to Spinal anesthesia (GAS) trial, was an international, prospective, randomized, multicenter, equivalence trial comparing infants undergoing herniorrhaphy receiving general anesthesia vs. neuraxial anesthesia. The results released are from a pre-determined secondary outcome of a behavioral/developmental assessment of 2 years old that found equivalence between the two groups. The Pediatric Anesthesia NeuroDevelopment Assessment (PANDA) trial was an ambi-directional cohort trial, comparing patients receiving general anesthesia for hernia repair before 3 years old vs. sibling-matched controls. The neuropsychological battery performed showed no difference between siblings. Taken together, there is cautious optimism that short anesthesia exposure may not lead to significant cognitive decline in humans, but one should also consider that the GAS trial has yet to release the primary endpoint, IQ testing at age 5, and the PANDA trial may not represent the general population given the high socioeconomic status and high control IQ scores. Furthermore, as seen in preclinical studies, the cognitive deficit might not be significant until later in life, and longer exposures to anesthesia may have a more deleterious effect on cognitive function. While these new studies greatly increase our understanding in humans, there are many more questions that need to be addressed.

Neurodevelopmental Assessment in Kindergarten in Children Exposed to General Anesthesia before the Age of 4 Years: A Retrospective Matched Cohort Study

BACKGROUND

Animal studies demonstrate general anesthetic (GA) toxicity in the developing brain. Clinical reports raise concern, but the risk of GA exposure to neurodevelopment in children remains uncertain.

METHODS

The authors undertook a retrospective matched cohort study comparing children less than 4 yr of age exposed to GA to those with no GA exposure. The authors used the Early Development Instrument (EDI), a 104-component questionnaire, encompassing five developmental domains, completed in kindergarten as the outcome measure. Mixed-effect logistic regression models generated EDI estimates for single versus multiple GA exposure and compared both single and multiple exposures by the age of 0 to 2 or 2 to 4 yr. Known sociodemographic and physical confounders were incorporated as covariates in the models.

RESULTS

A total of 18,056 children were studied: 3,850 exposed to a single GA and 620 exposed to two or more GA, who were matched to 13,586 nonexposed children. In children less than 2 yr of age, there was no independent association between single or multiple GA exposure and EDI results. Paradoxically, single exposure between 2 and 4 yr of age was associated with deficits, most significant for communication/general knowledge (estimate, -0.7; 95% CI, -0.93 to -0.47; P < 0.0001) and language/cognition (estimate, -0.34; 95% CI, -0.52 to -0.16; P < 0.0001) domains. Multiple GA exposure at the age of 2 to 4 yr did not confer greater risk than single GA exposure.

CONCLUSIONS

These findings refute the assumption that the earlier the GA exposure in children, the greater the likelihood of long-term neurocognitive risk. The authors cannot confirm an association between multiple GA exposure and increased risk of neurocognitive impairment, increasing the probability of confounding to explain the results.

Summary of the Update Session on Clinical Neurotoxicity Studies

During the Fifth Pediatric Anesthesia Neurodevelopmental Assessment Symposium, experts and stakeholders met to present and discuss recent advances made in the study of neurodevelopmental outcomes after exposure to anesthetic drugs in infants and children. This article summarizes the update of 5 ongoing clinical studies: General Anesthesia compared to Spinal Anesthesia, Toxicity of Remifentanil and Dexmedetomidine, Mayo Anesthesia Safety in Kids, the University of California San Francisco human cohort study, and Columbia University Medical Center Neonatal Magnetic Resonance Imaging study. The purpose of this summary is to discuss the contributions and limitations of these studies, how they fit into the published literature, and what questions remain to be answered.

From Drug-Induced Developmental Neuroapoptosis to Pediatric Anesthetic Neurotoxicity-Where Are We Now?

The fetal and neonatal periods are critical and sensitive periods for neurodevelopment, and involve rapid brain growth in addition to natural programmed cell death (i.e., apoptosis) and synaptic pruning. Apoptosis is an important process for neurodevelopment, preventing redundant, faulty, or unused neurons from cluttering the developing brain. However, animal studies have shown massive neuronal cell death by apoptosis can also be caused by exposure to several classes of drugs, namely gamma-aminobutyric acid (GABA) agonists and N-methyl-d-aspartate (NMDA) antagonists that are commonly used in pediatric anesthesia. This form of neurotoxic insult could cause a major disruption in brain development with the potential to permanently shape behavior and cognitive ability. Evidence does suggest that psychoactive drugs alter neurodevelopment and synaptic plasticity in the animal brain, which, in the human brain, may translate to permanent neurodevelopmental changes associated with long-term intellectual disability. This paper reviews the seminal animal research on drug-induced developmental apoptosis and the subsequent clinical studies that have been conducted thus far. In humans, there is growing evidence that suggests anesthetics have the potential to harm the developing brain, but the long-term outcome is not definitive and causality has not been determined. The consensus is that there is more work to be done using both animal models and human clinical studies.

A Population-based Study Evaluating the Association between Surgery in Early Life and Child Development at Primary School Entry

Background

It is unclear whether exposure to surgery in early life has long-term adverse effects on child development. The authors aimed to investigate whether surgery in early childhood is associated with adverse effects on child development measured at primary school entry.

Methods

The authors conducted a population-based cohort study in Ontario, Canada, by linking provincial health administrative databases to children’s developmental outcomes measured by the Early Development Instrument (EDI). From a cohort of 188,557 children, 28,366 children who underwent surgery before EDI completion (age 5 to 6 yr) were matched to 55,910 unexposed children. The primary outcome was early developmental vulnerability, defined as any domain of the EDI in the lowest tenth percentile of the population. Subgroup analyses were performed based on age at first surgery (less than 2 and greater than or equal to 2 yr) and frequency of surgery.

Results

Early developmental vulnerability was increased in the exposed group (7,259/28,366; 25.6%) compared with the unexposed group (13,957/55,910; 25.0%), adjusted odds ratio, 1.05; 95% CI, 1.01 to 1.08. Children aged greater than or equal to 2 yr at the time of first surgery had increased odds of early developmental vulnerability compared with unexposed children (odds ratio, 1.05; 95% CI, 1.01 to 1.10), but children aged less than 2 yr at the time of first exposure were not at increased risk (odds ratio, 1.04; 95% CI, 0.98 to 1.10). There was no increase in odds of early developmental vulnerability with increasing frequency of exposure.

Conclusions

Children who undergo surgery before primary school age are at increased risk of early developmental vulnerability, but the magnitude of the difference between exposed and unexposed children is small.

Umbilical hernia following gastroschisis closure: a common event?

PURPOSE

To assess incidence and natural history of umbilical hernia following sutured and sutureless gastroschisis closure.

METHODS

With audit approval, we undertook a retrospective clinical record review of all gastroschisis closures in our institution (2007-2013). Patient demographics, gastroschisis closure method and umbilical hernia occurrence were recorded. Data, presented as median (range), underwent appropriate statistical analysis.

RESULTS

Fifty-three patients were identified, gestation 36 weeks (31-38), birth weight 2.39 kg (1-3.52) and 23 (43 %) were male. Fourteen patients (26 %) underwent sutureless closure: 12 primary, 2 staged; and 39 (74 %) sutured closure: 19 primary, 20 staged. Sutured closure was interrupted sutures in 24 patients, 11 pursestring and 4 not specified. Fifty patients were followed-up over 53 months (10-101) and 22 (44 %) developed umbilical hernias. There was a significantly greater hernia incidence following sutureless closure (p = 0.0002). In sutured closure, pursestring technique had the highest hernia rate (64 %). Seven patients underwent operative hernia closure; three secondary to another procedure. Seven patients had their hernias resolve. One patient was lost to follow-up and seven remain under observation with no reported complications.

CONCLUSIONS

There is a significant umbilical hernia incidence following sutureless and pursestring sutured gastroschisis closure. This has not led to complications and the majority have not undergone repair.

School performance in cholesteatoma-operated children in Denmark: a nationwide population-based register-study

Conclusion Cholesteatoma in childhood had no long-term effect on school performance for the majority who completed lower secondary school. Aim To investigate whether individuals operated on for cholesteatoma in childhood have impaired school performance in adolescence. Methods All children born in Denmark between 1986-1991 with cholesteatoma surgery performed before the age of 15 years were included (cholestetaoma group). A control group consisting of a 5% random sample of all children born in Denmark during the same period was used for comparison. Final marks (average, mathematics, Danish, and English) achieved upon completion of lower secondary school (9th grade; age 15 or 16 years) were compared between groups. Results A total of 549 individuals met the inclusion criteria for the cholesteatoma group and 15 106 for the control group. High parental education and female sex were strongly associated with high 9th grade marks. The cholesteatoma group did equally as well as the control group in all outcome-measures except from in English (1st foreign language), where children with ≥2 cholesteatoma surgeries scored 0.26 marks lower (95% confidence interval = 0.03-0.48). In the cholesteatoma group, though, the odds ratio for not attaining a 9th grade exam was 1.33 (95% confidence interval = 1.03-1.72%) when compared with the control group.

Neurocognitive Adverse Effects of Anesthesia in Adults and Children: Gaps in Knowledge

Numerous preclinical and clinical studies investigating the neurodevelopmental and neurocognitive effects of exposure to anesthesia and the combination of anesthesia and surgery have demonstrated histopathological and both temporary and long-term cognitive and behavioral effects at the extremes of the human age spectrum. Increasing coverage in the lay press for both our youngest and oldest patient populations has led to heightened concerns regarding the potential harmful side effects of almost all commonly used anesthetic drug regimens. Although the majority of information regarding anesthetic risks in the developing brain derives from preclinical work in rodents, research involving the aged brain has identified a well-defined postoperative cognitive phenotype in humans. While preclinical and clinical data appear to support some association between anesthesia and surgery and the development of detrimental cognitive changes in both the developing and the aged brain, correlation between anesthesia and surgery and poor neurological outcomes does not imply causation. Given this information, no single anesthetic or group of anesthetics can be recommended over any other in terms of causing or preventing negative neurocognitive outcomes in either population. This review summarizes the growing body of preclinical and clinical literature dedicated to the detrimental effects of anesthesia on both the developing and the aging brain.

Epigenetic Manipulation of Brain-derived Neurotrophic Factor Improves Memory Deficiency Induced by Neonatal Anesthesia in Rats

BACKGROUND

Although neonatal exposure to anesthetic drugs is associated with memory deficiency in rodent models and possibly in pediatric patients, the underlying mechanisms remain elusive. The authors tested their hypothesis that exposure of the developing brain to anesthesia triggers epigenetic modification, involving the enhanced interaction among transcription factors (histone deacetylase 2, methyl-cytosine-phosphate-guanine-binding protein 2, and DNA methyltransferase 1) in Bdnf promoter region(s) that inhibit brain-derived neurotrophic factor (BDNF) expression, resulting in insufficient drive for local translation of synaptic mRNAs. The authors further hypothesized that noninvasive environmental enrichment (EE) will attenuate anesthesia-induced epigenetic inhibition of BDNF signaling and memory loss in rodent models.

METHODS

Seven days after birth (P7), neonatal rats were randomly assigned to receive either isoflurane anesthesia for 6 h or sham anesthesia. On P21, pups were weaned, and animals were randomly assigned to EE or a standard cage environment (no EE). Behavioral, molecular, and electrophysiological studies were performed on rats on P65.

RESULTS

The authors found a substantial reduction of hippocampal BDNF (n = 6 to 7) resulting from the transcriptional factors-mediated epigenetic modification in the promoter region of Bdnf exon IV in rats exposed postnatally to anesthetic drugs. This BDNF reduction led to the insufficient drive for the synthesis of synaptic proteins (n = 6 to 8), thus contributing to the hippocampal synaptic (n = 8 to 11) and cognitive dysfunction (n = 10) induced by neonatal anesthesia. These effects were mitigated by the exposure to an enriched environment.

CONCLUSIONS

The findings of this study elucidated the epigenetic mechanism underlying memory deficiency induced by neonatal anesthesia and propose EE as a potential therapeutic approach.

Measuring Pediatric Bronchoscopy Outcomes Using an Electronic Medical Record

RATIONALE

Bronchoscopy procedures should be tracked for safety, quality improvement, and federal regulations.

OBJECTIVE

The aim of this study was to develop and test a method for evaluating flexible bronchoscopy use and outcomes using the electronic medical record (EMR) system in current clinical use at a large children's hospital.

METHODS

We created a custom bronchoscopy procedure note for our EMR system (Epic Systems Corporation) to track demographics, bronchoscopist, coordinated procedures, and outcome. Unplanned outcomes in children were defined as a disposition (admission to the hospital or elevation of care) after flexible bronchoscopy that differed from the preoperative plan. Readmissions to the hospital and emergency visits within our hospital system were also tracked electronically. Unplanned outcomes and readmissions were evaluated by a bronchoscopy quality team.

MEASUREMENTS AND MAIN RESULTS

Over 2.5 years, we tracked 1,297 bronchoscopic procedures performed on 1,161 patients (60% male, 78% American Society of Anesthesiologists class 2 or 3, mean age 5.5 yr [range, 0.02-40 yr]). Overall, 27 unplanned outcomes occurred (2.1%). The risk of unplanned outcomes did not appear to be different between procedures performed by a trainee with faculty oversight and those performed by a faculty member alone. Patients with multiple same-day procedures were more likely to have unplanned outcomes (21 of 27 [78%], P = 0.004) than were patients who had flexible bronchoscopy alone. The relative risk (RR) of having an unplanned outcome was not different from flexible bronchoscopy alone in the subset of patients with multiple procedures coordinated through our multidisciplinary aerodigestive clinic (RR 0.7; 95% CI, 0.1-3.4). The risk of unplanned events was significantly elevated in children with coordinated procedures scheduled outside the aerodigestive group (RR, 5.8; 95% CI, 2.4-14.5). Ten patients (<1%) were readmitted or seen urgently within 1 week; three of these unplanned outcomes were attributed to complications of the bronchoscopy.

CONCLUSIONS

An EMR system may be used to track procedural outcomes. Unplanned outcomes after flexible bronchoscopy were infrequent at our institution. Children who underwent multiple procedures had unplanned outcomes more often; however, the subset of children who underwent coordinated procedures through our multidisciplinary aerodigestive clinic did not demonstrate this increased risk.

Multiple Anesthetic Exposure in Infant Monkeys Alters Emotional Reactivity to an Acute Stressor

BACKGROUND

Retrospective studies in humans have shown a higher prevalence of learning disabilities in children that received multiple exposures to general anesthesia before the age of 4 yr. Animal studies, primarily in rodents, have found that postnatal anesthetic exposure causes neurotoxicity and neurocognitive deficits in adulthood. The authors addressed the question of whether repeated postnatal anesthetic exposure was sufficient to cause long-term behavioral changes in a highly translationally relevant rhesus monkey model, allowing study of these variables against a background of protracted nervous system and behavioral development.

METHODS

Rhesus monkeys of both sexes underwent either three 4-h exposures to sevoflurane anesthesia (anesthesia group n = 10) or brief maternal separations (control group n = 10) on postnatal day 6 to 10 that were repeated 14 and 28 days later. Monkeys remained with their mothers in large social groups at all times except for overnight observation after each anesthetic/control procedure. At 6 months of age, each monkey was tested on the human intruder paradigm, a common test for emotional reactivity in nonhuman primates.

RESULTS

The frequency of anxiety-related behaviors was significantly higher in monkeys that were exposed to anesthesia as neonates as compared with controls: anesthesia 11.04 ± 1.68, controls 4.79 ± 0.77, mean ± SEM across all stimulus conditions.

CONCLUSION

Increased emotional behavior in monkeys after anesthesia exposure in infancy may reflect long-term adverse effects of anesthesia.