Anesthesia and the developing brain: a way forward for clinical research

MRI scan with the "feed and wrap" technique and with an optimized anesthesia protocol: a retrospective analysis of a single-center experience

Introduction

MRI examinations in the pediatric population require acquiring motionless images in the safest possible manner. At our institute, we have developed a protocol called "Good Practice" aimed at avoiding anesthesia in newborns and infants through the use of the "feed and wrap" technique, as well as preventing hospitalization for older children requiring anesthesia with an optimized sedation protocol. We evaluated this protocol in terms of patient safety, imaging quality, and parental satisfaction.

Materials and methods

Patient data were collected retrospectively. In the feed and wrap group, image quality and the necessity of repeating the examination were evaluated. In the optimized anesthesiologic protocol group, various parameters were analyzed to assess the safety of the protocol. Parental satisfaction was determined through a questionnaire.

Results

A total of 132 patients were included, with 82 undergoing the feed and wrap technique and 50 receiving the optimized anesthesiologic protocol. In the feed and wrap group, images were classified as follows: 4.87% poor, 18.29% sufficient, 37.80% good, and 39.92% excellent. In only 2 cases a new MRI examination was required. In the optimized anesthesiologic protocol group, no adverse effects were observed, and no post-anesthesia hospitalizations were needed. 100% of parents of babies examined with the feed and wrap technique rated it as excellent. Furthermore, 85.6% of parents considered the optimized anesthesiologic protocol excellent, and 13.6% rated it as good.

Conclusion

At our institute, the feed and wrap technique proved to be effective in obtaining high-quality images. Anesthesia using propofol showed no adverse effects and proved to be successful in avoiding hospitalization. Parents expressed relief at the avoidance of anesthesia and hospitalization for their children.

Neurodevelopmental outcomes in individuals with VACTERL association. A population-based cohort study

BACKGROUND

Studies on neurodevelopmental outcomes in individuals with congenital anomalies who undergo neonatal surgery are scarce and have reported contradictory findings based on small study groups. The congenital condition VACTERL association includes at least three malformations: vertebral anomalies, anorectal malformations, cardiac defects, tracheoesophageal fistula with or without esophageal atresia, renal anomalies and limb deformities. Most of these patients undergo surgery during their first days of life. Neurodevelopmental disorders include a broad group of disabilities involving some form of disruption to brain development. Attention deficit hyperactivity disorder (ADHD), autism spectrum disorders (ASD) and intellectual disability (ID) are diagnoses included in this group. The aim of the study was to investigate the risk of ADHD, ASD and ID in a cohort of individuals with VACTERL association.

METHOD

Data was obtained from four Swedish national health registers and analyzed using the Cox proportional hazards model. Patients born 1973-2018 in Sweden with the diagnosis of VACTERL association were included in the study. For each case five healthy controls matched for sex, gestational age at birth, birth year and birth county were obtained.

RESULTS

The study included 136 individuals with VACTERL association and 680 controls. Individuals with VACTERL had significantly higher risk of ADHD, ASD and ID than the controls; 2.25 (95% CI, 1.03-4.91), 5.15 (95% CI, 1.93-13.72) and 8.13 (95% CI, 2.66-24.87) times respectively.

CONCLUSIONS

A higher risk of ADHD, ASD and ID was found among individuals with VACTERL association compared to controls. These results are of importance to caregivers and to professionals participating in follow ups of these patients in providing early diagnosis and support, aiming to optimize the quality of life of these patients.

Congenital Cataracts in Preterm Infants: A Review

A congenital cataract is one of the most treatable causes of visual impairment during infancy. Preterm infants who are born alive before 37 weeks of pregnancy need special care, including proper age documentation, preoperative assessment, and monitoring postoperatively for at least 24 hours. Management of cataracts in preterm infants is critical as regards the timing of cataract surgery and the challenges associated with cataract surgery and posterior segment management for retinopathy of prematurity (ROP). This narrative review aims to provide comprehensive insight and up-to-date clinical research findings regarding the pathophysiology and management of congenital cataracts in preterm infants.

Needle-free pharmacological sedation techniques in paediatric patients for imaging procedures: a systematic review and meta-analysis

BACKGROUND

Sedation techniques and drugs are increasingly used in children undergoing imaging procedures. In this systematic review and meta-analysis, we present an overview of literature concerning sedation of children aged 0-8 yr for magnetic resonance imaging (MRI) procedures using needle-free pharmacological techniques.

METHODS

Embase, MEDLINE, Web of Science, and Cochrane databases were systematically searched for studies on the use of needle-free pharmacological sedation techniques for MRI procedures in children aged 0-8 yr. Studies using i.v. or i.m. medication or advanced airway devices were excluded. We performed a meta-analysis on sedation success rate. Secondary outcomes were onset time, duration, recovery, and adverse events.

RESULTS

Sixty-seven studies were included, with 22 380 participants. The pooled success rate for oral chloral hydrate was 94% (95% confidence interval [CI]: 0.91-0.96); for oral chloral hydrate and intranasal dexmedetomidine 95% (95% CI: 0.92-0.97); for rectal, oral, or intranasal midazolam 36% (95% CI: 0.14-0.65); for oral pentobarbital 99% (95% CI: 0.90-1.00); for rectal thiopental 92% (95% CI: 0.85-0.96); for oral melatonin 75% (95% CI: 0.54-0.89); for intranasal dexmedetomidine 62% (95% CI: 0.38-0.82); for intranasal dexmedetomidine and midazolam 94% (95% CI: 0.78-0.99); and for inhaled sevoflurane 98% (95% CI: 0.97-0.99).

CONCLUSIONS

We found a large variation in medication, dosage, and route of administration for needle-free sedation. Success rates for sedation techniques varied between 36% and 98%.

Anesthesia and Developing Brains: Unanswered Questions and Proposed Paths Forward

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

Association Between Exposure of Children to General Anesthesia and Autism Spectrum Disorder

This study tested the hypothesis that exposure of children prior to their third birthday to procedures requiring general anesthesia is associated with an increased incidence of autism spectrum disorder (ASD) in later life. This study employed a nested, 1:2 matched-case control study design using ASD cases identified in a population-based birth cohort of children born in Olmsted County, MN from 1976 to 2000. Matching variables included sex, date of birth, and mother's age in conditional logistic regression including 499 ASD cases and 998 controls. After adjusting for birth weight and health status, there was no significant association between exposure and ASD (OR 1.27 [95% CI 0.92-1.76]), indicating that general anesthesia is not associated with an increased risk of ASD.

Implementation of the Feed and Swaddle Technique as a Non-Pharmacological Strategy to Conduct Brain Magnetic Resonance Imaging in Very Low Birth Weight Infants

Purpose: Magnetic resonance imaging (MRI) is a useful tool for evaluating brain injury and maturation in preterm infants and often requires sedation to acquire images of sufficient quality. Infant sedation is often associated with adverse events, despite extreme precautions. In this study, the swaddling technique was investigated as an alternative non-pharmacological strategy to obtain brain MRIs of sufficient quality.Methods: We applied the feed and swaddle technique during routine brain MRI as a quality improvement project and compared its morbidity with that of sedation in a historic age-matched group. Seventy-nine very low birth weight infants in the neonatal intensive care unit of Ajou University Hospital (Suwon, Korea) were enrolled. Thirty-two (40.5%) infants were in the feed and swaddling group, and 47 (59.5%) were in the sedation group.Results: The morbidity associated with the cardiopulmonary system (swaddling group vs. sedation group: 53.13% [n=17] vs. 63.83% [n=30], P=0.723) and central nervous system (40.63% [n=13] vs. 29.79% [n=14], P=0.217) were not significantly different between groups. The MRI failure rate was not significantly different (swaddling group vs. sedation group: 12.5% [n=4] vs. 4.3% [n=2], P=0.174). The MRI scanning time was longer in the swaddling group than in the sedation group (76.5±20.3 minutes vs. 61.5±13.6 minutes, P=0.001). Cardiopulmonary adverse events were significantly less common in the swaddling group than in the sedation group (3.13% [n=1] vs. 34.04% [n=16], P=0.002).Conclusion: The success rate of MRI was comparable between the swaddling technique and sedation. Furthermore, despite the drawback of prolonged scan time, cardiopulmonary adverse events are fewer with swaddling than with sedative agents. Therefore, swaddling can be an alternative to sedation or anesthesia when performing neonatal MRI scans.

A Painful Beginning: Early Life Surgery Produces Long-Term Behavioral Disruption in the Rat

Early life surgery produces peripheral nociceptive activation, inflammation, and stress. Early life nociceptive input and inflammation have been shown to produce long-term processing changes that are not restricted to the dermatome of injury. Additionally stress has shown long-term effects on anxiety, depression, learning, and maladaptive behaviors including substance abuse disorder and we hypothesized that early life surgery would have long-term effects on theses complex behaviors in later life. In this study surgery in the rat hindpaw was performed to determine if there are long-term effects on anxiety, depression, audiovisual attention, and opioid reward behaviors. Male animals received paw incision surgery and anesthesia or anesthesia alone (sham) at postnatal day 6. At 10 weeks after surgery, open field center zone entries were decreased, a measure of anxiety (n = 20) (P = 0.03) (effect size, Cohen's d = 0.80). No difference was found in the tail suspension test as a measure of depression. At 16-20 weeks, attentional performance in an operant task was similar between groups at baseline and decreased with audiovisual distraction in both groups (P < 0.001) (effect size, η² = 0.25), but distraction revealed a persistent impairment in performance in the surgery group (n = 8) (P = 0.04) (effect size, η² = 0.13). Opioid reward was measured using heroin self-administration at 16-24 weeks. Heroin intake increased over time in both groups during 24-h free access (P < 0.001), but was greater in the surgery group (P = 0.045), with a significant interaction between time and treatment (P < 0.001) (effect size, Cohen f ² = 0.36). These results demonstrate long-term disruptions in complex behaviors from surgical incision under anesthesia. Future studies to explore sex differences in early life surgery and the attendant peripheral neuronal input, stress, and inflammation will be valuable to understand emerging learning deficits, anxiety, attentional dysfunction, and opioid reward and their mechanisms. This will be valuable to develop optimal approaches to mitigate the long-term effects of surgery in early life.

Early childhood general anesthesia exposure associated with later developmental delay: A national population-based cohort study

Exposure to general anesthesia has been reported to induce neurotoxicity, impair learning, memory, attention, motor functions, as well as affect behavior in adult rodents and nonhuman primates. Though many have speculated similar effects in humans, previous literature has shown conflicting findings. To investigate the differences in risk of developmental delay among young children exposed to general anesthesia compared to matched unexposed individuals, a population-based cohort study was conducted with a longitudinal dataset spanning 2000 to 2013 from the Taiwan National Health Insurance Research Database (NHIRD). Procedure codes were used to identify children who received anesthesia. For each exposed child, two unexposed children matched by gender and age were enrolled into the comparison cohort. Neurocognitive outcome was measured by the presence of ICD-9-CM codes related to developmental delay (DD). Cox regression models were used to obtain hazard ratios of developing DD after varying levels of anesthesia exposure. After excluding 4,802 individuals who met the exclusion criteria, a total of 11,457 children who received general anesthesia before two years of age was compared to 22,914 children (matched by gender and age) unexposed to anesthesia. Increased risk of DD was observed in the exposure group with a hazard ratio (HR) of 1.320 (95% CI 1.143-1.522, P < 0.001). Subgroup analysis demonstrated further elevated risks of DD with multiple anesthesia exposures (1 anesthesia event: HR 1.145, 95% CI 1.010-1.246, P = 0.04; 2 anesthesia events: HR 1.476, 95% CI 1.155-1.887, P = 0.005; ≥3 anesthesia events: HR 2.222, 95% CI 1.810-2.621, P < 0.001) and longer total anesthesia durations (Total anesthesia <2 hours: HR 1.124, 95% CI 1.003-1.499, P = 0.047; Total anesthesia 2-4 hours: HR 1.450, 95% CI 1.157-1.800, P = 0.004; Total anesthesia > 4 hours: HR 1.598, 95% CI 1.343-1.982, P < 0.001) compared with children unexposed to anesthesia. These results suggest that children exposed to general anesthesia before two years of age have an increased risk of DD. This risk is further elevated with increased frequency of anesthesia, and longer total anesthesia duration. The findings of this study should prompt clinical practitioners to proceed with caution when assessing young patients and planning managements involving procedures requiring general anesthesia.

A manual propofol infusion regimen for neonates and infants

AIMS

Manual propofol infusion regimens for neonates and infants have been determined from clinical observations in children under the age of 3 years undergoing anesthesia. We assessed the performance of these regimens using reported age-specific pharmacokinetic parameters for propofol. Where performance was poor, we propose alternative dosing regimens.

METHODS

Simulations using a reported general purpose pharmacokinetic propofol model were used to predict propofol blood plasma concentrations during manual infusion regimens recommended for children 0-3 years. Simulated steady state concentrations were 6-8 µg.mL^-1 in the first 30 minutes that were not sustained during 100 minutes infusions. Pooled clinical data (n = 161, 1902 plasma concentrations) were used to determine an alternative pharmacokinetic parameter set for propofol using nonlinear mixed effects models. A new manual infusion regimen for propofol that achieves a steady-state concentration of 3 µg.mL^-1 was determined using a heuristic approach.

RESULTS

A manual dosing regimen predicted to achieve steady-state plasma concentration of 3 µg.mL^-1 comprised a loading dose of 2 mg.kg^-1 followed by an infusion rate of 9 mg.kg^-1 .h^-1 for the first 15 minutes, 7 mg.kg^-1 .h^-1 from 15 to 30 minutes, 6 mg.kg^-1 .h^-1 from 30 to 60 minutes, 5 mg.kg^-1 .h^-1 from 1 to 2 hours in neonates (38-44 weeks postmenstrual age). Dose increased with age in those aged 1-2 years with a loading dose of 2.5 mg.kg^-1 followed by an infusion rate of 13 mg.kg^-1 .h^-1 for the first 15 minutes, 12 mg.kg^-1 .h^-1 from 15 to 30 minutes, 11 mg.kg^-1 .h^-1 from 30 to 60 minutes, and 10 mg.kg^-1 .h^-1 from 1 to 2 hours.

CONCLUSION

Propofol clearance increases throughout infancy to reach 92% that reported in adults (1.93 L.min.70 kg^-1 ) by 6 months postnatal age and infusion regimens should reflect clearance maturation and be cognizant of adverse effects from concentrations greater than the target plasma concentration. Predicted concentrations using a published general purpose pharmacokinetic propofol model were similar to those determined using a new parameter set using richer neonatal and infant data.

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.

Anesthesia and the developing brain: A way forward for laboratory and clinical research

All commonly used general anesthetics have been shown to cause neurotoxicity in animal models, including nonhuman primates. Opinion, however, remains divided over how cumulative evidence from preclinical and human studies in this field should be interpreted and its translation to current practices in pediatric anesthesia and surgery. A group of international experts in laboratory and clinical sciences recently convened in Genoa, Italy, to evaluate the current state of both laboratory and clinical research and discuss future directions for basic, translational, and clinical studies in this field. This paper describes those discussions and conclusions. A central goal identified was the importance of continuing to pursue laboratory research efforts to better understand the biological pathways underlying anesthesia neurotoxicity. The distinction between basic and translational experimental designs in this field was highlighted, and it was acknowledged that it will be important for future animal research to try to causally link structural changes with long-term cognitive abnormalities. While inherent limitations will continue to affect the ability of even large observational cohorts to determine if anesthesia impacts neurodevelopment or behavioral outcomes, the importance of conducting further large well-designed cohort studies was also emphasized. Adequately powered cohorts could clarify which populations are at increased risk, provide information on environmental and healthcare-related risk modifiers, and guide future interventional trials. If anesthetics cause structural or functional adverse neurological effects in young children, alternative or mitigating strategies need to be considered. While protective or mitigating strategies have been repeatedly studied in animals, there are currently no human data to support alternative anesthetic strategies in clinical practice. Lastly, it was noted that there is still considerable debate over the clinical relevance of anesthesia neurotoxicity, and the need to evaluate the impact of other aspects of perioperative care on neurodevelopment must also be considered.

The role of general anesthesia on traits of neurodevelopmental disorders in a Swedish cohort of twins

BACKGROUND

The role of general anesthetics as a risk factor for possible neurodevelopmental disorders (NDDs) in humans is unresolved. The investigation of the role of anesthetics in the development of postgeneral anesthesia (anesthesia onward) NDDs has proven to be complicated, partly because of the inherent confounding in clinical cohort studies, and partly by the fact that anesthetics are only one part in the complex process of anesthesia-surgery.

METHODS

Utilizing the Swedish databases Child and Adolescent Twins Study in Sweden (CATSS) and National Patient Register (NPR), we investigated twins discordant for anesthesia, born between 1997 and 2004 for traits of NDDs. We identified 68 twin pairs discordant for anesthesia and explored traits of Attention-Deficit/Hyperactivity Disorder (ADHD), Learning Disability (LD), and Autism Spectrum Disorder (ASD) in them while simultaneously taking congenital abnormalities and systemic disorders (CSDs) into account. We analyzed the possible effect of anesthesia on neurodevelopmental problems, and we analyzed the within-pair differences using conditional linear regression.

RESULTS

Twins with a recorded episode of anesthesia had higher traits of NDDs than twins without; similarly twins with CSDs had higher mean scores on all traits than twins without CSDs. The within-pair analyses suggested that exposure to anesthesia was associated with higher scores of ADHD (regression coefficient 1.02 and 95% confidence intervals: 0.27-1.78) in monozygotic (MZ) twins discordant for anesthesia. This effect remained when adjusting for congenital abnormalities.

DISCUSSION

Our finding that traits of ADHD were slightly associated with anesthesia in a genetically sensitive design is in need of replication and warrants further investigation. Future studies should aim to elucidate mechanisms behind this possible association (e.g. anesthetics doses, age at exposure, exposure duration).

Radiation Dose Comparison Between 70 kVp and 100 kVp With Spectral Beam Shaping for Non-Contrast-Enhanced Pediatric Chest Computed Tomography: A Prospective Randomized Controlled Study

OBJECTIVE

The aim of this prospective randomized controlled study was to compare 2 techniques for radiation dose reduction in non-contrast-enhanced pediatric chest computed tomography (CT): low peak kilovoltage imaging at 70 kVp and spectral beam shaping at 100 kVp using a dedicated tin filter (100-kVp Sn).

MATERIALS AND METHODS

All chest CT examinations were performed on a third-generation dual-source CT system (SOMATOM Force; Siemens Healthineers, Germany). Fifty children (mean age, 6.8 ± 5.1 years) were examined using the 100-kVp Sn protocol, whereas 25 children received the 70-kVp protocol (mean age, 5.7 ± 5.2 years; 2:1 randomization scheme). Radiation metrics and organ doses were compared between acquisition techniques using commercially available radiation dose analysis software (Radimetrics Inc, Bayer AG, Toronto, Ontario, Canada). Objective image quality, expressed by signal-to-noise ratio and subjective image quality based on a 4-point scale (1, best; 4, worst image quality), were compared.

RESULTS

Volume CT dose index and size-specific dose estimate were significantly lower in the 100-kVp Sn group compared with the 70-kVp group (0.19 ± 0.12 mGy vs 0.81 ± 0.70 mGy and 0.34 ± 0.13 mGy vs 1.48 ± 1.11 mGy; P < 0.0001 for both). Accordingly, mean effective dose was significantly lower for the 100-kVp Sn examinations (0.21 ± 0.10 mSv) compared with the 70-kVp examinations (0.83 ± 0.49 mSv; P < 0.0001). Calculated organ doses were also significantly lower using the 100-kVp Sn protocol when compared with the 70-kVp protocol; for example, breast dose was reduced by a factor of 4.3. Signal-to-noise ratio was slightly superior for 70-kVp images while lung image quality of the 100-kVp Sn protocol was preferred in subjective analysis (P = 0.0004).

CONCLUSIONS

Pediatric chest CT performed at 100 kVp with an additional tin filter for spectral shaping significantly reduces radiation dose when compared with low peak kilovoltage imaging at 70 kVp and therefore should be preferred in non-contrast-enhanced pediatric chest CT examinations, particularly (given the improved subjective image quality) when the main focus is evaluation of the lung parenchyma.

Feed and Wrap MRI Technique in Infants

The feed and wrap technique refers to the use of feeding and swaddling to induce natural sleep in infants. It can be used prior to an magnetic resonance imaging (MRI) scan, avoiding sedation or anesthesia. We performed a retrospective review of feed and wrap MRI scans in infants 3 months or younger over a 2-year period at our center (279 scans) to evaluate the efficacy of this technique. Of scan results reviewed, 79% addressed the clinical question, 20% partially addressed the clinical question, and 1% were technically inadequate. History of preterm birth (odds ratio [OR] = 2.368; P = .032) and spine MRI (OR = 2.821; P = .001) were associated with a less-successful scan outcome. The feed and wrap technique can be used successfully in infants undergoing MRI; however, it may be less successful in preterm infants and those requiring spinal MRI. A standardized technique performed by experienced personnel may avoid anesthesia and sedation in infants who require MRI.

Nonsedated handheld electroretinogram as a screening test of retinal dysfunction in pediatric patients with nystagmus

PURPOSE

To assess the feasibility, sensitivity, and specificity of nonsedated handheld cone flicker electroretinogram (ERG) as a screening tool to detect retinal dysfunction in children with nystagmus.

METHODS

Pediatric patients at a tertiary referral center from December 2015 to July 2016 were enrolled and placed into three age-matched groups: normal, nystagmus with a retinal dystrophy, and nystagmus without a retinal dystrophy. Unsedated 30 Hz cone flicker ERG responses were obtained using a handheld device (RETeval) from both eyes of each patient using skin electrode sensors after pupillary dilation.

RESULTS

A total of 71 children were enrolled; amplitudes and implicit times were successfully obtained in 65 (92%): 31 (mean age ± SD, 5.6 ± 2.7 years; range, 1-12 years) without nystagmus and 34 with nystagmus. Nystagmus patients were grouped by those with (n = 15; mean age, 8.5 ± 4.5 [range, 2-17 years) and without (n = 19; mean age, 4.3 ± 3.0 [range, 6 months-10 years]) a retinal dystrophy. The patients with retinal dystrophies had significantly smaller amplitudes and prolonged or nonmeasurable implicit times than the other two groups (P < 0.001). Among nystagmus patients, amplitude was able to discriminate between those with and without retinal dystrophies with area under curve of 0.986 (SE = 0.016; P < 0.001). An amplitude <5 μV in combination with an implicit time of >33 ms warrants further evaluation.

CONCLUSIONS

Unsedated handheld cone flicker ERG is a feasible screening test that effectively detects retinal dysfunction in children with nystagmus. In conjunction with clinical findings, the test helps reduce the need for sedated ERG in children.

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.

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.

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.

Congenital melanocytic nevi in young children: Histopathologic features and clinical outcomes

BACKGROUND

Although only large congenital melanocytic nevi (CMN) are associated with a significantly high risk for malignant transformation, CMN of all sizes are prone to changes in clinical appearance in early childhood and thus are often biopsied or excised. While CMNs typically exhibit benign behavior, atypical histopathologic findings might be common and may prompt additional unnecessary procedures.

OBJECTIVE

To assess the prevalence and associated clinical outcomes of atypical histopathologic features in CMN in children.

METHODS

A single center retrospective study was conducted with patients 0-35 months of age with CMN diagnosed by histopathology between 1993-2013.

RESULTS

One hundred seventy-nine patients with a total of 197 CMNs were identified. Cytologic atypia, architectural disorder, or pagetoid spread were present in 73% of CMN. With a mean follow up of 7.3 years, no cases of melanoma or CMN-related deaths were identified.

LIMITATIONS

Our findings were based on a largely Caucasian population and might not apply to darker skin types. Our findings might not apply to older children or adults with CMN.

CONCLUSION

Atypical histopathologic features of cytologic atypia, architectural disorder, and pagetoid spread are common in benign CMN of young children.

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.

Pediatric neuroanesthesia

PURPOSE OF REVIEW

A series of recent studies have changed the practice of pediatric neuroanesthesia, improving outcomes and making children's quality of life better.

RECENT FINDINGS

Potential long-term neurologic effects in infants and young children undergoing surgery and anesthesia have been recognized for over a decade. Several recent, well performed studies suggest that hypotension may also be a major contributor to postoperative neurologic impairment in children. Craniosynostosis surgery has also been the subject of extensive study, both related to decreasing blood loss and to optimizing postoperative outcomes.

SUMMARY

Although neurosurgical anesthesia research in the pediatric population can be ethically and logistically complex, resolving questions such as the optimal blood pressure during surgery and best management of infants undergoing repair of craniosynostosis will improve patient outcomes.

Pain after surgery in children: clinical recommendations

PURPOSE OF REVIEW

This article summarizes recent data related to the safety and efficacy of postoperative analgesia in children that influence clinical practice recommendations.

RECENT FINDINGS

Postoperative pain continues to be experienced by hospitalized children and following discharge after short stay or ambulatory surgery. Updated recommendations for post-tonsillectomy analgesia exclude codeine and suggest regular administration of paracetamol and NSAID, but evidence for the most appropriate dose and type of opioid for rescue analgesia is limited. The incidence of opioid-related respiratory depression/oversedation in hospitalized children ranges from 0.11 to 0.41%, with recent large series identifying high-risk groups and contributory factors that can be targeted to minimize the risk of serious or permanent harm. Data demonstrating feasibility and safety of regional analgesic techniques is increasing, but additional and procedure-specific evidence would improve technique selection and inform discussions of efficacy and safety with patients and families/carers. Persistent postsurgical pain is increasingly recognized following major surgery in adolescents. Evaluation of potential predictive factors in clinical studies and investigation of underlying mechanisms in laboratory studies can identify targets for both pharmacological and nonpharmacological interventions.

SUMMARY

Recommendations for postoperative pain in children continue to evolve, with data incorporated from randomized controlled trials, case series and large audits. Management of pain following surgery in children needs to not only encompass efficacy and safety in the immediate perioperative period, but also consider pain following discharge after ambulatory surgery and the potential risk of persistent postsurgical pain following major surgery.

Neurodevelopmental outcome at 2 years of age after general anaesthesia and awake-regional anaesthesia in infancy (GAS): an international multicentre, randomised controlled trial

BACKGROUND

Preclinical data suggest that general anaesthetics affect brain development. There is mixed evidence from cohort studies that young children exposed to anaesthesia can have an increased risk of poor neurodevelopmental outcome. We aimed to establish whether general anaesthesia in infancy has any effect on neurodevelopmental outcome. Here we report the secondary outcome of neurodevelopmental outcome at 2 years of age in the General Anaesthesia compared to Spinal anaesthesia (GAS) trial.

METHODS

In this international assessor-masked randomised controlled equivalence trial, we recruited infants younger than 60 weeks postmenstrual age, born at greater than 26 weeks' gestation, and who had inguinal herniorrhaphy, from 28 hospitals in Australia, Italy, the USA, the UK, Canada, the Netherlands, and New Zealand. Infants were randomly assigned (1:1) to receive either awake-regional anaesthesia or sevoflurane-based general anaesthesia. Web-based randomisation was done in blocks of two or four and stratified by site and gestational age at birth. Infants were excluded if they had existing risk factors for neurological injury. The primary outcome of the trial will be the Wechsler Preschool and Primary Scale of Intelligence Third Edition (WPPSI-III) Full Scale Intelligence Quotient score at age 5 years. The secondary outcome, reported here, is the composite cognitive score of the Bayley Scales of Infant and Toddler Development III, assessed at 2 years. The analysis was as per protocol adjusted for gestational age at birth. A difference in means of five points (1/3 SD) was predefined as the clinical equivalence margin. This trial is registered with ANZCTR, number ACTRN12606000441516 and ClinicalTrials.gov, number NCT00756600.

FINDINGS

Between Feb 9, 2007, and Jan 31, 2013, 363 infants were randomly assigned to receive awake-regional anaesthesia and 359 to general anaesthesia. Outcome data were available for 238 children in the awake-regional group and 294 in the general anaesthesia group. In the as-per-protocol analysis, the cognitive composite score (mean [SD]) was 98.6 (14.2) in the awake-regional group and 98.2 (14.7) in the general anaesthesia group. There was equivalence in mean between groups (awake-regional minus general anaesthesia 0.169, 95% CI -2.30 to 2.64). The median duration of anaesthesia in the general anaesthesia group was 54 min.

INTERPRETATION

For this secondary outcome, we found no evidence that just less than 1 h of sevoflurane anaesthesia in infancy increases the risk of adverse neurodevelopmental outcome at 2 years of age compared with awake-regional anaesthesia.

FUNDING

Australia National Health and Medical Research Council (NHMRC), Health Technologies Assessment-National Institute for Health Research UK, National Institutes of Health, Food and Drug Administration, Australian and New Zealand College of Anaesthetists, Murdoch Childrens Research Institute, Canadian Institute of Health Research, Canadian Anesthesiologists' Society, Pfizer Canada, Italian Ministry of Heath, Fonds NutsOhra, and UK Clinical Research Network (UKCRN).