Early childhood general anaesthesia exposure and neurocognitive development

Safety and feasibility of xenon as an adjuvant to sevoflurane anaesthesia in children undergoing interventional or diagnostic cardiac catheterization: study protocol for a randomised controlled trial

BACKGROUND

Xenon has minimal haemodynamic side effects when compared to volatile or intravenous anaesthetics. Moreover, in in vitro and in animal experiments, xenon has been demonstrated to convey cardio- and neuroprotective effects. Neuroprotection could be advantageous in paediatric anaesthesia as there is growing concern, based on both laboratory studies and retrospective human clinical studies, that anaesthetics may trigger an injury in the developing brain, resulting in long-lasting neurodevelopmental consequences. Furthermore, xenon-mediated neuroprotection could help to prevent emergence delirium/agitation. Altogether, the beneficial haemodynamic profile combined with its putative organ-protective properties could render xenon an attractive option for anaesthesia of children undergoing cardiac catheterization.

METHODS/DESIGN

In a phase-II, mono-centre, prospective, single-blind, randomised, controlled study, we will test the hypothesis that the administration of 50% xenon as an adjuvant to general anaesthesia with sevoflurane in children undergoing elective cardiac catheterization is safe and feasible. Secondary aims include the evaluation of haemodynamic parameters during and after the procedure, emergence characteristics, and the analysis of peri-operative neuro-cognitive function. A total of 40 children ages 4 to 12 years will be recruited and randomised into two study groups, receiving either a combination of sevoflurane and xenon or sevoflurane alone.

DISCUSSION

Children undergoing diagnostic or interventional cardiac catheterization are a vulnerable patient population, one particularly at risk for intra-procedural haemodynamic instability. Xenon provides remarkable haemodynamic stability and potentially has cardio- and neuroprotective properties. Unfortunately, evidence is scarce on the use of xenon in the paediatric population. Our pilot study will therefore deliver important data required for prospective future clinical trials.

TRIAL REGISTRATION

EudraCT: 2014-002510-23 (5 September 2014).

Neurodevelopmental outcome in congenital diaphragmatic hernia survivors: role of ventilatory time

BACKGROUND

Neurodevelopmental impairment is one of the most significant morbidities among CDH survivors.

PURPOSE

Assess correlation between ventilatory time (VT) and short-term neurodevelopmental outcome in congenital diaphragmatic hernia (CDH) survivors.

METHODS

A prospective longitudinal study was conducted between 2008 and 2012. Assessment of mental and motor development was performed at 6 and 12months by Bayley Scales of Infant and Toddler Development - 3rd Edition (BSID-III). ROC curve analysis was used.

RESULTS

Forty-two subjects were included in the study. There was a significant inverse correlation between neurodevelopment at 6 and 12months and VT during first admission (p<0.0001). VT predicting the risk of moderate (BSID-III <85) and severe (BSID-III <70) delay was 13 and 28days, respectively (area under the curve - delay <85: 6months mental 0.943 and motor 0.992; 12months mental 0.877 and motor 0.925; delay <70: 6months mental 0.934 and motor 0.943; 12months mental 0.906 and motor 0.975; p<0.0001).

CONCLUSIONS

VT should be considered an important marker to identify subjects at risk for short-term neurodevelopmental delay in CDH survivors. Early follow-up intervention therapy should be activated in every baby with a history exceeding 13days of VT.

Inhibiting Rho kinase 2 reduces memory dysfunction in adult rats exposed to sevoflurane at postnatal days 7-9

The aim of the present study was to investigate the roles of Rho protein A (RhoA) and Rho kinases 2 (ROCK2) in the memory dysfunction of adult rats exposed to sevoflurane at postnatal days 7-9 (P7-9). One-week-old Sprague-Dawley rats were divided into four groups known as C, S1, S3 and F. Rats in the S1 (2 h at P7) and S3 groups (2 h/day at P7-9) were exposed to sevoflurane. The rats in the F group were treated with the ROCK2 inhibitor and subsequent sevoflurane exposure (2 h/day at P7-9). The rats in the C group received no sevoflurane. The protein levels of RhoA, ROCK2 and cleaved caspase-3 (Cl-Csp3) in the adult hippocampus were assessed by western blot analysis. Learning and memory of rats at postnatal 45-50 days (P45-50) were detected by the Morris water maze (MWM) test. During the training of MWM, the latency and distance of rats in the S3 group were significantly longer than that of the C group (P<0.05, respectively). In the probe test, the percentages of time and distance in the target quadrant for the S3 group were evidently less than that of the C group (P<0.05). There was no significant difference in the behaviors between the C and S1 groups (P>0.05, respectively). Corresponding to the behavioral changes, the levels of RhoA, ROCK2 and Cl-Csp3 in the hippocampus of the S3 group significantly increased, compared to that of the C and S1 groups (P<0.05). Additionally, the ROCK2 inhibitor clearly decreased ROCK2 and Cl-Csp3 expression and shortened the latency during the training (P<0.05, P46-49 respectively) and probe test (P<0.05) in the F group, compared to that of the S3 group. Compared to the C group, the expression of RhoA, ROCK2 and Cl-Csp3 in the hippocampus of the S1 group had no significant difference (P>0.05). Multiple inhalation of sevoflurane can induce neurotoxicity and memory dysfunction. RhoA and ROCK2 played important roles in the impairment of learning and memory of adults rats exposed to sevoflurane at the postnatal early stage.

Early and late operation of cleft lip and intelligence quotient and psychosocial development in 3-7 years

BACKGROUND

Early and late operations of the cleft lip represent exposure to general anesthesia during the first year of life. The early exposure to the anesthetics may influence long term neurological outcome. Timing of the operation may also influence the quality of life as babies with early repair might be accepted better by their families.

AIMS

The aim of the study was to compare outcomes between two groups of patients operated on for the cleft lip in the first year of life.

STUDY DESIGN

Observational cohort study.

SUBJECTS

Early repair group included patients operated on in the first eight days of life and late repair group those operated on between 3 and 10 months.

OUTCOME MEASURES

Intelligence quotient (IQ) and psychosocial development of children who were operated on for cleft lip were compared at the age of 3-7 years.

RESULTS

No differences were found between early (n=15) and late (n=17) repair group in terms of IQ. In both IQ was within the normal range: 100.00 (SD 13.867), 98.76 (SD 10.109), respectively. Significantly better results in physical functioning (P=0.042) and self-esteem (P=0.014) concepts in early repair group were found.

CONCLUSIONS

We compared outcomes of two groups of patients operated on for cleft lip in the first year of life. The earlier anesthesia did not show a negative impact on intelligence quotient in 3-7 years compared to later anesthesia. The earlier repair of the cleft lip showed a significant positive impact on psychosocial development in 2 out of 13 concepts tested.

The Esophageal Anastomotic Stricture Index (EASI) for the management of esophageal atresia

BACKGROUND

Anastomotic stricture is the most common complication following repair of esophageal atresia. An Esophageal Anastomotic Stricture Index (EASI) based on the postoperative esophagram may identify patients at high risk of stricture formation.

METHODS

Digital images of early postoperative esophagrams of patients undergoing EA repair from 2005 to 2013 were assessed. Demographics and outcomes including dilations were prospectively collected. Upper (U-EASI) and lower (L-EASI) pouch ratios were generated using stricture diameter divided by maximal respective pouch diameter. Score performances were evaluated with area under the receiver operator curves (AUC) and the Fisher's exact test for single and multiple (>3) dilatations. Interrater agreement was evaluated using the intraclass correlation coefficient (ICC).

RESULTS

Forty-five patients had esophagrams analyzed; 28 (62%) required dilatation and 19 received >3 (42%). U-EASI and L-EASI ratios ranged from 0.17 to 0.70, with L-EASI outperforming the U-EASI as follows: L-EASI AUC: 0.66 for a single dilatation, 0.65 for >3 dilatations; U-EASI AUC: 0.56 for a single dilatation, 0.67 for >3 dilatations. All patients with an L-EASI ratio of ≤0.30 (n=8) required multiple esophageal dilatations, p=0.0006. The interrater ICC was 0.87.

CONCLUSION

The EASI is a simple, reproducible tool to predict the development and severity of anastomotic stricture after esophageal atresia repair and can direct postoperative surveillance.

Laparoscopic versus open repair of recto-bladderneck and recto-prostatic anorectal malformations: a systematic review and meta-analysis

OBJECTIVE

The laparoscopically-assisted anorectal pull-through (LAARP) for recto-bladderneck and recto-prostatic anorectal malformations (RB/RP-ARMs) is believed to improve patient outcomes. We performed a systematic review of the effect of LAARP on postoperative mucosal prolapse and defecation dysfunction.

METHODS

A comprehensive search of MEDLINE, EMBASE, CENTRAL, and grey literature was performed (2000-2014). Full-text screening, data abstraction and quality appraisal were conducted in duplicate. Included studies reported a primary diagnosis of RB/RP-ARM and compared LAARP versus open repair (OPEN).

RESULTS

From 3681 retrieved articles, 7 studies enrolling 187 patients were analyzed. One was a randomized control trial, 6 were retrospective observational studies, and all were single-centre. The majority were of poor-moderate quality (MINORS scores: mean 16.42 (SD 2.225) out of 24). Mucosal prolapse was not significantly different after LAARP versus OPEN (p = 0.18). Defecation outcomes were inconsistently reported but were no different between LAARP and OPEN for either children >3 years old (p = 0.84), or all ages combined (p = 0.11).

CONCLUSION

We found no significant difference in rates of mucosal prolapse or defecation scores for LAARP compared to OPEN for children with RB/RP-ARMs. However, studies are small and of poor-moderate quality and results are heterogeneous. Comprehensive, standardized, reliable reporting is necessary to guide practice and inform postoperative guidelines.

LEVEL OF EVIDENCE

1c.

Effect of one anesthetic exposure on long-term behavioral changes in children

STUDY OBJECTIVE

To determine the association between one anesthetic exposure and behavioral outcome at age 10 to 12 years.

DESIGN

Retrospective comparative study.

SETTING

University-affiliated pediatrics department.

MEASUREMENTS

The medical records of children who underwent anesthesia between January 2004 and December 2005 at our institution were reviewed. The records of 292 children were included in the study group and 300 children in the control group. The study group involved children who had one anesthetic exposure before age of 4 years and the control group had children who were not exposed to anesthesia. The primary outcome was behavioral change as assessed by the Eyberg Child Behavior Inventory (ECBI) questionnaire.

MAIN RESULTS

The rate of behavioral abnormalities before the age of 11 years was 28.4% in the study group (P<0.001) and 5.7% in the control group. The risk of developing behavioral abnormalities was prominent in children being exposed to surgery versus those exposed during a diagnostic procedure (32.4% vs 4.8%; P<0.0001). Eighty-three point nine percent of the children who were exposed to longer duration anesthesia (more than 3 hrs) had behavioral abnormalities (P<0.0001), while 48.8% of children who received anesthesia at younger ages (0 - 6 mos) had behavioral abnormalities (P<0.0001). Exposure to multiple anesthetic agents versus one anesthetic agent was a significant risk factor for development of behavioral abnormalities (P<0.0001).

CONCLUSION

The incidence of behavioral abnormalities increased when anesthesia and surgery were accompanied by younger age, longer duration of surgery, and use of multiple anesthetic agents.

Repeated exposure to anesthetic ketamine can negatively impact neurodevelopment in infants: a prospective preliminary clinical study

Animal experiments indicate that repeated exposure to ketamine adversely affects the developing brain. Whether it has the same effect on infants remains unclear. We recruited infants who were scheduled for 1 to 3 outpatient laser surgery treatments of benign facial growths with ketamine anesthesia. Patients were assigned to the Ket(1), Ket(2), or Ket(3) group, according to the number of treatments. The Bayley Scales of Infant Development-Second Edition (BSID-II) was used to assess neurodevelopmental outcomes before the first and after the last therapy. Levels of S-100β were also measured. Bayley Scales of Infant Development-Second Edition scores after the last procedure were lower than those before the first surgery in the Ket(3) group (P < .05). S-100β levels after the last procedure were significantly higher than those before the first surgery in all groups (P < .05). Our results suggest that 3 or more exposures to anesthetic ketamine have the potential to adversely affect neurodevelopment in infants.

The management of postoperative reflux in congenital esophageal atresia-tracheoesophageal fistula: a systematic review

PURPOSE

Esophageal atresia (EA), with or without tracheoesophageal fistula (TEF), is associated with postoperative gastroesophageal reflux (GER). We performed a systematic review of the literature regarding routine anti-reflux medication post EA-TEF repair and its impact on postoperative GER and associated complications.

METHODS

A comprehensive search was conducted using MEDLINE, EMBASE, CINHAL, CENTRAL (Cochrane library) electronic databases and gray literature. Full-text screening was performed in duplicate. Included articles reported a primary diagnosis of EA-TEF, a secondary diagnosis of postoperative GER, and primary treatment of GER with anti-reflux medications.

RESULTS

Screening of 2,910 articles resulted in 25 articles (1,663 patients) for analysis. Most were single-center studies (92%) and retrospective (76%); there were no randomized control trials. Fifteen studies named the class of anti-reflux agent used, 3 the duration of therapy, and none either the dose prescribed or number of doses. Complications were inconsistently reported. Anti-reflux surgery was performed in 433/1,663 (26.0%) patients. Average follow-up was 53.2 months (14 studies).

CONCLUSION

The quality of literature regarding anti-reflux medication for GER post EA-TEF repair is poor. There are no well-outlined algorithms for anti-reflux agents, doses, or duration of therapy. Standardized protocols and reliable reporting are necessary to develop guidelines to better manage postoperative GER in EA-TEF patients.

The pediatrician's role in the evaluation and preparation of pediatric patients undergoing anesthesia

Pediatricians play a key role in helping prepare patients and families for anesthesia and surgery. The questions to be answered by the pediatrician fall into 2 categories. The first involves preparation: is the patient in optimal medical condition for surgery, and are the patient and family emotionally and cognitively ready for surgery? The second category concerns logistics: what communication and organizational needs are necessary to enable safe passage through the perioperative process? This revised statement updates the recommendations for the pediatrician's role in the preoperative preparation of patients.

Sevoflurane induces tau phosphorylation and glycogen synthase kinase 3β activation in young mice

BACKGROUND

Children with multiple exposures to anesthesia and surgery may have an increased risk of developing cognitive impairment. Sevoflurane is a commonly used anesthetic in children. Tau phosphorylation contributes to cognitive dysfunction. The authors therefore assessed the effects of sevoflurane on Tau phosphorylation and the underlying mechanisms in young mice.

METHODS

Six-day-old wild-type and Tau knockout mice were exposed to sevoflurane. The authors determined the effects of sevoflurane anesthesia on Tau phosphorylation, levels of the kinases and phosphatase related to Tau phosphorylation, interleukin-6 and postsynaptic density protein-95 in hippocampus, and cognitive function in both young wild-type and Tau knockout mice.

RESULTS

Anesthesia with 3% sevoflurane 2 h daily for 3 days induced Tau phosphorylation (257 vs. 100%, P = 0.0025, n = 6) and enhanced activation of glycogen synthase kinase 3β, which is the kinase related to Tau phosphorylation in the hippocampus of postnatal day-8 wild-type mice. The sevoflurane anesthesia decreased hippocampus postsynaptic density protein-95 levels and induced cognitive impairment in the postnatal day-31 mice. Glycogen synthase kinase 3β inhibitor lithium inhibited the sevoflurane-induced glycogen synthase kinase 3β activation, Tau phosphorylation, increased levels of interleukin-6, and cognitive impairment in the wild-type young mice. Finally, the sevoflurane anesthesia did not induce an increase in interleukin-6 levels, reduction in postsynaptic density protein-95 levels in hippocampus, or cognitive impairment in Tau knockout young mice.

CONCLUSIONS

These data suggested that sevoflurane induced Tau phosphorylation, glycogen synthase kinase 3β activation, increase in interleukin-6 and reduction in postsynaptic density protein-95 levels in hippocampus of young mice, and cognitive impairment in the mice. Future studies will dissect the cascade relation of these effects.

Comparison of neurodegeneration and cognitive impairment in neonatal mice exposed to propofol or isoflurane

Background

While previous studies have demonstrated neuronal apoptosis and associated cognitive impairment after isoflurane or propofol exposure in neonatal rodents, the effects of these two anesthetics have not been directly compared. Here, we compare and contrast the effectiveness of isoflurane and propofol to cause neurodegeneration in the developing brain and associated cognitive dysfunction.

Methods

Seven-day-old mice were used. Mice in the isoflurane treatment group received 6 h of 1.5% isoflurane, while mice in propofol treatment group received one peritoneal injection (150 mg/kg), which produced persistent anesthesia with loss of righting for at least 6 h. Mice in control groups received carrying gas or a peritoneal injection of vehicle (intralipid). At 6 h after anesthetic treatment, a subset of each group was sacrificed and examined for evidence of neurodegeneration, using plasma levels of S100β, and apoptosis using caspase-3 immunohistochemistry in the cerebral cortex and hippocampus and Western blot assays of the cortex. In addition, biomarkers for inflammation (interleukin-1, interleukin-6, and tumor necrosis factor alpha) were examined with Western blot analyses of the cortex. In another subset of mice, learning and memory were assessed 32 days after the anesthetic exposures using the Morris water maze.

Results

Isoflurane significantly increased plasma S100β levels compared to controls and propofol. Both isoflurane and propofol significantly increased caspase-3 levels in the cortex and hippocampus, though isoflurane was significantly more potent than propofol. However, there were no significant differences in the inflammatory biomarkers in the cortex or in subsequent learning and memory between the experimental groups.

Conclusion

Both isoflurane and propofol caused significant apoptosis in the mouse developing brain, with isoflurane being more potent. Isoflurane significantly increased levels of the plasma neurodegenerative biomarker, S100β. However, these neurodegenerative effects of isoflurane and propofol in the developing brain were not associated with effects on inflammation or with cognitive dysfunction in later life.

Anesthetic sevoflurane reduces levels of hippocalcin and postsynaptic density protein 95

Sevoflurane, the commonly used inhalation anesthetic in children, has been shown to enhance cytosolic calcium levels and induce cognitive impairment in young mice. However, the downstream consequences of the sevoflurane-induced elevation in cytosolic calcium levels and the upstream mechanisms of the sevoflurane-induced cognitive impairment remain largely to be determined. Hippocalcin is one of the neuronal calcium sensor proteins, and also binds to postsynaptic density protein 95 (PSD-95). We therefore set out to determine the effects of sevoflurane on the levels of hippocalcin and PSD-95 in vitro and in vivo. Hippocampus neurons from mice and 6-day-old mice were treated with 4.1% sevoflurane for 6 h or 3% sevoflurane 2 h daily for 3 days, respectively. We then measured the levels of hippocalcin and PSD-95, and assessed whether BAPTA, an intracellular calcium chelator, and memantine, a partial antagonist of the NMDA receptor, could inhibit the sevoflurane's effects. We found that sevoflurane decreased the levels of hippocalcin and PSD-95 in the neurons; and decreased the levels of hippocalcin and PSD-95 in the hippocampus of mice immediately after the anesthesia, but only the PSD-95 levels three weeks after the anesthesia. BAPTA inhibited the sevoflurane's effects in the neurons. Memantine attenuated the sevoflurane-induced reductions in the levels of hippocalcin and PSD-95, as well as the sevoflurane-induced cognitive impairment in mice. These data suggested that sevoflurane decreased the levels of hippocalcin and PSD-95, which could serve as one of bridge mechanisms between the sevoflurane-induced elevation of cytosolic calcium levels and the sevoflurane-induced cognitive impairment.

Time-Dependent Effects of Anesthetic Isoflurane on Reactive Oxygen Species Levels in HEK-293 Cells

The inhalation anesthetic isoflurane has been reported to induce caspase activation and apoptosis, which may lead to learning and memory impairment. However, the underlying mechanisms of these effects are largely unknown. Isoflurane has been shown to induce elevation of cytosol calcium levels, accumulation of reactive oxygen species (ROS), opening of the mitochondrial permeability transition pore, reduction in mitochondria membrane potential, and release of cytochrome c. The time course of these effects, however, remains to be determined. Therefore, we performed a pilot study to determine the effects of treatment with isoflurane for various times on ROS levels in HEK-293 cells. The cells were treated with 2% isoflurane plus 21% O₂ and 5% CO₂ for 15, 30, 60, or 90 min. We then used fluorescence imaging and microplate fluorometer to detect ROS levels. We show that 2% isoflurane for 60 or 90 min, but not 15 or 30 min, induced ROS accumulation in the cells. These data illustrated that isoflurane could cause time-dependent effects on ROS levels. These findings have established a system to further determine the time course effects of isoflurane on cellular and mitochondria function. Ultimately, the studies would elucidate, at least partially, the underlying mechanisms of isoflurane-induced cellular toxicity.

Translational research in neuroanaesthesia

Translational research in anaesthesia provided great solutions to medicine, well beyond its scope, in the past. Exciting opportunities exist for neuroanaesthesiologists to conduct translational research not just in anaesthesia alone but in the wider realm of neurosciences. This research is expected to provide solutions to clinical neuroscience questions and to help understand some of the complex neurocognitive functions. Despite several technical developments, progress in translational sciences has been rather slow in the recent years. Re-orientation of the research programmes to a translational format with the involvement of all the stakeholders is likely to conserve the cost and provide rapid solutions to the healthcare.

Different effects of etomidate and propofol on memory in immature rats

This study is to investigate the effects of etomidate and propofol on memory and possible involved mechanisms using immature rats. Forty-eight rats randomly received intraperitoneal injection of 5 mg/kg etomidate (n = 16), 50 mg/kg propofol (n = 16) or normal saline (control, n = 16). Three hours after awakening, memory was assessed by Y-maze test using 10 rats in each drug group. Gamma-aminobutyric acid (GABA) content in hippocampal tissue was measured using six rats in each group. Etomidate group had more total reaction time (TRT) compared with the control group in Y-maze test ( p < 0.05). No other difference between these two groups was observed. Propofol group had less number of correct response ( p < 0.01) and more TRT ( p < 0.05) in Y-maze test, as well as more GABA concentration detected in hippocampal tissue ( p < 0.01) than the control group. Propofol group also showed less number of correct response ( p < 0.05) and more hippocampal GABA concentration ( p < 0.01) compared with etomidate group. Etomidate does not show significant effects on memory in rat and further investigation is required. Propofol can affect memory in rat possibly via increasing the synthesis and/or secretion of GABA as one of the factors.

Comparison of intelligence, weight and height in children after general anesthesia with and without perioperative desaturation in non-cardiac surgery: a historical and concurrent follow-up study

Purpose

To determine whether perioperative desaturation (PD) in preschool children undergoing non-cardiac surgery is associated with subsequent impairment of intelligence or subsequent change in age-specific weight and height percentile.

Method

A historical-concurrent follow-up study was conducted in children aged ≤ 60 months who underwent general anesthesia (GA) for non-cardiac surgery between January 2008 and December 2011 at Songklanagarind Hospital. Children who developed PD (PD group) and children who did not develop perioperative respiratory events (no-PRE group) were matched on sex, age, year of having index GA, type of surgery and choice of anesthesia. The children’s age-specific weight and height percentile and intelligence quotient (IQ) scores by Standford Binet-LM or Wechsler Intelligence Scale for Children, 3rd edition 12–60 months after GA were compared using Student’s t- test and Wilcoxon’s rank sum test. Multivariate linear regression models for standardized IQ and multivariate mixed effects linear regression models for the change of age-specific weight and height percentile from the time of index GA to the time of IQ test were performed to identify independent predictors. The coefficients and 95% confidence intervals (CI) were displayed and considered significant if the F test p-values were < 0.05.

Results

Of 103 subjects in each group (PD vs no-PRE), there were no statistically significant differences in IQ (94.7 vs 98.3, p = 0.13), standardized IQ (−0.1 vs 0.1, p = 0.14) or age-specific weight percentile (38th vs 63th, p = 0.06). However, age-specific height percentile in the PD group at the time of IQ test was significantly lower (38th vs 50th, p = 0.02). In the multivariate analysis, PD was not a significant predictor for standardized IQ (coefficient: −0.06, 95% CI: −0.3, 0.19, p = 0.57), change in age-specific weight percentile (coefficient: 4.66, 95% CI: −2.63, 11.95, p = 0.21) or change in age-specific height percentile (coefficient: −1.65, 95% CI: −9.74, 6.44, p = 0.69) from the time of index GA to the time of IQ test after adjusting for family and anesthesia characteristics.

Conclusion

Our study could not demonstrate any serious effect of PD on subsequent intelligence or on the change in age-specific weight and height percentile of children after non-cardiac surgery.

Electronic supplementary material

The online version of this article (doi:10.1186/2193-1801-3-164) contains supplementary material, which is available to authorized users.

The potential dual effects of sevoflurane on AKT/GSK3β signaling pathway

Background

Anesthesia with multiple exposures of commonly used inhalation anesthetic sevoflurane induces neuroinflammation and cognitive impairment in young mice, but anesthesia with a single exposure to sevoflurane does not. AKT/glycogen synthase kinase 3β (GSK3β) signaling pathway is involved in neurotoxicity and neurobehavioral deficits. However, whether sevoflurane can induce a dual effect (increase versus decrease) on the activation of AKT/GSK3β signaling pathway remains to be determined. We therefore set out to assess the effects of sevoflurane on AKT/GSK3β signaling pathway in vivo and in vitro.

Methods

Six day-old wild-type mice were exposed to 3% sevoflurane two hours daily for one or three days. In the in vitro studies, H4 human neuroglioma cells were treated with 4% sevoflurane for two or six hours. We then determined the effects of different sevoflurane treatments on the levels of phosphorylated (P)-GSK3β(ser9) and P-AKT(ser473) by using Western blot analysis.

Results

Here we show that anesthesia with 3% sevoflurane two hours daily for one day increased the levels of P-GSK3β(ser9) and P-AKT(ser473), but the anesthesia with 3% sevoflurane daily for three days decreased them in the mice. The treatment with 4% sevoflurane for two hours increased, but the treatment with 4% sevoflurane for six hours decreased, the levels of P-GSK3β(ser9) and P-AKT(ser473) in the H4 human neuroglioma cells.

Conclusions

Anesthetic sevoflurane might induce a dual effect (increase versus decrease) on the activation of the AKT/GSK3β signaling pathway. These studies have established a system to perform further studies to determine the effects of sevoflurane on brain function.

Caffeine accelerates recovery from general anesthesia

General anesthetics inhibit neurotransmitter release from both neurons and secretory cells. If inhibition of neurotransmitter release is part of an anesthetic mechanism of action, then drugs that facilitate neurotransmitter release may aid in reversing general anesthesia. Drugs that elevate intracellular cAMP levels are known to facilitate neurotransmitter release. Three cAMP elevating drugs (forskolin, theophylline, and caffeine) were tested; all three drugs reversed the inhibition of neurotransmitter release produced by isoflurane in PC12 cells in vitro. The drugs were tested in isoflurane-anesthetized rats. Animals were injected with either saline or saline containing drug. All three drugs dramatically accelerated recovery from isoflurane anesthesia, but caffeine was most effective. None of the drugs, at the concentrations tested, had significant effects on breathing rates, O2 saturation, heart rate, or blood pressure in anesthetized animals. Caffeine alone was tested on propofol-anesthetized rats where it dramatically accelerated recovery from anesthesia. The ability of caffeine to accelerate recovery from anesthesia for different chemical classes of anesthetics, isoflurane and propofol, opens the possibility that it will do so for all commonly used general anesthetics, although additional studies will be required to determine whether this is in fact the case. Because anesthesia in rodents is thought to be similar to that in humans, these results suggest that caffeine might allow for rapid and uniform emergence from general anesthesia in human patients.

High success rates of sedation-free brain MRI scanning in young children using simple subject preparation protocols with and without a commercial mock scanner--the Diabetes Research in Children Network (DirecNet) experience

BACKGROUND

The ability to lie still in an MRI scanner is essential for obtaining usable image data. To reduce motion, young children are often sedated, adding significant cost and risk.

OBJECTIVE

We assessed the feasibility of using a simple and affordable behavioral desensitization program to yield high-quality brain MRI scans in sedation-free children.

MATERIALS AND METHODS

222 children (4-9.9 years), 147 with type 1 diabetes and 75 age-matched non-diabetic controls, participated in a multi-site study focused on effects of type 1 diabetes on the developing brain. T1-weighted and diffusion-weighted imaging (DWI) MRI scans were performed. All children underwent behavioral training and practice MRI sessions using either a commercial MRI simulator or an inexpensive mock scanner consisting of a toy tunnel, vibrating mat, and video player to simulate the sounds and feel of the MRI scanner.

RESULTS

205 children (92.3%), mean age 7 ± 1.7 years had high-quality T1-W scans and 174 (78.4%) had high-quality diffusion-weighted scans after the first scan session. With a second scan session, success rates were 100% and 92.5% for T1-and diffusion-weighted scans, respectively. Success rates did not differ between children with type 1 diabetes and children without diabetes, or between centers using a commercial MRI scan simulator and those using the inexpensive mock scanner.

CONCLUSION

Behavioral training can lead to a high success rate for obtaining high-quality T1-and diffusion-weighted brain images from a young population without sedation.

Age-related changes in EEG power spectra in infants during sevoflurane wash-out

BACKGROUND

Few electroencephalography (EEG) data are available in anaesthetized infants. This study aimed to identify EEG characteristics that might warn of awakening (AW) from sevoflurane anaesthesia in infants.

METHODS

Twenty intubated infants [aged 39-77 weeks post-menstrual age (PMA)] were studied after surgery during sevoflurane wash-out. EEG was recorded at the end of surgery and throughout emergence. Changes in EEG time and frequency domains were described.

RESULTS

At the end of surgery, mean end-tidal sevoflurane concentration was 2.3% (range 1.5-3.5) before wash-out and reduced to 0.3% (0.1-0.6) when AW began. On AW, movement artifacts made signals difficult to interpret. Before awakening, most power was within frequencies ≤4 Hz, but trends over time were variable. Summated power in frequencies between 20 and 70 Hz was almost always <5 µV(2). During anaesthesia, there were two common power spectra: infants >52 weeks PMA had obvious summated power in the frequency range 5-20 Hz (P5-20 Hz) (mean 308, median 320, range 110-542 µV(2)), which decreased before awakening began [mean decrease 252 µV(2) (95% CI 153-351)], whereas younger infants had low P5-20 Hz throughout. P5-20 Hz during anaesthesia increased with age; power in this frequency band of ~100 µV(2) separated infants younger and older than 52 weeks PMA.

CONCLUSIONS

During sevoflurane wash-out, decreasing P5-20 Hz might warn of impending AW in infants >3 months old, but not in younger infants.

Anesthetic neurotoxicity

All routinely utilized sedatives and anesthetics have been found neurotoxic in a wide variety of animal species, including non-human primates. Neurotoxic effects observed in animals include histologic evidence for apoptotic neuronal cell death and subsequent learning and memory impairment. Several cohort studies in neonates with significant comorbidities requiring surgical procedures early in life have also demonstrated abnormal neurodevelopmental outcomes. This article provides an overview of the currently available data from both animal experiments and human clinical studies regarding the effects of sedatives and anesthetics on the developing brain.

Resident and fellow participation in strabismus surgery: effect of level of training and number of assistants on operative time and cost

OBJECTIVE

To investigate the effect of the level of training and number of assistants on operative time for uncomplicated, 2-muscle, horizontal strabismus surgery at an academic institution.

DESIGN

Comparative case series.

PARTICIPANTS

A total of 993 children and adults between the ages of 6 months and 75 years.

METHODS

Retrospective chart review of strabismus surgeries performed between July 1, 2008, and December 31, 2012, by any of 3 attending surgeons assisted by a resident in the postgraduate year 3 (PGY3), fellow in the postgraduate year 5 (PGY5), or both.

MAIN OUTCOME MEASURES

Operative time (minutes) and associated operative cost (dollars).

RESULTS

There were 373 cases with 1 assistant and 44 cases with 2 assistants. Of all cases with 1 assistant, there were 200 cases with a PGY3 assistant an average operative time of 62.5 minutes (standard deviation [SD], 15.1) and 173 cases with a PGY5 assistant an average operative time of 59.0 minutes (SD, 14.7); the difference of 3.5 minutes was statistically significant (P = 0.02). The average operative time for all cases with 2 assistants (both PGY3 and PGY5) was 10.6 minutes longer than all cases with 1 assistant (P = 0.0002). No statistically significant variation in operative times was demonstrated when comparing cases with a PGY3 (P = 0.29) and PGY5 (P = 0.44) assistant in their respective first and last halves of the academic year, but operative times within individual quarters of the academic year were significant for PGY3 (P = 0.03) but not for PGY5 (P = 0.24) assistant cases. Operative times were significantly different for individual PGY3 (P = 0.03) but not PGY5 (P = 0.22) assistant cases. Cost per PGY3 assistant per year for additional operative time is $3141.95.

CONCLUSIONS

Operative time in strabismus surgery increased with PGY3 participation and further increased with both assistants over either assistant alone. Operative times earlier in the year did not vary from those later in the year for PGY3 or PGY5 assistants. The difference in quarterly and individual PGY3 but not PGY5 assistant operative times suggests that efficiency in strabismus surgery varies by assistants with less experience or interest.

Evaluation of cerebral electrical activity and cardiac output after patent ductus arteriosus ligation in preterm infants

OBJECTIVE

To characterize and investigate the relationship between systemic blood flow and pre- and postoperative cerebral electrical activity in preterm neonates undergoing patent ductus arteriosus (PDA) ligation.

STUDY DESIGN

A prospective observational study was conducted in 17 preterm neonates undergoing PDA ligation. All infants had amplitude-integrated electroencephalography (aEEG) recorded continuously from 4 h preoperatively to 24 h postoperatively. Targeted neonatal echocardiography was performed to evaluate myocardial performance and systemic blood flow at four sequential time points: preoperatively; 1, 8 and 24 h postoperatively.

RESULT

PDA ligation was followed by a fall in the lower border of the aEEG trace lower left ventricular output, but recovery of diastolic flow in the middle cerebral artery. Altered lower margin was associated with gestational age and PDA diameter on univariate analysis, but not with low cardiac output.

CONCLUSION

PDA ligation was associated with altered cerebral electrical activity, although these changes were not related to low cardiac output state.

[Neonatal exposure to anesthesia and adverse cognitive outcome in childhood. Insight from epidemiology]

Adverse effects of general anesthesia have been observed repeatedly, mainly in animal model studies and in rodents. Already in 2005, the Food and Drug Administration recommended proceeding to similar studies in human infants, highlighting that there were several methodological issues to solve before being able to appreciate the risk of anesthetic agents on the developing brain. Most studies conducted in humans were observational studies, showing a very mild adverse effect on cognitive functions, an effect that disappeared when properly adjusted analysis was performed (with various modalities for analysis and protocols for these adjusted results). Due to numerous biases in these observational studies - bias related to selection of the population and the control subjects and their comparability as well as outcome measure assessment, it has become extremely important to conduct prospective studies. Two international studies are currently under way, but their results will not be available for a few years. How animal model results can be relevant to human babies remains controversial. Until today, and according to the current state of the art, no changes in practices are indicated, and it is important for infants and their families to avoid sensationalist messages.

Long-term effects of neonatal single or multiple isoflurane exposures on spatial memory in rats

General anesthetics are neurotoxic to neonatal rodents and non-human primates. Neonatal exposure to general anesthetics has been associated with long-term cognitive deficits in animal models. Some data from humans are consistent with long-term deleterious effects of anesthetic exposure early in life on cognitive development, with multiple exposures to general anesthetics being particularly damaging. We sought to determine whether repeated exposure of neonatal rats to anesthesia was associated with long-term cognitive impairments and whether the magnitude of impairments was greater than that resulting from a single exposure. Male or female Long–Evans rat pups were exposed to 1.8% isoflurane for 2 h on postnatal day (P) 7, or for 2 h each on P7, P10, and P13. Testing in a spatial working memory task began on P91. Rats that were repeatedly exposed to isoflurane were impaired relative to controls in the spatial working memory task. Male rats that received a single exposure to isoflurane showed an unexpected facilitation in spatial memory performance. These results support the hypothesis that multiple neonatal exposures to general anesthesia are associated with greater long-term cognitive impairment than a single exposure. The findings are congruent with human epidemiological studies reporting long-term cognitive impairments following multiple but not single general anesthetics early in life.

Novel end points for clinical trials in young children with cystic fibrosis

Cystic fibrosis (CF) lung disease commences early in the disease progression and is the most common cause of mortality. While new CF disease-modifying agents are currently undergoing clinical trial evaluation, the implementation of such trials in young children is limited by the lack of age-appropriate clinical trial end points. Advances in infant and preschool lung function testing, imaging of the chest and the development of biochemical biomarkers have led to increased possibility of quantifying mild lung disease in young children with CF and objectively monitoring disease progression over the course of an intervention. Despite this, further standardization and development of these techniques is required to provide robust objective measures for clinical trials in this age group.

The memory stages of a spatial Y-maze task are not affected by a low dose of ketamine/midazolam

Anesthetics, such as the ketamine/midazolam combination, are used in research with animals and in human clinical practice; thus, it is essential to clarify the potential effects of these anesthetics on memory. This study aimed to evaluate how a low dose of the ketamine/midazolam combination affects the acquisition, consolidation, or recall of a spatial memory task. Thirty-three adult male C57BL/6 mice were divided into four treatment groups: unanesthetized control animals and three groups of animals treated with 40 mg/kg of ketamine and 10mg/kg of midazolam administered in a single intraperitoneal injection. The different treatment groups received the same anesthetic dose at different time points, to study the acquisition, consolidation, and recall of spatial memory in the Y-maze task. The percentage of correct choices was measured. Six mice were killed 4 days and 12 days after anesthesia for histopathological analyses. There were no differences between treatment and control groups regarding the acquisition of spatial memory, measured as the slope of the learning curve, or in the percentage of correct choices in the consolidation or recall periods of the task. Similarly, no differences were detected between groups regarding the number of cells per square millimeter in the visual and retrosplenial cortex, in the dentate gyrus, and in the CA1 and CA3 regions of the hippocampus. Hence, a low dose of the ketamine/midazolam combination did not impair memory processes or brain integrity in adult mice, suggesting that this combination is unlikely to cause cognitive complications.

Sevoflurane anesthesia in pregnant mice induces neurotoxicity in fetal and offspring mice

BACKGROUND

Each year, over 75,000 pregnant women in the United States undergo anesthesia care. The authors set out to assess the effects of the anesthetic sevoflurane on neurotoxicity in pregnant mice and on learning and memory in fetal and offspring mice.

METHODS

Pregnant mice (gestational day 14) and mouse primary neurons were treated with 2.5% sevoflurane for 2 h and 4.1% sevoflurane for 6 h, respectively. Brain tissues of both fetal and offspring mice (P31) and the primary neurons were harvested and subjected to Western blot and immunohistochemistry to assess interleukin-6, the synaptic markers postsynaptic density-95 and synaptophysin, and caspase-3 levels. Separately, learning and memory function in the offspring mice was determined in the Morris water maze.

RESULTS

Sevoflurane anesthesia in pregnant mice induced caspase-3 activation, increased interleukin-6 levels (256 ± 50.98% [mean ± SD] vs. 100 ± 54.12%, P = 0.026), and reduced postsynaptic density-95 (61 ± 13.53% vs. 100 ± 10.08%, P = 0.036) and synaptophysin levels in fetal and offspring mice. The sevoflurane anesthesia impaired learning and memory in offspring mice at P31. Moreover, interleukin-6 antibody mitigated the sevoflurane-induced reduction in postsynaptic density-95 levels in the neurons. Finally, environmental enrichment attenuated the sevoflurane-induced increases in interleukin-6 levels, reductions of synapse markers, and learning and memory impairment.

CONCLUSIONS

These results suggest that sevoflurane may induce detrimental effects in fetal and offspring mice, which can be mitigated by environmental enrichment. These findings should promote more studies to determine the neurotoxicity of anesthesia in the developing brain.

Selective anesthesia-induced neuroinflammation in developing mouse brain and cognitive impairment

BACKGROUND

: Recent population studies have suggested that children with multiple exposures to anesthesia and surgery at an early age are at an increased risk of cognitive impairment. The authors therefore have established an animal model with single versus multiple exposures of anesthetic(s) in young versus adult mice, aiming to distinguish the role of different types of anesthesia in cognitive impairment.

METHODS

: Six- and 60-day-old mice were exposed to various anesthesia regimens. The authors then determined the effects of the anesthesia on learning and memory function, levels of proinflammatory cytokine interleukin-6 and tumor necrosis factor-α in brain tissues, and the amount of ionized calcium-binding adaptor molecule 1-positive cells, the marker of microglia activation, in the hippocampus.

RESULTS

: In this article, the authors show that anesthesia with 3% sevoflurane for 2 h daily for 3 days induced cognitive impairment and neuroinflammation (e.g., increased interleukin-6 levels, 151 ± 2.3% [mean ± SD] vs. 100 ± 9.0%, P = 0.035, n = 6) in young but not in adult mice. Anesthesia with 3% sevoflurane for 2 h daily for 1 day and 9% desflurane for 2 h daily for 3 days induced neither cognitive impairment nor neuroinflammation. Finally, an enriched environment and antiinflammatory treatment (ketorolac) ameliorated the sevoflurane-induced cognitive impairment.

CONCLUSIONS

: Anesthesia-induced cognitive impairment may depend on developmental stage, anesthetic agent, and number of exposures. These findings also suggest the cellular basis and the potential prevention and treatment strategies for anesthesia-induced cognitive impairment, which may ultimately lead to safer anesthesia care and better postoperative outcomes for children.

Impact of anaesthetics and surgery on neurodevelopment: an update

Accumulating preclinical and clinical evidence suggests the possibility of neurotoxicity from neonatal exposure to general anaesthetics. Here, we review the weight of the evidence from both human and animal studies and discuss the putative mechanisms of injury and options for protective strategies. Our review identified 55 rodent studies, seven primate studies, and nine clinical studies of interest. While the preclinical data consistently demonstrate robust apoptosis in the nervous system after anaesthetic exposure, only a few studies have performed cognitive follow-up. Nonetheless, the emerging evidence that the primate brain is vulnerable to anaesthetic-induced apoptosis is of concern. The impact of surgery on anaesthetic-induced brain injury has not been adequately addressed yet. The clinical data, comprising largely retrospective cohort database analyses, are inconclusive, in part due to confounding variables inherent in these observational epidemiological approaches. This places even greater emphasis on prospective approaches to this problem, such as the ongoing GAS trial and PANDA study.

Feasibility and pilot study of the Pediatric Anesthesia NeuroDevelopment Assessment (PANDA) project

BACKGROUND

Animal studies have documented that exposure of the developing brain to commonly used anesthetic agents induces neurotoxicity and late abnormal neurobehavioral functions as adults. Results from clinical studies have all been analyzed using existing data sets, and these studies produced inconsistent results. To provide more definitive evidence to address the clinical relevance of anesthetic neurotoxicity in children, an interdisciplinary team of investigators designed and developed the Pediatric Anesthesia NeuroDevelopment Assessment (PANDA) project. We present pilot study results in 28 sibling pairs recruited and tested at the Columbia University Medical Center (CUMC) and Children's Hospital of Boston (CHB) for the PANDA project.

METHODS

The PANDA project uses an ambidirectional cohort design. We performed prospective neuropsychological assessment in 28 exposed-unexposed sibling pairs from 6 to 11 years of age. The exposed siblings were ASA 1 or 2 and had received a single episode of anesthesia for inguinal hernia repair before the age of 36 months and the unexposed siblings had no anesthesia before the age of 36 months. All the sibling pairs were English speaking and were 36 weeks of gestational age or older. Each sibling pair underwent a direct testing using the Wechsler Abbreviated Scale of Intelligence (WASI) and the NEuroPSYchological Assessment, second edition (NEPSY II), and the parents completed questionnaires related to behavior using CBCL and Conners rating. Data are presented as means±SD. We conducted descriptive analyses of the demographic data. We compared both the exposed and the unexposed sibling groups on WASI and NEPSY II, and total and T scores from CBCL and Conners rating were analyzed as continuous data using the paired t test between the two groups. A P<0.05 was considered significant.

RESULTS

After the Institutional Review Board approval for the study at both CUMC and CHB, the full PANDA study protocol was implemented to perform a pilot feasibility study. Our success rate was 96.7% in obtaining detailed medical and anesthesia records in our historical cohort. The scores for verbal IQ (exposed=106.1±16.3, unexposed=109.2±17.9), performance IQ (exposed=109.1±16.0, unexposed=113.9±15.9), and full IQ (exposed=108.2±14.0, unexposed=112.8±16.8) were comparable between the siblings. There were no differences between the two groups in T scores for any of the NEPSY II subdomains, CBCL, or Conners rating. An abstraction protocol with web-based electronic data capture forms also was developed in conjunction with the International Center for Health Outcomes and Innovation Research (InCHOIR).

CONCLUSIONS

The pilot study provided useful information for feasibility to recruit the sample size and to obtain relevant clinical data. For the final study protocol, both the neuropsychological battery and the age range for testing were revised. Our results confirmed the feasibility of our study approach and yielded pilot data from neuropsychological testing.

Propofol sedation for infants with idiopathic clubfoot undergoing percutaneous tendoachilles tenotomy

OBJECTIVES

To determine whether percutaneous tenotomy of the Achilles tendon in infants with idiopathic clubfeet can be safely performed under propofol sedation.

BACKGROUND

Many orthopaedic surgeons prefer to do a tenotomy under general anesthesia. At our institution, we have been using 2 different methods of induction and maintenance of anesthesia: one method using combined propofol and sevoflurane and various types of airway management, and the other using only propofol with facemask.

METHODS

We reviewed the medical records of all patients less than 1 year of age with idiopathic clubfoot who underwent a percutaneous tendoachilles tenotomy under anesthesia. Collected data included: chronological age, earlier apneic events, medical risk factors, time from operating room entry to surgery, and surgical-related and anesthesia-related complications.

RESULTS

The study group comprised 114 patients who underwent 162 tenotomies. Sixty-five patients were in group 1 (sevoflurane/propofol) and 49 patients were in group 2 (propofol). The 2 groups did not differ with respect to sex, bilaterality, chronological age, number of preterm infants, ASA class, or associated risk factors. The average time from operating room entry to surgery was approximately 5 minutes longer with group 1, which included 14 cases taking longer than 20 minutes. However, there were no differences between the 2 groups with respect to postoperative complications.

CONCLUSIONS

Percutaneous tendoachilles tenotomy in infants with idiopathic clubfeet may be safely performed under anesthesia. Propofol sedation was safe and effective without the need for airway instrumentation for this short procedure.

LEVEL OF EVIDENCE

Level IV (retrospective).

Early developmental exposure to volatile anesthetics causes behavioral defects in Caenorhabditis elegans

BACKGROUND

Mounting evidence from animal studies shows that anesthetic exposure in early life leads to apoptosis in the developing nervous system. This loss of neurons has functional consequences in adulthood. Clinical retrospective reviews have suggested that multiple anesthetic exposures in early childhood are associated with learning disabilities later in life as well. Despite much concern about this phenomenon, little is known about the mechanism by which anesthetics initiate neuronal cell death. Caenorhabditis elegans, a powerful genetic animal model, with precisely characterized neural development and cell death pathways, affords an excellent opportunity to study anesthetic-induced neurotoxicity. We hypothesized that exposing the nematode to volatile anesthetics early in life would induce neuron cell death, producing a behavioral defect that would be manifested in adulthood.

METHODS

After synchronization and hatching, larval worms were exposed to volatile anesthetics at their 95% effective concentration for 4 hours. On day 4 of life, exposed and control worms were tested for their ability to sense and move to an attractant (i.e., to chemotax). We determined the rate of successful chemotaxis using a standardized chemotaxis index.

RESULTS

Wild-type nematodes demonstrated striking deficits in chemotaxis indices after exposure to isoflurane (ISO) or sevoflurane (SEVO) in the first larval stage (chemotaxis index: untreated, 85 ± 2; ISO, 52 ± 2; SEVO, 47 ± 2; P < 0.05 for both exposures). The mitochondrial mutant gas-1 had a heightened effect from the anesthetic exposure (chemotaxis index: untreated, 71 ± 2; ISO, 29 ± 12; SEVO, 24 ± 13; P < 0.05 for both exposures). In contrast, animals unable to undergo apoptosis because of a mutation in the pathway that mediates programmed cell death (ced-3) retained their ability to sense and move toward an attractant (chemotaxis index: untreated, 76 ± 10; ISO, 73 ± 9; SEVO, 76 ± 10). Furthermore, we discovered that the window of greatest susceptibility to anesthetic neurotoxicity in nematodes occurs in the first larval stage after hatching (L1). This coincides with a period of neurogenesis in this model. All values are means ± SD.

CONCLUSION

These data indicate that anesthetics affect neurobehavior in nematodes, extending the range of phyla in which early exposure to volatile anesthetics has been shown to cause functional neurological deficits. This implies that anesthetic-induced neurotoxicity occurs via an ancient underlying mechanism. C elegans is a tractable model organism with which to survey an entire genome for molecules that mediate the toxic effects of volatile anesthetics on the developing nervous system.

Newly postulated neurodevelopmental risks of pediatric anesthesia: theories that could rock our world

PURPOSE

General anesthetics can induce apoptotic neurodegeneration and subsequent maladaptive behaviors in animals. Retrospective human studies suggest associations between early anesthetic exposure and subsequent adverse neurodevelopmental outcomes. The relevance of animal data to clinical practice is unclear and to our knowledge the causality underlying observed associations in humans is unknown. We reviewed newly postulated neurodevelopmental risks of pediatric anesthesia and discuss implications for the surgical care of children.

MATERIALS AND METHODS

We queried the MEDLINE®/PubMed® and EMBASE® databases for citations in English on pediatric anesthetic neurotoxicity with the focus on references from the last decade.

RESULTS

Animal studies in rodents and primates demonstrate apoptotic neuropathology and subsequent maladaptive behaviors after exposure to all currently available general anesthetics with the possible exception of α2-adrenergic agonists. Similar adverse pathological and clinical effects occur after untreated pain. Anesthetic neurotoxicity in animals develops only after exposure above threshold doses and durations during a critical neurodevelopmental window of maximal synaptogenesis in the absence of concomitant painful stimuli. Anesthetic exposure outside this window or below threshold doses and durations shows no apparent neurotoxicity, while exposure in the context of concomitant painful stimuli is neuroprotective. Retrospective human studies suggest associations between early anesthetic exposure and subsequent adverse neurodevelopmental outcomes, particularly after multiple exposures. The causality underlying the associations is unknown. Ongoing investigations may clarify the risks associated with current practice.

CONCLUSIONS

Surgical care of all patients mandates appropriate anesthesia. Neurotoxic doses and the duration of anesthetic exposure in animals may have little relevance to clinical practice, particularly surgical anesthesia for perioperative pain. The causality underlying the observed associations between early anesthetic exposure and subsequent adverse neurodevelopmental outcomes is unknown. Anesthetic exposure may be a marker of increased risk. Especially in young children, procedures requiring general anesthesia should be performed only as necessary and general anesthesia duration should be minimized. Alternatives to general anesthesia and the deferral of elective procedures beyond the first few years of life should be considered, as appropriate. Participation in ongoing efforts should be encouraged to generate further data.

Dental care and treatments provided under general anaesthesia in the Helsinki Public Dental Service

BACKGROUND

Dental general anaesthesia (DGA) is a very efficient treatment modality, but is considered only in the last resort because of the risks posed by general anaesthesia to patients' overall health. Health services and their treatment policies regarding DGA vary from country to country. The aims of this work were to determine the reasons for DGA in the Helsinki Public Dental Service (PDS) and to assess the role of patient characteristics in the variation in reasons and in the treatments given with special focus on preventive care.

METHODS

The data covered all DGA patients treated in the PDS in Helsinki in 2010. The data were collected from patient documents and included personal background: age (<6, 6-12, 13-17, 18-68), gender, immigration, previous conscious sedation and previous DGA; medical background; reasons for DGA and treatments provided. Chi-square tests, Fisher's exact test, and logistic regression modelling were employed in the statistical analyses.

RESULTS

The DGA patients (n=349) were aged 2.3 to 67.2 years. Immigrants predominated in the youngest age group (p<0.001) and medically compromised patients among the adults (p<0.001) relative to the other age groups. The main reason for DGA was extreme non-cooperation (65%) followed by dental fear (37%) and an excessive need for treatment (26%). In total, 3435 treatments were performed under DGA, 57% of which were restorations, 24% tooth extractions, 5% preventive measures, 5% radiography, 4% endodontics and the remaining 5% periodontics, surgical procedures and miscellaneous. The reasons for DGA and the treatments provided varied according to age, immigration, previous sedation and DGA and medical background. The logistic regression model showed that previous sedation (OR 2.3; 95%CI 1.3-4.1; p=0.005) and extreme non-cooperation (OR 1.7; 95%CI 0.9-3.2; p=0.103) were most indicative of preventive measures given.

CONCLUSIONS

Extreme non-cooperation, dental fear and an excessive need for treatment were the main reasons for the use of comprehensive, conservative DGA in the Helsinki PDS. The reasons for the use of DGA and the treatments provided varied according to personal and medical background, and immigration status with no gender-differences. Preventive measures formed only a minor part of the dental care given under DGA.

Assessment and management of inguinal hernia in infants

Inguinal hernia repair in infants is a routine surgical procedure. However, numerous issues, including timing of the repair, the need to explore the contralateral groin, use of laparoscopy, and anesthetic approach, remain unsettled. Given the lack of compelling data, consideration should be given to large, prospective, randomized controlled trials to determine best practices for the management of inguinal hernias in infants.

Pediatric anesthesia and neurodevelopmental impairments: a Bayesian meta-analysis

Experimental evidence of anesthesia-induced neurotoxicity has caused serious concern about the long-term effect of commonly used volatile anesthetic agents on young children. Several observational studies based on existing data have been conducted to address this concern with inconsistent results. We conducted a meta-analysis to synthesize the epidemiologic evidence on the association of anesthesia/surgery with neurodevelopmental outcomes in children. Using Bayesian meta-analytic approaches, we estimated the synthesized odds ratios (OR) and 95% credible interval (CrI) as well as the predictive distribution of a future study given the synthesized evidence. Data on 7 unadjusted and 6 adjusted measures of association were abstracted from 7 studies. The synthesized OR based on the 7 unadjusted measures for the association of anesthesia/surgery with an adverse behavioral or developmental outcome was 1.9 (95% CrI, 1.2-3.0). The most likely unadjusted OR from a future study was estimated to be 2.2 (95% CrI, 0.6-6.1). The synthesized OR based on the 6 adjusted measures for the association of anesthesia/surgery with an adverse behavioral or developmental outcome was 1.4 (95% CrI, 0.9-2.2). The most likely adjusted OR from a future study was estimated to be 1.5 (95% CrI, 0.5-4.0). We conclude that existent epidemiologic evidence suggests a modestly elevated risk of adverse behavioral or developmental outcomes in children who were exposed to anesthesia/surgery during early childhood. The evidence, however, is considerably uncertain.