Anesthetic-induced neurotoxicity of the neonate: time for clinical guidelines?

Laparoscopic repair of duodenal atresia: systematic review and meta-analysis after consistent implementation of the technique in the past decade

BACKGROUND

Laparoscopic repair of duodenal atresia (LRDA) remains a technically challenging procedure and its benefits ambiguous. To assess the safety and efficacy of LRDA, we performed a systematic review of techniques and material for LRDA and a meta-analysis comparing outcomes with open repair (OR).

METHODS

Comprehensive search of EMBASSE, PubMed and Cochrane was performed from 2000 to 2023. Studies comparing LRDA with OR were identified and outcomes extracted included operative time, time to enteral feeds, length of hospitalisation, anastomotic leaks and stricture and total complications. χ2 was used to assess associations between complications and conversions rates of different LRDA approaches (laparoscopic technique, suturing technique). Comprehensive meta-analysis was used for Meta-analysis.

RESULTS

Twelve studies were identified and 1731 patients were enrolled in the study (398 [LRDA] and 1325 [OR]). Total rate of complications and conversion for LRDA was 15.58% and 18.84%, respectively. Complication rates were not significantly affected by operative technique and suturing technique. Conversion rates were not significantly affected operative technique; using a combination of interrupted and running suturing was significantly higher than using running or interrupted (χ2 = 7.45, p < 0.05). Anastomotic leaks, strictures and total complications were equivocal between LRDA and OR (OR 1.672, 95% CI 0.796-3.514; OR 2.010, 95% CI 0.758-5.333; OR 1.172, 95% CI 0.195-7.03). Operative time was significantly greater for LRDA (SDM 1.035, 95% CI 0.574-1.495, p < 0.001). Time to initial and full enteral feeds and length of hospitalisation were shorter in the LRDA group (SDM - 0.493, 95% CI - 2.166 to 1.752, p = 0.466; SDM - 0.207, 95% CI - 1.807 to 0.822, p = 0.019; SDM - 0.111, 95% CI - 1.101 to 0.880, p = 0.466, respectively).

CONCLUSIONS

LRDA showed equivalent complication rates compared to OR with an additional benefit of quicker establishment of feeds. There was no significant difference in complication and conversion rates between laparoscopic techniques. Despite a longer operative time, LRDA provides a safe minimal access approach for neonates after this consistent implementation of the technique in the past decade.

Effects of on-Table Extubation after Pediatric Cardiac Surgery

Background: Enhanced recovery after surgery (ERAS) protocols are utilizing a multidisciplinary approach, reassessing physiology to improve clinical outcomes, reducing length of hospital stay (LOS) stay, resulting in cost reduction. Since its introduction in colorectal surgery. the concept has been utilized in various fields and benefits have been recognized also in adult cardiac surgery. However, ERAS concepts in pediatric cardiac surgery are not yet widely established. Therefore, the aim of the present study was to assess the effects of on-table extubation (OTE) after pediatric cardiac surgery compared to the standard approach of delayed extubation (DET) during intensive care treatment. Study Design and Methods: We performed a retrospective analysis of all pediatric cardiac surgery cases performed in children below the age of two years using cardiopulmonary bypass at our institution in 2021. Exclusion criteria were emergency and off pump surgeries as well as children already ventilated preoperatively. Results: OTE children were older (267.3 days vs. 126.7 days, p < 0.001), had a higher body weight (7.0 ± 1.6 kg vs. 4.9 ± 1.9 kg, p < 0.001), showed significantly reduced duration of ICU treatment (75.9 ± 56.8 h vs. 217.2 ± 211.4 h, p < 0.001) and LOS (11.1 ± 10.2 days vs. 20.1 ± 23.4 days; p = 0.001) compared to DET group. Furthermore, OTE children had significantly fewer catecholamine dependencies at 12-, 24-, 48-, and 72-h post-surgery, while DET children showed a significantly increased intrafluid shift relative to body weight (109.1 ± 82.0 mL/kg body weight vs. 63.0 ± 63.0 mL/kg body weight, p < 0.001). After propensity score matching considering age, weight, bypass duration, Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality (STATS)-Score, and the outcome variables, including duration of ICU treatment, catecholamine dependencies, and hospital LOS, findings significantly favored the OTE group. Conclusion: Our results suggest that on-table extubation after pediatric cardiac surgery is feasible and in our cohort was associated with a favorable postoperative course.

Laparoscopic Versus Open Surgical Repair of Duodenal Atresia: An NSQIP-Pediatric Analysis

INTRODUCTION

Laparoscopic repair of duodenal atresia in neonates has gained popularity among some pediatric surgeons. Single-center studies suggest comparable short-term outcomes to open surgery. The purpose of this study was to utilize a large, multi-institutional pediatric dataset to examine 30-day post-operative outcomes by operative approach for newborns who underwent duodenal atresia repairs.

METHODS

We identified neonates aged ≤1 wk in the 2016-2018 National Surgical Quality Improvement Program-Pediatric -database that underwent a laparoscopic or open repair for duodenal atresia. Preoperative characteristics were compared between operative approaches. Postoperative complications, operative time, postoperative length of stay (LOS), and supplemental nutrition at discharge were assessed using multivariate regressions.

RESULTS

There were 267 neonates who met inclusion criteria. There were 233 (87%) infants who underwent open repairs and 34 (13%) who underwent laparoscopic repairs. Ten (29%) children who had laparoscopy were converted to open. After adjusting for confounding, laparoscopy was associated with an increase in operative time by 65 min (95% confidence interval 45-87 min, P < 0.001) but a five-day shorter LOS (95% confidence interval -9 to -2, P = 0.006) when compared to laparotomy. There were no significant differences in postoperative complications or supplemental nutrition at discharge.

CONCLUSIONS

Our findings suggest that laparoscopic repairs of duodenal atresia are associated with shorter postoperative LOS but longer operative times when compared to open repairs. Although the conversion rate to laparotomy remained relatively high, the laparoscopic approach was associated with comparable 30-day postoperative outcomes.

Long Term Neurodevelopmental Outcomes after Sevoflurane Neonatal Exposure of Extremely Preterm Children: A Cross-Sectional Observationnal Study

Sevoflurane, a volatile anesthetic, is used when extremely preterm neonates (EPT) undergo painful procedures. Currently, no existing studies analyze sevoflurane’s long-term effects during the EPT’s immediate neonatal period. Our primary objective was to compare the EPT’s neurocognitive development regardless of any sevoflurane exposure prior to 45 weeks corrected gestational age (GA). We analyzed those live discharges, less than 28 weeks GA, who were either exposed, unexposed, and/or multiply exposed to sevoflurane before 45 weeks GA. All data were obtained from a cross-sectional multicenter study (GPQoL study, NCT01675726). Children, both exposed and non-exposed to sevoflurane, were sampled using a propensity-guided approach. Neurological examinations (Touwen), cognitive and executive functions (WISC IV, NEPSY, Rey figure), and assessments when the children were between 7 and 10 years old, were correlated to their neonatal sevoflurane exposure. There were 139 children in the study. The mean gestational age was 26.2 weeks (±0.8) GA and the mean birth weight was 898 g (±173). The mean age of their evaluation was 8.47 years old (±0.70). Exposure to sevoflurane to the mean corrected age 27.10 (3.37) weeks GA had a significant correlation with cerebral palsy (adjusted odds ratio (aOR): 6.70 (CI 95%: 1.84–32.11)) and other major disorders (cerebral palsy and/or severe cognitive retardation) (aOR: 2.81 [95% CI: 1.13–7.35]). Our results demonstrate the possibility of long-term effects on EPT infants who had a sevoflurane exposure before 45 weeks corrected GA. However, these results will require further confirmation by randomized controlled trials.

Thoracoscopic versus open lobectomy in infants with congenital lung malformations: A multi-institutional propensity score analysis

PURPOSE

The impact of thoracoscopic surgery on outcomes in children with congenital lung malformations (CLM) remains controversial. The purpose of this study was to determine the effect of operative approach on perioperative outcomes in infants undergoing lobectomy for an asymptomatic CLM.

METHODS

After IRB approval, a retrospective cohort study was conducted on 506 children with a CLM resected at one of eleven children's hospitals over a seven-year period. Infants undergoing elective lobectomy were identified, and covariates were balanced based on operative approach using propensity scores with full matching. Outcomes were analyzed based on intention to treat with weighted conditional regression.

RESULTS

One hundred seventy-five infants met inclusion criteria. There were 67 (38.3%) open, 89 (50.9%) thoracoscopic, and 19 (10.9%) thoracoscopic-converted-to-open lobectomies. Thoracoscopic lobectomy was associated with significantly longer operative times (26 min, 95% CI 6-47 min, p = 0.012) but used less epidural anesthesia (OR 0.02, 95% CI 0.004-0.11, p<0.001) when compared to open lobectomy. There were no significant differences in intraoperative blood loss, postoperative complications, chest tube duration, or length of stay.

CONCLUSIONS

Thoracoscopy has become the most common operative approach for elective lobectomy in infants with asymptomatic CLMs. The non-inferiority of thoracoscopic lobectomy in postoperative outcomes supports its continued use as an alternative to open lobectomy.

LEVEL OF EVIDENCE

Treatment study, Level III.

Numerical analysis of mechanical ventilation using high concentration medical gas mixtures in newborns

When administered in relatively high concentrations the mechanical properties of inhaled gas can become significantly different from air. This fact has implications in mechanical ventilation where adequate respiration and injury to the lungs or respiratory muscles can worsen morbidity and mortality. Here we use an engineering pressure loss model to analyze the administration of medical gas mixtures in newborns. The model is used to determine the pressure distribution along the gas flow path. Numerical experiments comparing medical gas mixtures with helium, nitrous oxide, argon, xenon, and medical air as a control, with and without an endotracheal tube obstruction were performed. The engineering pressure loss model was incorporated into a model of mechanical ventilation during pressure control mode, a ventilator mode that is often used for neonates. Results are presented in the form of Rohrer equations relating pressure loss to flow rate for each gas mixture with and without obstruction. These equations were incorporated into a model for mechanical ventilation resulting in pressure, flow rate, and volume curves for the inhalation-exhalation cycle. In terms of accuracy, published values of airway resistance range from 50 to 150 cmH₂O/L per second for a normal 3 kg infant. With air, the current results are 55 to 80 cmH₂O/L per second for 0.3 to 5 L/min. It is shown that density through inertial pressure losses has a greater influence on airway resistance than viscosity in spite of relatively low flow rates and small airway dimensions of newborns. The results indicate that the high-density xenon mixture can be problematic during mechanical ventilation. On the other hand, low density heliox (a mixture of helium and oxygen) provides a wider margin of safety for mechanical ventilation than the other gas mixtures. The argon or nitrous oxide mixtures considered are only slightly different from air in terms of mechanical ventilation performance.

A technique for administering xenon gas anesthesia during surgical procedures in mice

Carrying out invasive procedures in animals requires the administration of anesthesia. Xenon gas offers advantages as an anesthetic agent compared with other agents, such as its protection of the brain and heart from hypoxia-induced damage. The high cost of xenon gas has limited its use as an anesthetic in animal experiments, however. The authors designed and constructed simple boxes for the induction and maintenance of xenon gas and isoflurane anesthesia in small rodents in order to minimize the amount of xenon gas that is wasted. While using their anesthesia delivery system to anesthetize pregnant mice undergoing caesarean sections, they measured the respiratory rates of the anesthetized mice, the survival of the pups and the percentages of oxygen and carbon dioxide within the system to confirm the system's safety.

Surgical management of bronchopulmonary malformations

BACKGROUND

Bronchopulmonary malformations (BPM) are rare conditions, which typically arise below the carina and can result in significant morbidity (infection and/or hemorrhage) and mortality (respiratory failure).

MATERIALS AND METHODS

All children with BPM surgically treated from 2001-2014 at a tertiary care children's hospital were identified. Patient demographics, surgical indications, procedure type, estimated blood loss, pathology, perioperative complications, length of stay, and outcomes were analyzed.

RESULTS

A total of 41 BPM patients underwent surgery with 98% overall survival (one abdominal BPM expired) but 100% for thoracic lesions. Resections were performed thoracoscopically (37%), thoracoscopy converted to open (22%), and via thoracotomy (37%). Poor visualization (67%) or inability to tolerate single lung ventilation (33%) led to conversions. No conversions resulted from hemorrhage or received blood transfusions. Patients with prenatally diagnosed BPM were more likely to undergo thoracoscopic surgery (odds ratio [OR], 18.2) versus nonprenatally diagnosed, P = 0.002. Open/converted patients had longer chest tube days (6.2) versus thoracoscopic (2.9), P = 0.048. Additionally, respiratory distress was a more common indication in patients aged <4 mo (OR, 28.0) versus ≥4 mo and <6 kg (OR, 40.5) versus ≥6 kg, P < 0.001. Open resections were more common in patients aged <4 mo (OR, 26.3) versus ≥4 mo, P = 0.002. Operative time was shorter and estimated blood loss (mL/kg) was greater for <6 versus ≥6 kg, P < 0.05.

CONCLUSIONS

BPM resections have high overall survival. Chest tube days are shorter among thoracoscopic patients, but conversion to thoracotomy can avoid hemorrhage and need for transfusion. Size and respiratory distress limit use of thoracoscopy in young infants with BPM.

Connexin-Related (DFNB1) Hearing Loss

Objectives

Determine if routine computed tomography (CT) imaging is necessary in the workup for children with connexin-related (DFNB1) sensorineural hearing loss (SNHL).

Study Design

Case-control retrospective chart and imaging review.

Setting

Tertiary care otolaryngology practice.

Subjects and Methods

High-resolution temporal bone CT scans of children (n = 21) with DFNB1 SNHL were compared to age-matched controls with either conductive hearing loss (CHL, n = 33) or a nonsyndromic, non-DFNB1 SNHL (n = 33). Sixteen measurements of cochleo-vestibular structures were recorded. Statistical analysis was performed using a repeated analysis of variance model that controlled for both age and gender. Area under the curve (AUC) and multidimensional AUC (MAUC) analyses were also performed.

Results

Overall, no statistically significant differences were found between the 3 experimental groups. In addition, comparisons between the DFNB1 and CHL groups, DFNB1 and non-DFNB1 SNHL groups, and CHL and non-DFNB1 SNHL groups failed to demonstrate any statistically significant differences. AUC and MAUC analyses also failed to detect any significant differences between the 3 groups.

Conclusions

Patients with DFNB1 SNHL do not have significant anatomic differences on temporal bone CT scans when compared to non-DFNB1 SNHL and CHL control groups. Based on the above analysis, it is reasonable to avoid routine CT imaging of the temporal bones in children with known DFNB1 SNHL unless otherwise clinically indicated.

Reducing the risk in neonatal anesthesia

Neonatal anesthesia is fraught with potential risk for the patient and stress for the anesthesiologist. Where possible, recognition of these risks, avoidance of, and being able to manage them appropriately, must impact positively on perioperative outcomes in this vulnerable group of patients. Good communication with the parents, as well as with other healthcare providers, is crucial to safe and successful anesthetic care.

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.

Thoracoscopic vs open lobectomy in infants and young children with congenital lung malformations

BACKGROUND

Although thoracoscopic lobectomy is a widely accepted surgical procedure in adult thoracic surgery, its role in small children remains controversial. The purpose of this study was to evaluate perioperative outcomes after thoracoscopic and open lobectomy in infants and young children with congenital lung malformations at a single academic referral center.

STUDY DESIGN

A cohort study of 62 consecutive children who underwent elective pulmonary lobectomy for a congenital lung lesion between 2001 and 2013 was performed. Patient demographics and perioperative outcomes were evaluated in univariate and logistic regression analyses.

RESULTS

Forty-nine patients underwent thoracoscopy and 13 had a thoracotomy. Six children undergoing thoracoscopy required conversion to thoracotomy (conversion 12.2%). Perioperative outcomes, including median blood loss (2.0 vs 1.1 mL/kg; p = 0.34), chest tube duration (3 vs 3 days; p = 0.33), hospital length of stay (3 vs 3 days; p = 0.42), and morbidity as defined by the Accordion Grading Scale (30.6% vs 30.8%; p = 0.73), were similar between thoracoscopy and thoracotomy, respectively. Although thoracoscopy was associated with increased operative duration compared with thoracotomy (239.9 vs 181.2 minutes, respectively; p = 0.03), thoracoscopy operative times decreased with increasing institutional experience (p = 0.048). Thoracoscopic lobectomy infants younger than 5 months of age had a 2.5-fold higher rate of perioperative adverse outcomes compared with older children (p = 0.048).

CONCLUSIONS

In small children undergoing pulmonary lobectomy, both thoracoscopy and thoracotomy are associated with similar perioperative outcomes. The cosmetic and musculoskeletal benefits of the thoracoscopic approach must be balanced against institutional expertise and a potentially higher risk for complications in younger patients.

Regional anesthesia in neonates and infants

Optimal pain management can significantly impact the surgical outcome and length of stay in the neonatal intensive care unit (NICU). Regional anesthesia is an effective alternative that can be used in both term and preterm neonates. A variety of neuraxial and peripheral nerve blocks have been used for specific surgical and NICU procedures. Ultrasound guidance has increased the feasibility of using these techniques in neonates. Education and training staff in the use of continuous epidural infusions are important prerequisites for successful implementation of regional anesthesia in NICU management protocols.

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.

The value of Tuffier's line for neonatal neuraxial procedures

The spine of L4 usually lies on a line drawn between the highest points of the iliac crests (Tuffier's line) in adults. Although its accuracy has been questioned, it is still commonly used to identify the spinous process of the 4th lumbar vertebra before performing lumbar neuraxial procedures. In children, this line is said to cross the midline at the level of L5. A literature search revealed that the description this surface anatomical line is vague in neonates. The aims of this study were to determine the vertebral level of Tuffier's line, as well as its distance from the apex of the sacrococcygeal membrane (ASM), in 39 neonatal cadavers in both a prone and flexed position. It was found that when flexed, Tuffier's line shifted from the level of L4/L5 (prone position) to the upper third of L5. The mean distance from the ASM to Tuffier's line was 23.64mm when prone and 25.47 mm when flexed, constituting a statistically significant increase in the distance (P=0.0061). Therefore, in the absence of advanced imaging modalities, Tuffier's line provides practitioners with a simple method of determining a level caudal to the termination of the spinal cord, at approximately the L4/L5 in a prone neonate and the upper margins of L5 when flexed.

Update on complications in pediatric anesthesia

Complications in pediatric anesthesia can happen, even in our modern hospitals with the most advanced equipment and skilled anesthesiologists. It is important, albeit in a tranquil and reassuring way, to inform parents of the possibility of complications and, in general, of the anesthetic risks. This is especially imperative when speaking to the parents of children who will be operated on for minor procedures: in our experience, they tend to think that the anesthesia will be a light anesthesia without risks. Often the surgeons tell them that the operation is very simple without stressing the fact that it will be done under general anesthesia which is identical to the one we give for major operations. Different is the scenario for the parents of children who are affected by malignant neoplasms: in these cases they already know that the illness is serious. They have this tremendous burden and we choose not to add another one by discussing anesthetic risks, so we usually go along with the examination of the child without bringing up the possibility of complications, unless there is some specific problem such as a mediastinal mass.

Bench to cribside: the path for developing a neuroprotectant

The consequences of perinatal brain injury include immeasurable anguish for families and substantial ongoing costs for care and support of effected children. Factors associated with perinatal brain injury in the preterm infant include inflammation and infection, and with increasing gestational age, a higher proportion is related to hypoxic-ischemic events, such as stroke and placental abruption. Over the past decade, we have acquired new insights in the mechanisms underpinning injury and many new tools to monitor outcome in perinatal brain injury in our experimental models. By embracing these new technologies, we can expedite the screening of novel therapies. This is critical as despite enormous efforts of the research community, hypothermia is the only viable neurotherapeutic, and this procedure is limited to term birth and postcardiac arrest hypoxic-ischemic events. Importantly, experimental and preliminary data in humans also indicate a considerable therapeutic potential for melatonin against perinatal brain injury. However, even if this suggested potential is proven, the complexity of the human condition means we are likely to need additional neuroprotective and regenerative strategies. Thus, within this review, we will outline what we consider the key stages of preclinical testing and development for a neuroprotectant or regenerative neurotherapy for perinatal brain injury. We will also highlight examples of novel small animal physiological and behavioral testing that gives small animal preclinical models greater clinical relevance. We hope these new tools and an integrated bench to cribside strategic plan will facilitate the fulfillment of our overarching goal, improving the long-term brain health and quality of life for infants suffering perinatal brain injury.

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.

Regional anesthesia in children: the future

Pediatric regional anesthesia continues to evolve. Education and attention to anatomical detail remain key elements to successful outcomes. New techniques, some adapted from adult practice, provide analgesia for pediatric surgical procedures such cleft palate or congenital hip dysplasia. Despite technological advances a number of controversial issues remain unresolved.

Neurological injury and anesthetic neurotoxicity following neonatal cardiac surgery: does the head rule the heart or the heart rule the head?

The improvements in care of children with heart disease have resulted in a major decrease in mortality and increased attention to adverse events and quality of survival. There is important neurological morbidity in children with congenital heart disease. Some problems such as stroke or seizure may be immediately apparent, but others, such as learning disability and motor delay emerge over time. The etiology is multifactorial and includes genetic, procedural and social causes. Only some factors are modifiable. Over the last decade, evidence has been presented that anesthetic drugs may be a potential cause of CNS morbidity. Neonates and infants may be particularly vulnerable to this. The purpose of this article is to describe the multiple known causes of neurodevelopmental impairment in children with heart disease, including anesthetic agents, and to explore the relationship between congenital heart disease and its treatment in this regard.

Erythropoietin attenuates isoflurane-induced neurodegeneration and learning deficits in the developing mouse brain

OBJECTIVES

To examine whether recombinant erythropoietin (rEPO) attenuates neurodegeneration and the learning disability induced by isoflurane with the postnatal day 7 (P7) mice.

BACKGROUND

Some of general anesthetic agents induce neurodegeneration in developing brain. Several drugs, but not rEPO, were reported as candidates for the prevention of or treatment for neurodegeneration.

METHOD AND MATERIALS

We divided P7 mice into three groups at random. One group (IE group) was exposed to 6-h isoflurane (1.0%) after 50,000 IU·kg(-1) rEPO administered subcutaneously. The second group (I) was exposed to isoflurane in the same manner as IE group except saline instead of rEPO. The third group (E) was exposed to air after rEPO administered. The mice were assigned to the radial arm maze on four consecutive days from P56 (day 1) to P59 (day 4). We divided the number of errors each day by that of day 1 to establish each-day performance ratio. After the test, neurodegenerative change in the hilus of dentate gyrus was assessed using Nissl staining.

RESULTS

In radial maze test, the performance ratios of day 3 (mean ± sd) were 0.3 ± 0.2 (P < 0.05, vs I group), 0.8 ± 0.5, and 0.6 ± 0.2 in IE, I, and E groups, respectively, while those of day 4 were 0.3 ± 0.1 (P < 0.05), 0.8 ± 0.5, and 0.3 ± 0.2 (P < 0.05), respectively. The histopathological study revealed that in IE group the degenerative neuronal change was attenuated compared with I group.

CONCLUSIONS

These results suggested that rEPO attenuated isoflurane-induced neurodegeneration.

Pro con debate: the use of regional vs systemic analgesia for neonatal surgery

In recent years the inclusion of regional techniques to pediatric anesthesia has transformed practice. Simple procedures such as caudal anesthesia with local anaesthetics can reduce the amounts of general anesthesia required and provide complete analgesia in the postoperative period while avoiding large amounts of opioid analgesia with potential side effects that can impair recovery. However, the application of central blocks (epidural and spinal local anesthesia) via catheters in the younger infant, neonate and even preterm neonate remains more controversial. The potential for such invasive maneuvers themselves to augment risk, can be argued to outweigh the benefits, others would argue that epidural analgesia can reduce the need for postoperative ventilation and that this not only facilitates surgery when intensive care facilities are limited, but also reduces cost in terms of PICU stay and recovery profile. Currently, opinions are divided and strongly held with some major units adopting this approach widely and others maintaining a more conservative stance to anesthesia for major neonatal surgery. In this pro-con debate the evidence base is examined, supplemented with expert opinion to try to provide a balanced overall view.

Fundamentals of neuronal apoptosis relevant to pediatric anesthesia

The programmed cell death or apoptosis is a complex biochemical process that has risen to prominence in pediatric anesthesia. Preclinical studies report a dose-dependent neuronal apoptosis during synaptogenesis following exposure to intravenous and volatile anesthetic agents. Although emerging clinical data do not universally indicate an increased neurodegenerative risk of general anesthesia in early human life, a great deal of uncertainty was created within the pediatric anesthesia community. This was at least partially caused by the demand of understanding of basic science concepts and knowledge of apoptosis frequently out of reach to the clinician. It is, however, important for the pediatric anesthesiologist to be familiar with the basic science concepts of neuronal apoptosis to be able to critically evaluate current and future preclinical data in this area and future clinical studies. This current review describes the extrinsic and intrinsic pathways involved in the cell death process and discusses techniques commonly employed to determine apoptosis. In addition, potential mechanisms of anesthesia-induced neuronal apoptosis are illustrated in this review.