Beyond survival; influences of blood pressure, cerebral perfusion and anesthesia on neurodevelopment

Development of a joint set of database parameters for the EU-ROP and Fight Childhood Blindness! ROP Registries

BACKGROUND/AIMS

The incidence of retinopathy of prematurity (ROP) is increasing and treatment options are expanding, often without accompanying safety data. We aimed to define a minimal, patient-centred data set that is feasible to collect in clinical practice and can be used collaboratively to track and compare outcomes of ROP treatment with a view to improving patient outcomes.

METHODS

A multinational group of clinicians and a patient representative with expertise in ROP and registry development collaborated to develop a data set that focused on real-world parameters and outcomes that were patient centred, minimal and feasible to collect in routine clinical practice.

RESULTS

For babies receiving ROP treatment, we recommend patient demographics, systemic comorbidities, ROP status, treatment details, ophthalmic and systemic complications of treatment, ophthalmic and neurodevelopmental outcomes at initial treatment, any episodes of retreatment and follow-up examinations in the short and long-term to be collected for use in ROP studies, registries and routine clinical practice.

CONCLUSIONS

We recommend these parameters to be used in registries and future studies of ROP treatment, to reduce the variation seen in previous reports and allow meaningful assessments and comparisons. They form the basis of the EU-ROP and the Fight Childhood Blindness! ROP Registries.

Automatic Max-Likelihood Envelope Detection Algorithm for Quantitative High-Frame-Rate Ultrasound for Neonatal Brain Monitoring

OBJECTIVE

Post-operative brain injury in neonates may result from disturbed cerebral perfusion, but accurate peri-operative monitoring is lacking. High-frame-rate (HFR) cerebral ultrasound could visualize and quantify flow in all detectable vessels using spectral Doppler; however, automated quantification in small vessels is challenging because of low signal amplitude. We have developed an automatic envelope detection algorithm for HFR pulsed wave spectral Doppler signals, enabling neonatal brain quantitative parameter maps during and after surgery.

METHODS

HFR ultrasound data from high-risk neonatal surgeries were recorded with a custom HFR mode (frame rate = 1000 Hz) on a Zonare ZS3 system. A pulsed wave Doppler spectrogram was calculated for each pixel containing blood flow in the image, and spectral peak velocity was tracked using a max-likelihood estimation algorithm of signal and noise regions in the spectrogram, where the most likely cross-over point marks the blood flow velocity. The resulting peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistivity index (RI) were compared with other detection schemes, manual tracking and RIs from regular pulsed wave Doppler measurements in 10 neonates.

RESULTS

Envelope detection was successful in both high- and low-quality arterial and venous flow spectrograms. Our technique had the lowest root mean square error for EDV, PSV and RI (0.46 cm/s, 0.53 cm/s and 0.15, respectively) when compared with manual tracking. There was good agreement between the clinical pulsed wave Doppler RI and HFR measurement with a mean difference of 0.07.

CONCLUSION

The max-likelihood algorithm is a promising approach to accurate, automated cerebral blood flow monitoring with HFR imaging in neonates.

A comparison of ultrafast and conventional spectral Doppler ultrasound to measure cerebral blood flow velocity during inguinal hernia repair in infants

BACKGROUND

Ultrafast cerebral Doppler ultrasound enables simultaneous quantification and visualization of cerebral blood flow velocity. The aim of this study is to compare the use of conventional and ultrafast spectral Doppler during anesthesia and their potential to show the effect of anesthesiologic procedures on cerebral blood flow velocities, in relation to blood pressure and cerebral oxygenation in infants undergoing inguinal hernia repair.

METHODS

A single-center prospective observational cohort study in infants up to six months of age. We evaluated conventional and ultrafast spectral Doppler cerebral ultrasound measurements in terms of number of successful measurements during the induction of anesthesia, after sevoflurane induction, administration of caudal analgesia, a fluid bolus and emergence of anesthesia. Cerebral blood flow velocity was quantified in pial arteries using conventional spectral Doppler and in the cerebral cortex using ultrafast Doppler by peak systolic velocity, end diastolic velocity and resistivity index.

RESULTS

Twenty infants were included with useable conventional spectral Doppler images in 72/100 measurements and ultrafast Doppler images in 51/100 measurements. Intraoperatively, the success rates were 53/60 (88.3%) and 41/60 (68.3%), respectively. Cerebral blood flow velocity increased after emergence for both conventional (end diastolic velocity, from 2.01 to 2.75 cm/s, p < 0.001) and ultrafast spectral Doppler (end diastolic velocity, from 0.59 to 0.94 cm/s), whereas cerebral oxygenation showed a reverse pattern with a decrease after the emergence of the infant (85% to 68%, p < 0.001).

CONCLUSION

It is possible to quantify cortical blood flow velocity during general anesthesia using conventional and ultrafast spectral Doppler cerebral ultrasound. Cerebral blood flow velocity and blood pressure decreased, while regional cerebral oxygenation increased during general anesthesia. Ultrafast spectral Doppler ultrasound offers novel insights into perfusion within the cerebral cortex, unattainable through conventional spectral ultrasound. Yet, ultrafast Doppler is curtailed by a lower success rate and a more rigorous learning curve compared to conventional method.

Propofol and thiopental for intravenous induction in neonates: Study protocol for a dose-finding trial

BACKGROUND

Propofol and thiopental are commonly used induction agents in neonatal anesthesia. Even though both hypnotics have been used off-label for many years, pharmacological knowledge regarding these agents is scarce in neonates. The significant variability in neonates' body composition, organ function, and maturation makes pharmacological studies highly relevant albeit challenging. As a result, there is currently limited data about the anesthetic induction dose of thiopental and propofol in neonates. In addition, a knowledge gap exists concerning the pharmacodynamics of induction doses.

OBJECTIVE

To determine the median effective anesthetic induction dose of propofol and thiopental in neonatal patients of different gestational and postnatal ages and evaluate the pharmacodynamics of the anesthesia induction doses on the neonatal systemic and cerebral hemodynamics.

METHODS

This is a single-center, prospective, open-label, interventional, dose-finding study, including neonatal patients from birth up to 28 postnatal days undergoing general anesthesia for surgical or diagnostic procedures. The patients will be stratified according to their gestational and postnatal age and allocated to one of the two trial arms: anesthesia induction with propofol or anesthesia induction with thiopental. We will use Dixon's up-and-down method to estimate the median effective anesthesia induction dose of both agents in neonates of different gestational and postnatal ages. In addition, we will study the relationship between anesthesia induction doses and changes in systemic and cerebral hemodynamics.

DISCUSSION

Alterations in the systemic and cerebral regional hemodynamics secondary to anesthesia induction may be harmful in neonates, especially premature and critically ill newborns, due to their immature organ systems, reduced physiological reserves, and impaired cerebral autoregulation. Perfusion homeostasis is considered one of the significant and modifiable determinants of anesthesia-related neurocognitive outcomes. Therefore, dose-finding and safety pharmacological studies of the anesthetic induction agents in neonates are urgently needed and acknowledged as a high priority by the European Medicine Agency. Estimating adequate induction doses to ensure optimal depth of anesthesia while avoiding systemic and cerebral hemodynamic disturbances will help ensure safe anesthesia and potentially improve anesthesia-related outcomes in this group of patients.

TRIAL REGISTRATION

EudraCT (EudraCT Identifier: 2019-001534-34), 05.07.2022.

Continuous monitoring of cerebral blood flow during general anaesthesia in infants

Background

General anaesthesia is associated with neurocognitive deficits in infants after noncardiac surgery. Disturbances in cerebral perfusion as a result of systemic hypotension and impaired autoregulation may be a potential cause. Our aim was to study cerebral blood flow (CBF) velocity continuously during general anaesthesia in infants undergoing noncardiac surgery and compare variations in CBF velocity with simultaneously measured near-infrared spectroscopy (NIRS), blood pressure, and heart rate.

Methods

NeoDoppler, a recently developed ultrasound system, was used to monitor CBF velocity via the anterior fontanelle during induction and maintenance of general anaesthesia until the start of surgery, and during recovery. NIRS, blood pressure, and heart rate were monitored simultaneously and synchronised with the NeoDoppler measurements.

Results

Thirty infants, with a median postmenstrual age at surgery of 37.6 weeks (range 28.6-60.0) were included. Compared with baseline, the trend curves showed a decrease in CBF velocity during induction and maintenance of anaesthesia and returned to baseline values during recovery. End-diastolic velocity decreased in all infants during anaesthesia, on average by 59%, whereas peak systolic- and time-averaged velocities decreased by 26% and 45%, respectively. In comparison, the reduction in mean arterial pressure was only 20%. NIRS values were high and remained stable. When adjusting for mean arterial pressure, the significant decrease in end-diastolic velocity persisted, whereas there was only a small reduction in peak systolic velocity.

Conclusions

Continuous monitoring of CBF velocity using NeoDoppler during anaesthesia is feasible and may provide valuable information about cerebral perfusion contributing to a more targeted haemodynamic management in anaesthetised infants.

Comparison of cerebral oxygen desaturation events between children under general anesthesia and chloral hydrate sedation - a randomized controlled trial

BACKGROUND

During pediatric general anesthesia (GA) and sedation, clinicians aim to maintain physiological parameters within normal ranges. Accordingly, regional cerebral oxygen saturation (rScO₂) should not drop below preintervention baselines. Our study compared rScO₂ desaturation events in children undergoing GA or chloral hydrate sedation (CHS).

METHODS

Ninety-two children undergoing long auditory assessments were randomly assigned to two study arms: CHS (n = 40) and GA (n = 52). Data of 81 children (mean age 13.8 months, range 1-36 months) were analyzed. In the GA group, we followed a predefined 10 N concept (no fear, no pain, normovolemia, normotension, normocardia, normoxemia, normocapnia, normonatremia, normoglycemia, and normothermia). In this group, ENT surgeons performed minor interventions in 29 patients based on intraprocedural microscopic ear examinations. In the CHS group, recommendations for monitoring and treatment of children undergoing moderate sedation were met. Furthermore, children received a double-barreled nasal oxygen cannula to measure end-tidal carbon dioxide (etCO₂) and allow oxygen administration. Chloral hydrate was administered in the parent's presence. Children had no intravenous access which is an advantage of sedation techniques. In both groups, recommendations for fasting were followed and an experienced anesthesiologist was present during the entire procedure. Adverse event (AE) was a decline in cerebral oxygenation to below 50% or below 20% from the baseline for ≥1 min. The primary endpoint was the number of children with AE across the study arms. Secondary variables were: fraction of inspired oxygen (F_IO₂), oxygen saturation (S_pO₂), etCO₂, systolic and mean blood pressure (BP), and heart rate (HR); these variables were analyzed for their association with drop in rScO₂ to below baseline (%drop_rScO₂).

RESULTS

The incidence of AE across groups was not different. The analysis of secondary endpoints showed evidence that %drop_rScO₂ is more dependent on HR and F_IO₂ than on BP and etCO₂.

CONCLUSIONS

This study highlights the strong association between HR and rScO2 in children aged < 3 years, whereas previous studies had primarily discussed the role of BP and etCO₂. Prompt HR correction may result in shorter periods of cerebral desaturation.

TRIAL REGISTRATION

The study was retrospectively registered with the German Clinical Trials Registry (DRKS00024362, 04/02/2021).

Use of combined cerebral and somatic renal near infrared spectroscopy during noncardiac surgery in children: a proposed algorithm

Cerebral near infrared spectroscopy (NIRS) monitoring has been extensively applied in neonatology and in cardiac surgery, becoming a standard in many pediatric cardiac centers. However, compensatory physiological mechanisms favor cerebral perfusion to the detriment of peripheral tissue oxygenation. Therefore, simultaneous measurement of cerebral and somatic oxygen saturation has been advocated to ease the differential diagnosis between central and peripheral sources of hypoperfusion, which may go undetected by standard monitoring and not mirrored by cerebral NIRS alone. A clinical algorithm already exists in cardiac surgery, aimed to correct intraoperative cerebral oxygen desaturations. A similar algorithm still lacks in noncardiac pediatric surgery. The goal of this paper is to propose a clinical algorithm for the combined use of cerebral and somatic NIRS monitoring during anesthesia in the pediatric population undergoing noncardiac surgery. A panel of experienced pediatric anesthetists developed the algorithm that is based on the clinical experience and intraoperative observations. It aims to lessen the current variability in interpreting NIRS measurement. Multisite NIRS monitoring was achieved applying one pediatric sensor to the forehead for cerebral tissue perfusion reading and a second one to the decumbent lumbar region for recording somatic renal tissue perfusion. The algorithm describes a sequence of acts aimed to identify the putative cause of intraoperative organ tissue desaturation and suggests clinical interventions expected to restore adequate tissue perfusion. It is composed of two arms: the main arm includes patients with an observed decrease in cerebral perfusion (CrO2), the second one includes those with a stable CrSO2 with declining RrSO2. Described also are five clinical cases of infants and neonates in whom pathological alterations of organ perfusion were detected using intraoperative multisite NIRS monitoring, portrayed in the accompanying figures (Annex).

Special Anaesthetic Considerations for Brain Tumour Surgery in Children

Brain tumours are among the most common neoplasm in children. Therefore, paediatric anaesthesiologists face the challenge of neurosurgical interventions in all age groups. To minimize perioperative mortality and morbidity, a comprehensive understanding of age-dependent differences in anatomy and cerebrovascular physiology is a mandatory prerequisite. Advances in subspeciality training in paediatric neurosurgery and paediatric anaesthesia may improve clinical outcomes and advance communication between the teams.

[Fetal and pediatric cardiovascular physiology : Things you should know as an (pediatric) anesthesiologist]

Immediately after birth the physiology of the cardiovascular system of the neonate undergoes some significant changes. The first breaths in life and the inflation of the lungs lead to a considerable drop in pulmonary arterial resistance. This results in the closure of the foramen ovale and ductus arteriosus; however, during the first weeks of life a sharp rise in pulmonary vascular resistance caused by hypoxia, hypercapnia and excessive positive pressure ventilation can lead to the reopening of the ductus arteriosus. This may result in subsequent strain of the left heart. In order to anticipate the reopening of the ductus arteriosus, it is recommended to measure the saturation of peripheral oxygen not only preductal (right hand), but also postductal (feet).An excessive volume therapy should be avoided as the neonatal myocardium is hallmarked by low cardiac compliance, reduced contractility and reduced ventricular filling.Until now there is still no uniform definition of hypotension in pediatric patients. Blood pressure values that are measured in awake children or are derived from the 50% age percentile values can thus only be used as approximate values. In all cases it is mandatory to recognize and consistently treat hypotension during pediatric anesthesia in order to prevent postoperative organ damage, particularly of the brain.The transcranial measurement of cerebral regional oxygen saturation (c‑rSO₂) by means of near-infrared spectroscopy (NIRS) provides valuable information about regional tissue oxygenation of the brain. This enables conclusions about the state of the multifactorial cerebral perfusion to be drawn. In this way monitoring of the hypoxia sensitive cerebral tissue can be accomplished and should be used in premature infants and neonates. When measuring a baseline in awake patients, a 20% drop of c‑rSO₂ from this baseline should be challenged and treated if necessary.

Did Age at Surgery Influence Outcome in Patients With Hirschsprung Disease? A Nationwide Cohort Study in the Netherlands

OBJECTIVES

Hirschsprung disease (HD) requires surgical resection of affected bowel, but the current evidence is inconclusive regarding the optimal age for resection. The aim of this study was to assess whether age at resection of the aganglionic segment is a determinant for surgical outcomes.

METHODS

A cross-sectional cohort study was done including all consecutive patients with HD between 1957 and 2015, aged 8 years or older (n = 830), who were treated in 1 of the 6 pediatric surgical centers in the Netherlands. Outcome measures were mortality, postoperative complications, stoma rate and redo surgery rate, retrieved from the medical records. Additionally, constipation and fecal incontinence rate in long term were assessed with the Defecation and Continence Questionnaire (DeFeC and P-DeFeC).

RESULTS

The medical records of 830 patients were reviewed, and 346 of the 619 eligible patients responded to the follow-up questionnaires (56%). There was a small increase in the risk of a permanent stoma [odds ratio (OR) 1.01 (95% confidence interval {CI}: 1.00-1.02); P = 0.019] and a temporary stoma [OR 1.01 (95% CI: 1.00-1.01); P = 0.022] with increasing age at surgery, regardless of the length of the aganglionic segment and operation technique. Both adjusted and unadjusted for operation technique, length of disease, and temporary stoma, age at surgery was not associated with the probability and the severity of constipation and fecal incontinence in long term.

CONCLUSIONS

In this study, we found no evidence that the age at surgery influences surgical outcomes, thus no optimal timing for surgery for HD could be determined.

[Perioperative Complications in Pediatric Anesthesia]

Perioperative complications are more frequent in younger children, especially under the age of 3 years and in infants. The anatomy and physiology of children cause more respiratory adverse events compared to adult patients. Respiratory adverse events account for 60% of all anesthetic complications. Main risk factors for respiratory adverse events are upper respiratory tract infections. Keeping the airway management as noninvasive as possible helps prevent major complications.Perioperative hypotension can compromise cerebral oxygenation, especially when hypocapnia and anemia are present. Congenital heart disease leads to a higher cardiovascular adverse event rate and should be diagnosed preoperatively whenever possible.Venous and arterial cannulation is more challenging in children and complications are more frequent even for experienced practitioners. Ultrasound is an essential tool for peripheral venous access as well as for central venous catheterization.Medication errors are more common in pediatric than in adult patients. Charts and electronic calculation of dosing can increase safety of prescriptions. Standardized storage of medications at all workplaces, avoiding look-alike medications in the same compartment and storing high-risk medications separately help prevent substitution errors.Emergence delirium and postoperative nausea and vomiting (PONV) are the most frequent postoperative adverse events. For diagnosing emergence delirium, the PAED scale is a helpful tool. Prevention of emergence delirium by pharmacological and general measures plays a key role for patient outcome. Routine prophylaxis of PONV above the age of 3 years is recommended.Frequency and severity of perioperative adverse events in pediatric anesthesia can be reduced by using algorithms and defined processes to allow for structured actions. Efficient communication and organization are mainstays for utilizing all medical options to reduce the risk of complications.

After nectarine: how should we provide anesthesia for neonates?

PURPOSE OF REVIEW

Neonates have a high risk of perioperative morbidity and mortality. The NEonate and Children audiT of Anaesthesia pRactice IN Europe (NECTARINE) investigated the anesthesia practice, complications and perioperative morbidity and mortality in neonates and infants <60 weeks post menstrual age requiring anesthesia across 165 European hospitals. The goal of this review is to highlight recent publications in the context of the NECTARINE findings and subsequent changes in clinical practice.

RECENT FINDINGS

A perioperative triad of hypoxia, anemia, and hypotension is associated with an increased overall mortality at 30 days. Hypoxia is frequent at induction and during maintenance of anesthesia and is commonly addressed once oxygen saturation fall below 85%.Blood transfusion practices vary widely variable among anesthesiologists and blood pressure is only a poor surrogate of tissue perfusion. Newer technologies, whereas acknowledging important limitations, may represent the currently best tools available to monitor tissue perfusion. Harmonization of pediatric anesthesia education and training, development of evidence-based practice guidelines, and provision of centralized care appear to be paramount as well as pediatric center referrals and international data collection networks.

SUMMARY

The NECTARINE provided new insights into European neonatal anesthesia practice and subsequent morbidity and mortality.Maintenance of physiological homeostasis, optimization of oxygen delivery by avoiding the triad of hypotension, hypoxia, and anemia are the main factors to reduce morbidity and mortality. Underlying and preexisting conditions such as prematurity, congenital abnormalities carry high risk of morbidity and mortality and require specialist care in pediatric referral centers.

Validation of a new combined transcutaneous tcPCO2 and tcPO2 sensor in children in the operating theater

BACKGROUND

Arterial blood gas analysis is the gold standard for monitoring of P_a CO₂ and PaO₂ during mechanical ventilation. However, continuous measurements would be preferred. Transcutaneous sensors continuously measure blood gases diffusing from the locally heated skin. These sensors have been validated in children mostly in intensive care settings. Accuracy in children during general anesthesia is largely unknown.

AIMS

We conducted a study in children undergoing general anesthesia to validate the use and to determine the accuracy of continuous transcutaneous measurements of the partial pressures of PCO₂ (tcPCO₂ ) and PO₂ (tcPO₂ ).

METHODS

A prospective observational study in a tertiary care pediatric hospital in The Netherlands, from April to October 2018, in children aged 0-18 years undergoing general anesthesia. Patients were included when endotracheally intubated and provided with an arterial catheter for regular blood sampling. Patients with a gestational age <31 weeks, burn victims, and patients with skin disease were excluded. TcPCO₂ and tcPO₂  measurements were performed with a SenTec OxiVenT^™ sensor (SenTec AG). Accuracy was determined with an agreement analysis between arterial and transcutaneous PCO₂ and PO₂  values, and between arterial and endtidal PCO₂ (etCO₂ ) values, according to Bland and Altman, accounting for multiple measurements per subject.

RESULTS

We included 53 patients (median age 4.1 years, IQR 0.7-14.4 years) and retrieved 175 samples. TcPCO₂ -P_a CO₂ agreement analysis provided a bias of 0.06 kPa (limits of agreement (LOA) -1.18 to 1.31), the etCO₂ -P_a CO₂ agreement showed a bias of -0.31 kPa (LOA -1.38 to 0.76). Results of the tcPO₂ -PaO₂ agreement showed a bias of 3.40 to 0.86* (mean tension) kPa.

CONCLUSIONS

This study showed good agreement between P_a CO₂ and tcPCO₂ in children of all ages during general anesthesia. Both transcutaneous and endtidal CO₂  measurements showed good accuracy. TcPO₂ is only accurate under 6 months of age.

Modes of ventilation for pediatric patients under anesthesia: A Pro/Con conversation

The development of sophisticated modes of ventilation for pediatric patients undergoing anesthesia is ongoing; what remains a challenge for the pediatric anesthesiologist is thoughtful selection of the mode(s) of ventilation for a particular patient in the context of the surgical procedure and the goals of the anesthetic. This article provides some historical accounting of a variety of modes of ventilation, defines the terminology of modern ventilatory modes, and reviews in detail the benefits and pitfalls of the specific modes of ventilation and their applicability to the practice of pediatric anesthesiology. In an attempt to debate the Pros and Cons of different modes of ventilation, and to finally resolve the debate "spontaneous vs. controlled ventilation," we share with you a thoughtful conversation of the continuum of modes of ventilation and their applicability to our pediatric anesthesia population.

Blood pressure and flow in pediatric anesthesia: An educational review

During recent years, a lot of interest has been focused on blood pressure in the context of pediatric anesthesia, trying to define what is normal in relation to age and what numeric values that should be regarded as hypotension, needing active intervention. However, blood pressure is mainly measured as a proxy for flow, that is, cardiac output. Thus, just focusing on specific blood pressure numbers may not necessarily be very useful or appropriate. The aim of this educational review is to put the issue of intraoperative blood pressure in the context of pediatric anesthesia in further perspective.

Long-term neurodevelopmental effects of intraoperative blood pressure during surgical closure of a septal defect in infancy or early childhood

BACKGROUND

Many children born with congenital heart defects are faced with cognitive deficits and psychological challenges later in life. The mechanisms behind are suggested to be multifactorial and are explained as an interplay between innate and modifiable risk factors. The aim was to assess whether there is a relationship between mean arterial pressure during surgery of a septal defect in infancy or early childhood and intelligence quotient scores in adulthood.

METHODS

In a retrospective study, patients were included if they underwent surgical closure of a ventricular septal defect or an atrial septal defect in childhood between 1988 and 2002. Every patient completed an intelligence assessment upon inclusion, 14-27 years after surgery, using the Wechsler Adult Intelligence Scale Version IV.

RESULTS

A total of 58 patients met the eligibility criteria and were included in the analyses. No statistically significant correlation was found between blood pressure during cardiopulmonary bypass and intelligence quotient scores in adulthood (r = 0.138; 95% CI-0.133-0.389). Although amongst patients with mean arterial pressure < 40 mmHg during cardiopulmonary bypass, intelligence quotient scores were significantly lower (91.4; 95% CI 86.9-95.9) compared to those with mean arterial pressure > 40 mmHg (99.8; 95% CI 94.7-104.9).

CONCLUSIONS

Mean arterial pressure during surgery of ventricular septal defects or atrial septal defects in childhood does not correlate linearly with intelligence quotient scores in adulthood. Although there may exist a specific cut-off value at which low blood pressure becomes harmful. Larger studies are warranted in order to confirm this, as it holds the potential of partly relieving CHD patients of their cognitive deficits.

Associations of perioperative characteristics with motor function in preschool children born with esophageal atresia

BACKGROUND

Children born with esophageal atresia experience long-term neurodevelopmental deficits, with unknown origin.

AIMS

To find associations between perioperative variables during primary esophageal atresia repair and motor function at age 5 years.

METHODS

This ambidirectional cohort study included children born with esophageal atresia who consecutively had been operated on in the Erasmus MC-Sophia Children's Hospital, University Medical Center, Rotterdam, from January 2007 through June 2013. The perioperative data of this cohort were collected retrospectively; the motor function data prospectively.

RESULTS

After exclusion of patients with syndromal congenital diseases (n = 8) and lost to follow-up (n = 10), the data of 53 children were included. The mean (SD) total motor function impairment z-score at 5 years of age was -0.66 (0.99), significantly below normal (p < .001). In multivariable linear regression analysis, number of postoperative days endotracheal intubation (B = -0.211, 95% CI: -0.389 to -0.033, p = .021) was negatively associated with motor outcome, whereas high blood pressure (B = 0.022, 95% CI 0.001 to 0.042, p = .038) was positively associated. Preoperative nasal oxygen supplementation versus room air (B = 0.706, 95% CI: 0.132 to 1.280, p = .016) was positively associated with motor outcome, which we cannot explain.

CONCLUSIONS

Motor function in 5-year-old esophageal atresia patients was impaired and negatively associated with the number of postoperative days of endotracheal intubation and positively associated with high blood pressure. Prospective studies with critical perioperative monitoring and monitoring during stay at the intensive care unit are recommended.

Cerebral Oxygenation by Near-Infrared Spectroscopy in Infants Undergoing Thoracoscopic Lung Resection

Background: Thoracoscopic resection is the standard of care for congenital lung malformations (CLMs) in infants. However, there is rising concern that capnothorax may affect cerebral perfusion and oxygenation, carrying potential long-term effects on neurodevelopmental behavior. The aim of our study was to investigate, using near-infrared spectroscopy (NIRS), the regional cerebral oxygenation (CrSO₂) in infants undergoing thoracoscopic lung resection; the secondary aim was to assess the relationship between rSO₂ and standard monitoring. Methods: In this retrospective study, we reviewed all infants (<1 year old, ASA II) who underwent thoracoscopic CLM resection in double-lung ventilation under fixed capnothorax parameters (5 mmHg of pressure, 1 L/minute flow), standardized anesthetic protocol, standard monitoring, and multisite NIRS in our center. We focused our attention on 8 anesthetic and surgical maneuvers, potentially affecting tissue oxygen saturation. Results: Ten infants met the inclusion criteria. At surgery, median age was 5.5 (4-7) months, median weight 7.2 (6.6-8) kg, median operative time 110 (55-180) minutes, and median capnothorax duration 79 (34-168) minutes. No conversion to open surgery occurred. CrSO₂ values remained within clinically accepted values during thoracoscopy, beside a CrSO₂ drop >20% of basal value in 1 patient, during capnothorax induction. Renal NIRS added very little to standard monitoring, which appeared generally inadequate to consistently appraise end-organ perfusion. ETCO₂ best correlated with CrSO₂ variations, suggesting to be able to realistically predict them. Conclusions: The thoracoscopic treatment of CLMs under the given conditions appears well tolerated in infants, pending the continuous adjustment of ventilator settings by an experienced anesthetist, confident with NIRS technology.

Applications and Limitations of Neuro-Monitoring in Paediatric Anaesthesia and Intravenous Anaesthesia: A Narrative Review

Safe management of anaesthesia in children has been one of the top areas of research over the last decade. After the large volume of articles which focused on the putative neurotoxic effect of anaesthetic agents on the developing brain, the attention and research efforts shifted toward prevention and treatment of critical events and the importance of peri-anaesthetic haemodynamic stability to prevent negative neurological outcomes. Safetots.org is an international initiative aiming at raising the attention on the relevance of a high-quality anaesthesia in children undergoing surgical and non-surgical procedures to guarantee a favourable outcome. Children might experience hemodynamic instability for many reasons, and how the range of normality within brain autoregulation is maintained is still unknown. Neuro-monitoring can guide anaesthesia providers in delivering optimal anaesthetic drugs dosages and also correcting underling conditions that can negatively affect the neurological outcome. In particular, it is referred to EEG-based monitoring and monitoring for brain oxygenation.

Effect of hemoglobin content on cerebral oxygen saturation during surgery for scoliosis in pediatric patients

BACKGROUND

Although regional cerebral oxygen saturation (rScO₂) monitoring has been widely used in clinical practice, the relationship between hemoglobin (dHB) content and rScO₂ is incompletely understood. The aim of this study was to analyze the effect of hemoglobin content on rScO₂ in pediatric patients undergoing general anesthesia for correction of scoliosis.

METHODS

Ninety-two pediatric patients aged 3 to 14 years undergoing scoliosis correction surgery were enrolled. Continuous monitoring of bilateral regional cerebral oxygen saturation by near-infrared spectroscopy (NIRS, CASMED, USA) was performed after entering the operation room. rScO₂ was recorded when the patients entered the operating room (T₀, baseline), after anesthesia induced intubation (T₁), and after radial artery puncture (T₂). The lowest value of rScO₂ during surgery was also recorded. The arterial blood pressure (ABP), heart rate (HR), pulse oxygen saturation (SpO₂), end tidal carbon dioxide partial pressure (PetCO₂) were continuously recorded. Patients were classified as low rScO₂ or high rScO₂ group according to whether the lowest intraoperative rScO₂ was 15% lower than the baseline value. An analysis and comparison of differences in hemoglobin content in these two groups was carried out.

RESULTS

The preoperative hemoglobin-postoperative hemoglobin of patients in the high rScO₂ group was significantly lower than that in the low rScO₂ group (t = - 7.86, p < 0.01), the amount of bleeding during the operation was also less than that in the low rScO₂ group (t = - 6.05, p < 0.01), and the systolic pressure of patients was higher than that in the low rScO₂ group (t = 4.27, p < 0.01).

CONCLUSIONS

The decrease in hemoglobin level which occurs during surgery leads to a decrease in cerebral oxygen saturation. In order to ensure patient safety during surgery, it is necessary to carry out volume management and appropriate transfusion and fluid replacement in a timely manner.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1800016359 . Registered 28 May 2018.

Morbidity and mortality after anaesthesia in early life: results of the European prospective multicentre observational study, neonate and children audit of anaesthesia practice in Europe (NECTARINE)

BACKGROUND

Neonates and infants requiring anaesthesia are at risk of physiological instability and complications, but triggers for peri-anaesthetic interventions and associations with subsequent outcome are unknown.

METHODS

This prospective, observational study recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. The primary aim was to identify thresholds of pre-determined physiological variables that triggered a medical intervention. The secondary aims were to evaluate morbidities, mortality at 30 and 90 days, or both, and associations with critical events.

RESULTS

Infants (n=5609) born at mean (standard deviation [sd]) 36.2 (4.4) weeks postmenstrual age (35.7% preterm) underwent 6542 procedures within 63 (48) days of birth. Critical event(s) requiring intervention occurred in 35.2% of cases, mainly hypotension (>30% decrease in blood pressure) or reduced oxygenation (SpO₂ <85%). Postmenstrual age influenced the incidence and thresholds for intervention. Risk of critical events was increased by prior neonatal medical conditions, congenital anomalies, or both (relative risk [RR]=1.16; 95% confidence interval [CI], 1.04-1.28) and in those requiring preoperative intensive support (RR=1.27; 95% CI, 1.15-1.41). Additional complications occurred in 16.3% of patients by 30 days, and overall 90-day mortality was 3.2% (95% CI, 2.7-3.7%). Co-occurrence of intraoperative hypotension, hypoxaemia, and anaemia was associated with increased risk of morbidity (RR=3.56; 95% CI, 1.64-7.71) and mortality (RR=19.80; 95% CI, 5.87-66.7).

CONCLUSIONS

Variability in physiological thresholds that triggered an intervention, and the impact of poor tissue oxygenation on patient's outcome, highlight the need for more standardised perioperative management guidelines for neonates and infants.

CLINICAL TRIAL REGISTRATION

NCT02350348.

Hypotension and adverse neurodevelopmental outcomes among children with multiple exposures to general anesthesia: Subanalysis of the Mayo Anesthesia Safety in Kids (MASK) Study

BACKGROUND

The potential adverse effects of exposures to general anesthesia on the developing human brain remain controversial. It has been hypothesized that hypotension accompanying anesthesia could be contributory. We hypothesized that among children exposed to multiple anesthetics prior to age 3, children developing adverse neurodevelopmental outcomes would be more likely to have intraoperative hypotension.

METHODS

Two previously published study cohorts were utilized for analysis: the retrospective and prospective Mayo Anesthesia Safety in Kids cohorts. The two lowest consecutive systolic blood pressure measurements were abstracted and standardized by calculating a z-score for noninvasive blood pressure reference ranges for children. The lowest systolic blood pressure z-score (continuous variable) and intraoperative hypotension (lowest systolic blood pressure z-score <-1.0) were used to assess the association of intraoperative hypotension with the incidence of learning disabilities or attention-deficit/hyperactivity disorder(retrospective cohort) and factor scores/cluster membership (prospective cohort).

RESULTS

One hunderd and sixteen and 206 children with multiple exposures to general anesthesia were analyzed in the retrospective and prospective cohorts with mean lowest systolic blood pressure z-scores -0.26 (SD 1.02) and -0.62 (SD 1.10), respectively. There was no overall association of the lowest z-score or hypotension with learning disabilities or attention-deficit/hyperactivity disorder in the retrospective cohort. In the prospective cohort, there was no overall association of the lowest systolic blood pressure or hypotension with factor scores or cluster membership.

CONCLUSIONS

We did not find evidence to support the hypothesis that, among children exposed to multiple anesthetics prior to age 3, children developing adverse neurodevelopmental outcomes would be more likely to have intraoperative hypotension compared with those who did not.

Bevacizumab and neurodevelopmental outcomes of preterm infants with retinopathy of prematurity: should we still worry?

AIM

Bevacizumab may affect preterm infants' ongoing organogenesis with its antiangiogenic effects. We aimed to compare neurodevelopmental outcomes (NDO) of preterm infants treated for retinopathy of prematurity (ROP) with laser photocoagulation (LP), intravitreal bevacizumab (IVB) or both treatments, and to find out the effects of IVB on NDO.

METHODS

Medical records of preterm infants with ROP treatment and evaluation for NDO were retrospectively collected between 1 January 2017 and 31 June 2019. Primary outcome was Bayley Scales of Infant and Toddler Development 3rd Edition (Bayley-III) scores including cognitive, language, and motor scores. Secondary outcomes were neurodevelopmental impairments (NDIs) classified as the presence of any of cerebral palsy (CP), sensorineural/mixed hearing loss, visual impairment, and developmental delay with any Bayley-III score <85. Severe NDI (sNDI) was defined as presence of any of CP with a Gross Motor Function Classification Scale of 3, 4, or 5, requirement for hearing aids or cochlear implants, bilateral visual impairment or severe developmental delay with any Bayley-III score <70.

RESULTS

LP, IVB, and IVB + LP groups included 32, 12, and 10 patients, respectively. Patent ductus arteriosus treatment rates were as 68.7, 75, and 90% in groups, respectively (p<.05 between LP and IVB + LP groups). Grades 3 and 4 intraventricular hemorrhage (IVH) was lower in LP group than IVB group (9.4% vs. 33.4%, p<.05) while IVB + LP group had no grades 3 and 4 IVH. Other neonatal characteristics were similar (p > .05). CP was in 50%, 28%, and 0% of LP, IVB, and IVB + LP groups (p<.05). There was no difference in median Bayley-III cognitive, language, and motor scores between groups (p > .05). Moderate and severe developmental delays were similar between groups (p > .05) whereas IVB group had more moderate cognitive delay; and more severe cognitive, language, and motor delay. NDI rate was not different (59.3%, 50%, and 40% in groups, p > .05). sNDI was highest in IVB group but not statistically significant (31.2, 41.7, and 10% in groups, p > .05). Multiple logistic regression analysis showed that ROP treatment type and grades 3 and 4 IVH did not have any significant effect on NDO (p > .05). Odds of NDI was not effected by ROP treatment type (p > .05).

CONCLUSIONS

Patients treated with bevacizumab should be carefully monitored for neurodevelopmental problems, although the frequency of grades 3 and 4 IVH in the bevacizumab group is thought to contribute to higher rates of sNDI and Bayley-III score <70.

Feasibility of Doppler Ultrasound for Cortical Cerebral Blood Flow Velocity Monitoring During Major Non-cardiac Surgery of Newborns

Background and Aim: Newborns needing major surgical intervention are at risk of brain injury and impaired neurodevelopment later in life. Disturbance of cerebral perfusion might be an underlying factor. This study investigates the feasibility of serial transfontanellar ultrasound measurements of the pial arteries during neonatal surgery, and whether perioperative changes in cerebral perfusion can be observed and related to changes in the perioperative management. Methods: In this prospective, observational feasibility study, neonates with congenital diaphragmatic hernia and esophageal atresia scheduled for surgical treatment within the first 28 days of life were eligible for inclusion. We performed transfontanellar directional power Doppler and pulsed wave Doppler ultrasound during major high-risk non-cardiac neonatal surgery. Pial arteries were of interest for the measurements. Extracted Doppler ultrasound parameters were: peak systolic velocity, end diastolic velocity, the resistivity index and pulsatility index. Results: In 10 out of 14 patients it was possible to perform perioperative measurements; the others failed for logistic and technical reasons. In 6 out of 10 patients, it was feasible to perform serial intraoperative transfontanellar ultrasound measurements with directional power Doppler and pulsed wave Doppler of the same pial artery during neonatal surgery. Median peak systolic velocity was ranging between 5.7 and 7.0 cm s^-1 and end diastolic velocity between 1.9 and 3.2 cm s^-1. In patients with a vasoactive-inotropic score below 12 the trend of peak systolic velocity and end diastolic velocity corresponded with the mean arterial blood pressure trend. Conclusion: Perioperative transfontanellar ultrasound Doppler measurements of the pial arteries are feasible and provide new longitudinal data about perioperative cortical cerebral blood flow velocity. Trial Registration: https://www.trialregister.nl/trial/6972, identifier: NL6972.

Cerebral Oxygenation and Activity During Surgical Repair of Neonates With Congenital Diaphragmatic Hernia: A Center Comparison Analysis

Background and aim: Neonatal brain monitoring is increasingly used due to reports of brain injury perioperatively. Little is known about the effect of sedatives (midazolam) and anesthetics (sevoflurane) on cerebral oxygenation (rScO₂) and cerebral activity. This study aims to determine these effects in the perioperative period. Methods: This is an observational, prospective study in two tertiary pediatric surgical centers. All neonates with a congenital diaphragmatic hernia received perioperative cerebral oxygenation and activity measurements. Patients were stratified based on intraoperatively administrated medication: the sevoflurane group (continuous sevoflurane, bolus fentanyl, bolus rocuronium) and the midazolam group (continuous midazolam, continuous fentanyl, and continuous vecuronium). Results: Intraoperatively, rScO₂ was higher in the sevoflurane compared to the midazolam group (84%, IQR 77-95 vs. 65%, IQR 59-76, p = < 0.001), fractional tissue oxygen extraction was lower (14%, IQR 5-21 vs. 31%, IQR 29-40, p = < 0.001), the duration of hypoxia was shorter (2%, IQR 0.4-9.6 vs. 38.6%, IQR 4.9-70, p = 0.023), and cerebral activity decreased more: slow delta: 2.16 vs. 4.35 μV ² (p = 0.0049), fast delta: 0.73 vs. 1.37 μV ² (p = < 0.001). In the first 30 min of the surgical procedure, a 3-fold increase in fast delta (10.48-31.22 μV ²) and a 5-fold increase in gamma (1.42-7.58 μV ²) were observed in the midazolam group. Conclusion: Sevoflurane-based anesthesia resulted in increased cerebral oxygenation and decreased cerebral activity, suggesting adequate anesthesia. Midazolam-based anesthesia in neonates with a more severe CDH led to alarmingly low rScO₂ values, below hypoxia threshold, and increased values of EEG power during the first 30 min of surgery. This might indicate conscious experience of pain. Integrating population-pharmacokinetic models and multimodal neuromonitoring are needed for personalized pharmacotherapy in these vulnerable patients. Trial Registration: https://www.trialregister.nl/trial/6972, identifier: NL6972.

Current state of noninvasive, continuous monitoring modalities in pediatric anesthesiology

PURPOSE OF REVIEW

The last decades, anesthesia has become safer, partly due to developments in monitoring. Advanced monitoring of children under anesthesia is challenging, due to lack of evidence, validity and size constraints. Most measured parameters are proxies for end organ function, in which an anesthesiologist is actually interested. Ideally, monitoring should be continuous, noninvasive and accurate. This present review summarizes the current literature on noninvasive monitoring in noncardiac pediatric anesthesia.

RECENT FINDINGS

For cardiac output (CO) monitoring, bolus thermodilution is still considered the gold standard. New noninvasive techniques based on bioimpedance and pulse contour analysis are promising, but require more refining in accuracy of CO values in children. Near-infrared spectroscopy is most commonly used in cardiac surgery despite there being no consensus on safety margins. Its place in noncardiac anesthesia has yet to be determined. Transcutaneous measurements of blood gases are used mainly in the neonatal intensive care unit, and is finding its way to the pediatric operation theatre. Especially CO2 measurements are accurate and useful.

SUMMARY

New techniques are available to assess a child's hemodynamic and respiratory status while under anesthesia. These new monitors can be used as complementary tools together with standard monitoring in children, to further improve perioperative safety.

[Near-infrared spectroscopy : Technique, development, current use and perspectives]

Near-infrared spectroscopy (NIRS) has been available in research and clinical practice for more than four decades. Recently, there have been numerous publications and substantial developments in the field. This article describes the clinical application of NIRS in relation to current guidelines, with a focus on pediatric and cardiac anesthesia. It discusses technical and physiological principles, pitfalls in clinical use and presents (patho)physiological influencing factors and derived variables, such as fractional oxygen extraction (FOE) and the cerebral oxygen index (COx). Recommendations for the interpretation of NIRS values in connection with influencing factors, such as oxygen transport capacity, gas exchange and circulation as well as an algorithm for cardiac anesthesia are presented. Limitations of the method and the lack of comparability of values from different devices as well as generally accepted standard values are explained. Technical differences and advantages compared to pulse oxymetry and transcranial Doppler sonography are illuminated. Finally, the prognostic significance and requirements for future clinical studies are discussed.

Effects of moderate and severe hypocapnia on intracerebral perfusion and brain tissue oxygenation in piglets

BACKGROUND

Hypocapnia is a common alteration during anesthesia in neonates.

AIM

To investigate the effects of hypocapnia and hypocapnia combined with hypotension (HCT) on cerebral perfusion and tissue oxygenation in anesthetized piglets.

METHOD

Thirty anesthetized piglets were randomly allocated to groups: moderate hypocapnia (mHC), severe hypocapnia (sHC), and HCT. Cerebral monitoring comprised a tissue oxygen partial pressure and a laser Doppler probe inserted into the brain tissue as well as a near-infrared spectroscopy (NIRS) sensor placed on the skin, measuring regional oxygen saturation. Hypocapnia was induced by hyperventilation (target PaCO₂ mHC: 3.7-4; sHC: 3.1-3.3 kPa) and hypotension by blood withdrawal and nitroprusside infusion (mean blood pressure: 35-38 mm Hg). Data were analyzed at baseline, during (Tr20, Tr40, Tr60) and after (Post20, Post40, Post60) treatment.

RESULTS

Compared to baseline, tissue oxygen partial pressure decreased significantly and equally during all treatments (mean [SD] at baseline: mHC 35.7 [32.45]; sHC: 28.1 [20.24]; HCT 25.4 [10.3] and at Tr60: mHC: 29.9 [27.36]; sHC: 22.2 [18.37]; HCT: 18.4 [9.5] mm Hg). Decreased laser Doppler flow was detected with all treatments at Tr20 (mHC: 0.9 [0.18]; sHC: 0.88 [0.15]; HCT: 0.97 [0.13] proportion from baseline). Independently of group, regional oxygen saturation varied only after reverting and not during treatment. Blood lactate, pH, HCO₃^- , and PaO₂ increased during treatment with no differences between groups.

CONCLUSION

This animal model revealed reduced cerebral blood flow and brain tissue oxygenation during hypocapnia without detectable changes in regional oxygen saturation as measured by NIRS. Changes occurred as early as during moderate hypocapnia.

A practical approach to cerebral near-infrared spectroscopy (NIRS) directed hemodynamic management in noncardiac pediatric anesthesia

Safeguarding cerebral function is of major importance during pediatric anesthesia. Premature, ex-premature, and full-term neonates can be vulnerable to physiological changes that occur during anesthesia and surgery. Data from studies performed during pediatric cardiac surgery and in neonatal/pediatric intensive care units have shown the benefits of near-infrared spectroscopy (NIRS) monitoring of regional cerebral oxygenation (c-rSO₂ ). However, NIRS monitoring is seldom used during noncardiac pediatric anesthesia. Despite compelling evidence that blood pressure does not reflect end-organ perfusion, it is still regarded as the most important determinant of cerebral perfusion and the most relevant hemodynamic management target parameter by most (pediatric) anesthetists. The principle of NIRS monitoring is not self-explanatory and sometimes seems even counterintuitive, which may explain why many anesthesiologists are reserved regarding its use. The first part of this paper is dedicated to a clinical introduction to NIRS monitoring. Despite scientific efforts, it has not yet been possible to define individual lower limit c-rSO₂ values and it is unlikely this will succeed in the near future. Nonetheless, published treatment algorithms usually specify c-rSO₂ values which may be associated with cerebral hypoxia. Our treatment guideline for maintaining sufficient cerebral oxygenation differs fundamentally from all previously published approaches. We define a baseline c-rSO₂ value, registered in the awake child prior to anesthesia induction, as the lowest acceptable limit during anesthesia and surgery. The cerebral rSO₂ is the single target parameter, while blood pressure, heart rate, P_a CO₂ , and SaO₂ are major parameters that determine the c-rSO2. Cerebral NIRS monitoring, interpreted together with its continuously available contributing parameters, may help avoid potentially harmful episodes of cerebral desaturation in anesthetized pediatric patients.

Perioperative Factors Affecting Neurologic Outcome in Infants Undergoing Surgery for Intracranial Lesion: A Retrospective Study

BACKGROUND

The short-term neurologic outcome of infants undergoing brain tumor surgery depends on various perioperative factors. This study was undertaken to analyze the effects of perioperative variables on the postoperative neurologic outcome in infants undergoing brain tumor surgery.

METHODS

We retrospectively reviewed the chart of infants undergoing craniotomy for brain tumor removal from 2000 to 2017. The data related to preoperative variables, intraoperative management details, and postoperative factors were collected and analyzed. The primary outcome measure was occurrence of new postoperative neurologic deficit (POND) and the secondary outcome measure was length of hospital stay (LOHS).

RESULTS

Complete data were available for 40 infants undergoing craniotomy for excision of intracranial tumor. New-onset POND was found in 14 infants (35%). Based on logistic regression analysis, POND was associated with use of mannitol and massive blood transfusion (MBT) trended toward significance. Based on linear regression analysis, the risk factor associated with prolonged LOHS was reintubation and POND trended toward significance.

CONCLUSIONS

In this study, factors associated with new POND were mannitol use and to a certain extent MBT. The variables associated with prolonged LOHS were reintubation and to a certain extent POND. The anesthetic technique, location of tumor, tumor histology, and extent of tumor resection did not influence the occurrence of new POND or prolonged LOHS in infantile intracranial tumor surgery. Further prospective studies with larger samples are required for confirmation of these findings and identification of new perioperative risk factors.

Spinal anaesthesia in neonates and infants: what about the cerebral oxygen saturation?

Background

Spinal Anaesthesia (SA) has been firmly established as an efficient and safe technique, with minimal cardio-respiratory disturbance when administered in the neonatal period. Our objective was to assess the haemodynamic consequences of SA in infants, particularly its impact on cerebral perfusion using near-infrared spectroscopy (NIRS)-based cerebral oximetry (rSco2).

Methods

All infants up to 60 weeks' postmenstrual age, whether formerly preterm or not, and undergoing spinal anaesthesia, were enrolled. Haemodynamic data records, rSco2 and mean arterial blood pressure (MAP), were prospectively collected before SA (T0) and every five min for 30 min (T30) after the puncture. Compared with baseline measures, any changes of > 10% in rSco2 and of > 20% in MAP were considered clinically significant. Relative variations of data between T0 and T30 were analysed.

Results

Data of 103 infants were analysed. The mean relative changes in rSco2 were -2.25% (97.5% CI [-3.97; -0.5]) at T15, and 0.11% (97.5% CI [-1.67; 1.90]) at T30. No significant variation of rSco2 was recorded. The mean changes in MAP were respectively -13.94% (97.5% CI [-17.74; -10.14]) at T15 and -20.27% (97.5% CI [-24,25; -16.29]) at T30. MAP decrease was statistically and clinically significant 30 min after SA. No correlation between changes in MAP and rSco2 was found. The subgroup analysis did not reveal any effect of added intrathecal clonidine or preterm birth history on these results.

Conclusions

In neonate and infants, SA did not cause clinically significant variation in cerebral oxygen saturation. Despite a significant decrease in MAP, cerebral auto-regulation seems to remain effective in neonates and not altered by spinal anaesthesia.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL TRIAL REGISTRATION

NCT02559102.

Dynamic changes in intramedullary pressure 72 hours after spinal cord injury

Intramedullary pressure increases after spinal cord injury, and this can be an important factor for secondary spinal cord injury. Until now there have been no studies of the dynamic changes of intramedullary pressure after spinal cord injury. In this study, telemetry systems were used to observe changes in intramedullary pressure in the 72 hours following spinal cord injury to explore its pathological mechanisms. Spinal cord injury was induced using an aneurysm clip at T10 of the spinal cord of 30 Japanese white rabbits, while another 32 animals were only subjected to laminectomy. The feasibility of this measurement was assessed. Intramedullary pressure was monitored in anesthetized and conscious animals. The dynamic changes of intramedullary pressure after spinal cord injury were divided into three stages: stage I (steep rise) 1–7 hours, stage II (steady rise) 8–38 hours, and stage III (descending) 39–72 hours. Blood-spinal barrier permeability, edema, hemorrhage, and histological results in the 72 hours following spinal cord injury were evaluated according to intramedullary pressure changes. We found that spinal cord hemorrhage was most severe at 1 hour post-spinal cord injury and then gradually decreased; albumin and aquaporin 4 immunoreactivities first increased and then decreased, peaking at 38 hours. These results confirm that severe bleeding in spinal cord tissue is the main cause of the sharp increase in intramedullary pressure in early spinal cord injury. Spinal cord edema and blood-spinal barrier destruction are important factors influencing intramedullary pressure in stages II and III of spinal cord injury.

Integrating intraoperative physiology data into outcome analysis for the ACS Pediatric National Surgical Quality Improvement Program

BACKGROUND

The Pediatric National Surgical Quality Improvement Program (P-NSQIP) samples surgical procedures for benchmarking and quality improvement. While generally comprehensive, P-NSQIP does not collect intraoperative physiologic data, despite potential impact on outcomes.

AIMS

The aims of this study were (a) to describe a methodology to augment P-NSQIP with vital signs data and (b) demonstrate its utility by exploring relationships that intraoperative hypothermia and hypotension have with P-NSQIP outcomes.

METHODS

Vital signs from 2012 to 2016 were available in a research databank. Episodes of hypotension and hypothermia were extracted and recorded alongside local P-NSQIP data. Multivariable regression analyses were performed to explore associations with undesired outcomes, including: surgical site infection, wound disruption, unplanned return to the operating room, and blood transfusion. Model variables were selected with the Akaike information criterion using 2012-2014 as the training set and validated with receiver operating characteristics analysis using 2015-2016 as the testing set.

RESULTS

Data from 6737 patients were analyzed, with 43.9% female, median [interquartile range] age 5.8 [1.3-12.4] years, undergoing procedures lasting 118 [75-193] minutes. Hypothermia, observed in 45% of cases, was associated with wound disruption (odds ratio 1.75, 95% CI 1.1-2.83). Hypotension, observed in 60% of cases, was associated with unplanned returns (odds ratio 1.58, 95% CI 1.02-2.51), and transfusions (odds ratio 1.95, 95% CI 1.14-3.52). Surgical site infection, wound disruption, unplanned return, and transfusion models had areas under the receiver operating characteristic curve of 0.69/0.67, 0.59/0.63, 0.78/0.79, and 0.92/0.93 for validation models including hypothermia/hypotension respectively.

CONCLUSION

Adding intraoperative vital signs to P-NSQIP data allowed identification of two modifiable risk factors: hypothermia was associated with increased wound disruption, and hypotension with increased blood transfusions and unplanned returns to the operating room. These findings may motivate prospective studies and prompt other centers and P-NSQIP to augment outcome data with intraoperative physiological data.

Effects of moderate and severe arterial hypotension on intracerebral perfusion and brain tissue oxygenation in piglets

BACKGROUND

Hypotension is common in anaesthetised children, and its impact on cerebral oxygenation is unknown. The goal of the present study was to investigate the effects of moderate systemic arterial hypotension (mHT) and severe hypotension (sHT) on cerebral perfusion and brain tissue oxygenation in piglets.

METHODS

Twenty-seven anaesthetised piglets were randomly allocated to a control group, mHT group, or sHT group. Cerebral monitoring comprised a tissue oxygen partial pressure ( [Formula: see text] ) and laser Doppler (LD) perfusion probe advanced into the brain tissue, and a near-infrared spectroscopy sensor placed over the skin measuring regional oxygen saturation (rSO₂). Arterial hypotension was induced by blood withdrawal and i.v. nitroprusside infusion [target MAP: 35-38 (mHT) and 27-30 (sHT) mm Hg]. Data were analysed at baseline, and every 20 min during and after treatment.

RESULTS

Compared with control, [Formula: see text] decreased equally with mHT and sHT [mean (SD) after 60 min: control: 17.1 (6.4); mHT: 6.4 (3.6); sHT: 7.2 (4.3) mm Hg]. No differences between groups were detected for rSO₂ and LD during treatment. However, in the sHT group, rSO₂ increased after restoring normotension [from 49.3 (9.5) to 58.9 (8.9)% Post60]. sHT was associated with an increase in blood lactate [from 1.5 (0.4) to 2.4 (0.9) mmol L^-1], and a decrease in bicarbonate [28 (2.4) to 25.8 (2.6) mmol L^-1] and base excess [4.7 (1.9) to 2.0 (2.7) mmol L^-1] between baseline and 60 min after the start of the experiment.

CONCLUSIONS

Induction of mHT and sHT by hypovolaemia and nitroprusside infusion caused alterations in brain tissue oxygenation in a piglet model, but without detectable changes in brain tissue perfusion and regional oxygen saturation.

Safe anesthesia for neonates, infants and children

This review provides an overview of the perioperative safety concerns in pediatric anesthesia and exploration of strategies to minimize these risks through education and training in pediatric anesthesia. There is increasing human data on the effects of general anesthesia for surgery and procedures on later neurodevelopment. However, the magnitude and relevance of this remains unclear while the long-term outcomes from recent human studies are awaited. The current known and established risks associated with pediatric anesthesia can be minimized by establishing a robust and safe conduct of anesthesia. This not only includes maintenance of normal physiological variables but also other aspects such as reduction of preoperative fear and anxiety and postoperative care. This can be achieved through effective multidisciplinary team working, cross specialty training and further development of fellowships and secondments.

Choosing Wisely in pediatric anesthesia: An interpretation from the German Scientific Working Group of Paediatric Anaesthesia (WAKKA)

Inspired by the Choosing Wisely initiative, a group of pediatric anesthesiologists representing the German Working Group on Paediatric Anaesthesia (WAKKA) coined and agreed upon 10 concise positive ("dos") or negative ("don'ts") evidence-based recommendations. (i) In infants and children with robust indications for surgical, interventional, or diagnostic procedures, anesthesia or sedation should not be avoided or delayed due to the potential neurotoxicity associated with the exposure to anesthetics. (ii) In children without relevant preexisting illnesses (ie, ASA status I/II) who are scheduled for elective minor or medium-risk surgical procedures, no routine blood tests should be performed. (iii) Parental presence during the induction of anesthesia should be an option for children whenever possible. (iv) Perioperative fasting should be safe and child-friendly with shorter real fasting times and more liberal postoperative drinking and enteral feeding. (v) Perioperative fluid therapy should be safe and effective with physiologically composed balanced electrolyte solutions to maintain a normal extracellular fluid volume; addition of 1%-2.5% glucose to avoid lipolysis, hypoglycemia, and hyperglycemia, and colloids as needed to maintain a normal blood volume. (vi) To achieve safe and successful airway management, the locally accepted airway algorithm and continued teaching and training of basic and alternative techniques of ventilation and endotracheal intubation are required. (vii) Ultrasound and imaging systems (eg, transillumination) should be available for achieving central venous access and challenging peripheral venous and arterial access. (viii) Perioperative disturbances of the patient's homeostasis, such as hypotension, hypocapnia, hypothermia, hypoglycemia, hyponatremia, and severe anemia, should not be ignored and should be prevented or treated immediately. (ix) Pediatric patients with an elevated perioperative risk, eg, preterm and term neonates, infants, and critically ill children, should be treated at institutions where all caregivers have sufficient expertise and continuous clinical exposure to such patients. (x) A strategy for preventing postoperative vomiting, emergence delirium, and acute pain should be a part of every anesthetic procedure.

An International, Multicenter, Observational Study of Cerebral Oxygenation during Infant and Neonatal Anesthesia

BACKGROUND

General anesthesia during infancy is associated with neurocognitive abnormalities. Potential mechanisms include anesthetic neurotoxicity, surgical disease, and cerebral hypoxia-ischemia. This study aimed to determine the incidence of low cerebral oxygenation and associated factors during general anesthesia in infants.

METHODS

This multicenter study enrolled 453 infants aged less than 6 months having general anesthesia for 30 min or more. Regional cerebral oxygenation was measured by near-infrared spectroscopy. We defined events (more than 3 min) for low cerebral oxygenation as mild (60 to 69% or 11 to 20% below baseline), moderate (50 to 59% or 21 to 30% below baseline), or severe (less than 50% or more than 30% below baseline); for low mean arterial pressure as mild (36 to 45 mmHg), moderate (26 to 35 mmHg), or severe (less than 25 mmHg); and low pulse oximetry saturation as mild (80 to 89%), moderate (70 to 79%), or severe (less than 70%).

RESULTS

The incidences of mild, moderate, and severe low cerebral oxygenation were 43%, 11%, and 2%, respectively; mild, moderate, and severe low mean arterial pressure were 62%, 36%, and 13%, respectively; and mild, moderate, and severe low arterial saturation were 15%, 4%, and 2%, respectively. Severe low oxygen saturation measured by pulse oximetry was associated with mild and moderate cerebral desaturation; American Society of Anesthesiology Physical Status III or IV versus I was associated with moderate cerebral desaturation. Severe low cerebral saturation events were too infrequent to analyze.

CONCLUSIONS

Mild and moderate low cerebral saturation occurred frequently, whereas severe low cerebral saturation was uncommon. Low mean arterial pressure was common and not well associated with low cerebral saturation. Unrecognized severe desaturation lasting 3 min or longer in infants seems unlikely to explain the subsequent development of neurocognitive abnormalities.

All Wrapped Up: Environmental Effects on Myelination

To date, studies have demonstrated the dynamic influence of exogenous environmental stimuli on multiple regions of the brain. This environmental influence positively and negatively impacts programs governing myelination, and acts on myelinating oligodendrocyte (OL) cells across the human lifespan. Developmentally, environmental manipulation of OL progenitor cells (OPCs) has profound effects on the establishment of functional cognitive, sensory, and motor programs. Furthermore, central nervous system (CNS) myelin remains an adaptive entity in adulthood, sensitive to environmentally induced structural changes. Here, we discuss the role of environmental stimuli on mechanisms governing programs of CNS myelination under normal and pathological conditions. Importantly, we highlight how these extrinsic cues can influence the intrinsic power of myelin plasticity to promote functional recovery.

Anaesthetic considerations for surgery in newborns

Almost 30 years ago, the American Academy of Pediatrics Committee on Fetus and Newborn coauthored a policy statement strongly advocating for the use of anaesthesia in all neonates stating 'local or systemic pharmacologic agents now available permit relatively safe administration of anesthesia or analgesia to neonates undergoing surgical procedures and that such administration is indicated according to the usual guidelines for the administration of anesthesia to high-risk, potentially unstable patients'. With current techniques and advanced monitoring, preterm and full-term infants routinely undergo surgical procedures under general anaesthesia to repair congenital defects that were lethal in years past. Recent research in immature animal models, however, has shown evidence of enhanced neuroapoptosis and other signs of neurotoxicity with all of the currently used anaesthetic agents. There is also increasing concern about the potential adverse effects of perioperative hypotension and hypocapnia on neurocognitive development in infants. This review outlines the most recent animal and human evidence regarding the effects of general anaesthesia and anaesthetic-related haemodynamic changes on the developing brain of newborns.

Differences in intraoperative hemodynamics between spinal and general anesthesia in infants undergoing pyloromyotomy

BACKGROUND

Hypotension and bradycardia are known side effects of spinal anesthesia in pregnant women undergoing cesarean section and adults undergoing other surgical procedures. Whether children experience similar hemodynamic changes is unclear.

AIMS

The purpose of this study is to evaluate hemodynamic effects of spinal anesthesia compared to general anesthesia in a cohort of healthy infants.

METHODS

The University of Vermont Medical Center almost exclusively used spinal anesthesia for infant pyloromyotomy surgery between 2008 and 2013, while Columbia University Medical Center relied on general anesthesia. The primary outcome assessed was the percentage change in intraoperative heart rate and blood pressure (systolic [SBP] and mean [MAP] blood pressure) from baseline. Analysis was performed using t-tests for continuous variables, followed by linear regression to account for differences in demographic and clinical covariates.

RESULTS

The study sample consisted of 51 infants with spinal anesthesia at the University of Vermont and 52 infants with general anesthesia at Columbia University. The decrease from baseline for mean intraoperative SBP was -8.2 ± 16.8% for spinal anesthesia and -24.2 ± 17.2% for general anesthesia (difference between means: 16.2% [95% confidence interval (CI), 9.5-22.9]), while the decrease from baseline for mean intraoperative MAP was -16.3 ± 19.9% for spinal anesthesia and -24.6 ± 19.3% for general anesthesia (difference between means: 8.4% [95% CI, 0.8-16]). Spinal anesthesia patients also had smaller drops in minimum intraoperative MAP and SBP. These blood pressure differences persisted even after adjusting for covariates. No differences in heart rate were seen between spinal and general anesthesia.

DISCUSSION

Our findings show that spinal anesthesia performed in healthy infants undergoing pyloromyotomy results in reduced intraoperative blood pressure changes from baseline, significantly higher blood pressure readings, and no increased bradycardia compared to general anesthesia. Further research is needed to assess whether any clinical impact of these hemodynamic differences between spinal and general anesthesia exists.

Neurodevelopmental outcomes of neonates undergoing surgery under general anesthesia for malrotation of intestines

BACKGROUND

It is difficult to differentiate between the potential adverse effects of general anesthesia (GA) on the developing brain and the role of associated co-morbidities and syndromes that can adversely affect neurodevelopmental outcomes in neonates undergoing GA. Neonates with malrotation of the intestines without volvulus usually do not have co-morbidities or syndromes. In addition, majority of them recover very well after surgery and are discharged home within a few days. Neonates with malrotation are a clean cohort of babies to study the role of a single episode of GA on the developing brain.

AIMS

The study aimed to evaluate the neurodevelopmental outcomes of neonates undergoing GA for malrotation surgery.

STUDY DESIGN

Retrospective review of neonates born at gestational age of ≥32weeks undergoing laparotomy for malrotation.

OUTCOME MEASURES

Neurodevelopment in the study cohort at the age of one year.

RESULTS

33 eligible infants were identified from the departmental database. All 33 survived and were assessed using the Griffiths Mental Development Scales (GMDS) at one year. Mean general quotient (GQ) of the study population was 98 (SD 7.33) which was similar to the population norms (100.2, SD 12.8); p value 0.10. None of the infants developed cerebral palsy, tone abnormality, sensorineural deafness or blindness. There was no significant difference in the centiles at birth versus one year for weight and length (p values 0.454 and 0.178 respectively). Reassuringly, the head circumference centiles at one year showed a trend towards higher values (p value: 0.0735).

CONCLUSION

One year developmental outcomes of neonates undergoing surgery under GA for malrotation were similar to population norms.

Defining hypotension in anesthetized infants by individual awake blood pressure values: a prospective observational study

BACKGROUND

Blood pressure (BP) is the most commonly applied clinical surrogate parameter for tissue perfusion and cerebral autoregulation. Hypotension during anesthesia may contribute to unfavorable outcome in young children. Hypotension in anesthetized infants can be defined using BP values relative to individual awake baseline or absolute BP values.

AIM

The aim of this study was to investigate the applicability of the two definitions and to compare the incidences of hypotension.

METHOD

This was a prospective observational study in 151 infants <12 months of age. The percentage of successful awake BP measurements was calculated and related to the infant's behavioral state. Hypotension under sevoflurane anesthesia was defined by a decrease of mean arterial pressure (MAP) relative to awake baseline (>20% in infants <6 months, >40% in infants >6 months) or absolute MAP values (<35 mmHg in infants <6 months, <43 mmHg in infants >6 months). The incidences of hypotension using the two definitions were compared.

RESULTS

Awake BP values were obtained in 85% of the patients. Calm patients were more likely to allow their BP to be measured than anxious patients. Anxious patients had higher preinduction MAP values than calm patients. The relative BP approach resulted in a higher incidence of postinduction hypotension than using absolute BP values.

CONCLUSIONS

Awake BP values were unobtainable in 15% of our patients, resulting in the necessity to define hypotension under anesthesia using absolute BP values. Definitions of hypotension using either absolute MAP or values relative to awake baseline are not interchangeable.