Perioperative cerebral oxygen saturation in neonates with hypoplastic left heart syndrome and childhood neurodevelopmental outcome

Presurgical Use of Hypoxic Mixture for Systemic Perfusion Improvement in Neonates With Complex Congenital Heart Disease: A Systematic Review and Meta-Analysis

Oxygen therapy is essential for the survival of preterm babies and critically ill newborns; however, it has the potential to cause harm through hypoxemia or hyperoxemia. Newborns with complex congenital heart diseases (CHD) suffer from oxygen fluctuations due to the disease and its treatments, altering pre and postnatal development. The objective of this study is to evaluate the evidence for using a hypoxic mixture to decrease pulmonary over-circulation and improve systemic perfusion before surgical interventions in newborns with complex CHD that course with pulmonary over-circulation and systemic hypoperfusion. A search was conducted in PubMed, EMBASE, LILACS, Scielo, Taylor and Francis, SAGE, and Science Direct databases from 2000 to 2022 by two independent authors, including articles with hypoxic mixture treatment in observational studies or trials, with pre-treatment and post-treatment measurements in the same patient, or two groups or more comparisons. Six articles were selected, with a total of 75 patients. The primary outcome was improved systemic circulation and decreased pulmonary over-circulation measured directly with Qp/Qs and indirectly with oxygen saturation and cerebral near-infrared spectroscopy (NIRS). In addition, we performed a meta-analysis for oxygen saturation and cerebral NIRS. Oxygen saturation was the value uniformly reported; three studies reported a significantly lower oxygen saturation after the hypoxic mixture. The cerebral NIRS was measured in 4 studies, with inconsistent results. After using the hypoxic mixture, the Qp/Qs calculation was lower in the two studies but was not statistically significant. The meta-analysis for oxygen saturation showed a fixed effect post-hypoxic therapy of -0.7 (-1.06; -0.35), p < 0.001. The meta-analysis of two studies that measured cerebral NIRS did not show a statistically significant difference at 12 and 24 hours. In conclusion, this is the first systematic review and meta-analysis regarding the pre-operative use of hypoxic gas mixtures for newborns with complex congenital heart disease. Treatment results in lower oxygen saturations, but there is a lack of evidence of improvement in systemic perfusion. The utilization of this therapy is controversial, and better evidence is necessary.

Neuroimaging and Neurodevelopmental Outcomes Among Individuals With Complex Congenital Heart Disease: JACC State-of-the-Art Review

Although neuroimaging advances have deepened our understanding of brain health in individuals with congenital heart disease (CHD), it is less clear how neuroimaging findings relate to neurodevelopmental and mental health outcomes across the lifespan. We systematically synthesized and critically evaluated evidence on associations between neuroimaging and neurodevelopmental, neurocognitive, psychiatric, or behavioral outcomes among individuals with transposition of great arteries or single-ventricle CHD (Protocol CRD42021229617). Six databases were searched and 45 papers from 25 unique studies were identified. Structural brain injury was generally linked to poorer neurodevelopment in infancy. Brain volumes and microstructural and functional brain changes appear linked to neurocognitive outcomes, including deficits in attention, learning, memory, and executive function in children and adolescents. Fetal neuroimaging studies were limited. Four papers investigated psychiatric outcomes; none found associations with neuroimaging. Multicenter, longitudinal studies incorporating functional neuroimaging and mental health outcomes are much-needed to inform early neuroprotective and therapeutic strategies in CHD.

Nurses' perceptions and use of near infrared spectroscopy in paediatric cardiac intensive care

BACKGROUND

Near-infrared spectroscopy (NIRS) is a non-invasive technology that estimates regional oxygen saturation. Literature demonstrates that NIRS can provide valuable data for clinical staff. However, little research has addressed the nursing care and management of NIRS in the critical care environment.

AIMS

To assess nurses' perception around the use of NIRS and current NIRS practice within paediatric cardiac intensive care unit (PCICUs).

STUDY DESIGN

A 53-item cross-sectional electronic survey was developed to assess indications for NIRS, critical value thresholds and interventions, barriers to use, policies and procedures, and nursing perceptions. Descriptive statistics were used to summarize and aggregate data.

RESULTS

Among the 28 responding sites (63.6% response rate), usage of NIRS was variable and patient-dependent. Most nurses reported using NIRS in patients with unstable physiology such as post-operative single ventricle (n = 25, 89.3%) and concern for shock (n = 21, 75.0%). Critically low cerebral values varied among respondents from less than 40 (n = 3, 10.7%) to less than 60 (n = 4, 14.3%), with lower critical values permitted for single ventricle physiology: less than 40 (n = 8, 28.6%) to less than 50 (n = 6, 21.4%). Reported barriers to using NIRS included skin breakdown (n = 9, 32.1%), lack of consistency in decision-making among physicians (n = 13, 46.4%), and not using NIRS data when developing a plan of care (n = 11, 39.3%). Most (n = 24, 85.7%) nurses reported that NIRS provided valuable information and was perceived to be beneficial for patients.

CONCLUSIONS

NIRS monitoring is a common technology in the care of complex congenital heart disease patients. Most nurses valued this technology, but inconsistencies and practicalities around its use in guiding patient management were found to be problematic.

RELEVANCE TO CLINICAL PRACTICE

NIRS is commonly used in the PCICU and although nurses perceived NIRS to be useful for their practice, the variability in the interpretation of values and inconsistent protocols and decision-making by physicians was challenging.

Postnatal cerebral hemodynamics in infants with severe congenital heart disease: a scoping review

Patients with severe congenital heart disease (CHD) are at risk for impaired neurodevelopment. Cerebral blood supply may be diminished by congenital anomalies of cardiovascular anatomy and myocardial function. The aim of this scoping review was to summarize the current knowledge on cerebral hemodynamics in infants with severe CHD. A scoping review was performed. Five databases were searched for articles published from 01/1990 to 02/2022 containing information on cerebral hemodynamics assessed by neuroimaging methods in patients with severe CHD within their first year of life. A total of 1488 publications were identified, of which 26 were included. Half of the studies used Doppler ultrasound, and half used magnetic resonance imaging techniques. Studies focused on preoperative findings of cerebral hemodynamics, effects of surgical and conservative interventions, as well as on associations between cerebral hemodynamics and brain morphology or neurodevelopment. Cerebral perfusion was most severely affected in patients with single ventricle and other cyanotic disease. Neuroimaging methods provide a large variety of information on cerebral hemodynamics. Nevertheless, small and heterogeneous cohorts complicate this field of research. Further studies are needed to improve our understanding of the link between CHD and altered cerebral hemodynamics to optimize neuroprotection strategies. IMPACT: Postnatal cerebral hemodynamics are altered in infants with congenital heart disease (CHD) as compared to healthy controls, especially in most severe types such as single ventricle or other cyanotic CHD. Associations of these alterations with brain volume and maturation reveal their clinical relevance. Research in this area is limited due to the rarity and heterogeneity of diagnoses. Furthermore, longitudinal studies have rarely been conducted. Further effort is needed to better understand the deviation from physiological cerebral perfusion and its consequences in patients with CHD to optimize neuroprotection strategies.

Use of extracorporeal membrane oxygenation and cerebral oximetry in a stage 1 norwood repair for hypoplastic left heart syndrome

The role of extracorporeal membrane oxygenation (ECMO) and its indications in stage I Norwood palliation are controversial. The decision to initiate ECMO and its timing remains difficult with no definitive cut-off points or evidence-based guidelines. It varies on a case-to-case basis. We report a case where the use of ECMO was beneficial after stage I Norwood palliation with severe ventricular dysfunction. The systemic-to-pulmonary artery shunt was kept open to balance the systemic and pulmonary circulations. Cerebral oximetry can be useful as an additional monitoring modality to guide management, monitor cerebral perfusion, and help detect cerebral steal.

Impact of cardiopulmonary bypass on cerebrovascular autoregulation assessed by ultrafast ultrasound imaging

Newborns with congenital heart disease undergoing cardiac surgery are at risk of neurodevelopmental impairment with limited understanding of the impact of intra-operative cardiopulmonary bypass (CPB), deep hypothermia and selective cerebral perfusion on the brain. We hypothesized that a novel ultrasound technique, ultrafast power Doppler (UPD), can assess variations of cerebral blood volume (CBV) in neonates undergoing cardiac surgery requiring CPB. UPD was performed before, during and after surgery in newborns with hypoplastic left heart syndrome undergoing a Norwood operation. We found that global CBV was not significantly different between patients and controls (P = 0.98) and between pre- and post-surgery (P = 0.62). UPD was able to monitor changes in CBV throughout surgery, revealing regional differences in CBV during hypothermia during which CBV correlated with CPB flow rate (R²  = 0.52, P = 0.021). Brain injury on post-operative magnetic resonance imaging was observed in patients with higher maximum variation in CBV. Our findings suggest that UPD can quantify global and regional brain perfusion variation during neonatal cardiac surgery with this first intra-operative application demonstrating an association between CBV and CPB flow rate, suggesting loss of autoregulation. Therefore, the measurement of CBV by UPD could enable optimization of cerebral perfusion during cardiac surgery in neonates. KEY POINTS: The impact of cardiopulmonary bypass (CPB) on the neonatal brain undergoing cardiac surgery is poorly understood. Ultrafast power Doppler (UPD) quantifies cerebral blood volume (CBV), a surrogate of brain perfusion. CBV varies throughout CPB surgery and is associated with variation of the bypass pump flow rate during deep hypothermia. Association between CBV and bypass pump flow rate suggests loss of cerebrovascular autoregulatory processes. Quantitative monitoring of cerebral perfusion by UPD could provide a direct parameter to optimize CPB flow rate.

Retroperitoneoscopic Surgery in Children Does Not Cause Pathological Desaturation in Cerebral/Renal Oxygenation on Near-Infrared Spectroscopy Compared with Laparoscopic and Thoracoscopic Surgery

Introduction: Cerebral and renal regional oxygen saturation (C-rSO₂ and R-rSO₂, respectively) were monitored using near-infrared spectroscopy in pediatric patients (range: 0.3-14.3 years) during minimally invasive surgery (MIS) taking at least 3 hours performed by laparoscopy (Lap), thoracoscopy (Tho), or retroperitoneoscopy (Ret) from January 2019 to December 2021. Materials and Methods: Criteria compared were operative time, preoperative/intraoperative hemoglobin, blood loss, mean arterial pressure, arterial partial pressure of carbon dioxide (PaCO₂), peripheral oxygen saturation (SpO₂), C-rSO₂, and R-rSO₂. Pathological desaturation (PD) was defined as >20% decrease from baseline, and statistical significance as P < .05. Results: Subjects (n = 79) were similar for gender, age, and body mass index. MIS procedures were: Lap = 45, Tho = 20, Ret = 14; one Lap case required conversion for severe adhesions, not PD. Intraoperative PaCO₂ (mmHg) was significantly higher in Tho (maximum: 59.5 ± 17.0, minimum: 39.9 ± 7.5) versus Lap (maximum: 39.9 ± 5.1, minimum: 34.6 ± 3.9) and Ret (maximum: 37.8 ± 4.2, minimum: 35.0 ± 3.3); P < .0001 (maximum), P = .0013 (minimum). Minimum intraoperative SpO₂ was significantly lower in Tho (P < .0001). Mean operative times were significantly shorter in Tho (259 ± 114 minutes) versus Lap (433 ± 154 minutes) and Ret (342 ± 100 minutes); P < .0001, respectively. PD was absent during Ret (C-rSO₂: 0/14 = 0% and R-rSO₂: 0/14 = 0%). Differences in PD for Lap (C-rSO₂: 7/45 = 15.6% and R-rSO₂: 10/45 = 22.2%) and Tho (C-rSO₂: 9/20 = 45.0%, and R-rSO₂: 7/20 = 35.0%) were significant; P = .0028 for C-rSO₂ and P = .0497 for R-rSO₂. Hemoglobin and blood loss were similar. Conclusions: PD was absent during Ret, despite longer operative times. If Ret is indicated for a procedure, neurodevelopmental sequelae of MIS could be minimized.

Near-infrared spectroscopy in the medical management of infants

Near-infrared spectroscopy (NIRS) is a technology that is easy to use and can provide helpful information about organ oxygenation and perfusion by measuring regional tissue oxygen saturation (rSO2) with near-infrared light. The sensors can be placed in different anatomical locations to monitor rSO2 levels in several organs. While NIRS is not without limitations, this equipment is now becoming increasingly integrated into modern healthcare practice with the goal of achieving better outcomes for patients. It can be particularly applicable in the monitoring of pediatric patients because of their size, and especially so in infant patients. Infants are ideal for NIRS monitoring as nearly all of their vital organs lie near the skin surface which near-infrared light penetrates through. In addition, infants are a difficult population to evaluate with traditional invasive monitoring techniques that normally rely on the use of larger catheters and maintaining vascular access. Pediatric clinicians can observe rSO2 values in order to gain insight about tissue perfusion, oxygenation, and the metabolic status of their patients. In this way, NIRS can be used in a non-invasive manner to either continuously or periodically check rSO2. Because of these attributes and capabilities, NIRS can be used in various pediatric inpatient settings and on a variety of patients who require monitoring. The primary objective of this review is to provide pediatric clinicians with a general understanding of how NIRS works, to discuss how it currently is being studied and employed, and how NIRS could be increasingly used in the near future, all with a focus on infant management.

The impact of prematurity and associated comorbidities on clinical outcomes in neonates with congenital heart disease

Prematurity is a common risk factor in children, affecting approximately 10% of live births, globally. It is more common in children with critical congenital heart disease (CCHD) and carries important implications in this group of patients. While outcomes have been improving over the years, even late preterm birth is associated with worse outcomes in children born with critical congenital heart disease compared to those without. Infants with both prematurity and CCHD are at particularly high risk for important comorbidities, including: necrotizing enterocolitis, intraventricular hemorrhage, white matter injury, neurodevelopmental anomalies and retinopathy of prematurity. Lesion-specific intensive care management of these infants, interventional and peri-operative management specifically tailored to their needs, and multidisciplinary care all have the potential to improve outcomes in this challenging group.

Hypoxic gas therapy in neonatology, considerations in practice

BACKGROUND

Adequate oxygenation is essential in sick newborns. Each disease determines the target of oxygenation. Nevertheless, hyperoxia and hypoxia are related to adverse outcomes. Most studies about this had been made in preterm infants or term babies with pulmonary pathology.

INTRODUCTION

Congenital heart diseases may also require careful oxygenation control and management of oxygen supply.

PROBLEM

Presurgical stabilization of complex heart diseases (CHD) may be difficult, especially after the physiological decrease of pulmonary resistance, which generates pulmonary edema (due to over-circulation) and systemic hypoperfusion. Several strategies have been described to avoid this phenomenon, such as prostaglandin, vasodilators, inotropes, positive airway pressure, and even hypoxic mixture (Inspired fraction of oxygen (FiO2) below 21%).

DISCUSSION

The last therapy is mainly used in single ventricular physiology heart diseases, such as the hypoplasic left heart syndrome (HLHS) or systemic ductus dependent flow CHD (interruption of the aortic arch and coarctation of the aorta). Alveolar oxygen affects pulmonary vascular resistance modifying lung flow. This modification could help the stabilization during the presurgical period of complex CDH. Many centers use hypoxic therapy to avoid hypotension, metabolic acidosis, coronary-cerebral ischemia, and liver, renal and intestinal injury. Despite the theoretical benefits, there are doubts about how tissue oxygen supply would change during hypoxic gas ventilation. It is worrisome that FiO2 < 21% causes a decrease in brain oxygenation, adding neurological injury to the already established because of CHD and other not modifiable factors. Brain monitoring through near-infrared spectroscopy (NIRS) during hypoxic gas therapy is mandatory. Recent studies have shown that hypoxic gas ventilation therapy in patients with HLHS in the preoperative period decreases the ratio between systemic and pulmonary circulation (Qp/Qs) but does not improve regional oxygenation delivery. The use of hypoxic gas ventilation therapy continues to be controversial. It could be an option in some complex CHD, mainly HLHS.

Significant neonatal intraoperative cerebral and renal oxygen desaturation identified with near-infrared spectroscopy

INTRODUCTION

Near-infrared spectroscopy (NIRS) was used to monitor intraoperative regional oxygen saturation (rSO₂) during open (Op) and minimally invasive (MI) surgery performed in neonates (N) and children.

MATERIALS AND METHODS

NIRS sensors were applied to the forehead and flanks for cerebral rSO₂ (C-rSO₂) and renal rSO₂ (R-rSO₂), respectively. MI included laparoscopy (La), retroperitoneoscopy (Re) and thoracoscopy (Th). In children, Op and MI were major operations taking at least 3 h (MOp; MMI). Pathological desaturation (PD) was defined as > 20% deterioration in rSO₂.

RESULTS

Mean ages at surgery were N: 5.2 ± 8.2 days, MOp: 2.4 ± 2.9 years, and MMI: 3.8 ± 4.3 years. Despite significantly shorter operative times in N (169 ± 94 min; p < 0.0001), PD was significantly worse; PD(C-rSO₂): N = 14/35 (40.0%) versus MOp = 3/36 (8.3%) and MMI = 7/58 (12.1%); p = 0.0006, and PD(R-rSO₂): N = 27/35 (77.1%) versus MOp = 6/36 (16.7%) and MMI = 7/58 (12.1%); p < 0.0001, respectively. PD(R-rSO₂) occurred immediately with visceral reduction in NOp (Fig. 1) and PD was frequent during NMI(Th) (Fig. 2). rSO₂ was stable throughout MOp and MMI (Fig. 3). Fig. 1 Pathological desaturation in renal rSO₂ after visceral reduction for gastroschisis. Renal rSO₂ deteriorated immediately after viscera were returned to the abdominal cavity rSO₂ regional oxygen saturation Fig. 2 Fragility of tissue perfusion during thoracoscopic lung lobectomy in a neonate. Pathological desaturation occurred frequently during neonatal thoracoscopic surgery rSO₂ regional oxygen saturation Fig. 3 Changes in cerebral and renal rSO₂ according to operative time. Cerebral and renal rSO₂ did not appear to change according to operative time during major open and major minimally invasive surgery in children. rSO₂ regional oxygen saturation CONCLUSIONS: NIRS is a non-invasive technique for monitoring rSO₂ as an indicator of intraoperative stress and vascular perfusion. PD was so significant in neonates that intraoperative NIRS is highly recommended during thoracoscopy and procedures requiring visceral manipulation.

The Predictive Power of Near-Infrared Spectroscopy in Improving Cognitive Problems in Patients Undergoing Brain Surgeries: A Systematic Review

One of the main objectives in neurosurgical procedures is the prevention of cerebral ischemia and hypoxia leading to secondary brain injury. Different methods for early detection of intraoperative cerebral ischemia and hypoxia have been used. Near-infrared spectroscopy (NIRS) is a simple, non-invasive method for monitoring cerebral oxygenation increasingly used today. The aim of this study was to systematically review the brain monitoring with NIRS in neurosurgery. The search process resulted in the detection of 324 articles using valid keywords on the electronic databases, including Embase, PubMed, Scopus, Web of Science, and Cochrane Library. Subsequently, the full texts of 34 studies were reviewed, and finally 11 articles (seven prospective studies, three retrospective studies, and one randomized controlled trial) published from 2005 to 2020 were identified as eligible for systematic review. Meta-analysis was not possible due to high heterogeneity in neurological and neurosurgical conditions of patients, expression of different clinical outcomes, and different standard reference tests in the studies reviewed. The results showed that NIRS is a non-invasive cerebral oximetry that provides continuous and measurable cerebral oxygenation information and can be used in a variety of clinical settings.

S100B in cardiac surgery brain monitoring: friend or foe?

Recent advances in perioperative management of adult and pediatric patients requiring open heart surgery (OHS) and cardiopulmonary bypass (CPB) for cardiac and/or congenital heart diseases repair allowed a significant reduction in the mortality rate. Conversely morbidity rate pattern has a flat trend. Perioperative period is crucial since OHS and CPB are widely accepted as a deliberate hypoxic-ischemic reperfusion damage representing the cost to pay at a time when standard of care monitoring procedures can be silent or unavailable. In this respect, the measurement of neuro-biomarkers (NB), able to detect at early stage perioperative brain damage could be especially useful. In the last decade, among a series of NB, S100B protein has been investigated. After the first promising results, supporting the usefulness of the protein as predictor of short/long term adverse neurological outcome, the protein has been progressively abandoned due to a series of limitations. In the present review we offer an up-dated overview of the main S100B pros and cons in the peri-operative monitoring of adult and pediatric patients.

Effects of Arterial Carbon Dioxide Tension on Cerebral and Somatic Regional Tissue Oxygenation and Blood Flow in Neonates After the Norwood Procedure With Deep Hypothermic Cardiopulmonary Bypass

Neonates undergoing the Norwood procedure for hypoplastic left heart syndrome are at higher risk of impaired systemic oxygen delivery with resultant brain, kidney, and intestinal ischemic injury, shock, and death. Complex developmental, anatomic, and treatment-related influences on cerebral and renal-somatic circulations make individualized treatment strategies physiologically attractive. Monitoring cerebral and renal circulations with near infrared spectroscopy can help drive rational therapeutic interventions. The primary aim of this study was to describe the differential effects of carbon dioxide tension on cerebral and renal circulations in neonates after the Norwood procedure. Using a prospectively-maintained database of postoperative physiologic and hemodynamic parameters, we analyzed the relationship between postoperative arterial carbon dioxide tension and tissue oxygen saturation and arteriovenous saturation difference in cerebral and renal regions, applying univariate and multivariate multilevel mixed regression techniques. Results were available from 7,644 h of data in 178 patients. Increases in arterial carbon dioxide tension were associated with increased cerebral and decreased renal oxygen saturation. Differential changes in arteriovenous saturation difference explained these effects. The cerebral circulation showed more carbon dioxide sensitivity in the early postoperative period, while sensitivity in the renal circulation increased over time. Multivariate models supported the univariate findings and defined complex time-dependent interactions presented graphically. The cerebral and renal circulations may compete for blood flow with critical limitations of cardiac output. The cerebral and renal-somatic beds have different circulatory control mechanisms that can be manipulated to change the distribution of cardiac output by altering the arterial carbon dioxide tension. Monitoring cerebral and renal circulations with near infrared spectroscopy can provide rational physiologic targets for individualized treatment.

The Current Status of Neuroprotection in Congenital Heart Disease

Neurological deficits are a serious and common sequelae of congenital heart disease (CHD). While their underlying mechanisms have not been fully characterized, their manifestations are well-known and understood to persist through adulthood. Development of therapies to address or prevent these deficits are critical to attenuate future morbidity and improve quality of life. In this review, we aim to summarize the current status of neuroprotective therapy in CHD. Through an exploration of present research in the pre-operative, intra-operative, and post-operative phases of patient management, we will describe existing clinical and bench efforts as well as current endeavors underway within this research area.

Near-infrared spectroscopy for perioperative assessment and neonatal interventions

Perioperative applications of near-infrared spectroscopy (NIRS) to monitor regional tissue oxygenation and perfusion in cardiac and noncardiac surgery are of increasing interest in neonatal care. Complex neonatal surgery can impair adequate oxygen delivery and tissue oxygen consumption and increase the risk of neurodevelopmental delay. Coupled with conventional techniques, NIRS monitoring may enable targeted hemodynamic management of the circulation in both cardiac and noncardiac surgical procedures. In this narrative review, we discuss the application of perioperative NIRS in specific neonatal interventions, including surgical intervention for congenital heart defects, definitive closure of the patent ductus arteriosus, neurological and gastrointestinal disorders, and use of extracorporeal membrane oxygenation. We identified areas for future research within disease-specific indications and offer a roadmap to aid in developing evidence-based targeted diagnostic and management strategies in neonates. IMPACT: There is growing recognition that perioperative NIRS monitoring, used in conjunction with conventional monitoring, may provide critical hemodynamic information that either complements clinical impressions or delivers novel physiologic insight into the neonatal circulatory and perfusion pathways.

Equal cerebral perfusion during extended aortic coarctation repair

OBJECTIVES

Aortic coarctation with distal aortic arch hypoplasia can be effectively addressed by coarctation resection with extended end-to-end-anastomosis (REEEA). Particularly, when unilateral cerebral perfusion (UCP) is established by clamping of left-sided supra-aortic vessels, the extent of cerebral blood flow distribution during repair remains undetermined, so far. Transfontanellar contrast-enhanced ultrasound (T-CEUS) can be utilized for real-time visualization and quantitative evaluation of cerebral blood flow. This study quantitatively evaluates cerebral perfusion during REEEA by using intraoperative T-CEUS.

METHODS

In a prospective study, 9 infants with open fontanelle undergoing REEEA [median age: 13 days (range 1-34) and median weight 3.1 kg (range 2.2-4.4)] were intraoperatively examined with T-CEUS at 3 consecutive time-points: before skin incision, during UCP and after skin suture. A software-based analysis of 11 parameters was used for data evaluation. Absolute and relative blood flow in contralateral hemispheres was measured in side-by-side comparison, and referenced to baseline measurements.

RESULTS

No side-depend absolute or relative cerebral perfusion differences were found during REEEA, except for an increased relative 'wash-out-rate' (P = 0.0013) in favour of the right hemisphere after surgery. Compared to ipsilateral baseline levels, 'rise time' was transiently increased in right (P = 0.0277) and 'time-to-peak' in both hemispheres (right: P = 0.0403 and left: P = 0.0286), all during UCP.

CONCLUSIONS

The use of T-CEUS provided evidence for homogenous distribution of contrast agent in both hemispheres during UCP. T-CEUS can be utilized for the postprocedural evaluation of cerebral perfusion during congenital cardiac surgery.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov Unique, Identifier: NCT03215628.

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.

Assessment of postoperative risk factors for EEG abnormalities in routine clinical management after paediatric cardiopulmonary bypass

OBJECTIVES

The postoperative risk factors for electroencephalogram(EEG) abnormalities after paediatric cardiopulmonary bypass (CPB) remain to be identified. We investigated the characteristics of EEG abnormalities and risk factors in routine clinical management post-CPB.

METHODS

EEG and cerebral oxygen saturation (ScO2) were monitored in 96 patients (aged 3 days, 37 months, median 5 months) for 72 h post-CPB. Clinical measurements included 4-hourly arterial and central venous pressure, arterial blood gases, doses of inotropic and vasoactive drugs, daily C-reactive protein (CRP) and NT-proB-type Natriuretic Peptide (NT-proBNP). Demographics, STAT categories and outcomes (duration of mechanical ventilation,CICU stay) were recorded. Un.

RESULTS

Seizures occurred in 20 patients (20.8%) beginning at 0-48 hand lasting 10 min-31 h; background abnormalities occurred in 67 (69.8%) beginning at 0-8 h and lasting 4-48 h. Patients with EEG abnormalities had worse outcomes. In univariable regression, seizures positively correlated with STAT categories, CPB time, temperature, blood pressure, central venous pressure, NT-proBNP, CRP, lactate and epinephrine, negatively with ScO2 and PaCO2 (P < 0.001 for lactate and epinephrine, P < 0.1 for the remaining). The degree of background abnormalities positively correlated with STAT categories, CPB time, operative time, central venous pressure, milrinone, negatively with blood pressure (P = 0.0003-0.087); it negatively correlated with lower dose of epinephrine (P < 0.001) and positively with higher dose (P = 0.03l). In multivariable regression, seizures positively correlated with epinephrine, lactate and temperature; the background abnormality correlations remain significant except for milrinone and operative time (P < 0.001 for epinephrine, P < 0.05 for the remaining).

CONCLUSIONS

Numerous perioperative risk factors are associated with EEG abnormalities post-CPB. The most significant and consistent risk factor is epinephrine.

Near-Infrared Spectroscopy Monitoring in Pediatric Anesthesiology: A Pro-Con Discussion

Near-infrared spectroscopy (NIRS) has been increasingly used as a non-invasive measurement of cerebral tissue oxygen saturation. The aim of this short review is to discuss the benefits and drawbacks of its use in the pediatric anesthesia population. In the context of cardiac surgery, lower intraoperative NIRS values have shown a modest association with neurodevelopmental outcomes while lower neonatal intensive care unit NIRS values have been correlated with reduced neurodevelopment in children. However, it is still unclear if management aimed at increasing cerebral tissue oxygenation would have any benefit on these outcomes. Without prospective research looking into the effects of intervention given proper thresholds, the true benefit of NIRS use is still up for debate. Even with current research gaps, its use in the clinical setting continues.

Interrelations of Intraoperative Changes in Cerebral Tissue Oxygen Saturation with Brain Volumes and Neurodevelopment Outcome After the Comprehensive Stage II Procedure in Infants With Hypoplastic Left Heart Syndrome: A Retrospective Cohort Study

OBJECTIVES

The monitoring of cerebral tissue oxygen saturation by near-infrared spectroscopy (S_cerebO₂) is used widely in pediatric cardiac anesthesia. However, little information is available on the effects of changes in perioperative S_cerebO₂ on brain morphology and neurologic outcome. The primary hypothesis tested in this study was that intraoperative S_cerebO₂ during the comprehensive stage II procedure correlated with brain volumes assessed by magnetic resonance imaging and neurodevelopmental scores.

DESIGN

Retrospective observational cohort study.

SETTING

University Hospital, Pediatric Heart Centre.

PATIENTS AND MEASUREMENTS

In 19 infants, the intraoperative course of S_cerebO₂ during the comprehensive stage II procedure was examined. Minimal S_cerebO₂ and integrated S_cerebO₂ below 45% (AUC) during surgery, as well as cerebral magnetic resonance imaging (MRI) examinations and Bayley III test at the ages of two-to-three years, were analyzed.

MAIN RESULTS

A positive correlation between minimal S_cerebO₂ and intracranial volume (p = 0.0243), total brain volume (p = 0.0243), and white matter volume (p = 0.0276) was observed, as was a negative correlation between AUC and intracranial volume (p = 0.0454) and white matter volume (p = 0.0381), respectively. No association was found between S_cerebO₂ and Bayley-III Score.

CONCLUSION

The correlation between S_cerebO₂ and brain volumes measured by MRI pointed out a possible importance of neuroprotective strategies aimed at optimizing S_cerebO₂ during complex congenital heart surgery. That no correlation between S_cerebO₂ and Bayley III Score was found suggested multifactorial causes for neurologic outcome in children with congenital heart defects.

Mechanisms of perioperative brain damage in children with congenital heart disease

Congenital heart disease, particularly cyanotic congenital heart disease (CCHD), may lead to a neurodevelopmental delay through central nervous system injury, more unstable central nervous system development, and increased vulnerability of the nervous system. Neurodevelopmental disease is the most serious disorder of childhood, affecting the quality of life of children and their families. Therefore, the monitoring and optimization of nerve damage treatments are important. The factors contributing to neurodevelopmental disease are primarily related to preoperative, intraoperative, postoperative, genetic, and environmental causes, with intraoperative causes being the most influential. Nevertheless, few studies have examined these factors, particularly the influencing factors during early postoperative care. Children with congenital heart disease may experience brain damage during early heart intensive care due to unstable haemodynamics and total body oxygen transfer, particularly early postoperative inflammatory reactions in the brain, blood glucose levels, and other factors that potentially influence long-term neural development. This study analyses the forms of structural and functional brain damage in the early postoperative period, along with the recent evolution of research on its contributing factors.

Relationships between Physiologic and Neuropsychologic Functioning after Fontan

OBJECTIVE

To investigate potential relationships between neuropsychologic functioning and cardiac, gastroenterologic/hepatologic, and pulmonary complications in the single ventricle heart disease (SVHD) post-Fontan population.

STUDY DESIGN

Following the initiation of a Fontan Multidisciplinary Clinic, patients with SVHD were evaluated systematically according to a clinical care pathway, and data from multiple subspecialty evaluations were collected prospectively from 2016 to 2019. Biomarkers of cardiology, pulmonary, and hepatology/gastroenterology functioning were abstracted, along with neuropsychologic testing results. Bivariate correlations and regression analyses examined cross-sectional relationships between physiologic predictors and neuropsychologic outcomes.

RESULTS

The sample included a cohort of 68 youth with SVHD age 3-19 years, after Fontan palliation. Sleep-disordered breathing was related to poorer visual-motor integration skills (r = -0.33; P < .05) and marginally related to poorer executive functioning (r = -0.33; P = .05). Lower arterial blood oxygen content was related to poorer executive functioning (r = .45; P < .05). Greater atrioventricular valve regurgitation was related to lower parent-rated adaptive functioning (ρ = -0.34; P < .01). These results were maintained in regression analyses controlling for history of stroke and/or seizures.

CONCLUSIONS

We demonstrated associations between neuropsychologic functioning and potentially modifiable aspects of physiologic functioning in a prospectively evaluated cohort of patients with SVHD with Fontan physiology. Our findings emphasize the importance of multidisciplinary screening and care after a Fontan procedure and suggest avenues for intervention that may improve patient outcomes and quality of life.

Decreased cerebral oxygen saturation levels during direct laryngoscopy with spontaneous ventilation in children

INTRODUCTION

Direct laryngoscopy in children is usually performed with spontaneous ventilation and monitored by pulse oximetry. It is currently unknown if spontaneous ventilation has an effect on cerebral oxygenation. We hypothesized that cerebral oxygenation may be impeded during direct laryngoscopy with spontaneous ventilation in children.

OBJECTIVE

Our objective was to determine if children who undergo direct laryngoscopy under general anesthesia with spontaneous breathing experience significant reductions in cerebral oxygen saturation levels, and whether or not these reductions are accompanied by decreases in peripheral oxygen saturation levels.

METHODS

This pilot study included 16 consecutive children who underwent direct laryngoscopy under general anesthesia and spontaneous ventilation. The INVOS™ system, which is currently used to monitor cerebral oxygen saturation levels during neurosurgery and cardiothoracic surgery, consists of a processing unit and 2 sensors that are applied to the patient's forehead. We used it to record cerebral oxygenation levels throughout the procedure. Peripheral pulse oximetry was recorded simultaneously, and the results were compared to the levels recorded by the INVOS™ system.

RESULTS

Cerebral oxygen saturation levels decreased by more than 20% from baseline in 7/10 children with tracheostomy and in 2/6 children without tracheostomy, while peripheral oxygen saturation levels remained intact in all the children. The mean time from induction of anesthesia to significant decrease in the cerebral oxygenation level (rSO2) was 14 ± 6 min for the tracheostomy group and 14.5 ± 1.5 min for the no tracheostomy group.

CONCLUSIONS

Children who undergo direct laryngoscopy under general anesthesia with spontaneous ventilation may display reductions in brain oxygenation levels that are not detected by standard pulse oximetry, which reflects only peripheral oxygenation levels. Further study is required to explore the possible effect of this phenomenon in children who undergo direct laryngoscopy.

Standardization of the Perioperative Management for Neonates Undergoing the Norwood Operation for Hypoplastic Left Heart Syndrome and Related Heart Defects

OBJECTIVES

In-hospital complications after the Norwood operation for single ventricle heart defects account for the majority of morbidity and mortality. Inpatient care variation occurs within and across centers. This multidisciplinary quality improvement project standardized perioperative management in a large referral center.

DESIGN

Quality improvement project.

SETTING

High volume cardiac center, tertiary care children's hospital.

PATIENTS

Neonates undergoing Norwood operation.

INTERVENTIONS

The quality improvement team developed and implemented a clinical guideline (preoperative admission to 48 hr after surgery). The composite process metric, Guideline Adherence Score, contained 13 recommendations in the guideline that reflected consistent care for all patients.

MEASUREMENTS AND MAIN RESULTS

One-hundred two consecutive neonates who underwent Norwood operation (January 1, 2013, to July 12, 2016) before guideline implementation were compared with 50 consecutive neonates after guideline implementation (July 13, 2016, to May 4, 2018). No preguideline operations met the goal Guideline Adherence Score. In the first 6 months after guideline implementation, 10 of 12 operations achieved goal Guideline Adherence Score and continued through implementation, reaching 100% for the last 10 operations. Statistical process control analysis demonstrated less variability and decreased hours of postoperative mechanical ventilation and cardiac ICU length of stay during implementation. There were no statistically significant differences in major hospital complications or in 30-day mortality. A higher percentage of patients were extubated by postoperative day 2 after guideline implementation (67% [30/47] vs 41% [41/99], respectively; p = 0.01). Of these patients, reintubation within 72 hours of extubation significantly decreased after guideline implementation (0% [0/30] vs 17% [7/41] patients, respectively; p = 0.02).

CONCLUSIONS

This initiative successfully implemented a standardized perioperative care guideline for neonates undergoing the Norwood operation at a large center. Positive statistical process control centerline shifts in Guideline Adherence Score, length of postoperative mechanical ventilation, and cardiac ICU length of stay were demonstrated. A higher percentage were successfully extubated by postoperative day 2. Establishment of standard processes can lead to best practices to decrease major adverse events.

Health-related quality of life for children and adolescents in school age with hypoplastic left heart syndrome: a single-centre study

Data from neurological and radiological research show an abnormal neurological development in patients treated for hypoplastic left heart syndrome. Thus, the aim of this study was to survey the quality of life scores in comparison with healthy children and children with other heart diseases (mild, moderate, and severe heart defects, heart defects in total). Children with hypoplastic left heart syndrome (aged 6.3-16.9 years) under compulsory education requirements, who were treated at the Children's Heart Center Linz between 1997 and 2009 (n = 74), were surveyed. Totally, 41 children and 44 parents were examined prospectively by psychologists according to Pediatric Quality of Life Inventory, a health-related quality of life measurement. The results of the self-assessments of health-related quality of life on a scale of 1-100 showed a wide range, from a minimum of 5.00 (social functioning) to a maximum of 100 (physical health-related summary scores, emotional functioning, school functioning), with a total score of 98.44. The parents' assessments (proxy) were quite similar, showing a range from 10 (social functioning) up to 100. Adolescent hypoplastic left heart syndrome patients rated themselves on the same level as healthy youths and youths with different heart diseases. The results show that patients with hypoplastic left heart syndrome aged 6-16 years can be successfully supported and assisted in their psychosocial development even if they show low varying physical and psychosocial parameters. The finding that adolescent hypoplastic left heart syndrome patients estimated themselves similar to healthy individuals suggests that they learnt to cope with a severe heart defect.

Survival, Neurocognitive, and Functional Outcomes After Completion of Staged Surgical Palliation in a Cohort of Patients With Hypoplastic Left Heart Syndrome

Background

Management of patients with hypoplastic left heart syndrome has benefited from advancements in medical and surgical care. Outcomes have improved, although survival and long‐term functional and cognitive deficits remain a concern.

Methods and Results

This is a cohort study of all consecutive patients with hypoplastic left heart syndrome undergoing surgical palliation at a single center. We aimed to examine demographic and perioperative factors from each surgical stage for their association with survival and neurocognitive outcomes. A total of 117 consecutive patients from 1996 to 2010 underwent surgical palliation. Seventy patients (60%) survived to the Fontan stage and 68 patients (58%) survived to undergo neurocognitive assessment at a mean (SD) age of 56.6 months (6.4 months). Full‐scale, performance, and verbal intelligence quotient, as well as visual‐motor integration mean (SD) scores were 86.7 (16.1), 86.3 (15.8), 88.8 (17.2), and 83.2 (14.8), respectively. On multivariable analysis, older age at Fontan, sepsis peri‐Norwood, lowest arterial partial pressure of oxygen postbidirectional cavopulmonary anastomosis, and presence of neuromotor disability pre‐Fontan were strongly associated with lower scores for all intelligence quotient domains. Older age at Fontan and sepsis peri‐Norwood remained associated with lower scores for all intelligence quotient domains in a subgroup analysis excluding patients with disability pre‐Fontan or with chromosomal abnormalities.

Conclusions

Older age at Fontan and sepsis are among independent predictors of poor neurocognitive outcomes for patients with hypoplastic left heart syndrome. Further studies are required to identify the appropriate age range for Fontan completion, balancing a lower risk of acute and long‐term hemodynamic complications while optimizing long‐term neurocognitive outcomes.

Near-Infrared Spectroscopy in Pediatric Congenital Heart Disease

Near-infrared spectroscopy (NIRS) is widely used to monitor tissue oxygenation in the pediatric cardiac surgical population. Clinicians who use NIRS must understand the underlying measurement principles in order to interpret and use this monitoring modality appropriately. The aims of this narrative review are to provide a brief overview of NIRS technology, discuss the normative and critical values of cerebral and somatic tissue oxygen saturation and the interpretation of these values, present the clinical studies (and their limitations) of NIRS as a perioperative monitoring modality in the pediatric congenital heart disease population, and introduce the emerging and future applications of NIRS.

Multisite measurement of regional oxygen saturation in Fontan patients with and without protein-losing enteropathy at rest and during exercise

BACKGROUND

Protein-losing enteropathy (PLE) is a severe complication of Fontan circulation with increased risk of end-organ dysfunction. We evaluated tissue oxygenation via near-infrared spectroscopy (NIRS) at different exercise levels in Fontan patients.

METHODS

Assessment of multisite NIRS during cycle ergometer exercise and daily activities in three groups: Fontan patients with PLE; without PLE; patients with dextro-transposition of the great arteries (d-TGA); comparing univentricular with biventricular circulation and Fontan with/without PLE. Renal threshold analysis (<65%;<55%;<45%) of regional oxygen saturation (rSO2) was performed.

RESULTS

Fontan patients showed reduced rSO2 (p < 0.05) in their quadriceps femoris muscle compared with biventricular d-TGA patients at all time points. rSO2 in renal tissue was reduced at baseline (p = 0.002), exercise (p = 0.0062), and daily activities (p = 0.03) in Fontan patients with PLE. Renal threshold analysis identified critically low renal rSO2 (rSO2 < 65%) in Fontan patients with PLE during exercise (95% of monitoring time below threshold) and daily activities (83.7% time below threshold).

CONCLUSION

Fontan circulation is associated with decreased rSO2 values in skeletal muscle and hypoxemia of renal tissue solely in patients with PLE. Reduced rSO2 already during activities of daily life, might contribute to comorbidities in patients with Fontan circulation, including PLE and renal failure.

Postoperative cerebral oxygenation was not associated with new brain injury in infants with congenital heart disease

OBJECTIVE

The aim of this study was to evaluate postoperative indices of cerebral oxygenation and autoregulation in infants with critical congenital heart disease in relation to new postoperative ischemic brain injury.

METHODS

This prospective, clinical cohort included 77 infants with transposition of the great arteries (N = 19), left ventricular outflow tract obstruction (N = 30), and single ventricle physiology (N = 28) undergoing surgery at 30 days or less of life. Postoperative near-infrared spectroscopy and physiologic monitoring were applied to extract mean arterial blood pressure, regional cerebral oxygen saturation, fractional tissue oxygen extraction, and regional cerebral oxygen saturation mean arterial blood pressure correlation coefficient (≥0.5 considered sign of impaired cerebral autoregulation). New postoperative ischemic injury was defined as moderate-severe white matter injury or focal infarction on magnetic resonance imaging. Low cardiac output syndrome was measured as lactate greater than 4 mmol/L with pH less than 7.30.

RESULTS

After surgery, regional cerebral oxygen saturation was decreased in all congenital heart disease groups with a notable increase in regional cerebral oxygen saturation between 6 and 12 hours after surgery, on average with a factor of 1.4 (range, 1.1-2.4). Both single ventricle physiology and postoperative low cardiac output syndrome were associated with lower regional cerebral oxygen saturation and increased time with correlation coefficient of 0.5 or greater. New postoperative ischemic injury was seen in 39 patients (53%) and equally distributed across congenital heart disease groups. Postoperative regional cerebral oxygen saturation, fractional tissue oxygen extraction, and correlation coefficient were not independently associated with new postoperative white matter injury or focal infarction (mixed-model analysis, all F > 0.12).

CONCLUSIONS

Postoperative indices of cerebral oxygenation and cerebral autoregulation are not independent predictors of new ischemic brain injury in infants with critical congenital heart disease. Further exploration of the complex interplay among low regional cerebral oxygen saturation, low cardiac output syndrome, and heart defect is required to identify potential biomarkers enabling early intervention for ischemic brain injury.

S100B and its relation to cerebral oxygenation in neonates and infants undergoing surgery for congenital heart disease

OBJECTIVES

Neonates and infants undergoing surgery for congenital heart disease are at risk for developmental impairment. Hypoxic-ischemic brain injury might be one contributing factor. We aimed to investigate the perioperative release of the astrocyte protein S100B and its relation to cerebral oxygenation.

METHODS

Serum S100B was measured before and 0, 12, 24, and 48 hours after surgery. Cerebral oxygen saturation was derived by near-infrared spectroscopy. S100B reference values based on preoperative samples; concentrations above the 75th percentile were defined as elevated. Patients with elevated S100B at 24 or 48 hours were compared to cases with S100B in the normal range. Neonates (≤28 days) and infants (>28 and ≤365 days) were analyzed separately due to age-dependent release of S100B.

RESULTS

Seventy-four patients underwent 94 surgical procedures (neonates, n = 38; infants, n = 56). S100B concentrations were higher in neonates before and after surgery at all time points (P ≤ .015). Highest values were noticed immediately after surgery. Postoperative S100B was elevated after 15 (40.5%) surgeries in neonates. There was no difference in pre-, intra-, or postoperative cerebral oxygenation. In infants, postoperative S100B was elevated after 23 (41.8%) procedures. Preoperative cerebral oxygen saturations tended to be lower (53 ± 12% vs 59 ± 12%, P = .069) and arterial-cerebral oxygen saturation difference was higher (35 ± 11% vs 28 ± 11%, P = .018) in infants with elevated postoperative S100B. In the early postoperative course, cerebral oxygen saturation was lower (54 ± 13% vs 63 ± 12%, P = .011) and arterial-cerebral oxygen saturation difference was wider (38 ± 11% vs 30 ± 10%, P = .008). Cerebral oxygen saturation was also lower for the entire postoperative course (62 ± 18% vs 67 ± 9%, P = .047).

CONCLUSIONS

Postoperative S100B was elevated in about 40% of neonates and infants undergoing cardiac surgery. Infants with elevated postoperative S100B had impaired perioperative cerebral tissue oxygenation. No relation between S100B and cerebral oxygenation could be demonstrated in neonates.

Correlation between Regional Cerebral Saturation and Invasive Cardiac Index Monitoring after Heart Transplantation Surgery

The present study assessed the correlations between cerebral regional saturation detected by near infrared spectroscopy (NIRS) and cardiac index (CI) measured by pulmonary artery catheter. This was a retrospective cohort study conducted in the cardiac intensive care unit in a tertiary care children's hospital. Patients younger than 18 years of age who underwent heart transplantation and had a pulmonary artery catheter on admission to the pediatric cardiac intensive care unit between January, 2010, and August, 2013, were included. There were no interventions. A total of 10 patients were included with median age of 14 years (range, 7-17). Indications for transplantation were dilated cardiomyopathy ( n  = 9) and restrictive cardiomyopathy ( n  = 1). Mixed venous oxygen saturation (SvO 2 ), cerebral regional tissue saturation (rSO 2 ), and CI were recorded hourly for 8 to 92 hours post-transplantation. Spearman's rank correlation coefficient was used to assess correlations between SvO 2 and cerebral rSO 2 and between CI and cerebral rSO 2 . A total of 410 data points were collected. Median, 25th and 75th percentiles of cerebral rSO 2 , CI, and SvO 2 were 65% (54-69), 2.9 L/min/m 2 (2.2-4.0), and 75% (69-79), respectively. The correlation coefficient between cerebral rSO 2 and CI was 0.104 ( p  = 0.034) and that for cerebral rSO 2 and SvO 2 was 0.11 ( p  = 0.029). The correlations between cerebral rSO 2 and CI and between cerebral rSO 2 and SvO 2 were weak. Cerebral rSO 2 as detected by NIRS may not be an accurate indicator of CI in critically ill patients.

Near-Infrared Cerebral Oximetry to Predict Outcome After Pediatric Cardiac Surgery: A Prospective Observational Study

OBJECTIVES

To assess whether near-infrared cerebral tissue oxygen saturation, measured with the FORESIGHT cerebral oximeter (CAS Medical Systems, Branford, CT) predicts PICU length of stay, duration of invasive mechanical ventilation, and mortality in critically ill children after pediatric cardiac surgery.

DESIGN

Single-center prospective, observational study.

SETTING

Twelve-bed PICU of a tertiary academic hospital.

PATIENTS

Critically ill children and infants with congenital heart disease, younger than 12 years old, admitted to the PICU between October 2012 and November 2015. Children were monitored with the FORESIGHT cerebral oximeter from PICU admission until they were weaned off mechanical ventilation. Clinicians were blinded to cerebral tissue oxygen saturation data.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Primary outcome was the predictive value of the first 24 hours of postoperative cerebral tissue oxygen saturation for duration of PICU stay (median [95% CI], 4 d [3-8 d]) and duration of mechanical ventilation (median [95% CI], 111.3 hr (69.3-190.4 hr]). We calculated predictors on the first 24 hours of cerebral tissue oxygen saturation monitoring. The association of each individual cerebral tissue oxygen saturation predictor and of a combination of predictors were assessed using univariable and multivariable bootstrap analyses, adjusting for age, weight, gender, Pediatric Index of Mortality 2, Risk Adjustment in Congenital Heart Surgery 1, cyanotic heart defect, and time prior to cerebral tissue oxygen saturation monitoring. The most important risk factors associated with worst outcomes were an increased SD of a smoothed cerebral tissue oxygen saturation signal and an elevated cerebral tissue oxygen saturation desaturation score.

CONCLUSIONS

Increased SD of a smoothed cerebral tissue oxygen saturation signal and increased depth and duration of desaturation below the 50% saturation threshold were associated with longer PICU and hospital stays and with longer duration of mechanical ventilation after pediatric cardiac surgery.

Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association

Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.

Evolution of the concept of oxygen transport in the critically ill, with a focus on children after cardiopulmonary bypass

The concept of oxygen transport, defined as the relation between oxygen consumption (VO2) and delivery (DO2), is of fundamental importance in critically ill patients. The past 200 years have witnessed a stepwise progressive improvement in the understanding of pathophysiological disturbances in the balance of DO2 and VO2 in critically ill patients including those after cardiopulmonary bypass surgery. Intermittent spectacular technological achievements have accelerated the rate of progress. Therapeutic advances have been particularly impressive during the recent decades. Examination of the relation between DO2 and VO2 provides a useful framework around which the care of the critically ill may be developed. Until now, only a few groups have used this framework to examine children after cardiopulmonary bypass. The key topics that will be covered in this review article are the evolution of the concept from its early development to its present, increasingly sophisticated, role in the management of critically ill patients, with a focus on children after cardiopulmonary bypass surgery.

Comparison of tissue oximeters on a liquid phantom with adjustable optical properties: an extension

Cerebral near-infrared spectroscopy (NIRS) oximetry may help clinicians to improve patient treatment. However, the application of NIRS oximeters is increasingly causing confusion to the users due to the inconsistency of tissue oxygen haemoglobin saturation (StO2) readings provided by different oximeters. To establish a comparability of oximeters, in our study we performed simultaneous measurements on the liquid phantom mimicking properties of neonatal heads and compared the tested device to a reference NIRS oximeter (OxiplexTS). We evaluated the NIRS oximeters FORE-SIGHT, NIRO and SenSmart, and reproduced previous results with the INVOS and OxyPrem v1.3 oximeters. In general, linear relationships of the StO2 values with respect to the reference were obtained. Device specific hypoxic and hyperoxic thresholds (as used in the SafeBoosC study, www.safeboosc.eu) and a table allowing for conversion of StO2 values are provided.

Neuroprotective Anesthesia Regimen and Intensive Management for Pediatric Cardiac Surgery with Cardiopulmonary Bypass: a Review and Initial Experience

This article describes our proposal for routine anesthesia, intraoperative medical management, cerebral and physiological monitoring during pediatric cardiac surgery with cardiopulmonary bypass that intend to provide appropriate anesthesia (analgesia, hypnosis), neuroprotection, adequate cerebral and systemic oxygen supply, and preventing against drugs neurotoxicity. A concise retrospective data is presented.

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.

Non-invasive assessment of cerebral oxygen metabolism following surgery of congenital heart disease

OBJECTIVES

Cerebral protection is a major issue in the treatment of infants with complex congenital heart disease. We tested a new device combining tissue spectrometry and laser Doppler flowmetry for non-invasive determination of cerebral oxygen metabolism following cardiac surgery in infants.

METHODS

We prospectively measured regional cerebral oxygen saturation cSO 2 and microperfusion (rcFlow) in 43 infants 12-24 h following corrective ( n  = 30) or palliative surgery ( n  = 13) of congenital heart defects. For comparison, cerebral blood flow (CBF) was determined by colour duplex sonography of the extracranial cerebral arteries. Cerebral fractional tissue oxygen extraction, approximated cerebral metabolic rate of oxygen (aCMRO 2 ) and cerebral metabolic rate of oxygen (CMRO 2 ) were calculated.

RESULTS

cSO 2 was lower [54.6% (35.7-64.0) vs 59.7% (44.5-81.7); P  < 0.01] after neonatal palliation, while rcFlow [69.7 AU (42.5-165.3) vs 77.0 AU (41.2-168.1); P  = 0.06] and cerebral fractional tissue oxygen extraction [0.34 (0.24-0.82) vs 0.38 (0.17-0.55); P  = 0.63] showed a trend towards lower values. We found a positive correlation between aCMRO 2 and CMRO 2 ( r  = 0.27; P  = 0.03). aCMRO 2 was significantly lower after neonatal palliation [4.0 AU (2.1-6.3) vs 4.9 AU (2.2-15.6); P  = 0.02].

CONCLUSIONS

According to our experience, combined photospectrometry and laser Doppler flowmetry enable non-invasive assessment of cerebral oxygen metabolism. The method promises new insights into perioperative cerebral perfusion following palliation or corrective surgery in infancy.