Factors influencing neurologic outcome after neonatal cardiopulmonary bypass: what we can and cannot control

Temperature and Neurologic Outcomes in Neonates Undergoing Cardiac Surgery: A Society of Thoracic Surgeons Study

BACKGROUND

There is significant variability in postoperative neurological injury rates in patients with congenital heart disease, with early injuries impacting long-term neurodevelopmental outcomes; therefore, there is an urgent need for identifying effective strategies to mitigate such injuries.

OBJECTIVES

This study aims to assess the association between nadir intraoperative temperature (NIT) and early neurological outcomes in neonates undergoing congenital heart surgery.

METHODS

Analyzing data from 24,345 neonatal cardiac operations from the Society for Thoracic Surgeons Congenital Heart Surgery Database between 2010 and 2019, NIT was assessed using a mixed-effect logistic regression model, targeting major neurological injury (stroke, seizure, or deficit at discharge) as a primary endpoint.

RESULTS

The study observed a shift from hypothermic circulatory arrest to cerebral perfusion with an increase in mean nadir temperature from 23.9 °C to 25.6 °C (P < 0.0001). Major neurological injury was noted in 4.9% of the cohort, with variations based on surgical procedure. After adjusting for risk, NIT was not significantly associated with major neurological injuries overall, but a lower NIT showed protective effects in the Norwood subgroup. Factors increasing the risk of major neurological injury included younger age at surgery, the Norwood procedure, longer cardiopulmonary bypass times, younger gestational age, presence of noncardiac abnormalities, and chromosomal anomalies.

CONCLUSIONS

Whereas neurological injuries are prevalent after neonatal cardiac surgery, current practices lean towards higher core temperatures. This trend is supported by the nonsignificant impact of NIT on neurological outcomes. However, lower NIT in the Norwood subgroup indicates that reduced temperatures may be beneficial amidst specific risk factors.

Health and Well-Being in Older Adults With a Surgically Closed or an Unrepaired Ventricular Septal Defect

Background Older adults with a congenital ventricular septal defect (VSD) recently exhibited reduced heart rate variability and exercise capacity. It is unknown whether these findings affect health-related quality of life. Methods and Results Adults with VSDs and healthy controls, all concurrently included as part of another clinical study, completed the Danish National Health Survey questionnaire. Questionnaire data distributed to the general population were included and matched 10:1 with patients. Thirty patients with surgically closed VSDs (mean±SD age, 51±8 years), 300 adults from the general population (mean±SD age, 50±8 years), and 30 controls (mean±SD age, 51±9 years), as well as 30 patients with unrepaired VSDs (mean±SD age, 55±11 years), 300 adults from the general population (mean±SD age, 55±12 years), and 30 controls (mean±SD age, 55±10 years) completed the questionnaire. Educational level, social relations, and physical activity were comparable between groups. A larger proportion of patients with unrepaired VSDs compared with the general population experienced migraine (47% versus 24%; P=0.04), whereas more patients with surgically closed VSDs were affected by depression (13% versus 4%; P=0.02). For health-related quality of life, patients with surgically closed VSDs reported lower physical functioning (P<0.01), physical component summary (P<0.01), general health perception (P<0.01), and higher stress score (P=0.03) compared with the general population and healthy controls. Patients with unrepaired VSDs reported lower scores on physical functioning (P=0.03), bodily pain (P<0.01), and mental health (P=0.02), and a higher stress score (P=0.03), than controls. Conclusions Older patients with VSDs report lower self-perceived physical functioning, lower general health, and higher stress levels, all in line with previous findings, like lower exercise capacity and dysfunctional cognitive abilities, in adults with VSDs. Incessant follow-up is paramount, as neither successfully closed nor hemodynamically insignificant VSD is equivalent with untroubled healthy aging. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03684161.

Modification of pulmonary endarterectomy to prevent neurologic adverse events

PURPOSE

Neurologic adverse events (NAEs) are a major complication after pulmonary endarterectomy (PEA) performed under periods of deep hypothermic circulatory arrest (HCA) for chronic thromboembolic pulmonary hypertension. We modified the PEA strategy to prevent NAEs and evaluated the effectiveness of these modifications.

METHODS

We reviewed the surgical outcomes of 87 patients divided into the following three groups based on the surgical strategy used: group S (n = 49), periods of deep HCA with alpha-stat strategy; group M1 (n = 19), deep HCA with modifications of slower cooling and rewarming rates and the pH-stat strategy for cooling: and group M2 (n = 13), multiple short periods of moderate HCA.

RESULTS

PEA provided significant improvement of pulmonary hemodynamics in each group. Sixteen (29%) of the 49 group S patients suffered NAEs, associated with total circulatory arrest time (cutoff, 57 min) and Jamieson type I disease. The Group M1 and M2 patients did not suffer NAEs, although the group M1 patients had prolonged cardiopulmonary bypass (CPB) and more frequent respiratory failure.

CONCLUSIONS

NAEs were common after PEA performed under periods of deep HCA. The modified surgical strategy could decrease the risk of NAEs but increase the risk of respiratory failure. Multiple short periods of moderate HCA may be useful for patients at risk of NAEs.

Cardiovascular surgery in very low birth weight (≤1500 g) neonates

OBJECTIVES

Low birth weight and prematurity are known risks of increased morbidity and mortality with undergoing cardiovascular surgery. Our aim was to review the outcomes of very low birth weight (≤1500 g) patients who have undergone cardiovascular surgery.

METHODS

A retrospective review was performed for 32 very low birth weight (≤1500 g) patients who underwent cardiovascular surgery from 2004 to 2021 in our institution.

RESULTS

Fifteen patients weighting ≤1500 g at surgery (≤1500-g group) were compared to 17 patients born with a weigh of ≤1500 g and weighting between 1500 and 2500 g at surgery (>1500- to ≤2500-g group) in this study. In-hospital mortality was 33% (5/15) in the ≤1500-g group and 24% (4/17) in the >1500- to ≤2500-g group (P = 0.55). All patients with simple biventricular lesion survived following full repair. The occurrence of postoperative intracerebral haemorrhage was significantly higher in those operated at weight ≤1500 g than those weighting >1500 to ≤2500 g (40% vs 0%; P = 0.01). The 1- and 3-year survival rates were 66.0 ± 12.4% and 46.2 ± 14.8% in the ≤1500-g group and 76.5 ± 10.3% and 70.6 ± 11.1% in the >1500- to ≤2500-g group (log-rank P = 0.12).

CONCLUSIONS

Cardiac surgery for a very low birth weight neonate resulted in a high early and late mortality. Early surgery is only acceptable for simple biventricular lesions if needed. Delayed surgery seems to provide better long-term outcomes in patients with complex lesions. Alternative strategies for neonatal cardiopulmonary bypass should be investigated in patients with complex biventricular and single ventricular lesions.

Self- and informant-reported executive function in young adults operated for atrial or ventricular septal defects in childhood

BACKGROUND

Adults with simple congenital heart defects (CHD) have increased risk of neurodevelopmental challenges including executive dysfunction. It is unknown if the executive dysfunction is universal or if it is driven by dysfunction in specific clinical subscales and how it might affect psychosocial aspects of everyday life.

METHODS

The self-reported and informant-reported executive function of adults with an average age of 26 ± 5 (range 18-41) who underwent childhood surgery for atrial septal defects (n = 34) or ventricular septal defects (n = 32) and matched controls (n = 40) were evaluated using the Behavior Rating Inventory of Executive Functions - Adult version (BRIEF-A).

RESULTS

The CHD group reported having more executive dysfunction than controls in all BRIEF-A clinical subscales (p < 0.020) and more than their informants reported on their behalf (p < 0.006). The CHD group had received three times more special teaching (44% compared to 16%) and pedagogical psychological counselling (14% compared to none) and had a three times higher occurrence of psychiatric disorders than controls (33% compared to 11%). Lower educational levels and psychiatric disorders were associated with higher BRIEF-A scores (p < 0.03).

CONCLUSIONS

Adults operated for septal defects in childhood report more challenges with all aspects of the executive functions than controls and more than relatives are aware of.

Inattention and hyperactivity in children and adolescents with repaired D-transposition of the great arteries: Prevalence, perioperative risk factors, and clinical outcomes

Objective

The present study objectives were to determine the prevalence of attention-deficit/hyperactivity disorder symptoms (ADHD-like symptoms) in children and adolescent with d-transposition of great artery (D-TGA) after arterial switch operation (ASO) and examine associated risk factors and adverse personal, family dysfunctions.

Methods

This cohort study included 103 patients with D-TGA who underwent ASO in early infancy at Shanghai Children’s Medical Center between 2011 and 2016 and then follow-up. Data analysis was conducted from September 2020 to April 2022. A standardized Swanson, Nolan, and Pelham IV (SNAP-IV) questionnaire is used to evaluate inattention and hyperactivity symptoms. Demographic, preoperative, intraoperative, and postoperative factor were collected. Univariate and multivariable regression analyses were performed with odds ratios (OR) and 95% confidence intervals (CIs).

Results

Prevalence of ADHD-like symptoms was 27.18% (28/103). Attention-deficit (18/28, 64.29%) symptom was the predominant subphenotype. After underwent TGA surgery, 39% of patients with ADHD-like symptoms receive remedial special academic services. There is none had repeated grade. Univariate analysis showed that, positive inotropic drug score (P = 0.03) and delayed sternal closure (P = 0.02) were risk factors of ADHD-like symptoms; increased preoperative oxygen saturation (SpO2) (P = 0.01) and surgical height (P = 0.01) and TGA subtype (VSD) (P = 0.02) were protective factor of ADHD-like symptoms. Multivariable analysis showed that delayed sternal closure (DSC) (OR, 1.50; 95% CI, 1.02–2.18) is a risk factor for the occurrence of ADHD-like symptom while increased preoperative oxygen saturation [odds ratio (OR), 0.95; 95% confidence interval (CI), 0.92–0.99] is a protective factor of ADHD-like symptom.

Conclusion

The children and adolescents with D-TGA after ASO were at high risk of ADHD-like symptoms. Preoperative hypoxic status and postoperative DSC became predominant risk factors. Modification of the risk factors may be helpful to relieve ADHD-like symptoms for these patients.

Impact of a Multidisciplinary Research Team Approach to Prevent Avoidable Mistakes for Neonatal CPB Population

Significant progress has been made in neonatal cardiopulmonary bypass (CPB) over the years. At Penn State Health Children's Hospital, we have established a multidisciplinary research team that brings clinicians, engineers, scientists, research nurses, neuromonitoring technicians, perfusionists, and students from various departments to help reduce adverse outcomes following CPB in neonates. With the help of this team, we evaluate each CPB component in simulated conditions identical to those used in clinical practice. The objective of this review is to demonstrate the results of these translational projects and present critical mistakes to avoid for neonatal CPB patients.

Age-Related Changes in Cerebral Hemodynamics in Children Undergoing Congenital Cardiac Surgery: A Prospective Observational Study

OBJECTIVE

To explore age-related cerebral hemodynamic characteristics before and after pediatric cardiac surgery.

DESIGN

Prospective observational study.

SETTING

Single-center study based at a tertiary care center in Shanghai, China.

PATIENTS

Fifty-three children with congenital heart disease (CHD) aged zero-to-six years undergoing cardiac surgery with cardiopulmonary bypass were enrolled, and 44 children finally were analyzed.

INTERVENTION

Cerebral hemodynamics were measured by transcranial color-coded duplex sonography in the right temporal window before and after surgery. The resistance index (RI), pulsatility index (PI), and cerebral blood flow velocity (CBFV), including time average maximum flow velocity (V_tamax), mean blood flow velocity (V_mean), and the peak systolic flow velocity (V_peak), of the right middle cerebral artery (MCA) and regional cerebral oxygen saturation (rScO₂) of the right frontal lobe were measured and analyzed. Heart rate and mean arterial pressure were also recorded during ultrasound.

MEASUREMENTS AND MAIN RESULTS

RI and PI decreased exponentially with age before and after cardiac surgery. While PI remained unchanged after cardiac surgery, RI was significantly reduced. Furthermore, RI reduction after cardiac surgery was more significant in children >18 months compared to those ≤18 months. CBFV of the right MCA also showed exponential increase with age, but rScO₂ linearly increased. Cardiac surgery significantly changed the cerebral hemodynamics, but it did not affect rScO₂ in children regardless of age.

CONCLUSIONS

Age-related cerebral hemodynamic changes exist in children with CHD. Cardiopulmonary bypass surgery led to greater cerebrovascular dilation in children aged ≤18 months than those >18 months.

Perioperative GABA Blood Concentrations in Infants with Cyanotic and Non-Cyanotic Congenital Heart Diseases

Perioperative stress detection in children with congenital heart disease (CHD), particularly in the brain, is still limited. Among biomarkers, γ-amino-aminobutyric acid (GABA) assessment in biological fluids appears to be promising for its regulatory action on the cardiovascular and cerebral systems. We aimed to investigate cyanotic (C) or non-cyanotic (N) CHD children for GABA blood level changes in the perioperative period. We conducted an observational study in 68 CHD infants (C: n = 33; N: n = 35) who underwent perioperative clinical, standard laboratory and monitoring parameter recordings and GABA assessment. Blood samples were drawn at five predetermined time-points before, during and after surgery. No significant perioperative differences were observed between groups in clinical and laboratory parameters. In C, perioperative GABA levels were significantly lower than N. Arterial oxygen saturation and blood concentration significantly differed between C and N children and correlated at cardiopulmonary by-pass (CPB) time-point with GABA levels. The present data showing higher hypoxia/hyperoxia-mediated GABA concentrations in C children suggest that they are more prone to perioperative cardiovascular and brain stress/damage. The findings suggest the usefulness of further investigations to detect the “optimal” oxygen concentration target in order to avoid the side effects associated with re-oxygenation during CPB.

Risk of Lifetime Psychiatric Morbidity in Adults With Atrial Septal Defect (from a Nation-Wide Cohort)

In this nation-wide cohort study we report the first long-term results of the association between having a atrial septal defects (ASD) on psychiatric disorders and use of psychotropic agents. Through population-based registries we included Danish individuals born before 1994 who received an ASD diagnosis between 1959and 2013. We used Cox proportional hazards regression and Fine and Grey competing risk regression to estimate the risk of receiving a psychiatric diagnosis and use of psychotropic medicine compared with a gender and age matched background population cohort. In 2,277 patients with a median follow-up from ASD diagnosis of 23.4 years (range 0.2 to 59.3 years) we found ASD patients to have a higher risk of psychiatric disorders (adjusted hazard ratio [HR]: 3.9; 95% confidence interval [CI] 3.4 to 4.5) compared with the comparison cohort and a cumulative incidence of using psychotropic agents 30 years after the ASD diagnosis of 47.4% (95% CI: 40.3 to 55.1) in the ASD patients and 25.5%, (95% CI: 23.5 to 27.8) in the comparison cohort. Diagnosis of the ASD before the age of 15 years (adjusted HR: 3.4; 95% confidence interval: 2.0 to 4.0) and surgical correction of the defect (HR: 1.5 (95% CI: 1.2 to 1.8), p <0.0001) had a higher risk than those with an ASD diagnosis after the age of 15 years and those with transcatheter closure of the defect. In conclusion, ASD patients had increased long-term risk of psychiatric disorder and use of psychotropic agents compared with a gender and age matched general population controls.

Motor outcome, executive functioning, and health-related quality of life of children, adolescents, and young adults after ventricular assist device and heart transplantation

OBJECTIVE

The aim of the current study is to measure long-term executive function, motor outcome, and QoL in children, adolescents, and young adults after VAD and Htx.

METHODS

Patients were examined during routine follow-up. Investigation tools were used as follows: Examination for MND of motor outcomes, Epitrack^® for attention and executive functioning, and Kidscreen-52 and EQ-5D-5L questionnaires for QoL. Additional data were retrospectively obtained by an analysis of patient medical records.

RESULTS

Out of 145 heart transplant recipients at the department of pediatric cardiology of the University Hospital Munich, 39 were implanted with a VAD between 1992 and 2016. Seventeen (43.6%) patients died before or after Htx; 22 (56.4%) patients were included in our study. Mean age at transplant was 9.52 years (range: 0.58-24.39 years, median 9), and the mean follow-up time after Htx was 6.18 years (range: 0.05-14.60 years, median 5.82). MND examination could be performed in 13 patients (normal MND: n = 11, simple MND: n = 1, complex MND: n = 1). Executive functioning was tested in 15 patients. Two (13.3%) patients had good results, six (40%) average results, three (20%) borderline results, and four (26.7%) impaired results. QoL (Kidscreen n = 7, EQ-5D-5L n = 8) was similar to a healthy German population.

CONCLUSION

Motor outcome, executive functioning and QoL in survivors of VAD bridging therapy and Htx can be good, though underlying diseases and therapies are associated with a high risk of cerebral ischemic or hemorrhagic complications.

Pumping O2 with no N2: An Overview of Hollow Fiber Membrane Oxygenators with Integrated Arterial Filters

The advancement of cardiac surgery benefits from the continual technological progress of cardiopulmonary bypass (CPB). Every improvement in the CPB technology requires further clinical and laboratory tests to prove its safety and effectiveness before it can be widely used in clinical practice. In order to reduce the priming volume and eliminate a separate arterial filter in the CPB circuit, several manufacturers developed novel hollow-fiber membrane oxygenators with integrated arterial filters (IAF). Clinical and experimental studies demonstrated that an oxygenator with IAF could reduce total priming volume, blood donor exposure and gaseous microemboli delivery to the patient. It can be easily set up and managed, simplifying the CPB circuit without sacrificing safety. An oxygenator with IAF is expected to be more beneficial to the patients with low body weight and when using a minimized extracorporeal circulation system. The aim of this review manuscript was to discuss briefly the concept of integration, the current oxygenators with IAF, and the in-vitro / in-vivo performance of the oxygenators with IAF.

Staged Versus Complete Repair in the Symptomatic Neonate With Tetralogy of Fallot

BACKGROUND

The optimal management of tetralogy of Fallot (TOF) in symptomatic neonates remains unknown. We compared outcomes for those undergoing palliation vs complete repair in the neonatal period.

METHODS

In a retrospective cohort study of symptomatic neonates with TOF who had a neonatal complete repair (group 1, n = 112) or staged repair (group 2, n = 26) from 2000 to 2013, we compared outcomes at 4 time points: neonatal complete repair vs palliation (group 1 vs 2A), neonatal vs later complete repair (group 1 vs 2B), the single vs combined admissions to achieve a complete repair (group 1 vs group 2A + 2B), and cumulative events 2 years after complete repair for both groups.

RESULTS

Demographics, anatomy, comorbidities, surgical approach, and mortality were similar between groups 1 and 2. Group 1 had a longer duration of cardiopulmonary bypass and deep hypothermic circulatory arrest and more postprocedure cardiac events compared with group 2A; a longer duration of intubation, intensive care, and postprocedure hospital stay compared with groups 2A and 2B; and a longer total hospital stay compared with group 2B. With combined admissions for group 2, there was no difference in the total duration of intensive care, total hospital stay, or reinterventions compared with group 1.

CONCLUSIONS

Both management options result in similar survival; however, early morbidity was greater with neonatal complete repair. The impact of increased neonatal exposures, such as cardiopulmonary bypass, deep hypothermic circulatory arrest, and intensive care, on neurocognitive development requires further study but should be considered when choosing an optimal strategy.

Glutathione Blood Concentrations: A Biomarker of Oxidative Damage Protection during Cardiopulmonary Bypass in Children

Background. Pediatric open-heart surgery with cardiopulmonary bypass (CPB) still remains a risky interventional procedure at high mortality/morbidity. To date, there are no clinical, laboratory, and/or monitoring parameters providing useful information on perioperative stress. We therefore investigated whether blood concentrations of glutathione (GSH), a powerful endogenous antioxidant, changed in the perioperative period. Methods. We conducted an observational study in 35 congenital heart disease (CHD) children in whom perioperative standard laboratory and monitoring parameters and GSH blood levels were assessed at five monitoring time points. Results. GSH showed a pattern characterized by a progressive increase from pre-surgery up to 24 h after surgery, reaching its highest peak at the end of CPB. GSH measured at the end of CPB correlated with CPB duration, cross-clamping, arterial oxygen partial pressure, and with body core temperature. Conclusions. The increase in GSH levels in the perioperative period suggests a compensatory mechanism to oxidative damage during surgical procedure. Caution is needed in controlling different CPB phases, especially systemic reoxygenation in a population that is per se more prone to oxidative stress/damage. The findings may point the way to detecting the optimal temperature and oxygenation target by biomarker monitoring.

School-Age Developmental and Educational Outcomes Following Cardiac Procedures in the First Year of Life: A Population-Based Record Linkage Study

The purpose of the study was to evaluate school-age developmental and educational outcomes for children with and without a cardiac procedure in the first year of life to improve understanding of longer-term neurodevelopmental outcomes in children who have had a cardiac procedure for congenital heart disease, the most common serious congenital anomaly. A population-based cohort study using record linkage of state-wide data was undertaken, evaluating children born in New South Wales, Australia, 2001-2007. Those with and without a cardiac procedure in the first year of life with a linked developmental (Australian version Early Development Instrument testing result, age 4-6 years) and/or educational outcome (Australian National Assessment Program result, age 7-9 years) were included. Perinatal, perioperative and sociodemographic factors were examined using multivariable logistic regression models. Of 468,329 eligible children, 768 had a cardiac procedure in the first year of life and 582 were included. For those with a cardiac procedure and developmental outcome (n = 260), 13.1% were classified as having 'special needs' compared to 4.4% without a cardiac procedure. Of those with an educational outcome, after adjusting for perinatal, perioperative and demographic variables, children with a cardiac procedure (n = 396) were twice as likely to score below National Minimum Standard in school literacy and numeracy tests compared to their peers. Significant predictors included low birthweight, parent not completing school and having > 4 re-hospitalisations in their first six years. The developmental and educational trajectory of children who have had a cardiac procedure in their first year remains altered into primary school years. While perioperative factors did not impact outcomes, ongoing health and sociodemographic factors were important in identifying those children at greatest risk.

In-Vitro Evaluation of Two Types of Neonatal Oxygenators in Handling Gaseous Microemboli and Maintaining Optimal Hemodynamic Stability During Cardiopulmonary Bypass

Objective

Usually only FDA-approved oxygenators are subject of studies by the international scientific community. The objective of this study is to evaluate two types of neonatal membrane oxygenators in terms of transmembrane pressure gradient, hemodynamic energy transmission and gaseous microemboli capture in simulated cardiopulmonary bypass systems.

Methods

We investigated the Braile Infant 1500 (Braile Biomédica, São José do Rio Preto, Brazil), an oxygenator commonly used in Brazilian operating rooms, and compared it to the Dideco Kids D100 (Sorin Group, Arvada, CO, USA), that is an FDA-approved and widely used model in the USA. Cardiopulmonary bypass circuits were primed with lactated Ringer's solution and packed red blood cells (Hematocrit 40%). Trials were conducted at flow rates of 500 ml/min and 700 ml/min at 35ºC and 25ºC. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For gaseous microemboli testing, 5cc of air were manually injected into the venous line. Gaseous microemboli were recorded using the Emboli Detection and Classification Quantifier.

Results

Braile Infant 1500 had a lower pressure drop (P<0.01) and a higher total hemodynamic energy delivered to the pseudopatient (P<0.01). However, there was a higher raw number of gaseous microemboli seen prior to oxygenator at lower temperatures with the Braile oxygenator compared to the Kids D100 (P<0.01).

Conclusion

Braile Infant 1500 oxygenator had a better hemodynamic performance compared to the Dideco Kids D100 oxygenator. Braile had more gaseous microemboli detected at the pre-oxygenator site under hypothermia, but delivered a smaller percentage of air emboli to the pseudopatient than the Dideco oxygenator.

S100B increases in cyanotic versus noncyanotic infants undergoing heart surgery and cardiopulmonary bypass (CPB)

AIMS

S100B has been proposed as a consolidated marker of brain damage in infants with congenital heart disease (CHD) undergoing cardiac surgery and cardiopulmonary bypass (CPB). The present study aimed to investigate whether S100B blood levels in the perioperative period differed in infants complicated or not by cyanotic CHD (CHDc) and correlated with oxygenation status (PaO₂).

METHODS

We conducted a case-control study of 48 CHD infants without pre-existing neurological disorders undergoing surgical repair and CPB. 24 infants were CHDc and 24 were CHD controls. Blood samples for S100B assessment were collected at six monitoring time-points: before the surgical procedure (T0), after sternotomy but before CPB (T1), at the end of the cross-clamp CPB phase (T2), at the end of CPB (T3), at the end of the surgical procedure (T4), at 24 h postsurgery (T5).

RESULTS

In the CHDc group, S100B multiples of median (MoM) were significantly higher (p < .05, for all) from T0 to T5. PaO₂ was significantly lower (p < .05, for all) in CHDc infants at T0-T1 and at T4 while no differences (p > .05, for all) were found at T2, T3, T5. Linear regression analysis showed a positive correlation between S100B MoM at T3 and PaO₂ (R = 0.84; p < .001).

CONCLUSIONS

The present data showing higher hypoxia/hyperoxia-mediated S100B concentrations in CHDc infants suggest that CHDc are more prone to perioperative brain stress/damage and suggest the usefulness of further investigations to detect the "optimal" PaO₂ target in order to avoid the side effects associated with reoxygenation during CPB.

Assessment of cerebral blood flow in adult patients with aortic coarctation

BACKGROUND

Survival into adult life in patients with aortic coarctation is typical following surgical and catheter-based techniques to relieve obstruction. Late sequelae are recognised, including stroke, hypertension, and intracerebral aneurysm formation, with the underlying mechanisms being unclear. We hypothesised that patients with a history of aortic coarctation may have abnormalities of cerebral blood flow compared with controls.

METHODS

Patients with a history of aortic coarctation underwent assessment of cerebral vascular function. Vascular responsiveness of intracranial vessels to hypercapnia and degree of cerebral artery stiffness using Doppler-derived pulsatility indices were used. Response to photic stimuli was used to assess neurovascular coupling, which reflects endothelial function in response to neuronal activation. Patient results were compared with age- and sex-matched controls.

RESULTS

A total of 13 adult patients (males=10; 77%) along with 13 controls underwent evaluation. The mean age was 36.1±3.7 years in the patient group. Patients with a background of aortic coarctation were noted to have increased pulse pressure on blood pressure assessment at baseline with increased intracranial artery stiffness compared with controls. Patients with a history of aortic coarctation had less reactive cerebral vasculature to hypercapnic stimuli and impaired neurovascular coupling compared with controls.

RESULTS

Adult patients with aortic coarctation had increased intracranial artery stiffness compared with controls, in addition to cerebral vasculature showing less responsiveness to hypercapnic and photic stimuli. Further studies are required to assess the aetiology and consequences of these documented abnormalities in cerebral blood flow in terms of stroke risk, cerebral aneurysm formation, and cognitive dysfunction.

Brain injury with systemic inflammation in newborns with congenital heart disease undergoing heart surgery

The potential role of systemic inflammation on brain injury in newborns with congenital heart disease (CHD) was assessed by measuring levels of central nervous system (CNS)-derived proteins in serum prior to and following cardiac surgery. A total of 23 newborns (gestational age, 39±1 weeks) with a diagnosis of CHD that required cardiac surgery with cardiopulmonary bypass (CPB) were enrolled in the current study. Serum samples were collected immediately prior to surgery and 2, 24 and 48 h following CPB, and serum levels of phosphorylated neurofilament-heavy subunit (pNF-H), neuron-specific enolase (NSE) and S100B were analyzed. Systemic inflammation was assessed by measuring serum concentrations of complement C5a and complement sC5b9, and the following cytokines: Interleukin (IL)-1β, IL-6, IL-8, IL-10, IL12p70, interferon γ and tumor necrosis factor (TNF)-α. Analysis of cord blood from normal term deliveries (n=26) provided surrogate normative values for newborns. pNF-H and S100B were 2.4- to 2.8-fold higher (P<0.0001) in patient sera than in cord blood prior to surgery and remained elevated following CPB. Pre-surgical serum pNF-H and S100B levels directly correlated with interleukin (IL)-12p70 (ρ=0.442, P<0.05). pNF-H was inversely correlated with arterial pO₂ prior to surgery (ρ=−0.493, P=0.01) and directly correlated with arterial pCO₂ post-CPB (ρ=0.426, P<0.05), suggesting that tissue hypoxia and inflammation contribute to blood brain barrier (BBB) dysfunction and neuronal injury. Serum IL12p70, IL-6, IL-8, IL-10 and TNF-α levels were significantly higher in patients than in normal cord blood and levels of these cytokines increased following CPB (P<0.001). Activation of complement was observed in all patients prior to surgery, and serum C5a and sC5b9 remained elevated up to 48 h post-surgery. Furthermore, they were correlated (P<0.05) with low arterial pO₂, high pCO₂ and elevated arterial pressure in the postoperative period. Length of mechanical ventilation was associated directly with post-surgery serum IL-12p70 and IL-8 concentrations (P<0.05). Elevated serum concentrations of pNF-H and S100B in neonates with CHD suggest BBB dysfunction and CNS injury, with concurrent hypoxemia and an activated inflammatory response potentiating this effect.

Rates of autism and potential risk factors in children with congenital heart defects

OBJECTIVE

Atypical development, behavioral difficulties, and academic underachievement are common morbidities in children with a history of congenital heart defects and impact quality of life. Language and social-cognitive deficits have been described, which are associated with autism spectrum disorders. The current study aimed to assess the rates of autism spectrum disorders in a large sample of children with a history of congenital heart defects and to assess medical, behavioral, and individual factors that may be associated with the risk of autism spectrum disorders.

DESIGN

Participants included 195 children with a history of congenital heart defects, who are followed in a large-scale longitudinal study. Measures included behavioral data from 4-year-old neurodevelopmental evaluations and parent-report data from a later annual follow-up.

RESULTS

Using established cutoffs on an autism spectrum disorder screener, children with congenital heart defects showed higher rates of "possible" autism spectrum disorders than national rates, (Chi-square Test of Equal Proportions), all Ps < .05. A stepwise variable selection method was used to create a "best prediction model" and multivariable logistic regression was used to identify variables predicting diagnostic status. Factors associated with diagnostic risk included medical (delayed sternal closure, prematurity, positive genetic findings), behavioral (cognitive, language, attention issues), and individual (socioeconomic, cultural/racial) variables. ROC analyses identified a cutoff of 7 to maximize sensitivity/specificity based on parent-reported diagnosis.

CONCLUSIONS

Risk of autism spectrum disorder screening status in children with congenital heart defects was higher than expected from population rates. Findings highlight the need for referral to a specialist to assess the presence and severity of social-communication issues and congenital heart defects population-specific screening thresholds for children with concern for autism spectrum disorders.

In vitro elimination of gaseous microemboli utilizing hypobaric oxygenation in the Terumo® FX15 oxygenator

BACKGROUND

This study examines the efficacy of hypobaric oxygenation as it relates to the elimination of gaseous microemboli (GME) at designated flow, pressure and temperature combinations.

METHODS

Hypobaric oxygenation was employed for experimental trials (n=60), but not for control trials (n=60), while circuit design, data measurements and testing conditions were maintained for both settings. Hypobaric oxygenation conditions were created by applying 100% oxygen at sub-atmospheric sweep gas pressures of 0.67 atmospheres to the gas phase of an integrated hollow-fiber microporous membrane oxygenator. GME were quantified using an Emboli Detection and Classification system (EDAC), while a continuous air infusion, at a rate of 100 ml/min, was applied to the circuit. Trials were conducted at 37°C, 28°C, and 18°C and at two flow and line pressure combinations of: 3.5 L/min & 150 mmHg and 5 L/min & 200 mmHg.

RESULTS

Sub-atmospheric sweep gas pressures allowed adequate oxygenation independent of carbon dioxide removal while significantly reducing the potential entrance of nitrogen into the blood. GME was reduced significantly across all temperatures and flows when compared to control trials; GME counts were reduced by 99.7% post-oxygenator and 99.99% at the arterial cannula.

CONCLUSION

Correlation between the use of hypobaric oxygenation and GME counts suggests hypobaric oxygenation could play a significant role in the reduction of GME.

Benefits of Balloon-Dilatable Bilateral Pulmonary Artery Banding in Patients With Hypoplastic Left Heart Syndrome and Other Complex Cardiac Anomalies

OBJECTIVES

The purpose of this study was to evaluate the potential of balloon-dilatable bilateral pulmonary artery banding (b-PAB) and its impact on the configuration of the pulmonary artery (PA).

BACKGROUND

We have previously used balloon-dilatable b-PAB as first-stage palliation for patients with hypoplastic left heart syndrome (HLHS) and other complex cardiac anomalies.

METHODS

Two pliable tapes were placed around each branch of the PA and tightened with 7-0 polypropylene sutures in a manner that allowed for the subsequent adjustment of PA diameters. We retrospectively examined the adjustability of PA diameters by balloon dilation and the need for surgical PA angioplasty at later stages.

RESULTS

From January 2010 to October 2013, we performed b-PAB in 8 patients, including 3 borderline cases between biventricular repair (BVR) and univentricular repair (UVR). The b-PAB procedures were performed at a median age of 6.5 days (range, 2-10 days). Balloon dilations were performed in 10 lesions in 4 patients. All of the procedures were performed safely. Two patients reached definite BVR. The remaining 6 patients underwent open palliative procedures with univentricular physiologies that resulted in 2 deaths unrelated to the initial b-PAB. In all but 1 of the patients, the PA configuration was properly maintained and did not require surgical pulmonary angioplasty.

CONCLUSIONS

Balloon-dilatable b-PAB can be performed safely and prevents PA distortion at later stages. This technique should be considered for patients with complex cardiac anomalies if uncertainty exists regarding the optimal surgical strategy (BVR or UVR) in early infancy.

White matter injury and the inflammatory response following neonatal cardiac surgery

White matter injury (WMI) is a known complication following neonatal heart surgery in term infants. In preterm infants, WMI has been associated with the degree of systemic inflammation. It is not known whether inflammation is an important mechanism of WMI as documented by magnetic resonance imaging (MRI) following neonatal heart surgery with cardiopulmonary bypass. Term neonates with congenital heart disease were enrolled in a prospective study with postoperative MRI. White matter injury was recorded by the number of T1 hyperintense foci with >5 foci consistent with significant WMI. Eleven candidate cytokine markers (INF-gamma, TNF-alpha, IL-1 beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, and IL-13) were assayed preoperatively and daily for 5 days following surgery. Multiple clinical factors were recorded and correlated with WMI. Ninety-two subjects were enrolled in the study. The median age at surgery was 5 days (interquartile range 4-7 days). Compared with the presurgery level, there were statistically significant increases (p < 0.005) for 8 out of 11 inflammatory markers. In all, 64 postoperative MRIs were performed. No significant correlation was detected between WMI and clinical variables or inflammatory markers assessed immediately postoperative and on postoperative days 1 and 3, with exception of IL-1 beta on postoperative day 1. WMI correlates poorly with the systemic inflammatory response after congenital heart surgery and a number of herein measured clinical factors. WMI following neonatal heart surgery is a complex, still incompletely understood phenomenon that warrants continued investigation.

Hippocampal Neuroprotection by Minocycline and Epigallo-Catechin-3-Gallate Against Cardiopulmonary Bypass-Associated Injury

Surgical correction of congenital cardiac malformations mostly implies the use of cardiopulmonary bypass (CPB). However, a possible negative impact of CPB on cerebral structures like the hippocampus cannot be neglected. Therefore, we investigated the effect of CPB on hippocampus CA1 and CA3 regions without or with the addition of epigallocatechin-3-gallate (EGCG) or minocycline. We studied 42 piglets and divided them into six experimental groups: control without or with EGCG or minocycline, CPB without or with EGCG or minocycline. The piglets underwent 90 minutes CPB and subsequently, a 120-minute recovery and reperfusion phase. Thereafter, histology of the hippocampus was performed and the adenosine triphosphate (ATP) content was measured. Histologic evaluation revealed that CPB produced a significant peri-cellular edema in both CA regions. Moreover, we found an increased number of cells stained with markers for hypoxia, apoptosis and nitrosative stress. Most of these alterations were significantly reduced to or near to control levels by application of EGCG or minocycline. ATP content was significantly reduced within the hippocampus after CPB. This reduction could not be antagonized by EGCG or minocycline. In conclusion, CPB had a significant negative impact on the integrity of hippocampal neural cells. This cellular damage could be significantly attenuated by addition of EGCG or minocycline.

In vitro air removal characteristics of two neonatal cardiopulmonary bypass systems: filtration may lead to fractionation of bubbles

Introduction of gaseous microemboli (GME) into the arterial line of a pediatric cardiopulmonary bypass (CPB) circuit may lead to cognitive decline and adverse outcomes of the pediatric patient.Arterial filters are incorporated into CPB circuits as a safeguard for gross air and to reduce GME. Recently, arterial filters were integrated in two neonatal oxygenators to reduce volume and foreign surface area. In this study a clinical CPB scenario was simulated. The oxygenators, the corresponding venous reservoirs and the complete CPB circuits were compared regarding air removal and bubble size distribution after the introduction of an air bolus or GME. During a GME challenge, the Capiox FX05 oxygenator removed a significantly higher volume of GME than the QUADROX-i Neonatal oxygenator (97% vs. 86%). Detailed air removal characteristics showed that more GME in the range of 20-50 µm were leaving the devices than were entering. This phenomenon seems to be more present in the Capiox FX05. The circuits were also challenged with an air bolus. Each individual component tested removed 99.9%, which resulted in an air volume reduction of 99.99% by either complete CBP circuit. Overall, we conclude that both CPB systems were very adequate in removing GME and gross air. The air removal properties of both systems are considered safe and reliable. Detailed GME distribution data show that the Capiox FX05 showed more small GME (<50 µm) due to fractionation of larger GME when compared to the QUADROX-i Neonatal. We may conclude that filtration may lead to fractionation.

Changes in cerebral oxygen saturation correlate with S100B in infants undergoing cardiac surgery with cardiopulmonary bypass

OBJECTIVES

The relationship of cerebral saturation measured by near-infrared spectroscopy with serum biomarker of brain injury S100B was investigated in infants undergoing cardiac surgery with cardiopulmonary bypass.

DESIGN

Prospective cohort study.

SETTING

Single-center children's hospital.

PATIENTS

Forty infants between 1 and 12 months old weighing greater than or equal to 4 kg with congenital heart disease undergoing cardiac surgery with cardiopulmonary bypass were enrolled.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Serum S100B was measured at eight time points over 72 hours using enzyme-linked immunosorbent assay. Physiologic data including arterial, cerebral, and somatic regional oxygen saturations measured by near-infrared spectroscopy were synchronously recorded at 1-minute intervals from anesthesia induction through 72 postoperative hours. The arterial-cerebral oxygen saturation difference was calculated as the difference between arterial saturation and cerebral regional saturation. Thirty-eight patients, 5.4 ± 2.5 months old, were included in the analysis; two were excluded due to the use of postoperative extracorporeal membrane oxygenation. Seventeen patients (44.7%) had preoperative cyanosis. S100B increased during cardiopulmonary bypass in all patients, from a median preoperative baseline of mean ± SE: 0.055 ± 0.038 to a peak of 0.610 ± 0.038 ng/mL, p less than 0.0001. Patients without preoperative cyanosis had a higher S100B peak at the end of cardiopulmonary bypass. Although the absolute cerebral regional saturation on cardiopulmonary bypass was not associated with S100B elevation, patients who had arterial-cerebral oxygen saturation difference greater than 50 at any time during cardiopulmonary bypass had a higher S100B peak (mean ± SE: 1.053 ± 0.080 vs 0.504 ± 0.039 ng/mL; p < 0.0001).

CONCLUSIONS

A wide cerebral arteriovenous difference measured by near-infrared spectroscopy during cardiopulmonary bypass is associated with increased serum S100B in the perioperative period and may be a modifiable risk factor for neurological injury.

Academic proficiency in children after early congenital heart disease surgery

Children with early surgery for congenital heart disease (CHD) are known to have impaired neurodevelopment; their performance on school-age achievement tests and their need for special education remains largely unexplored. The study aimed to determine predictors of academic achievement at school age and placement in special education services among early CHD surgery survivors. Children with CHD surgery at <1 year of age from January 1, 1998 to December 31, 2003, at the Arkansas Children's Hospital were identified. Out-of-state births and infants with known genetic and/or neurologic conditions were excluded. Infants were matched to an Arkansas Department of Education database containing standardized assessments at early school age and special-education codes. Predictors for achieving proficiency in literacy and mathematics and the receipt of special education were determined. Two hundred fifty-six children who attended Arkansas public schools and who had surgery as infants were included; 77.7 % had either school-age achievement-test scores or special-education codes of mental retardation or multiple disabilities. Scores on achievement tests for these children were 7-13 % lower than those of Arkansas students (p < 0.01). They had an eightfold increase in receipt of special education due to multiple disabilities [odds ratio (OR) 10.66, 95 % confidence interval (CI) 4.23-22.35] or mental retardation (OR 4.96, 95 % CI 2.6-8.64). Surgery after the neonatal period was associated with decreased literacy proficiency, and cardiopulmonary bypass during the first surgery was associated with decreased mathematics proficiency. Children who had early CHD surgery were less proficient on standardized school assessments, and many received special education. This is concerning because achievement-test scores at school age are "real-world" predictors of long-term outcomes.

Effects of phentolamine infusion during selective cerebral perfusion in neonatal piglets

BACKGROUND

An optimal selective cerebral perfusion protocol in pediatric cardiac surgery is unknown. Phentolamine is frequently used in pediatric cardiopulmonary bypass. We sought to determine the effects of continuous phentolamine infusion during selective cerebral perfusion.

METHODS

Twenty-seven neonatal piglets (3.38 ± 0.32 kg) were randomly assigned to 3 groups; sham (n = 7, anesthesia alone, no surgery or bypass), control (n = 10, saline infusion), or experimental (n = 10, phentolamine infusion 0.1 mg/kg per hour). Animals underwent 90 minutes of selective cerebral perfusion. Cerebral vascular resistance index (CVRI) and metabolic rate of oxygen (CMRO2) were determined every 15 minutes. Standardized sections of hippocampus, basal ganglia, and neo-cortex were obtained. Tissue samples were stained for caspase-3 and analyzed for positive apoptotic cell count. Data were analyzed with repeated measures and one-way analysis of variance.

RESULTS

The CVRI tended to increase over time in the control group and decrease over time in the experimental group, but difference was not statically significant (0.46 ± 0.24 vs 0.39 ± 0.10 mm Hg × min × kg(2/3)/mL, p = 0.15). Mean CMRO2 was higher in the control group compared with the experimental group (0.90 ± 0.27 vs 0.59 ± 0.12 mLO2/min × kg(2/3), p = 0.005) and decreased over time in both groups. The percentage of caspase-3 positive cells was significantly different among regions (hippocampus = 16.9 ± 8.8; basal ganglia = 14.6 ± 7.5; neocortex = 10.8 ± 6.3; p < 0.0001) but not significantly different among sham (11.8% ± 2.68%), control (14.4% ± 2.24%), and experimental (15.5% ± 2.24%) groups.

CONCLUSIONS

A continuous infusion of phentolamine during selective cerebral perfusion significantly decreases CMRO2 and tends to decrease CVRI when compared with control. At the dose studied and at the time of tissue sampling, phentolamine does not appear to decrease apoptosis during or early after selective cerebral perfusion.

Recent advances in paediatric cardiac anaesthesia

Paediatric cardiac anaesthesia involves anaesthetizing very small children with complex congenital heart disease for major surgical procedures. The unique nature of this patient population requires considerable expertise and in-depth knowledge of the altered physiology. There have been several developments in the last decade in this subspecialty that has contributed to better care and improved outcome in this vulnerable group of patients. The purpose of this review is to present some of the recent advances in the anesthetic management of these children from preoperative evaluation to postoperative care. This article reviews the role of magnetic resonance imaging and contrast-enhanced magnetic resonance angiography in preoperative evaluation, the use of ultrasound to secure vascular access, the use of cuffed endotracheal tubes, the optimal haematocrit and the role of blood products, including the use of recombinant factor VIIa. It also deals with the advances in technology that have led to improved monitoring, the newer developments in cardiopulmonary bypass, the use of centrifugal pumps and extracorporeal membrane oxygenation and the role of DHCA. The role of new drugs, especially the α-2 agonists in paediatric cardiac anesthetic practice, fast tracking and effective postoperative pain management have also been reviewed.

Evaluation of four pediatric cardiopulmonary bypass circuits in terms of perfusion quality and capturing gaseous microemboli

This study compared four pediatric cardiopulmonary bypass (CPB) circuits with four different hollow-fiber membrane oxygenators and their specific reservoirs, Capiox RX15, Quadrox-i pediatric, Quadrox-i pediatric with integrated arterial filter (IAF) and KIDS D101, in a simulated CPB circuit identical to that used in the clinical setting at our institution to test their ability to maintain hemodynamic properties, remove gaseous microemboli (GME), and to test the amount of blood “stolen” by the arterial filter purge line. The circuit was first primed with Ringer’s Lactate solution, then red blood cells were added and the hematocrit was maintained at 30%. A 5-cc bolus of air was injected just proximal to the venous reservoir over a thirty-second interval and GME were monitored using an Emboli Detection and Classification quantifier. Transducers were placed at pre-oxygenator, post-oxygenator and distal arterial line (post-filter) positions. Flow probes were also placed both pre and post filter. The injections were made at three flow rates, hypothermic and normothermic temperatures, and with the purge line in both the opened and closed positions. Six injections were done at each of the 12 experimental conditions. Results demonstrated that GME in the arterial line increased with increasing temperature and flow rate. The Capiox RX15 had the least GME in the arterial line at all experimental conditions. The KIDS D101 had the largest pressure drop and the lowest retention of hemodynamic energy, while the Capiox had the lowest pressure drop. All of the oxygenators had a similar amount of “stolen” blood flow and it was consistently under 10% of the total flow reaching the patient.

Congenital heart defects and developmental and other psychiatric disorders: a Danish nationwide cohort study

BACKGROUND

We examined the risk of psychiatric in-patient admissions and out-patient visits among Danish patients with congenital heart defects (CHD).

METHODS AND RESULTS

Using the Danish National Registry of Patients, we identified CHD patients born January 1, 1977, to January 1, 2002. For each patient, we randomly selected 10 population-comparison cohort members from the Danish Civil Registration System, matched by sex and birth year. We computed cumulative risk and hazard ratios (HRs) of time to first psychiatric in-patient admission or out-patient visit identified in the Danish Psychiatric Central Registry and adjusted for parents' educational level and parents' psychiatric morbidity. We identified 6927 CHD patients. At 15 years of age, the cumulative risk of psychiatric admissions or out-patient visits was 5.9% (95% confidence interval [CI], 5.2%-6.6%) among CHD patients. The HRs for CHD patients and comparison cohort members aged 0 to 14 years were 1.8 (95% CI: 1.5-2.1) for males and 2.5 (95% CI: 2.0-3.1) for females. For patients aged 15 to 30 years, the HRs were 1.6 (95% CI: 1.2-2.0) for males and 1.0 (95% CI: 0.8-1.3) for females. Congenital heart defect patients, both with and without invasive therapeutic interventions or extracardiac defects or syndromes, had a higher risk of psychiatric in-patient admissions or out-patient visits than comparison cohort members. After restriction of the comparison cohort to patients with diabetes mellitus or asthma (n=2554), the HR was 1.41 (95% CI: 1.07-1.85) for patients aged 0 to 14 years and 0.70 (95% CI: 0.52-0.94) for patients aged 15 to 30 years.

CONCLUSION

Congenital heart disease patients with or without invasive therapeutic interventions are at increased risk of developmental and other psychiatric disorders, which seem to develop earlier than in patients with diabetes mellitus or asthma.

Neurocognitive monitoring and care during pediatric cardiopulmonary bypass-current and future directions

Neurologic injury in patients with congenital heart disease remains an important source of morbidity and mortality. Advances in surgical repair and perioperative management have resulted in longer life expectancies for these patients. Current practice and research must focus on identifying treatable risk factors for neurocognitive dysfunction, advancing methods for perioperative neuromonitoring, and refining treatment and care of the congenital heart patient with potential neurologic injury. Techniques for neuromonitoring and future directions will be discussed.

Near Infrared Spectroscopy during pediatric cardiac surgery: errors and pitfalls

As a result of improvements in early outcomes, long-term neurologicalal outcomes are becoming a major issue in pediatric cardiac surgery. The mechanisms of brain injury are numerous, but a vast majority of injuries are impervious to therapy and only a few are modifiable. The quality of perfusion during cardiac surgery is a modifiable factor and cerebral monitoring during bypass is the way to assess the quality of intra-operative cerebral perfusion. Near infrared spectroscopy (NIRS), as a diagnostic tool, has gained in popularity within the perfusion community. However, NIRS is becoming the standard of care before its scientific validation. This manuscript relates four clinical cases, demonstrating the limitations of NIRS monitoring during pediatric cardiac surgery as well as uncertainties about the interpretation of the recorded values.

The clinical relevance of cerebral oxymetry is needed before the use of NIRS as a decision making tool. Multimodal brain monitoring with NIRS, trans-cranial Doppler and electroencephalogram are currently under way in several pediatric centers. The benefit of this time-consuming and expensive monitoring system has yet to be demonstrated.

The effect of cardioplegic solution-induced sodium concentration fluctuation on postoperative seizure in pediatric cardiac patients

BACKGROUND

Despite potential benefits of histidine-tryptophan-ketoglutarate (HTK) solution as a cardioplegic solution, it can cause hyponatremia, especially in pediatric patients. Fluctuations in the sodium concentration during cardiopulmonary bypass (CPB) can adversely affect the central nervous system. We evaluated the relationship between the cardioplegic solution, the fluctuation of sodium concentration, and the incidence of postoperative seizure in pediatric cardiac patients.

METHODS

The medical records of 628 patients were reviewed for the occurrence of a postoperative seizure, type of cardioplegic solution (HTK or del Nido solution), and intraoperative data. A change of sodium concentration exceeding 15 mmol/L (ΔNa>15) during CPB was defined as a significant fluctuation of sodium concentration.

RESULTS

Postoperative seizures were detected in 18 patients (2.9%). The ΔNa>15 was detected in 63 of 189 patients (33.3%) who received the HTK solution and in 14 of 439 patients (3.2%) who received the del Nido solution (p<0.001). The incidence of ΔNa>15 was strongly associated with postoperative seizure (odds ratio, 6.3; 95% confidence interval, 2.4 to 16.4, p=0.001). After adjusting for potential confounders, the ΔNa>15 remained significantly associated with postoperative seizure (odds ratio, 3.9; 95% confidence interval, 1.3 to 12.3, p=0.018).

CONCLUSIONS

Histidine-tryptophan-ketoglutarate solution during CPB frequently causes fluctuations of sodium concentration, usually combined with hyponatremia, which is associated with postoperative seizure. Special attention to sodium concentration is required, particularly when HTK solution is used in pediatric cardiac patients.

Educational achievement among long-term survivors of congenital heart defects: a Danish population-based follow-up study

BACKGROUND

Congenital heart defect patients may experience neurodevelopmental impairment. We investigated their educational attainments from basic schooling to higher education.

PATIENTS AND METHODS

Using administrative databases, we identified all Danish patients with a cardiac defect diagnosis born from 1 January, 1977 to 1 January, 1991 and alive at age 13 years. As a comparison cohort, we randomly sampled 10 persons per patient. We obtained information on educational attainment from Denmark's Database for Labour Market Research. The study population was followed until achievement of educational levels, death, emigration, or 1 January, 2006. We estimated the hazard ratio of attaining given educational levels, conditional on completing preceding levels, using discrete-time Cox regression and adjusting for socio-economic factors. Analyses were repeated for a sub-cohort of patients and controls born at term and without extracardiac defects or chromosomal anomalies.

RESULTS

We identified 2986 patients. Their probability of completing compulsory basic schooling was approximately 10% lower than that of control individuals (adjusted hazard ratio = 0.79, ranged from 0.75 to 0.82 0.79; 95% confidence interval: 0.75-0.82). Their subsequent probability of completing secondary school was lower than that of the controls, both for all patients (adjusted hazard ratio = 0.74; 95% confidence interval: 0.69-0.80) and for the sub-cohort (adjusted hazard ratio = 0.80; 95% confidence interval: 0.73-0.86). The probability of attaining a higher degree, conditional on completion of youth education, was affected both for all patients (adjusted hazard ratio = 0.88; 95% confidence interval: 0.76-1.01) and for the sub-cohort (adjusted hazard ratio = 0.92; 95% confidence interval: 0.79-1.07).

CONCLUSION

The probability of educational attainment was reduced among long-term congenital heart defect survivors.

Executive function and theory of mind in school-aged children after neonatal corrective cardiac surgery for transposition of the great arteries

AIM

cardiac malformations resulting in cyanosis, such as transposition of the great arteries (TGA), have been associated with neurodevelopmental dysfunction. The purpose of this study was to assess, for the first time, theory of mind (ToM), which is a key component of social cognition and executive functions in school-aged children with TGA.

METHOD

twenty-one children (14 males, seven females; mean age 7y 4mo; SD 3mo) who underwent neonatal open-heart surgery for TGA using full-flow cardiopulmonary bypass were compared with 21 typically developing age-matched children (12 males, nine females; mean age 7y 6mo; SD 3.8mo) using different neuropsychological measures specifically designed to assess executive function (cognitive and response inhibition, verbal and spatial working memory, and planning). They were also given two ToM tasks (first- and second-order false belief understanding).

RESULTS

general IQ was within the normal range in both the TGA group and the comparison group (mean IQ 113 [SD 9.3] and 118 [SD 10.1] respectively), but performance on all executive functions and on ToM (first and second level) was significantly lower in the TGA group (p values of 0.02, 0.01, and 0.004 respectively). A discriminant multivariate analysis provided evidence for cognitive and behavioural inhibition as well as performance on false belief tasks as being the most important contributors to the differentiation between the groups (p=0.03).

INTERPRETATION

children with TGA demonstrate great difficulties in exerting cognitive and behavioural inhibition. They also present specific deficits in false belief understanding, which were related to immature executive abilities.