Early post-operative neurodevelopment and visual assessment in neonates with congenital heart disease undergoing cardiac surgery

OBJECTIVE

Assessment of neurobehavior and visual function of newborns with congenital heart disease during the post-operative period to identify infants at risk of neurodevelopmental and visual impairment.

STUDY DESIGN

Prospective study that included 45 newborns who underwent cardiac surgery. Newborn Behavioral Observations test (NBO) and "ML Battery of Optotypes" were used for assessment.

RESULTS

The median NBO global score was 2.4 [2.1-2.6]. Total days of oral morphine [p = 0.005] and total days of sedation [p = 0.009] were strongly related to abnormal evaluations. Time of cerebral regional oxygen saturation (CrSO2) under 40% during surgery and increased lactate were related to abnormal motor evaluation. Only 14.5% of patients presented pathological results in visual evaluation.

CONCLUSIONS

We have demonstrated alterations in attention, autonomic, motor, and oral motor function. Duration of sedative medication, time of CrSO2 under 40% during surgery, and increased lactate are the most important risk factors. No significant visual impairment was detected.

Pediatric Animal Model of Extracorporeal Cardiopulmonary Resuscitation after Prolonged Circulatory Arrest

Congenital heart disease (CHD) is the most prevalent congenital malformation, with about one million births impacted worldwide per year. Comprehensive investigation of this disease requires appropriate and validated animal models. Piglets are commonly used for translational research due to their analogous anatomy and physiology. This work aimed to describe and validate a neonatal piglet model of cardiopulmonary bypass (CPB) with circulatory and cardiac arrest (CA) as a tool for studying severe brain damage and other complications of cardiac surgery. In addition to including a list of materials, this work provides a roadmap for other investigators to plan and execute this protocol. After experienced practitioners performed several trials, the representative results of the model demonstrated a 92% success rate, with failures attributed to small piglet size and variant vessel anatomy. Furthermore, the model allowed practitioners to select from a wide variety of experimental conditions, including varying times in CA, temperature alterations, and pharmacologic interventions. In summary, this method uses materials readily available in most hospital settings, is reliable and reproducible, and can be widely employed to enhance translational research in children undergoing heart surgery.

Oxidative Stress and Indicators of Brain Damage Following Pediatric Heart Surgery

Pediatric cardiac surgery induces an increased oxidative stress (OS) response. Increased OS is associated with poor neurologic outcomes in neonatal populations with similar patterns of brain injury. We investigated OS and brain injury in infants undergoing heart surgery. Patients 6 months or younger, undergoing cardiac surgery with or without cardiopulmonary bypass (CPB), were included in this prospective, observational study. Patients were divided into infant (30 days−6 months) and neonatal (<30 days) groups for analysis. Urine OS biomarker 8-iso-prostaglandin F2α (8-iso-PGF2α) was quantified pre-surgery and at 0 and 24 h post-surgery. A serum brain damage biomarker S100B protein was also measured pre-surgery and at 0 and 72 h post-surgery. Amplitude-integrated electroencephalography during surgery was analyzed. Neuropsychological evaluation using the Bayley III or Vineland test was performed in all patients at 24 months of age. Sixty-two patients were included, 44 of whom underwent follow-up neurologic evaluation. 8-iso-PGF2α and S100B levels were increased after surgery. Postoperative levels of S100B were positively correlated with 8-iso-PGF2α levels 24 h after surgery (rho = 0.5224; p = 0.0261). There was also a correlation between immediate post-surgery levels of 8-iso-PGF2α and intra-surgery seizure burden (rho = 0.4285, p = 0.0205). Patients with an abnormal neurological evaluation had increased levels of S100B 72 h after surgery (p = 0.048). 8-iso-PGF2α levels 24 h after surgery were also related to abnormal neurologic outcomes. Levels of 8-iso-PGF2α following pediatric cardiac surgery are associated with several indicators of brain injury including brain damage biomarkers, intra-operative seizures, and abnormal neurological evaluation at follow-up, suggesting the importance of oxidative stress response in the origin of brain damage in this population.

A UPLC-MS/MS method for the determination of oxidative stress biomarkers in amniotic fluid

Oxidative stress in the fetal period is associated with preterm birth as well as short and long-term adverse clinical outcomes. Here, an Ultra-Performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS) method for the simultaneous quantification of biomarkers of oxidative stress-derived damage to proteins and DNA in amniotic fluid (AF) samples is presented. Appropriate accuracy and precision levels, as well as sensitivity with limits of detection in the low nanomolar (<2 nM) range were achieved. The analytical method was applied to a set of AF samples and reference ranges of the biomarker panel are presented. Median concentrations of biomarkers of protein oxidation (ortho-, 3-chloro-, and 3-nitrotyrosine) and their precursors (para-tyrosine and phenylalanine) ranged between 0.6 and 3 nM and 23 and 30 μM, respectively, while levels of a biomarker of DNA-oxidation (8-hydroxydeoxyguanosine, 8OHdG) and its precursor (2'-deoxyguanosine) were found to be 0.18 and 3 nM, respectively. Detection frequencies of all metabolites were 100% with exception of 3-chlorotyrosine (3Cl-Tyr) and 8OHdG, that were only detected in 8% of samples. The developed method may be applied in research studies focusing on oxidative stress-related complications during pregnancy.

Brain Oxygen Perfusion and Oxidative Stress Biomarkers in Fetuses with Congenital Heart Disease - A Retrospective, Case-Control Pilot Study

Fetuses with congenital heart disease (CHD) have circulatory changes that may lead to predictable blood flow disturbances that may affect normal brain development. Hypoxemia and hypoperfusion may alter the redox balance leading to oxidative stress (OS), that can be assessed measuring stable end-products. OS biomarkers (OSB) were measured in amniotic fluid in fetuses with (n = 41) and without CHD (n = 44) and analyzed according to aortic flow, expected cyanosis after birth, and a CHD classification derived from this. Birth head circumference (HC) was used as a neurodevelopment biomarker. CHD fetuses had higher levels of ortho-Tyrosine (o-Tyr) than controls (p = 0.0003). There were no differences in o-Tyr levels considering aortic flow obstruction (p = 0.617). Fetuses with expected extreme cyanosis presented the highest levels of o-Tyr (p = 0.003). Among groups of CHD, fetuses without aortic obstruction and extreme cyanosis had the highest levels of o-Tyr (p = 0.005). CHD patients had lower HC than controls (p = 0.023), without correlation with OSB. Patients with HC < 10th percentile, presented high levels of o-Tyr (p = 0.024). Fetuses with CHD showed increased OSB and lower HC when compared to controls, especially those with expected extreme cyanosis. Our results suggest that increased levels of OSB are more influenced by the effect of low oxygenation than by aortic flow obstruction. Future studies with larger sample size are needed to further investigate the role of OSB as an early predictor of neurodevelopmental problems in CHD survivors.

Blind Endotracheal Intubation in Neonatal Rabbits

The newborn rabbit is a useful animal model for various pathologies and procedures. Airway management of the rabbit is complex due to its anatomical characteristics, which is further complicated in the case of the newborn. Of the different methods of advanced airway management, endotracheal intubation is less aggressive than tracheostomy, and is more feasible than supraglottic management given the lack of supraglottic devices of such a small size. As direct glottis visualization is very difficult in animals this size, this blind intubation model is presented as an effective alternative, especially for experiments requiring prolonged anesthesia. Using this method, we performed blind intubations with a 90% success rate.

Acute Neurologic Injury in Children Admitted to the Cardiac Intensive Care Unit

BACKGROUND

Children with acquired and congenital heart disease both have low mortality but an increased risk of neurologic morbidity that is multifactorial. Our hypothesis was that acute neurologic injuries contribute to mortality in such children and are an important cause of death.

METHODS

All admissions to the pediatric cardiac intensive care unit (CICU) from January 2011 through January 2015 were retrospectively reviewed. Patients were assessed for any acute neurologic events (ANEs) during admission, as defined by radiologic findings or seizures documented on an electroencephalogram.

RESULTS

Of the 1,573 children admitted to the CICU, the incidence of ANEs was 8.6%. Mortality of the ANE group was 16.3% compared with 1.5% for those who did not have an ANE. The odds ratio for death with ANEs was 8.55 (95% confidence interval, 4.56 to 16.03). Patients with ANEs had a longer hospital length of stay than those without ANEs (41.4 ± 4 vs 14.2 ± 0.6 days; p < 0.001). Need for extracorporeal membrane oxygenation, previous cardiac arrest, and prematurity were independently associated with the presence of an ANE.

CONCLUSIONS

Neurologic injuries are common in pediatric CICUs and are associated with an increase in mortality and hospital length of stay. Children admitted to the CICU are likely to benefit from improved surveillance and neuroprotective strategies to prevent neurologic death.