Bilateral remote ischemic conditioning in children: A two-center, double-blind, randomized controlled trial in young children undergoing cardiac surgery.

Objective: The study objective was to determine whether adequately delivered bilateral remote ischemic preconditioning is cardioprotective in young children undergoing surgery for 2 common congenital heart defects with or without cyanosis. Methods: We performed a prospective, double-blind, randomized controlled trial at 2 centers in the United Kingdom. Children aged 3 to 36 months undergoing tetralogy of Fallot repair or ventricular septal defect closure were randomized 1:1 to receive bilateral preconditioning or sham intervention. Participants were followed up until hospital discharge or 30 days. The primary outcome was area under the curve for high-sensitivity troponin-T in the first 24 hours after surgery, analyzed by intention-to-treat. Right atrial biopsies were obtained in selected participants. Results: Between October 2016 and December 2020, 120 eligible children were randomized to receive bilateral preconditioning (n = 60) or sham intervention (n = 60). The primary outcome, area under the curve for high-sensitivity troponin-T, was higher in the preconditioning group (mean: 70.0 ± 50.9 µg/L/h, n = 56) than in controls (mean: 55.6 ± 30.1 µg/L/h, n = 58) (mean difference, 13.2 µg/L/h; 95% CI, 0.5-25.8; P = .04). Subgroup analyses did not show a differential treatment effect by oxygen saturations (pinteraction = .25), but there was evidence of a differential effect by underlying defect (pinteraction = .04). Secondary outcomes and myocardial metabolism, quantified in atrial biopsies, were not different between randomized groups. Conclusions: Bilateral remote ischemic preconditioning does not attenuate myocardial injury in children undergoing surgical repair for congenital heart defects, and there was evidence of potential harm in unstented tetralogy of Fallot. The routine use of remote ischemic preconditioning cannot be recommended for myocardial protection during pediatric cardiac surgery.

Rare type of tracheal agenesis: Unexpected presentation and immediate consideration of emergent esophageal intubation in neonatal resuscitation program. Case reports and review of the literature.

BACKGROUND: Tracheal agenesis, or tracheal atresia, is a rare congenital anomaly. The presence of a tracheoesophageal fistula (TEF) can help with breathing for newborns with tracheal agenesis. In this article, we presented three unique cases and outcomes of neonates with tracheal agenesis along with a review of the literature. METHODS: This study consisted of a single center case series followed by a review of literature. Case reports were generated using both written and electronic medical records from a single hospital. We summarized three unique cases and outcomes of neonates with tracheal agenesis and performed a review of the literature. RESULTS: We identified three cases of tracheal agenesis presented with severe cyanosis without spontaneous crying upon birth. Experienced pediatricians attempted to intubate the babies but were unsuccessful. Endotracheal tubes were subsequently either accidentally or purposely placed into the esophagus, and oxygen saturation levels improved. This suggested tracheal agenesis with TEF. Two cases underwent surgical intervention after resuscitation with esophageal intubation. CONCLUSION: Esophageal intubation may be a life-sustaining ventilation support for patients with tracheal agenesis and TEF at initial resuscitation. Clinicians should suspect tracheal agenesis when a newborn presents with severe cyanosis and voiceless crying upon birth, and esophageal intubation should be immediately attempted.

Impact of Age-Related Change in Caval Flow Ratio on Hepatic Flow Distribution in the Fontan Circulation.

BACKGROUND: The Fontan operation is a palliative technique for patients born with single ventricle heart disease. The superior vena cava (SVC), inferior vena cava (IVC), and hepatic veins are connected to the pulmonary arteries in a total cavopulmonary connection by an extracardiac conduit or a lateral tunnel connection. A balanced hepatic flow distribution (HFD) to both lungs is essential to prevent pulmonary arteriovenous malformations and cyanosis. HFD is highly dependent on the local hemodynamics. The effect of age-related changes in caval inflows on HFD was evaluated using cardiac magnetic resonance data and patient-specific computational fluid dynamics modeling. METHODS: SVC and IVC flow from 414 patients with Fontan were collected to establish a relationship between SVC:IVC flow ratio and age. Computational fluid dynamics modeling was performed in 60 (30 extracardiac and 30 lateral tunnel) patient models to quantify the HFD that corresponded to patient ages of 3, 8, and 15 years, respectively. RESULTS: SVC:IVC flow ratio inverted at ≈8 years of age, indicating a clear shift to lower body flow predominance. Our data showed that variation of HFD in response to age-related changes in caval inflows (SVC:IVC, 2, 1, and 0.5 corresponded to ages, 3, 8, and 15+, respectively) was not significant for extracardiac but statistically significant for lateral tunnel cohorts. For all 3 caval inflow ratios, a positive correlation existed between the IVC flow distribution to both the lungs and the HFD. However, as the SVC:IVC ratio changed from 2 to 0.5 (age, 3-15+) years, the correlation's strength decreased from 0.87 to 0.64, due to potential flow perturbation as IVC flow momentum increased. CONCLUSIONS: Our analysis provided quantitative insights into the impact of the changing caval inflows on Fontan's long-term HFD, highlighting the importance of SVC:IVC variations over time on Fontan's long-term hemodynamics. These findings broaden our understanding of Fontan hemodynamics and patient outcomes.

The Prevalence of Scoliosis after Fontan Circulation Surgery Followed-Up to Adolescence.

Introduction: The advancement of surgical techniques and perioperative management for congenital heart disease (CHD) has increased life expectancy. The surgical creation of the Fontan circulation maintains pulmonary blood flow without relying on an effective pump from the abnormal heart, relying on peripheral vascular resistance to maintain effective flow through the lungs. Unfortunately, this delicate mechanism is compromised when scoliosis restricts ventilation, leading to Fontan failure and a poor prognosis for life. This report describes the prevalence of scoliosis with Fontan completion surgery and the role of screening and surgical correction. Methods: Ninety-six consecutive Japanese patients undergoing Fontan completion surgery for CHD between 2000 and 2017 were identified in our institutional records. The inclusion criterion was at least 7 years of follow-up after Fontan completion surgery, while the exclusion criteria were congenital, syndromic, and neuromuscular scoliosis. Radiographic and clinical parameters, including cardio-thoracic ratio (CTR) for cardiomegaly and cyanosis saturation, were compared between with and without scoliosis. Results: There were 23 and 40 patients in the scoliosis and no scoliosis groups, respectively. The mean age at the final follow-up was 18.5 and 16.7 years in the scoliosis and no scoliosis groups, respectively (p=0.02). Mean CTR was 43.7% and 39.4% in the scoliosis and no scoliosis groups (p=0.016), and the mean saturation in room air at the final follow-up was 88.8% and 93.2%, respectively (p=0.036). There were no significant differences to clarify the risk factors with multivariate logistic regression analysis. Conclusions: The prevalence of scoliosis with Fontan completion surgery was 36.5%. Screening for scoliosis is important for children with Fontan circulation surgery as part of their routine follow-up at least until they reach adolescence.Evidence Level: 4.

A rare case of methemoglobinemia in a preterm newborn with unclear etiology.

 Cyanosis is a bluish discoloration of the tissues due to increased levels of deoxygenated hemoglobin in capillaries. It is a common finding in newborn infants that can be caused by different diseases, including pulmonary, cardiac, infectious, and hematological disorders. Methemoglobinemia is a rare cause of cyanosis, in which hemoglobin is oxidized, changing its heme iron configuration from the ferrous (Fe2 +) to the ferric (Fe3 +) state, creating methemoglobin (Met-Hb), a form that does not bind oxygen, leading to decreased oxygen delivery to the tissues and cyanosis. We report a rare case of a preterm newborn, who developed cyanosis and worsening hypoxemia on day ten of life, she was found to have elevated Met-Hb percentage in blood gas analysis that required treatment with intravenous methylene blue. Her symptoms resolved after a period of maintenance treatment with oral methylene blue and ascorbic acid, and the etiology of her disease remains unclear.

A review of the current policies and guidance regarding Apgar scoring and the detection of jaundice and cyanosis concerning Black, Asian and ethnic minority neonates.

BACKGROUND: Ethnic inequalities in maternal and neonatal health in the UK are well documented. Concerns exist regarding the use of skin colour in neonatal assessments. Healthcare professionals should be trained to recognise symptoms of diverse skin tones, and comprehensive, and inclusive guidance is necessary for the safe assessment of all infants. Disparities in healthcare provision have been emphasised during the COVID-19 pandemic, and additional research is needed to determine whether such policies adequately address ethnic minority neonates. METHODS: A desktop search included searches of guidance produced for the United Kingdom (UK). Further searches of the Cochrane and World Health Organization (WHO) were used to identify any international guidance applicable in the UK context. RESULTS: Several policies and one training resource used descriptors 'pink,' 'pale,' 'pallor,' and 'blue' about neonatal skin and mucous membrane colour. No policies provided specific guidance on how these colour descriptors may appear in neonates with different skin pigmentation. Only the NICE guidance and HEE e-learning resource acknowledged the challenges of assessing jaundice in infants with diverse skin tones, while another guideline noted differences in the accuracy of bilirubin measurements for the assessment of jaundice. Three policies and one training resource advised against relying on visual observation of skin colour when diagnosing neonatal conditions. The training resource included images of ethnic minority neonates, although most images included white infants. CONCLUSIONS: Inadequate consideration of ethnicity in UK policy and training perpetuates disparities, leading to inaccurate assessments. A review is needed for inclusivity in neonatal care, regardless of skin pigmentation.

Causes of acquired methemoglobinemia - A retrospective study at a large academic hospital.

Methemoglobinemia is a potentially life-threatening condition caused by the formation of methemoglobin, a form of hemoglobin that cannot bind oxygen. While there are some rare congenital causes of methemoglobinemia, most cases are acquired from the effects of specific drugs or environmental exposures. In this retrospective study, we analyzed a large data set of whole blood samples analyzed for methemoglobin at an academic medical center in Midwestern United States that provides both pediatric and adult services. For a 14 year timeframe (May 2009- June 2023), we performed detailed chart analysis of all patients with a methemoglobin concentration of 3.1 % or higher. For an earlier 13 year timeframe (January 1996-April 2009), we performed chart review for all patients with a methemoglobin concentration of 10.0 % or higher. For the 2009-2023 data, dapsone was the most frequent cause of methemoglobinemia (methemoglobin 3.1 % or higher) in both pediatric (73.3 %, 115 clinical encounters, 105 unique patients) and adult (65.3 %, 195 clinical encounters, 190 unique patients) populations. Inhaled nitric oxide as medical therapy was the next most frequent cause in both pediatric (18.1 %) and adult (13.2 %) populations. Causes associated with two or more unique episodes with methemoglobin concentrations of 10.0 % and higher included the following: dapsone (n = 40 episodes), benzocaine (n = 10), recreational use of amyl or isobutyl nitrite (n = 3), suicide attempt with sodium nitrite (n = 3 with 1 fatality; all 3 cases within last 3 years), food contaminated with nitrates (n = 2), and sepsis (n = 2). A total of 18 patients received treatment with methylene blue including 5 cases associated with benzocaine and all of the cases associated with amyl nitrite, isobutyl nitrite, sodium nitrite, and contaminated food. Only 3 patients with dapsone-associated methemoglobinemia received methylene blue, reflecting primary management by dose reduction or discontinuation of drug. Overall, our data reinforce previous studies showing dapsone, inhaled nitric oxide, and nitrites as common agents causing methemoglobinemia in a patient population seen at a medical center. Our data also are consistent with recent epidemiology trends showing increase in suicide attempts using sodium nitrite.

Failing with Cyanosis-Heart Failure in End-Stage Unrepaired or Partially Palliated Congenital Heart Disease.

Heart failure in cyanotic congenital heart disease (CHD) is diagnosed clinically rather than relying solely on ventricular function assessments. Patients with cyanosis often present with clinical features indicative of heart failure. Although myocardial injury and dysfunction likely contribute to cyanotic CHD, the primary concern is the reduced delivery of oxygen to tissues. Symptoms such as fatigue, lassitude, dyspnea, headaches, myalgias, and a cold sensation underscore inadequate tissue oxygen delivery, forming the basis for defining heart failure in cyanotic CHD. Thus, it is pertinent to delve into the components of oxygen delivery in this context.

Early and Long-Term Clinical Outcomes of Ductal Stenting Versus Surgical Aortopulmonary Shunt Among Young Infants with Duct-Dependent Pulmonary Circulation.

Surgical aortopulmonary shunting (SAPS) and ductal stenting (DS) are the main palliations in infants with cyanotic congenital heart diseases (CHD). We aimed to study the safety and efficacy of DS and to compare it with SAPS as a palliative procedure in infants with CHD and duct-dependent pulmonary circulation. Retrospective institutional clinical data review of consecutive infants aged < 3 months who underwent DS or SAPS over 5 years. The primary outcome was procedural success which was defined as event-free survival (mortality, need for re-intervention, procedural failure) at 30 days post-procedure. The secondary outcome was defined by a composite of death, major adverse cardiovascular events, or need for re-intervention at 6 months and on long-term follow-up. We included 102 infants (DS, n = 53 and SAPS, n = 49). The median age at DS and SAPS was 4 days (IQR 2.0-8.5) and 8 days (IQR 4.0-39.0), respectively. The median weight at intervention was 3.0 kg (IQR 3.0-3.0) and 3.0 kg (IQR 2.5-3.0) in the two respective arms. Tetralogy of Fallot with pulmonary atresia was the most common indication for DS and SAPS. The 30-day mortality was significantly higher in SAPS group as compared with DS group (p < 0.05). However, 30-day major adverse cardiac events (MACE) rates were similar in both groups (p = 0.29). DS was associated with shorter duration of mechanical ventilation, duration of stay in the intensive care and hospital stay than with SAPS. At 6 months, there was no significant difference in terms of mortality or event-free survival. Long-term MACE-free survival was also comparable (p = 0.13). DS is an effective and safer alternative to SAPS in infants with duct-dependent pulmonary circulation, offering reduced procedure-related mortality and morbidity than SAPS. Careful study of ductal anatomy is crucial to procedural success. However, long-term outcomes are similar in both procedures.

Nucleated Red Blood Cell Counts Differentiate Cardiac from Respiratory Causes of Cyanosis at Birth.

Tissue hypoxia increases erythropoietin production and release of immature erythrocytes that can be measured using nucleated red blood cell counts (nRBC). We hypothesized that hypoxia due to congenital heart disease (CHD) is chronic and is better tolerated than hypoxia due to respiratory disease (RD), which is an acute stress in newborns leading to higher nRBC. This study assesses the utility of nRBC as a marker to differentiate hypoxia due to CHD vs RD in term neonates. This was a single-center, retrospective study of term neonates with cyanosis from 2015 to 2022. Neonates < 37 weeks of gestation, with hypoxic-ischemic encephalopathy, and those with other causes of cyanosis were excluded. The patients were divided into 2 groups: cyanotic CHD and cyanotic RD. Clinical and laboratory data done within 12 h and 24-36 h after birth were collected. Data are represented as median and Interquartile range. Of 189 patients with cyanosis, 80 had CHD and 109 had RD. The absolute nRBC count at ≤ 12 h of age was lower in the CHD (360 cells/mm3) compared to RD group (2340 cells/mm3) despite the CHD group having significantly lower baseline saturations. A value of 1070 cells/mm3 was highly sensitive and specific for differentiating CHD from RD. The positive predictive value for this cut-off value of 1070 cells/mm3 was 0.94 and the negative predictive value was 0.89. The absolute nRBC is a simple screening test and is available worldwide. A nRBC < 1070 cells/mm3 in cyanotic newborns should hasten the search for CHD etiology with the possible need for prostaglandin therapy.

A large type I right pulmonary artery to left atrium fistula: underwent successful percutaneous device closure with duct occluder-a rare case report.

BACKGROUND: Pulmonary artery to left atrium fistula is an unusual structural cause of silent cyanosis. Only less than 100 cases have been reported so far. A high index of clinical suspicion and proper evaluation with bubble contrast echocardiography and cardiac computed tomography (CT) will help to detect this treatable anomaly. The advent of safer percutaneous closure methods has replaced the need for more invasive surgical closure. CASE PRESENTATION: We report an adolescent boy, who presented with long-standing cyanosis and progressive dyspnea with normal clinical cardiovascular examination. On evaluation, echocardiography and bubble contrast study revealed a large right pulmonary artery (RPA) to left atrium (LA) fistula. Cardiac CT confirmed the same with normal pulmonary venous drainage s/o a large 20 mm Type I RPA LA Fistula. He underwent successful percutaneous closure of the fistula tract with a 22 × 24 mm Cera™ duct occluder via transseptal approach uneventfully. CONCLUSION: Our case enlightens the methodological approach to diagnosing this rare anomaly as well as the feasibility of percutaneous intervention in such cases as it is one of the largest fistula tracts closed percutaneously to date.

Case Report: A case report and literature review of hemoglobin variation associated with neonatal cyanosis.

We will discuss a recent case of unexplained neonatal cyanosis, evaluate its origin, clinical presentation, diagnosis, and treatment, and share with you some of our clinical insights. We report a transient cyanosis in a newborn due to a mutation in the globulin gene (HBG2), as well as diagnosis and treatment. Clinically, the infant was in good overall health, and despite low oxygen saturation, the arterial oxygen partial pressure was always normal. Early respiratory support includes mechanical ventilation, nasal tube oxygen, and eventually stopping oxygen therapy. With the above treatment measures, the blood oxygen saturation of the child always fluctuated at 85%, but the arterial blood oxygen partial pressure was up to 306 mmHg. Further improvement of laboratory tests revealed elevated methemoglobin levels, reticulocytosis, mild anemia, and basically normal on chest x-ray and echocardiography. To clarify the etiology, WES testing was performed. The results showed heterozygous variation in HBG2 gene (c.190C>T. p.H64Y). There is heterozygous variation at this site in the proband father, and no variation at this site in the proband mother. Given the age of the affected infants, we hypothesized that the mutation originated in the gamma peptide chain of the head protein. The baby was discharged from the hospital 10 days after birth, with blood oxygen saturation fluctuating around 90%. The cyanosis disappeared 2 months after discharge, and the blood oxygen saturation level returned to normal.

The Unrepaired Tetralogy of Fallot: A Tale of Delayed Presentation and Limited Access to Care.

Tetralogy of Fallot (TOF) is a common cyanotic congenital heart disease characterized by four distinct anatomical features. While surgical repair has significantly improved long-term outcomes, some individuals, particularly those from low socioeconomic backgrounds who lack access to medical care, may suffer from complications such as pulmonary hypertension (pHTN) and heart failure. We present a case report of a young female with unrepaired TOF who presented with acute-on-chronic hypoxic respiratory failure and heart failure, highlighting the complex nature and challenges associated with this condition.

Tetralogy of Fallot with vertebral defect and left aberrant subclavian artery: a rare occurrence.

BACKGROUND: The most prevalent cyanotic congenital heart disease is Tetralogy of Fallot (TOF). It has a variety of presentations and is made up of four anatomic abnormalities. Documented literature shows an incidence of 13-20% of a right aortic arch with an anomalous left subclavian artery among individuals diagnosed with TOF. This is the first case that discusses the rare occurrence of overriding of the aortic arch along with the left aberrant subclavian artery and vertebral defect in a 3-week-old girl. Timely identification and management are pivotal in ensuring the best possible outcomes for these young patients. CASE PRESENTATION: A 3-week-old female child came with complaints of dyspnea, dysphagia, fatigue, and cyanosis on extreme crying, feeding, and moderate activity. Echocardiography revealed severe pulmonary stenosis with right ventricular dilatation and ventricular septal defect (VSD); a chest computed tomography was performed that revealed four characteristic features of TOF (pulmonary artery stenosis, VSD, right aortic root deviation, and concentric right ventricular hypertrophy) along with overriding of the aortic arch accompanied with the left aberrant subclavian artery (compressing the trachea and infundibulum) and vertebral defect (butterfly vertebra). CONCLUSIONS: The case of this 3-week-old female infant emphasizes the importance of early and accurate diagnosis in congenital heart diseases, particularly when faced with complex presentations such as the TOF. It serves as a testament to the valuable role of advanced diagnostic imaging techniques in unraveling the complexity of congenital heart conditions.

Familial Psychomotor Delay of an Uncommon Cause: Type II Congenital Methemoglobinemia.

Methemoglobinemia is due to oxidization of divalent ferro-iron of hemoglobin to ferri-iron of methemoglobin (MetHb) which is incapable of transferring oxygen to tissues. This disease may be acquired by intoxication with oxidizing agents or inherited with a mutation of CYB5R3, the gene coding for the methemoglobin reductase or cytochrome B5 reductase 3 responsible for the reduction of MetHb to hemoglobin. We report the case of 2 sisters aged respectively of 15 and 8 months. They were born to a second-degree consanguineous marriage with a history of precocious and unexplained deaths in 3 relatives. Both sisters presented neurological features including psychomotor retardation, microcephaly, and axial hypotonia. Cerebral magnetic resonance imaging revealed cerebral atrophy in both cases associated with hypoplasia of the corpus callosum in the younger child. The association of neurological disability, cyanosis, and hypoxemia prompted a search for methemoglobinemia, with MetHB levels respectively of 26% and 15.8%in the 2 sisters. Initial treatment was based on methylene blue, then ascorbic acid. The genetic study revealed a c.463+8G>C mutation of CYB5R3 confirming the diagnosis of methemoglobinemia type II. The diagnosis of methemoglobinemia, although rare, should be considered in the presence of psychomotor retardation with cyanosis and subacute onset hypoxemia, especially in the presence of a family history.

Effective control of refractory pulmonary hypertension with iloprost inhalation in an infant with congenital absence of the right pulmonary artery: a case report.

Unilateral absence of the pulmonary artery is a rare congenital cardiovascular anomaly that can lead to pulmonary hypertension and poor outcomes. We report the case of a 1-month-old infant with isolated unilateral absence of the pulmonary artery and severe pulmonary hypertension on the right and left sides, respectively. The patient was unresponsive to multiple medications for pulmonary hypertension, and surgical revascularisation was unfeasible. However, iloprost inhalation was effective.

Recurrent Acute Methemoglobinemia in an Infant With Persistent Gastroenteritis: A Case Report.

Acute toxic methemoglobinemia is a rare and fatal condition with increased levels of oxidized hemoglobin. The clinical presentation of methemoglobinemia varies primarily based on total methemoglobin levels in the blood. Patients sometimes have significant cardiopulmonary compromise, but the majority are asymptomatic, with only cyanosis as the most prevalent sign. We report the case of a 41-day-old male who developed methemoglobinemia and persistent gastroenteritis after consumption of well water. In this case, we believe that the recurrence of acute methemoglobinemia episodes resulted from multifactorial reasons such as age at presentation, infection with nitrate-producing organisms, and consumption of nitrite-containing well water. The rationale for prophylactic therapy was implemented, aiming to prevent further episodes. This case report demonstrates the potential of prophylactic therapy as part of the management of infants with recurrent acute methemoglobinemia episodes.

Amplatzer Vascular Plug closure of an iatrogenic interatrial tunnel-type communication.

A 50-year-old woman who had atrial septal defect surgery at 11 months old underwent ascending aortic aneurysm resection and two attempts at closure of a residual atrial septal defect. Post-operatively, she had severe cyanosis. She was referred to our centre where a transesophageal echocardiogram and cardiac catheterisation showed an iatrogenic interatrial tunnel-type communication that was closed with an Amplatzer Vascular Plug.