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girl with down syndrome sleeping

Characteristics of central breathing abnormalities in children with trisomy 21

girl with down syndrome sleeping

Trisomy 21 (TS21), also known as Down syndrome, is the most common genetic syndrome in the United States. Many children with TS21 have a higher prevalence of sleep-related breathing disorders including central sleep apnea. While the mechanisms of central sleep apnea in TS21 are not completely understood, children with Down syndrome have multiple factors that make them more susceptible to developing central breathing abnormalities, including nervous system impairment, hypothyroidism and hypotonia.

In a recent multi-institutional study published in the journal Pediatric Pulmonology, Gustavo Nino, M.D., MSHS, D’ABSM, director of sleep medicine at Children’s National Hospital, and colleagues investigated the clinical features of central breathing abnormalities in TS21 across different pediatric age groups. The researchers also conducted analyses to look at the effects of biological sex and concomitant obstructive sleep apnea in children with central breathing abnormalities.

The authors conclude that “central breathing abnormalities are common in TS21 among young children (≤2 years of age) and in females older than 2 years of age,” and that “central apnea is often associated with concomitant obstructive sleep apnea and/or hypoxemia in children with TS21.”

Read the full study in Pediatric Pulmonology.

illustration of lungs with virus

Segmenting viral bronchiolitis patients to better predict clinical outcomes

illustration of lungs with virus

By evaluating viral bronchiolitis patients at first presentation and categorizing them based on clinical phenotype, the researchers were able to better predict outcomes and disease progression patterns.

Researchers from Children’s National Hospital have recently published a pilot study of children with viral bronchiolitis. By evaluating viral bronchiolitis patients at first presentation and categorizing them based on clinical phenotype, the researchers were able to better predict outcomes and disease progression patterns. Nasal airway cytokine levels were also measured to assess the underlying airway immunobiology of different clinical phenotypes. The researchers believe this novel subdivision of viral bronchiolitis patients based on a robust combination of clinical and molecular assessment can help lead to more individualized care and better patient outcomes.

Viral bronchiolitis is broadly used to group together infants with first-time severe viral respiratory infection, which is the most common cause of early life sick visits and hospitalizations worldwide. However, viral respiratory infections can vary significantly in clinical manifestations, which has raised concern among experts that the use of viral bronchiolitis as a catchall term may be compromising patient care. Children’s National researchers hypothesized that a novel segmentation technique of viral bronchiolitis patients by phenotype at first episode could provide better outcome prediction. In addition, lung X-rays and nasal cytokine profiles could help illuminate the underlying airway disease processes that drive the phenotypical differences observed at bedside.

The study examined 50 children ≤ 2 years old, including 41 patients admitted at Children’s National with PCR-confirmed viral respiratory infection and 9 controls. Researchers examined clinical features at presentation by reviewing each patient’s electronic medical record. Key parameters served as the basis for patient segmentation into three phenotypical groups: hypoxemia, wheezing and mild phenotypes. Patients in the hypoxia group (n = 16) were characterized by their need for supplemental oxygen; patients in the wheezing phenotype (n = 16) were distinguished by wheezing or subcostal retractions and patients in the mild phenotype (n = 9) displayed persistent respiratory symptoms but not hypoxia, wheezing or subcostal retractions. Chest x-rays further revealed that patients in the hypoxia phenotype displayed significantly more lung opacities than the other phenotypes.

As hypothesized, the three phenotype groups displayed distinct clinically relevant outcomes. Patients in the hypoxia group had more severe clinical symptoms at presentation and were significantly more likely to require prolonged hospitalization and pediatric intensive care unit (PICU) settings for treatment. Patients in the wheezing phenotype had shorter hospital stays but were significantly more likely to make a respiratory sick visit after initial discharge, with 69% coming back to the hospital with the same symptoms. Patients in the mild phenotype had the shortest hospital stays and did not require transfer to the PICU.

Nasal cytokine profiles were also assessed for all study subjects. Controls had lower cytokine levels than patients, with no significant difference between phenotype groups. However, wheezing patients with ≥1 recurrent respiratory sick visit had higher nasal levels of type 2 cytokines IL-13 and IL-4, consistent with the pathobiology of allergic asthma. This result adds support for the potential of initial sub-setting in guiding timely intervention.

The researchers hope that the strong results of their pilot study will guide clinicians to revise current practices regarding viral bronchiolitis and personalize care of viral respiratory illnesses from first presentation in order to improve outcomes. Study author and Children’s National pulmonologist Maria Arroyo, M.D., says, “if we can prevent these patients from coming [back] to the hospital just by doing a clinical evaluation the first time that they present with [viral respiratory infection]…that would be very impactful.”

The associated article, “Phenotypical Sub-setting of the First Episode of Severe Viral Respiratory Infection Based on Clinical Assessment and Underlying Airway Disease: A Pilot Study,” was published April 2, 2020 in Frontiers in Pediatrics. Notable authors include Maria Arroyo, M.D., Kyle Salka, M.S., and Gustavo Nino, M.D., M.S.H.S., D.A.B.S.M.

preterm baby

Validating a better way to stratify BPD risk in vulnerable newborns

preterm baby

Factoring in the total number of days that extremely preterm infants require supplemental oxygen and tracking this metric for weeks longer than usual improves clinicians’ ability to predict respiratory outcomes according to bronchopulmonary dysplasia severity.

Factoring in the total number of days that extremely preterm infants require supplemental oxygen and tracking this metric for weeks longer than usual improves clinicians’ ability to predict respiratory outcomes according to bronchopulmonary dysplasia (BPD) severity, a research team led by Children’s National Hospital writes in Scientific Reports. What’s more, the researchers defined a brand-new category (level IV) for newborns who receive supplemental oxygen more than 120 days as a reliable way to predict which infants are at the highest risk of returning to the hospital due to respiratory distress after discharge.

About 1 in 10 U.S. infants is born preterm, before 37 weeks gestation, according to the Centers for Disease Control and Prevention. That includes extremely preterm infants who weigh about 1 lb. at birth. These very low birthweight newborns have paper thin skin, frail hearts and lungs that are not yet mature enough to deliver oxygen throughout the body as needed. Thanks to advances in neocritical care, an increasing number of them survive prematurity, and many develop BPD, a chronic lung disease characterized by abnormal development of the lungs and pulmonary vasculature.

“About half of the babies born prematurely will come back to the hospital within the first year of life with a respiratory infection. The key is identifying them and, potentially, preventing complications in this high-risk population,” says Gustavo Nino, M.D., a Children’s National pulmonologist and the study’s lead author.

For decades, the most common way to stratify BPD risk in these vulnerable newborns has been to see if they require supplemental oxygen at 36 weeks corrected gestational age.

“The problem with this classification is it doesn’t take into account the very premature babies who are on oxygen for much longer than other babies. So, we asked the question: Can we continue risk stratification beyond 36 weeks in order to identify a subset of babies who are at much higher risk of complications,” Dr. Nino says.

The longitudinal cohort study enrolled 188 infants born extremely preterm who were admitted to the neonatal intensive care unit (NICU) at Children’s National and tracked their data for at least 12 months after discharge. The team used a multidimensional approach that tracked duration of supplemental oxygen during the newborns’ NICU stay as well as scoring lung imaging as an independent marker of BPD severity. To validate the findings, these U.S.-born newborns were matched with 130 infants who were born preterm and hospitalized at two NICUs located in Bogotá, Colombia.

“Babies who are born very preterm and require oxygen beyond 120 days should have expanded ventilation of the lungs and cardiovascular pulmonary system before going home,” he notes. “We need to identify these newborns and optimize their management before they are discharged.”

And, the babies with level IV BPD risk need a different type of evaluation because the complications they experience – including pulmonary hypertension – place them at the highest risk of developing sleep apnea and severe respiratory infection, especially during the first year of life.

“The earlier we identify them, the better their outcome is likely to be,” Dr. Nino says. “We really need to change the risk stratification so we don’t call them all ‘severe’ and treat them the same when there is a subset of newborns who clearly are at a much higher risk for experiencing respiratory complications after hospital discharge.”

In addition to Dr. Nino, Children’s National study co-authors include Awais Mansoor, Ph.D., staff scientist at the Sheikh Zayed Institute for Pediatric Surgical Innovation (SZI); Geovanny F. Perez, M.D., pediatric pulmonologist; Maria Arroyo, M.D., pulmonologist; Xilei Xu Chen, M.D., postdoctoral fellow; Jered Weinstock, pediatric pulmonary fellow; Kyle Salka, MS, research technician; Mariam Said, M.D., neonatologist, and Marius George Linguraru, DPhil, MA, MSc, SZI principal investigator and senior author. Additional co-authors include Ranniery Acuña-Cordero, Universidad Militar Nueva Granada, Bogotá, Colombia; and Monica P. Sossa-Briceño and Carlos E. Rodríguez-Martínez, both of Universidad Nacional de Colombia.

Funding for research described in this post was provided by the National Institutes of Health (NIH) under award Nos. HL145669, AI130502 and HL141237. In addition, the NIH has awarded Dr. Nino an RO1 grant to continue this research.