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HHS recommends pulse oximetry for newborns
Quick, painless test catches certain life-threatening heart defects
A new federal Department of Health Human and Human Services (HHS) recommendation that nurseries screen newborns for critical congenital heart defects (CCHDs) with pulse oximetry (PO) may help hospitals identify many affected babies.
Congenital heart defects (CHDs) account for 24% of infant deaths due to birth defects, while 11.6 of every 1,000 babies born have a CCHD, according to a U.S. Centers for Disease Control and Prevention (CDC) fact sheet. Infants discharged from newborn nurseries with unrecognized CCHDs are often at risk for life-threatening complications within the first few days or weeks of life and often require emergency care.
PO can alert hospital staff to the roughly 25% of CCHDs that cause low blood oxygen levels and need quick repair. These include seven categories of defects, including hypoplastic left heart, pulmonary atresia (with intact septum), tetralogy of Fallot, total anomalous pulmonary venous return, transposition of the great arteries, tricuspid atresia, and truncus arteriosus.
While PO screening is intended to find certain heart defects, it can also be a first step toward particular genetic diagnoses, says Gerard Martin, MD, Senior Vice President of the Center for Heart, Lung, and Kidney Disease at Children's National Medical Center in Washington, DC. These include Turner syndrome, CHARGE syndrome, and trisomy 21.
A report published in the November 2011 issue of Pediatrics says nurseries should screen infants at least 24 hours after birth and by the second day of life.
“Screening for CCHD fits nicely into the newborn screening paradigm. Many CCHDs are easy to detect, there's a good, cheap test, and we can do something about heart defects,” says Alex Kemper, MD, Associate Professor in the Department of Pediatrics at Duke University Medical Center and member of the HHS Secretary's Advisory Committee on Heritable Disorders in Newborns and Children (SACHDNC) work group that issued a report recommending screening. Based on the report, HHS Secretary Kathleen Sebelius added CCHD to the federal Recommended Uniform Screening Panel, which often influences states' decisions to add tests to their own newborn testing panels.
Published in the November 2011 Pediatrics, the report says nurseries should screen infants at least 24 hours after birth and by the second day of life. That's because earlier screening can lead to false-positive results due to the transition from fetal to neonatal circulation and stabilization of systemic oxygen saturation levels (Kemper et al., 2011).
In addition, certain defects may not be clinically apparent in the first 48 hours. But if a CCHD causes low blood oxygen levels, PO can alert staff to a problem, thereby triggering further testing and, ultimately, proper care. For example, babies with many CCHDs need medication that prevents the ductus arteriosus's closure, allowing blood's passage to the lungs or body until surgery to repair defects.
“For years we've been asking physicians to detect heart defects based on physical exam alone or prenatal test. But we're missing cases. Pulse oximetry will detect many kids with CCHD before they are released. We will have more surviving kids, who will live healthier lives,” Dr. Martin says.
Pulse Oximetry Problems
PO screening does face some challenges. These include lack of access to high-quality echocardiograms in some areas and a current lack of standard cutoff point indicating a positive screen. Dr. Kemper says the threshold named in the workgroup's report is based on populations living at sea level, so hospital staff in high altitude locations would need to adjust algorithms. But the greatest challenge, he says, is establishing systems that can accomplish adequate, timely evaluation of newborns identified as having possible CCHD by pulse oximetry.
Lack of such systems is an issue in about half of all states, which currently do not conduct widespread testing with PO. Other states have pilots or multicenter screening programs, while just three, New Jersey, Indiana, and Maryland, mandate it for all newborns, according to 1 in 100, a CCHD advocacy group.
That's a situation Annamarie Saarinen, founder of both the Newborn Coalition and 1 in 100, hopes to change. Her experience with her daughter, Eve, born three years ago with Wolf-Parkinson-White (WPW) syndrome, shows the value of detecting CCHDs early. Eve's odd skin tone, noisy breathing, and heart murmur didn't worry nursery staff much, but a pediatrician decided to test Eve with an echocardiogram cart sent from the University of Minnesota for another infant. Eve then went to intensive care with heart failure. Three and a half months later, after multiple emergencies due to severe mitral valve prolapse, Eve had life-saving surgery to ablate the electronic pathway and repair her valve.
Early genetic diagnosis was crucial. After Eve's WPW diagnosis at three weeks, the hospital was going to send her home on digoxin. “But Eve's doctor knew this medication wasn't compatible with WPW,” Saarinen recalls. “The earlier you know about a problem and its cause, the smarter you can be about treating these kids from a clinical and pharmaceutical standpoint,” Saarinen says.
Dr. Martin spearheaded development of an educational toolkit that he is using to help other hospitals implement screening in their nurseries. It's based on a soon-to-be-published study of PO screening implementation at Holy Cross Hospital in Silver Spring, Maryland. Nursery staff screened 6,489 newborns; PO yielded 4 true positives, 3 false positives, and 2 inconclusive results. Each screening took about 4 minutes of nurses' time.
All pediatricians should advocate for PO screening in their hospitals and states, Dr. Martin says. “Geneticists should get behind this,” he adds.