Simple test saves lives of newborns with congenital heart disease

A study performed by researchers at the Sahlgrenska Academy shows that routine screening of the oxygen level in the blood of all newborns increases the detection of heart diseases, which entails that fewer infants die and the risk of life-long brain damage decreases.

One to two children per 1,000 babies are born with a so-called ductus-dependent heart disease. This heart disease is directly life-threatening in that the flow of blood to the lungs or the rest of the body is shut off when the ductus arteriosus, a blood vessel that is open during the fetal period, gradually closes after birth.

When only conventional pediatric examinations are carried out at maternity wards before discharge, many of these diseases are missed, since the heart disease often has no murmur. About 30 percent of children with ductus-dependent heart disease therefore leave the maternity ward undiagnosed, which means that they fall ill at home, often with severe complications such as circulation collapse and organ failure as a result.

“One of six children that suffer circulation collapse or organ failure at home do not make it to the hospital in time and die. But if the heart disease is detected in time, the majority can be operated on with good results,” says Ingegerd Östman-Smith, professor of pediatric cardiology at the Sahlgrenska Academy and one of the researchers behind the study, which is now being published in British Medical Journal.

Simple and quick test saves lives

Pulse oximetry screening is a quick and simple method for measuring the oxygen concentration in the child's blood. By placing a sensor on a hand, and in this study also on a foot, the concentration of oxygen is metered before the child leaves the hospital. If the oxygen concentration is lower than normal, it may indicate that the child has a heart problem and needs to be examined further. The screening is carried out by a midwife and takes about five minutes.

“The method is simple and reliable, and the fact that the infants are diagnosed to a greater extent before the heart disease has caused any damage that requires intensive care renders this method highly cost-effective,” says Ingegerd Östman-Smith.

Professor Ingegerd Östman-Smith and doctoral candidate Anne De-Wahl Granelli, together with colleagues, have assessed the efficacy of pulse oximetry screening in the Western Götaland region and compared the ductus-dependent heart diseases detected in other regions and county councils that performed only conventional pediatric examinations before discharge. Nearly 40,000 infants were screened, all born in the Western Götaland region between July 1, 2004, and March 31, 2007,

The researchers found that among apparently healthy infants 82.8 percent of all ductus-dependent heart diseases were discovered when the babies were examined both by a pediatrician and with the aid of pulse oximetry. When the children were only examined by a pediatrician, 62.5 percent of the heart diseases were detected. Some infants had been diagnosed before their pediatric examination, so a total of 92 percent of children with ductus-dependent heart diseases were identified in the Western Götaland region during the period under study. This was significantly better than the regions compared, which only performed pediatric examinations, where 72 percent were detected.

“The risk of leaving the maternity ward with an undetected life-threatening heart disease was thus only 8 percent in Western Götaland, compared with 28 percent in the regions compared,” says Ingegerd Östman-Smith.

Higher mortality among unscreened children

The study shows that infants that left the maternity ward with undiagnosed heart disease evinced much higher mortality than those who were diagnosed before discharge: 18 percent versus 0.9 percent when comparing children who were not premature or were lacking a functioning left ventricle. No children died at home with undiagnosed heart disease in the Western Götaland region during the study period, compared with five deaths in the home in the regions under comparison.

The assessment of costs showed that screening is cost-neutral when introduced. All that is needed is a machine with a one-off outlay of about SEK 12,000 (~$1,500) per delivery unit as well as the time, roughly five minutes per infant, it takes for a midwife to perform the screening. Since the method would entail a probable decrease in neurological damage cause by circulation collapse, and less need for pre-operative intensive care, this screening is cost-effective in the long term.

The prestigious British Medical Journal, which is publishing the study, is also including an editorial commentary by Professor Keith Barrington, Montreal, Canada. He points out that, on the basis of the evidence from this study, routine pulse oximetry screening is a low-risk and low-cost strategy to enhance the detection of critical congenital heart diseases, and that its “introduction should be seriously considered in all countries with access to pediatric heart surgery.”

The screening study constitutes a dissertation project for Anne De-Wahl Granelli, directed by the professor of pediatric cardiology, Ingegerd Östman-Smith, Department of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, and Queen Silvia Hospital for Children and Adolescents.

Journal: BMJ, British Medical Journal
Title of article: Impact of pulse oximetry screening on the detection of duct dependent congenital heart disease: a Swedish prospective screening in 39 821 newborns
Author: Ingegerd Östman-Smith
For more information please contact:
Professor Ingegerd Östman-Smith, phone: +46 (0)31-343 4512; cell phone: +46 (0)705-749 501, e-mail: ingegerd.ostman-smith@pediat.gu.se