Pulse Oximetry in the Screening of Congenital Heart Disease: Easy to Perform, Cost-Effective, Low False-Positive Rates

Katherine A. Kahn, DVM

October 13, 2008

October 13, 2008 (Boston, Massachusetts) — Pulse oximetry, as a screening tool for the detection of congenital heart disease in neonates, is most likely to be valuable outside the tertiary-care environment where other methods of detecting congenital heart disease in asymptomatic newborns may not be as robust, the authors of a new study conclude. Lead investigator John Hokanson, MD, presented the findings here at the American Academy of Pediatrics 2008 National Convention and Exhibition. Dr. Hokanson is a pediatric cardiologist at the University of Wisconsin School of Medicine and Public Health, in Madison.

"Routine pulse oximetry has been proposed as a method by which previously undetected congenital heart disease can be recognized," Dr. Hokanson told Medscape Pediatrics. "Any screening protocol will have its good points and bad points. It remains controversial about how useful these types of [screening] protocols might be."

Hokanson and colleagues performed pulse oximetry on all asymptomatic term neonates born at the Meriter Hospital in Madison, Wisconsin, between July 2007 and September 2008. A total of 4239 neonates underwent pulse-oximetry screening in 1 foot 24 hours after birth. Nursing staff received in-service training in the screening protocol and performed the pulse-oximetry procedure.

Whether further clinical diagnostics were used depended on the oxygen saturation results of the screening. If oxygen saturation was higher than 94%, no further action was taken. If saturation was 90% to 94%, the test was repeated 2 hours later. If it was below 90%, a full clinical evaluation was undertaken. If saturation rose to 94% or more in patients with an original saturation between 90% and 94%, no further action was taken. If saturation remained between 90% and 94%, an echocardiogram was ordered. If saturation fell to below 90%, a full clinical evaluation was conducted.

Of the neonates screened, 23 were found to have significant congenital heart disease. However, all of these cases were diagnosed before the 24-hour delay to screening, not by pulse oximetry. Fourteen neonates were diagnosed prenatally and the remaining 9 were diagnosed when heart murmurs were discovered before they were 24 hours old.

A repeat oximetry was required in 3 of the last 2336 babies screened. In addition, no echocardiograms were triggered in the 4239 neonates and no discharges were delayed. The only material cost, Dr. Hokanson told attendees, was the reusable pulse-oximetry wrap, which costs $0.43 per patient.

A pulse-oximetry screening protocol has yet to be studied outside the tertiary-care environment, Dr. Hokanson told Medscape Pediatrics. "Any screening protocol for congenital heart disease has to do with incidence of unrecognized disease. I would argue that the place where this may be needed most — and the place it hasn't been studied — is in the smaller, more rural hospitals where prenatal detection rates of congenital heart disease are not as high."

Although the pulse oximetry did not uncover any undetected heart disease, "at least from this study we've been able to show that this type of protocol can be introduced easily, cheaply, and with minimal disruption to the flow through the normal nursery," Dr. Hokanson concluded.

Robert Beekman III, MD, chair of the section on cardiology and cardiac surgery of the American Academy of Pediatrics, and director of cardiology at Cincinnati Children's Hospital, in Ohio, told Medscape Pediatrics: "The role of pulse oximetry in screening for congenital heart disease is not well defined. There are some rare babies born with severe congenital heart disease who will be detected by oximetry, but it's not known if they wouldn't have been detected by other techniques."

Dr. Beekman stated that the American Heart Association and the American Academy of Pediatrics are currently working onrecommendations regarding pulse-oximetry screening. "There's a lot of interest in this topic from patient advocacy groups. Their perspective is that they or loved ones have lost a baby to congenital heart disease that could have been detected; therefore, this should be a mandated screening test. That perspective is important and we should be sensitive to it," he said. "On the other hand, for the American Heart Association and the American Academy of Pediatrics to recommend that oximetry be performed on every [neonate], there needs to be some careful assessment of how beneficial it is and what the costs are, including costs associated with false positives."

The researchers have disclosed no relevant financial relationships.

American Academy of Pediatrics (APA) 2008 National Conference and Exhibition. Abstract 613. Presented October 11, 2008.


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