Study: Detecting congenital heart defects with pulse oximetry

Investigators in Norway demonstrated the efficacy of first-day-of-life pulse oximetry screening for detecting congenital heart defects (CHDs) and other potentially severe diseases, especially pulmonary disorders. Using a foot probe, they measured arterial oxygen saturation (SpO₂) in about 50,000 babies born in 14 hospitals during a one-year period.

Of the screened infants-who had a median age of six hours-1,360 (3%) had SpO₂ of <95%, the cutoff investigators used in screening for CHDs. Three-hundred-twenty-four (0.6%) of these infants were classified as pathologic, either because they had symptoms of disease when first tested or because of persistent SpO₂ <95% when retested. Of these 324 infants, 43 (13%) had CHDs (27 were critical), including transposition of the great arteries, atrioventricular septal defect, and ventricular septal defect. Other disorders, primarily pulmonary disease, were diagnosed in 134 (41%) of the 324 infants. The remaining 147 infants (45%) were classified as healthy newborns with prolonged transitional circulation.

Investigators noted that the sensitivity of pulse oximetry is low for detecting CHDs in general, because most CHDs present with a normal SpO₂. For detecting critical CHDs, however, pulse oximetry screening demonstrated a sensitivity of 77.1%, a specificity of 99.4%, and a false-positive rate of 0.6% (Meberg A et al: J Pediatr 2008;152:761)

These authors make a strong argument for adopting the practice of routine pulse oximetry measurement in the newborn nursery. The screening test is noninvasive and inexpensive. The authors state that their false positive rate of 0.6% might be lowered by delaying testing until 24 hours of life, which would exclude normal babies with slightly delayed transitioning. Minimizing false positives will be important, as most will generate an additional echocardiogram.

DR. BURKE, section editor for Journal Club, is chairman of the department of pediatrics at Saint Agnes Hospital, Baltimore. He is a contributing editor for Contemporary Pediatrics. He has nothing to disclose in regard to affiliations with, or financial interests in, any organization that may have an interest in any part of this article.