Pulse Oximeters - Screening Critical Congenital Heart Defects

Critical congenital heart defects (CCHDs) are structural heart defects and have accounted for about 25% of all congenital heart defects. Newborn babies with CCHD frequently suffer from bypoxemia. A simple test using a pulse oximeter for detecting hypoxemia can be an effective screening tool. Anyone with an infant oximeter can perform the test easily and the test would take less than one minute.

According to Centers for Disease Control and Prevention, 1% of all babies in the US (approximately 40,000 babies) have some kind of congenital heart defect each year. The defect can be life-threatening if not treated early.

Prior to 2012, the standard method for screening CCHDs were prenatal ultrasound and physical examination; however only 50-60% of the cases were identified using ultrasound and only 20-25% were found in physical examination. Up to 30% were unidentified. Since 2012, there has been a big push to make oximeter screen a standard procedure during newborn screening. In some states, this was written into various legislature.

CCHD screening procedure

This procedure is recommended in hospital for all babies older than 24 hours in the well-baby nursery or shortly before discharged if less than 24 hours old.

1. Take two measurements, one on the right hand and one on the right foot.
2. If either measurement is greater than 95% and the two measurements differ by less than 3%, the test is negative.
3. If either measurement is less than 90%, the test is positive.
4. Otherwise the result is inconclusive. Wait an hour and repeat the measurements again. After three inconsistent results, the test is positive.

A baby with a positive screen should have a diagnostic echocardiogram and the baby's pediatrician should be notified immediately. A cardiologist may be required.

To minimize false positives, the infant should be fully alert. In general, this testing should be part of the newborn screening, which should include blood test, hearing screening, and CCHD screening.

This screening does not detect all CCHD; so it possible that the baby may still have CCHD or other heart defects. Furthermore, this screening does not replace a complete physical exam.

Reference

Screening for Critical Congenital Heart Defects, Centers for Disease Control and Prevention

Assessment of Current Practices and Feasibility of Routine Screening for Critical Congenital Heart Defects — Georgia, 2012

Missed Diagnosis of Critical Congenital Heart Disease