Use of Pulse Oximetry Pulsatility Index Screening for Critical Congenital Heart Disease

This study aimed to compare oximetry data (pre- and postductal oxygen saturation [SpO₂], pre- and postductal pulsatility index [PI]) in healthy newborns (≥35 weeks' gestational age) to infants who have critical congenital heart disease (CCHD).

This is a retrospective analysis of data obtained from electronic medical records, recorded as part of routine pulse oximetry screening (POS) for CCHD in infants born between the years 2013 and 2020. Testing was performed at 24 ± 2 hours of life. Data were analyzed to detect differences in pre- and postductal SpO₂ and pre- and postductal PI in healthy newborns compared with infants who have CCHD. Newborns were excluded from analysis if they: (1) had a prenatal diagnosis of CCHD in the medical record, (2) had previously been admitted to the neonatal intensive care unit, or (3) had failed POS but were found no CCHD by diagnostic echocardiography.

A total of 88,754 healthy newborns had received POS between the years 2013 and 2020. Of the 88,736 newborn records available for analysis,18 newborns were diagnosed with CCHD. Eight were identified by POS before discharge and 10 were diagnosed after discharge. Infants diagnosed with CCHD by POS had lower pre- and postductal SpO₂ compared with normal infants. Their postductal PI was significantly lower. Infants who had CCHD that was not identified by POS had similar pre- and postductal SpO₂ values, but their postductal PI was lower. Using a postductal PI cutoff of 1.21 had a receiver operating curve of area under the curve 0.77 (95% confidence interval: 0.672, 0.869) with 74% sensitivity and 61% specificity.

In our large cohort of infants born in San Diego County, the postductal PI is lower in infants with CCHD. Given that PI is routinely displayed on every pulse oximeter and the high morbidity of missed CCHD, PI should be incorporated into routine CCHD screening.

· Postductal PI is lower in newborn who presented later with congenital heart disease.. · Postductal PI cut-off of 1.21 may help practitioners determine if a newborn is at risk for CCHD.. · This large cohort study demonstrates that a low PI can detect additional CCHD cases..