Dulal Kalita1, Bipul Kumar Das2, Anuradha Deuri3, Vivekananda Matada Shivananda4
Congenital heart diseases are the most common congenital malformations and account for 6-10% of all infant deaths. Congenital heart defects affect 8 to 10 out of every 1000 live births. Pulse oximetry in newborn screening can detect mild hypoxemia that may not be recognised by clinical examination. Thus, pulse oximetry can help to identify babies that may be affected with critical congenital heart disease before they leave the newborn nursery. There are many studies carried out on pulse oximetry with different sensitivity and specificity for detection of congenital heart disease. The objectives of the present study were to screen all newborns admitted in NICU to rule out congenital heart disease before discharge and to find out the utility of pulse oximetry to detect congenital heart disease.
This prospective study was conducted in Neonatal Intensive Care unit, Gauhati Medical College and Hospital in 1720 neonates over a period of 12 months (February 2015 to January 2016). Both pulse oximetry and clinical examination were done. Persistent pulse oximetry (SPO2) reading below 95% or more than 3% difference between right hand and one foot, it was considered as positive pulse oximetry. Newborns with positive pulse oximetry and abnormal clinical examination findings were subjected to echocardiography.
Positive pulse oximetry cases were 47(2.73%), out of which 39 cases had only positive pulse oximetry (with negative clinical examination). Positive clinical examination cases were 58(3.37%), out of which 50 cases had only positive clinical examination findings (with negative pulse oximetry). Eight (8) cases had both positive pulse oximetry and positive clinical examination. Total congenital heart disease cases detected in our study was 34(1.98%) out of 1720. VSD was the most common CHD followed by PDA, TOF, TGA in this study. The sensitivity, specificity, positive predictive value and negative predictive value of pulse oximetry were 41.18%, 98.04%, 29.79%, 98.80% respectively.
Pulse oximetry is a useful tool to detect congenital heart disease. Its accuracy in detecting congenital heart disease increases if combined with positive clinical examination.