Near-infrared spectroscopy as a screening tool for patent ductus arteriosus in extremely low birth weight infants

Patent ductus arteriosus (PDA) is frequent and potentially pathologic in preterm infants. A simple bedside tool to screen for ductal patency would assist in the care of extremely low birth weight (ELBW) infants.

To investigate the utility of near-infrared spectroscopy (NIRS) in identifying ELBW infants who would benefit from early echocardiography.

Tissue oxygen saturation (S(t)O(2)) was measured by NIRS in the lungs, brain, skeletal muscle and kidney of 20 ELBW infants. Comparisons were made between the S(t)O(2) in these organs and the need for intervention for a PDA. All studies were performed within the first 4 days of life. Similar measurements were performed following treatment with indomethacin in nine of the patients.

The S(t)O(2) of skeletal muscle (left deltoid) and kidney differed between the infants who were treated for PDA and those who were not (p = 0.01 for both). As a screen for a PDA requiring intervention, deltoid S(t)O(2) had sensitivity 77% and specificity 83%, and kidney S(t)O(2) had sensitivity 85% and specificity 83%. Following treatment with indomethacin, the low S(t)O(2) in the deltoid and kidney increased toward the range seen in patients who did not require treatment of a PDA. Inter- and intra-observer variability ranged from minimal to high.

This pilot study of a portable NIRS device shows encouraging efficacy in identifying ELBW infants who were likely to benefit from early echocardiography and subsequent intervention to close a PDA. Further study is warranted.