A Left-to-Right Shunt via the Ductus Arteriosus Is Associated with Increased Regional Cerebral Oxygen Saturation during Neonatal Transition

Abstract

Background: Oxygen delivery to the brain is dependent on cardiac output and arterial oxygen content. Objectives: The study was designed to investigate the influence of a left-to-right shunt via the ductus arteriosus (DA) on regional oxygen saturation (rSO₂) of the brain and peripheral tissue during postnatal transition. Methods: Nested case-control study. In term neonates after elective cesarian section, rSO₂ of the brain and pre- and postductal peripheral tissue were measured 15 min after uncomplicated postnatal transition. Two groups were formed according to shunt flow characteristics via the DA: shunt group (with a left-to-right shunt), and nonshunt group (no shunt). Results: Of 80 infants, in 58 (72%) a left-to-right shunt was identified, and in 22 (28%) no flow was seen via the DA. The 22 infants formed the nonshunt group. They were matched with 22 newborn infants with a left-to-right shunt via the DA (shunt group). Infants in the nonshunt group had significantly lower cerebral rSO₂ values and higher fractional tissue oxygen extraction and heart rate values. There were no significant differences in regard to peripheral rSO₂ values. Conclusion: During postnatal transition, term infants with a left-to-right shunt via the DA have significantly higher cerebral rSO₂ values compared to infants without shunt flow.