Liver Regional Oxygen Saturation in Preterm Infants with Patent Ductus Arteriosus Status

Background/Objectives: Near-infrared spectroscopy measures regional oxygen saturation (RSO₂) in target tissues. Cerebral and renal RSO₂ are associated with hemodynamically significant patent ductus arteriosus (PDA) in preterm infants. The aim of this study was to determine whether liver RSO₂ is associated with PDA status. Methods: Preterm infants born before 32 weeks of gestation and/or weighing <1.5 kg were enrolled. Cerebral, renal, and liver RSO₂ values were recorded on day 2 (D2; 48-72 h), day 7 (D7; 7 ± 2 days), and day 14 (D14; 14 ± 3 days), along with the corresponding point-of-care echocardiographic findings. Results: Of the forty preterm infants enrolled (mean ± SD gestational age, 28.8 ± 2.2 weeks; birthweight, 1209.9 ± 364.2 g), 22 (55.0%) had spontaneous PDA closure, 18 (45.0%) underwent pharmacological closure, and 4 (10.0%) required surgical closure. Cerebral, renal, and liver RSO₂ values were significantly lower in infants with PDA than those without. Liver RSO₂ was significantly lower in the presence of PDA at D7 (68.19 ± 13.24 vs. 82.14 ± 5.58, p < 0.001) and D14 (59.33 ± 12.06 vs. 80.0 ± 6.48, p < 0.001). Liver RSO₂ showed a strong inverse association with a higher LA/Ao ratio (β -38.71, 95%CI -55.03 to -22.40, p <0.001) in the linear mixed model analysis. Conclusions: Liver RSO₂ was associated with different PDA statuses. Future studies exploring the potential utility of liver RSO₂ as an adjunct parameter for detecting and guiding the management of hemodynamically significant PDA in preterm infants may be warranted.