Abstract:Objective To study the change in regional oxygen saturation (rSO2) of intestinal tissue in preterm infants with hemodynamically significant patent ductus arteriosus (hsPDA) by near-infrared spectroscopy, and the clinical significance of the change in intestinal oxygen level in preterm infants with hsPDA. Methods The preterm infants with patent ductus arteriosus (PDA) who had gestational age <32 weeks and/or birth weight <1 500 g were prospectively enrolled, who were admitted to the Department of Neonatology, Shenzhen Longgang Central Hospital from October 2017 to October 2020.According to the diagnostic criteria for hsPDA, the preterm infants with patent ductus arteriosus (PDA) were divided into two groups: hsPDA and non-hsPDA. According to closure of the ductus arteriosus after oral administration of ibuprofen, the preterm infants in the hsPDA group were subdivided into two groups: hsPDA closure and hsPDA non-closure. Hemodynamic parameters were measured at diagnosis of PDA and after treatment, and the level of intestinal tissue rSO2 was monitored continuously to analyze its change. Results A total of 241 preterm infants with PDA were enrolled, with 55 infants (22.8%) in the hsPDA group and 186 infants (77.2%) in the non-hsPDA group. There were 36 infants (65%) in the hsPDA closure group and 19 infants (35%) in the hsPDA non-closure group. Compared with the non-hsPDA group, the hsPDA group had a significantly higher left atrial diameter/aortic root diameter ratio and significantly lower left ventricular ejection fraction and fractional shortening (P<0.05). At each time point within 6 hours after diagnosis (1, 2, 4, and 6 hours), the hsPDA group had significantly lower intestinal tissue rSO2 than the non-hsPDA group (P<0.05), and intestinal tissue rSO2 gradually decreased over time in the hsPDA group (P<0.05), with the lowest level of 0.448±0.014 at 6 hours. Compared with the hsPDA non-closure group, the hsPDA closure group had a significantly lower left atrial diameter/aortic root diameter ratio and significantly higher left ventricular ejection fraction and fractional shortening (P<0.05). At each time point within 48-96 hours after treatment (48, 72, and 96 hours), the hsPDA closure group had significantly higher intestinal tissue rSO2 than the hsPDA non-closure group (P<0.05), and intestinal tissue rSO2 gradually increased since 24 hours after treatment in the hsPDA closure group (P<0.05), with the highest level of 0.578±0.031 at 96 hours. Conclusions hsPDA has an impact on intestinal tissue oxygenation in preterm infants, and continuous monitoring of intestinal tissue rSO2 by near-infrared spectroscopy can help to guide the clinical management of hsPDA in preterm infants.