Objective: To analyze the levels of regional tissue oxygenation in preterm infants in association with echocardiographically significant patent ductus arteriosis (PDA).Study Design: Preterm infants with gestational age less than 32 week were enrolled before the first dose of the pharmacological treatment for the PDA. Non-invasive near-infrared spectroscopy (NIRS) technology was utilized to measure cerebral (rSO 2 -C), renal (rSO 2 -R) and mesenteric (rSO 2-M ) tissue oxygenation for approximately 60 min. Regional fractional oxygen extraction (FOE) was calculated using simultaneously measured arterial saturation (SaO 2 ). We analyzed regional tissue oxygenation and oxygen extraction, hemodynamic parameters, and demographic and clinical information in association with the size of the PDA (moderate vs large).Result: Among the 38 enrolled infants, the majority were diagnosed with a large (63.2%, n ¼ 24) and the rest with a moderate-sized PDA. Infants with large and moderate PDA were comparable in terms of gestational age, study age and weight, mode of delivery and hemodynamic parameters. A significantly higher proportion of infants with a moderate PDA were mechanically ventilated as compared with those with a large PDA. We found no significant differences in the rSO 2 -C and rSO 2 -R, irrespective of the type of respiratory support. However, in infants with a large PDA on continuous nasal positive airway pressure (NCPAP), the rSO 2 -M was lower and mesenteric FOE was higher than that in mechanically ventilated neonates with a large PDA, and in those with moderate PDA irrespective of the type of respiratory support.
Conclusion:The PDA size did not affect cerebral and renal tissue oxygenation, but the mesenteric tissue oxygenation was decreased in infants with a large PDA on NCPAP.