Objective: Hypoxemia and respiratory compromise occur in very low birth weight (VLBW, <1,500 g) infants and may be associated with shunting across patent ductus arteriosus (PDA). The impact of pharmacologic PDA treatment on acute hypoxemia and respiratory metrics is unclear. This study aimed to determine whether pharmacologic PDA treatment is associated with acute improvement in hypoxemia and respiratory metrics in VLBW infants.
Study design: At a single center (2012-2022), all VLBW infants with echocardiographic evidence of PDA and without exclusions were classified as having received or not received pharmacologic PDA treatment (PDA-T and PDA-NT). Mean daily fraction of inspired oxygen (FIO2) and Respiratory Acuity Score (RAS, PMID 30374050) were compared at baseline (day 0) and 3 days after the start of treatment. For PDA-T infants with archived 0.5 Hz (every 2-second) oxygen saturation (SpO2) data, mean daily SpO2 and the percentage of time with severe hypoxemia (SpO2 <80%) were compared before and after treatment. Severe hypoxemia was further analyzed after stratification by clinical variables (sex, medication, gestational age, and postnatal age).
Results: We analyzed 125 VLBW infants with PDA, of whom 66 received pharmacologic PDA treatment. We analyzed a subgroup of 43 PDA-T infants with every 2-second SpO2 data available. PDA-T infants had higher baseline FiO2 and RAS and lower SpO2 than PDA-NT infants (p < 0.05). Compared to baseline, RAS decreased from a median of 258 (interquartile range [IQR]: 171, 348) to 254 (IQR: 174, 419), 3 days after the start of treatment (p = 0.012), but median FiO2 increased from 37% (IQR: 28, 46) to 40% (IQR: 29, 52; p = 0.008). SpO2 and the percent time with severe hypoxemia were unchanged.
Conclusion: In this 10-year, retrospective, single-center analysis, pharmacologic PDA treatment in VLBW infants was not associated with a major improvement in acute measures of oxygenation or level of respiratory support.
Key points: · Infants with pharmacologically treated PDA had worse baseline respiratory and oxygenation metrics.. · RAS decreased but FiO2 increased 3 days after pharmacologic PDA treatment.. · Pharmacologic PDA treatment did not acutely improve SpO2 or severe hypoxemia..