Objectives— Early screening and dynamic monitoring of pulmonary vascular disease (PVD) in bronchopulmonary dysplasia (BPD) high-risk infants is of great clinical significance. Pulmonary artery acceleration time (PAAT) is a reliable and non-invasive method for assessing PVD in children over 1 year, but to date, few studies have used PAAT to assess pulmonary hemodynamics of preterm infants, especially those with BPD. Through dynamic monitoring the main hemodynamic indicators reflected PVD after birth, this study aimed to assess the value of PAAT in evaluating early PVD in BPD infants. Methods— 81 preterm infants at risk of BPD were divided into BPD and non-BPD groups according to whether BPD occurred. Clinical characteristics, PAAT, right ventricular ejection time (RVET) and other main hemodynamic indicators at 4 different time points after birth were studied and compared. Results— PAAT and PAAT/RVET increased gradually within 72 hours after birth in the BPD group ( P < 0.05), but the curve tended to be flat over time after 72 hours( P > 0.05). At PMA32 and 36 weeks, the PAAT (49.7±4.8 vs.54.8±5.7, P=0.001; 50.0±5.3 vs.57.0±5.3, P=0.001) and PAAT/RVET (0.33 ± 0.04 vs. 0.35 ± 0.03, P=0.001; 0.34 ± 0.03 vs. 0.37 ± 0.04, P = 0.001) in BPD group were significantly lower than those in the non-BPD group. Conclusions— PAAT and PAAT/RVET in the BPD group infants showed different change patterns compared to non-BPD group infants. PAAT can be used as a noninvasive and reliable screening method for screening and dynamic monitoring of PVD in BPD high-risk infants.

Abstract Introduction: Pulmonary artery acceleration time (PAAT) is a reliable and noninvasive method of assessing pulmonary hemodynamics in children and adults, but it lacks validity for preterm infants. The aim of this study was to assess changes in PAAT among preterm infants with neonatal respiratory distress syndrome (NRDS) who are receiving pulmonary surfactant (PS) therapy, and to determine its potential significance in terms of respiratory outcomes. Methods: Between January and December 2019, 62 preterm infants with a gestational age of 27–31 weeks, a risk of NRDS, and who had been started on nasal continuous positive airway pressure were reviewed. Infants who received PS treatment were allocated to the PS group, and those who did not were allocated to the control group. We then studied PAAT and other ultrasonic parameters at three different time points after birth, comparing the groups’ values . Results: PAAT increased after PS treatment, but over time (up to 36 weeks postmenstrual age) PAAT in the PS group increased at a slower rate than that in the control group. Conclusion: PAAT is a convenient and sensitive method of accurately assessing pulmonary vascular diseases among preterm infants. Preterm infants with NRDS might still have respiratory diseases in the late postnatal period; thus, they require full attention and long-term follow-up observation.