262 - Assessing normative values for pulmonary venous flow in term neonates during the transitional period

Publication Number: 4258.262

iyshwarya Stapleton, INFANT Research Centre, University College Cork, Cork, Cork, Ireland; Neil Collins, Cork University Maternity Hospital, Cork, Cork, Ireland; Neidin Bussmann, CUMH, Cork, Cork, Ireland; Daragh Finn, University College Cork, Cork, Cork, Ireland; Vicki Livingstone, University College Cork, Cork, Cork, Ireland; Eugene Dempsey, University Colleeg Cork, Cork, Cork, Ireland

Background: Pulmonary vein (PV) Doppler assessment is an important tool in evaluating left atrial filling and ventricular diastolic function. No normative reference ranges exist for neonatal PV flow patterns.

Objective: The aim of this study was to assess pulmonary vein measurements in a cohort of babies born over 35 weeks' gestation and develop normative reference values for the first and second days of life (DOL).

Design/Methods: This was a single-centre prospective observational study of 59 well babies born at greater than or equal to 35 weeks' gestation (Table 1). Echocardiography was performed on DOL 1 (6 to 18 hours of life) and DOL 2 (30 to 42 hours of life). Both scans included a comprehensive structural assessment to confirm normal anatomy. Doppler assessment was performed in the suprasternal view to capture all four veins. The systolic wave (S), the diastolic wave (D), atrial reversal (Ar) and mean flow (Vmean) velocities for each of the four pulmonary veins was measured.
Inter-rater reliability was assessed using two raters (IS, NC) independently calculating measurements on 46 scans (23 each from DOL 1 and 2). Intra-rater reliability was assessed by one rater (IS) taking measurements on 30 scans (15 each from DOL 1 and 2) and repeating them after three months. Inter- and intra-rater reliability was evaluated using intra-class correlation coefficient (ICC) and scatterplots.
Shapiro-Wilk test was used to assess normality in the data. As the values were not normally distributed, median and interquartile range (IQR) were calculated for each of the 16 measurements for DOL 1 and DOL 2 and are presented in Table 2.

Results: The S, D and Vmean values had the best inter- and intra-rater reliability. Ar values were found to have poor inter- and intra-rater reliability. S [DOL 1 median (IQR) = 50cm/s (40 - 59)] and D [DOL 1 median (IQR) = 58cm/s (48 - 68)] waves were greatest for the left inferior PV. The inferior veins had better inter- and intra-rater reliability than the superior veins. Overall, DOL 1 measures were greater than DOL 2 measures for all four veins (Figure 1).

Conclusion(s): We describe normal transitional pulmonary venous flow patterns and provide reference ranges for DOL 1 and 2 in healthy transitioning newborns.

Table 1: Inclusion and exclusion criteria


Table 2: Median and interquartile range (IQR) of pulmonary venous flow measurements on day of life (DOL) 1 and DOL 2


Figure 1: Right inferior (RI), left inferior (LI), right superior (RS) and left superior (LS) pulmonary venous (PV) flow measurements (S wave, D wave, Ar wave, Vmean) on day of life (DOL) 1 and DOL 2