RT Journal Article
SR Electronic
T1 Effect of breathing on venous return during delayed cord clamping: an observational study
JF Archives of Disease in Childhood - Fetal and Neonatal Edition
JO Arch Dis Child Fetal Neonatal Ed
FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health
SP fetalneonatal-2020-321431
DO 10.1136/archdischild-2020-321431
A1 Emma Brouwer
A1 Ronny Knol
A1 Annie Kroushev
A1 Thomas Van Den Akker
A1 Stuart B Hooper
A1 Arno A Roest
A1 Arjan B te Pas
YR 2021
UL http://fn.bmj.com/content/early/2021/06/08/archdischild-2020-321431.abstract
AB Objective To investigate the effect of spontaneous breathing on venous return in term infants during delayed cord clamping at birth.Methods Echocardiographic ultrasound recordings were obtained directly after birth in healthy term-born infants. A subcostal view was used to obtain an optimal view of the inferior vena cava (IVC) entering the right atrium, including both the ductus venosus (DV) and the hepatic vein (HV). Colour Doppler was used to assess flow direction and flow velocity. Recordings continued until the umbilical cord was clamped and were stored in digital format for offline analyses.Results Ultrasound recordings were obtained in 15 infants, with a median (IQR) gestational age of 39.6 (39.0–40.9) weeks and a birth weight of 3560 (3195–4205) g. Flow was observed to be antegrade in the DV and HV in 98% and 82% of inspirations, respectively, with flow velocity increasing in 74% of inspirations. Retrograde flow in the DV was observed sporadically and only occurred during expiration. Collapse of the IVC occurred during 58% of inspirations and all occurred caudal to the DV inlet (100%).Conclusion Spontaneous breathing was associated with collapse of the IVC and increased antegrade DV and HV flow velocity during inspiration. Therefore, inspiration appears to preferentially direct blood flow from the DV into the right atrium. This indicates that inspiration could be a factor driving placental transfusion in infants.Data are available upon reasonable request.