Delayed cord clamping and blood flow in the superior vena cava in preterm infants: an observational study

2011 ◽  
Vol 2011 ◽  
pp. 26-27
Author(s):  
L.A. Papile
Keyword(s):  
Blood Flow ◽  
Observational Study ◽  
Preterm Infants ◽  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Delayed Cord Clamping ◽  
Cord Clamping

Interobserver agreement and image quality of functional cardiac ultrasound measures used in a randomised trial of delayed cord clamping in preterm infants

2017 ◽  
Vol 103 (3) ◽  
pp. F257-F263 ◽  
Author(s):  
Himanshu Popat ◽  
Kristy P Robledo ◽  
Lucille Sebastian ◽  
Nicholas Evans ◽  
Andrew Gill ◽  
...  
Keyword(s):  
Image Quality ◽  
Preterm Infants ◽  
Interobserver Agreement ◽  
Ductus Arteriosus ◽  
Randomised Trial ◽  
Vena Cava ◽  
Mean Difference ◽  
Cardiac Ultrasound ◽  
Delayed Cord Clamping ◽  
Cord Clamping

ObjectiveFunctional cardiac ultrasound measures are used clinically and in trials for assessing the haemodynamic status of newborn infants. Superior vena cava (SVC) flow and right ventricular output (RVO) are established measures of systemic blood flow on the first postnatal day. The objective was to assess image quality and interobserver agreement of these measures in preterm infants enrolled in a randomised trial of immediate versus delayed cord clamping.Design and settingImage quality and interobserver agreement for SVC flow, RVO and ductus arteriosus (DA) size were assessed on measurements taken at 3–6, 6–12 and 20–28 hours for the first 10 infants enrolled at each of four sites (total 40). Bland-Altman plots were constructed; mean difference (bias) and limits of agreement (LOA) were calculated. Potential sources of variation were explored.ResultsQuality was judged satisfactory for >97% of images. The mean difference and LOA between the observers were 5.4 mL/kg/min and −49.0 to 59.8 mL/kg/min for SVC flow, −26.6 mL/kg/min and −131.4 to 78.2 mL/kg/min for RVO, and 0 mm and −0.8 to 0.8 mm for DA diameter, respectively. The principal source of measurement error for SVC flow was diameter, and for RVO, diameter and velocity time integral. The difference between observers for both SVC and RVO was significantly associated with site.ConclusionInterobserver variability for SVC flow is consistent with that previously reported, but higher for RVO. The findings should be incorporated into clinical practice, training, accreditation and trial design.

A Computational Pulsatile Model of the Bidirectional Cavopulmonary Anastomosis: The Influence of Pulmonary Forward Flow

1996 ◽  
Vol 118 (4) ◽  
pp. 520-528 ◽  
Author(s):  
Francesco Migliavacca ◽  
Marc R. de Leval ◽  
Gabriele Dubini ◽  
Riccardo Pietrabissa
Keyword(s):  
Blood Flow ◽  
Pulmonary Artery ◽  
Superior Vena Cava ◽  
Superior Vena ◽  
Main Pulmonary Artery ◽  
Vena Cava ◽  
Similar Distribution ◽  
Pulsatile Blood Flow ◽  
Cavopulmonary Anastomosis ◽  
Bidirectional Cavopulmonary Anastomosis

The bidirectional cavopulmonary anastomosis (BCPA or bidirectional Glenn) is an operation to treat congenital heart diseases of the right heart by diverting the systemic venous return from the superior vena cava to both lungs. The main goal is to provide the correct perfusion to both lungs avoiding an excessive increase in systemic venous pressure. One of the factors which can affect the clinical outcome of the surgically reconstructed circulation is the amount of pulsatile blood flow coming from the main pulmonary artery. The purpose of this work is to analyse the influence of this factor on the BCPA hemodynamics. A 3-D finite element model of the BCPA has been developed to reproduce the flow of the surgically reconstructed district. Geometry and hemodynamic data have been taken from angiocardiogram and catheterization reports, respectively. On the basis of the developed 3-D model, four simulations have been performed with increasing pulsatile blood flow rate from the main pulmonary artery. The results show that hemodynamics in the pulmonary arteries are greatly influenced by the amount of flow through the native main pulmonary artery and that the flow from the superior vena cava allows to have a similar distribution of the blood to both lungs, with a little predilection for the left side, in agreement with clinical postoperative data.

scholarly journals Effect of spontaneous breathing on umbilical venous blood flow and placental transfusion during delayed cord clamping in preterm lambs

2019 ◽  
Vol 105 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Emma Brouwer ◽  
Arjan B te Pas ◽  
Graeme R Polglase ◽  
Erin V McGillick ◽  
Stefan Böhringer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Body Weight ◽  
Spontaneous Breathing ◽  
Venous Blood ◽  
Vena Cava ◽  
Venous Blood Flow ◽  
Delayed Cord Clamping ◽  
Venous Flow ◽  
Cord Clamping ◽  
Pregnant Sheep

IntroductionDuring delayed umbilical cord clamping, the factors underpinning placental transfusion remain unknown. We hypothesised that reductions in thoracic pressure during inspiration would enhance placental transfusion in spontaneously breathing preterm lambs.ObjectiveInvestigate the effect of spontaneous breathing on umbilical venous flow and body weight in preterm lambs.MethodsPregnant sheep were instrumented at 132–133 days gestational age to measure fetal common umbilical venous, pulmonary and cerebral blood flows as well as arterial and intrapleural (IP) pressures. At delivery, doxapram and caffeine were administered to promote breathing. Lamb body weights were measured continuously and breathing was assessed by IP pressure changes.ResultsIn 6 lambs, 491 out of 1117 breaths were analysed for change in body weight. Weight increased in 46.6% and decreased in 47.5% of breaths. An overall mean increase of 0.02±2.5 g per breath was calculated, and no net placental transfusion was observed prior to cord clamping (median difference in body weight 52.3 [−54.9–166.1] g, p=0.418). Umbilical venous (UV) flow transiently decreased with each inspiration, and in some cases ceased, before UV flow normalised during expiration. The reduction in UV flow was positively correlated with the standardised reduction in (IP) pressure, increasing by 109 mL/min for every SD reduction in IP pressure. Thus, the reduction in UV flow was closely related to inspiratory depth.ConclusionsSpontaneous breathing had no net effect on body weight in preterm lambs at birth. UV blood flow decreased as inspiratory effort increased, possibly due to constriction of the inferior vena cava caused by diaphragmatic contraction, as previously observed in human fetuses.

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