Objective To assess accuracy and repeatability of a modified echocardiographic approach to quantify superior vena cava (SVC) flow volume that uses a short-axis view to directly measure SVC area and a suprasternal view to measure flow velocity, both at the level of the right pulmonary artery.
Setting Three tertiary-level neonatal intensive care units.
Design This was a multicentre, prospective, observational study. Accuracy of the traditional and modified approach was first assessed by comparing echo measurements according to both techniques with Phase contrast MRI (PCMRI) assessments, in a cohort of 10 neonates. In a second cohort of 40 neonates, intraobserver scan–rescan repeatability and interobserver analysis–reanalysis repeatability were assessed by repeated SVC flow echo measurements, according to both techniques.
Results The traditional echocardiographic approach to assessment of SVC flow had a moderate agreement with PCMRI (r2 0.259), a scan–rescan intraobserver repeatability index (RI) of 37% (limits of agreement (LOA) −47/+51 mL/kg/min) and an interobserver analysis–reanalysis RI of 31% (LOA −38/+40 mL/kg/min). The modified approach showed a stronger agreement with PCMRI (r2 0.775), an improved intraobserver scan–rescan repeatability (RI 22%, LOA −24/+18 mL/kg/min) and improved interobserver analysis–reanalysis repeatability (RI 18%, LOA −18/+20 mL/kg/min).
Conclusions Echocardiographic assessment of SVC flow volume by tracing area from a short-axis view and measuring velocity–time integral from a suprasternal view offered an improvement in accuracy and repeatability, building on the traditional approach previously described.
- Intensive Care
Statistics from Altmetric.com
Twitter Follow Alan Groves at @neonatalecho
Contributors BF and AMG were involved in the design of the study, the acquisition and analysis of data, writing and revising the manuscript. EB, MAP, AEF, KMB, ANP, DJC and GD were involved in the acquisition of data and revision of the manuscript. EMP contributed to the analysis of data and revision of the manuscript.
Funding This work was supported by the Medical Research Council grant number 0701896, the Garfield Weston Foundation, the National Institutes for Health Research Imperial College Comprehensive Biomedical Research Centre, and the National Institute for Health Research Biomedical Research Centre at Guy's and St. Thomas' National Health Service Foundation Trust and King's College London.
Competing interests Specialist imaging coils were provided by Philips Medical Systems (Best, The Netherlands). Study sponsors had no involvement in data collection, analysis or interpretation.
Patient consent Obtained.
Ethics approval Hammersmith Hospital REC, St. Thomas’ Hospital REC, Azienda Ospedaliera Universitaria Integrata Verona REC.
Provenance and peer review Not commissioned; externally peer reviewed.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.