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Continuous non-invasive measurement of cardiac output in neonatal intensive care using regional impedance cardiography: a prospective observational study
  1. Jayanta Banerjee1,2,3,4,
  2. Nidal Khatib2,3,
  3. Roshni C Mansfield1,2,3,
  4. Sundar Sathiyamurthy1,
  5. Ujwal Kariholu1,
  6. Christoph Lees2,3,5
  1. 1 Neonatology, Imperial College Healthcare NHS Trust, London, UK
  2. 2 Institute of Reproductive and Developmental Biology, Imperial College London Institute of Clinical Sciences, London, UK
  3. 3 Biomedical Research Centre, Imperial College Healthcare NHS Trust, London, UK
  4. 4 Origins of Child Health and Disease, Centre for Paediatrics and Child Health, Imperial College London, London, UK
  5. 5 Fetal Medicine, Queen Charlotte's and Chelsea Hospital, London, UK
  1. Correspondence to Dr Jayanta Banerjee, Neonatology, Imperial College Healthcare NHS Trust, London, W6 8RF, UK; jayanta.banerjee{at}


Objectives To compare agreement between echocardiography and regional impedance cardiography (RIC)-derived cardiac output (CO), and to construct indicative normative ranges of CO for gestational age groups.

Design, setting and participants Prospective cohort observational study performed in a tertiary centre in London, UK, including neonates born between 25 and 42 weeks’ gestational age.

Exposures Neonates on the postnatal ward had 2 hours of RIC monitoring; neonates in intensive care had RIC monitoring for the first 72 hours, then weekly for 2 hours, with concomitant echocardiography measures.

Main outcomes and measures RIC was used to measure CO continuously. Statistical analyses were performed using R (V.4.2.2; R Core Team 2022). RIC-derived CO and echocardiography-derived CO were compared using Pearson’s correlations and Bland-Altman analyses. Differences in RIC-derived CO between infants born extremely, very and late preterm were assessed using analyses of variance and mixed-effects modelling.

Results 127 neonates (22 extremely, 46 very, 29 late preterm and 30 term) were included. RIC and echocardiography-measured weight-adjusted CO were correlated (r=0.62, p<0.001) with a Bland-Altman bias of −31 mL/min/kg (limits of agreement −322 to 261 mL/min/kg). The RIC-derived CO fell over 12 hours, then increased until 72 hours after birth. The 72-hour weight-adjusted mean CO was higher in extremely preterm (424±158 mL/min/kg) compared with very (325±131 mL/min/kg, p<0.001) and late preterm (237±81 mL/min/kg, p<0.001) neonates; this difference disappeared by 2–3 weeks of age.

Conclusions RIC is valid for continuous, non-invasive CO measurement in neonates. Indicative normative CO ranges could help clinicians to make more informed haemodynamic management decisions, which should be explored in future studies.

Trial registration number NCT04064177.

  • Cardiology
  • Intensive Care Units, Neonatal
  • Neonatology

Data availability statement

Data are available upon reasonable request. Deidentified participant data will be shared upon reasonable request. Requests need to be addressed to the corresponding author.

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Data availability statement

Data are available upon reasonable request. Deidentified participant data will be shared upon reasonable request. Requests need to be addressed to the corresponding author.

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  • Contributors JB and CL conceived and designed this study, oversaw study setup, conduct and analysis setup, contributed to the first draft, approved the final version and take responsibility for the accuracy of reported findings. SS, RCM and UK contributed to study design, setup and conduct, contributed to the first draft and approved the final version. NK wrote the statistical analysis plan and performed all the data analyses, contributed to the first draft and approved the final version. JB, SS, RCM and UK recruited patients, collected data, contributed to manuscript writing and approved the final version. All authors had full access to the presented data in this article and had final responsibility for the decision to submit for publication. JB is guarantor.

  • Funding This study was funded by Imperial NIHR Biomedical Research Centre (BRC). JB and CL are supported by the UK National Institute for Health Research (NIHR) BRC based at Imperial College Healthcare National Health Service Trust and Imperial College London. RCM was supported by the Imperial BRC and the Imperial Health Charity grant (RFPR2021_29). NK received funding from the Imperial BRC. Non-invasive cardiac system (NICaS) equipment was supplied by NI Medical, Petah Tikvah, Israel.

  • Disclaimer This article is independent research funded by the NIHR BRC, and the views expressed in this publication are those of the authors and not necessarily those of the NHS, NIHR or the Department of Health. None of the funders have had any influence over study design, collection, analysis and interpretation of the data, in writing the report and in the decisions to submit this article for publication.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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