title: Impedance cardiography (electrical velocimetry) and transthoracic echocardiography for non-invasive cardiac output monitoring in pediatric intensive care patients: a prospective single-center observational study.
abstract: BACKGROUND
  Electrical velocimetry (EV) is a type of impedance cardiography, and is a non-invasive and continuously applicable method of cardiac output monitoring. Transthoracic echocardiography (TTE) is non-invasive but discontinuous.
  
  
  METHODS
  We compared EV with TTE in pediatric intensive care patients in a prospective single-center observational study. Simultaneous, coupled, left ventricular stroke volume measurements were performed by EV using an Aesculon® monitor and TTE (either via trans-aortic valve flow velocity time integral [EVVTI], or via M-mode [EVMM]). H0: bias was less than 10% and the mean percentage error (MPE) was less than 30% in Bland-Altman analysis between EV and TTE. If appropriate, data were logarithmically transformed prior to Bland-Altman analysis.
  
  
  RESULTS
  A total of 72 patients (age: 2 days to 17 years; weight: 0.8 to 86 kg) were analyzed. Patients were divided into subgroups: organ transplantation (OTX, n = 28), sepsis or organ failure (SEPSIS, n = 16), neurological patients (NEURO, n = 9), and preterm infants (PREM, n = 26); Bias/MPE for EVVTI was 7.81%/26.16%. In the EVVTI subgroup analysis for OTX, NEURO, and SEPSIS, bias and MPE were within the limits of H0, whereas the PREM subgroup had a bias/MPE of 39.00%/46.27%. Bias/MPE for EVMM was 8.07%/37.26% where the OTX and NEURO subgroups were within the range of H0, but the PREM and SEPSIS subgroups were outside the range. Mechanical ventilation, non-invasive continuous positive airway pressure ventilation, body weight, and secondary abdominal closure were factors that significantly affected comparison of the methods.
  
  
  CONCLUSIONS
  This study shows that EV is comparable with aortic flow-based TTE for pediatric patients.
authors.affiliation: Department of Pediatrics, Division of Neonatology and Pediatric Intensive Care, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany. m.blohm@uke.de.
authors.forename: Martin Ernst
authors.initials: ME
authors.lastname: Blohm
authors.affiliation: Department of Pediatrics, Division of Neonatology and Pediatric Intensive Care, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany. denise.obrecht@gmx.de.
authors.forename: Denise
authors.initials: D
authors.lastname: Obrecht
authors.affiliation: Department of Pediatrics, Division of Neonatology and Pediatric Intensive Care, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany. jana.hartwich@gmx.de.|Current address: Department of Neurology, Elbe Kliniken Stade, Bremervörder Str. 111, Stade, 21682, Germany. jana.hartwich@gmx.de.
authors.forename: Jana
authors.initials: J
authors.lastname: Hartwich
authors.affiliation: Department of Pediatric Cardiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany. go.mueller@uke.de.
authors.forename: Goetz Christoph
authors.initials: GC
authors.lastname: Mueller
authors.affiliation: Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany. j.kersten@uke.de.
authors.forename: Jan Felix
authors.initials: JF
authors.lastname: Kersten
authors.affiliation: Department of Pediatric Cardiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany. j.weil@uke.de.
authors.forename: Jochen
authors.initials: J
authors.lastname: Weil
authors.affiliation: Department of Pediatrics, Division of Neonatology and Pediatric Intensive Care, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany. d.singer@uke.de.
authors.forename: Dominique
authors.initials: D
authors.lastname: Singer
mesh_terms: D000293:Adolescent; D002302:Cardiac Output / Q000502:physiology*; D002307:Cardiography, Impedance / Q000379:methods / Q000592:standards; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015278:Intensive Care Units, Pediatric / Q000592:standards; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods* / Q000592:standards; D011446:Prospective Studies; D012212:Rheology / Q000379:methods* / Q000592:standards; D013318:Stroke Volume / Q000502:physiology