Non-invasive Cardiac Output Measurement Using Physioflow® in Anaesthetised Paediatric Patients- a comparison with mass spectrometry

  • Dr Katherine Taylor, Department of Anesthesia,Hospital for Sick Children, Toronto, Canada
  • Dr Helen Holtby, Hospital for Sick Children, Toronto, Canada
  • Dr Gustavo La Rotta, Department of Cardiology , Labatt Family Heart Centre, Hospital for Sick Children, Toronto, Canada
  • Dr Cedric Manlhiot, Cardiovascular Clinical Research Unit, Labatt Family Heart Centre,Hospital for Sick Children, Toronto, Canada
  • Dr Andrew Redington, Labatt Family Heart Centre,Hospital for Sick Children, Toronto, Canada

    • Objectives:
    The study objective is to evaluate the accuracy and reliability of cardiac output (CO) measurements using electrical bioimpedance cardiography, (Physioflow®) (CO) compared to mass spectrometry (CO), in children undergoing cardiac catheterisation.

    Methods:
    After Institutional Ethics Committee approval and informed consent, eligible patients undergoing cardiac catheterization including oxygen consumption measurement by mass spectrometry were recruited for additional simultaneous monitoring using Physioflow® (PF). After anaesthesia induction, 6 Physioflow® ECG electrodes were applied. An Amis 2000 quadrupole mass spectrometer (Innovision A/S. Odense, Denmark ) was adapted for patients ventilated with the Drager Primus ventilator (Drager,Germany). Measurements of CO were made after VO and heart rate stability and before angiography. The Physioflow® measured continuous real time measurements. CO measurements were averaged, indexed and compared with the indexed CO measurements using Bland-Altman analysis.

    Results:
    Preliminary results of 26 patients (10 males/16 females)are presented. Median(range) age was 5.5 years (1.4-16.3 years) and median (range) BSA was 0.74m (0.41-1.71 m).5958/8435 (71%) measurements were valid. Median measurements per patient=316 (40-616).Physioflow omitted 11 % CI measurements and identified 27% as artifact. A further 3% were identified by investigators as biologically implausible, Physioflow missed 30 % of these. Mean bias(PF-MS)=+0.65 p<0.001, limits of agreement (95%) =-0.97-2.27. In 35% of patients CO was within 20 % of CO and 69 % of measurements were within 40 %.

    Impact:
    This represents the first study using Physioflow® to assess CO in anaesthetised children, and is an attempt to formally assess the utility of new equipment in the paediatric population.
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