The PhysioFlow thoracic impedancemeter is not valid for the measurements of cardiac hemodynamic parameters in chronic anemic patients

PLoS One. 2013 Oct 22;8(10):e79086. doi: 10.1371/journal.pone.0079086. eCollection 2013.

Abstract

The aim of the present study was to test the validity of the transthoracic electrical bioimpedance method PhysioFlow® to measure stroke volume in patients with chronic anemia. Stroke volume index (SVI), as well as cardiac index (CI) obtained by transthoracic electrical bioimpedance method and doppler echocardiography were compared in healthy subjects (n = 25) and patients with chronic anemia (i.e. mainly with sickle cell anemia; n = 32), at rest. While doppler echocardiography was able to detect difference in SVI between the two populations, the Physioflow® failed to detect any difference. Bland & Altman analyses have demonstrated no interchangeability between the two methods to assess CI and SVI in anemic patients and healthy subjects. While doppler echocardiography displayed a good concordance for SVI results with those obtained in the literature for anemic patients, the Physioflow® did not. Finally, in contrast to doppler echocardiography: 1) the CI obtained with the Physioflow® was not correlated with the hemoglobin level and 2) the stroke volume determined by the Physioflow® was highly influenced by body surface area. In conclusion, our findings indicate that the Physioflow® device is inaccurate for the measurement of SVI and CI in patients with chronic anemia and has a poor accuracy for the measurement of these parameters in African healthy subjects.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Anemia / diagnostic imaging
  • Anemia / physiopathology*
  • Chronic Disease
  • Cote d'Ivoire
  • Echocardiography, Doppler / methods
  • Electric Impedance
  • Female
  • Humans
  • Male
  • Stroke Volume*

Grants and funding

The authors have no support or funding to report.