Skip to main content

Haemodynamic changes during the peri-extubation period using bioreactance flow monitoring


Here we present a prospective, observational study examining the effect of extubation on cardiac index, measured by bioreactance (Nicom Cheetah), in critically ill patients with or without a history of left ventricular impairment [1]. A number of simple interventions are known to improve the process of weaning patients from mechanical ventilation. Despite this progress, the pathophysiology underlying failure to wean remains incompletely understood. In particular, the role of cardiac ventricular dysfunction may be underestimated [2].


Cardiac index was measured by bioreactance monitoring at 30-second to 60-second intervals for 1 hour pre and 1 hour post extubation. Individual data were presented by box plot, showing median and interquartile ranges (Figure 1). Combined results from multiple patients in each test group were analysed by covariance (Stata version 11.2).

Figure 1
figure 1

abstract P224


Group A (n = 5) had impaired left ventricular systolic function, documented on formal transthoracic echo, of which three had ejection fractions <25%. One patient in this group failed extubation due to cardiogenic pulmonary oedema. Group B (n = 6) had normal systolic function. Figure 1 shows representative absolute data obtained from a patient in each group. There was a statistical difference between the two groups (P = 0.02). In the impaired LV group, the cardiac index fell from 3.2 l/minute/m2 (± 0.5) to 2.9 l/minute/m2 (± 2.5).


In this small observational study we demonstrated a consistent fall in cardiac index post extubation in patients with known cardiac ventricular dysfunction when compared with patients with normal hearts. These data suggest that bioreactance monitoring may be valuable during spontaneous breathing trials and extubation.


  1. Benomar B, Ouattara A, Estagnasie P, Brusset A, Squara P: Fluid responsiveness predicted by non-invasive bioreactance-based passive leg raise test. Intensive care Med 2010, 36: 1875-1881. 10.1007/s00134-010-1990-6

    Article  PubMed  Google Scholar 

  2. Papanikolaou J, Makris D, Saranteas T, et al.: New insights into weaning from mechanical ventilation: left ventricular diastolic dysfunction is a key player. Intensive Care Med 2011, 37: 1976-1985. 10.1007/s00134-011-2368-0

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Cite this article

Thirsk, J., Magimairaj, D., Douiri, A. et al. Haemodynamic changes during the peri-extubation period using bioreactance flow monitoring. Crit Care 16, P224 (2012).

Download citation

  • Published:

  • DOI:


  • Cardiac Index
  • Systolic Function
  • Spontaneous Breathing
  • Ventricular Systolic Function
  • Haemodynamic Change