Comparison of invasive and less-invasive techniques of cardiac output measurement under different haemodynamic conditions in a pig model

Abstract

Our data suggest that pulmonary arterial thermodilution and PiCCO may be interchangeably used for cardiac output measurement even under acute haemodynamic changes. The method described by Bland and Altman demonstrated an overestimation of cardiac output for both thermodilution methods. HemoSonic and NICO offer non-invasive alternatives and complementary monitoring tools in numerous clinical situations. Trend monitoring and haemodynamic optimizing can be applied sufficiently, when absolute measures are judged critically in a clinical context. The use of the NICO system seems to be limited during acute circulatory changes.

Minimally Invasive Measurement of Cardiac Output during Surgery and Critical Care

“…105 Bajorat et al compared bolus thermodilution with a similar flow probe in a pig model where hemodynamic instability was induced pharmacologically, and found a percentage er-ror of 48.6% overall. 106 A number of the minimally invasive methods that we have reviewed here were also tested in parallel in these studies. Notably, thermodilution did not perform significantly better than any of them.…”

Non-invasive Estimation of Cardiac Output in Mechanically Ventilated Patients: A Prolonged Expiration Method

“…The first are directly related to the approach: (1) systematic overestimation of the slope value of the P A CO 2 -R linear relationship; (2) underestimation of CO 2 values measured at the mouth, probably caused by contamination of gas during expiration through dead space, and storage of some expired CO 2 in the lungs; (3) decrease in venous return to the heart that accompanies the prolonged expiration, as in the Valsalva maneuver; and (4) underestimation of the shunt fraction. The second group of factors is related to the overestimation of CO by thermodilution: Botero et al 3 found an overestimation greater than 41%, and Bajorat et al 1 of about 48% if compared to a method using an aortic flow probe. Moreover, thermodilution can be affected by injection time and bolus temperature.…”

Comparison of cardiac output as assessed by transesophageal echo-Doppler and transpulmonary thermodilution in patients undergoing thoracic surgery

“…Thus, we used the transpulmonary thermodilution technique as the reference method for CI measurements. The reliability of this technique versus that of the standard thermodilution and the Fick methods showed excellent correlation (r = 0.96 and r = 0.97, respectively) with minimal mean bias (ranging from 0.03 to 0.21 L/min/m 2 , respectively) and clinically acceptable limits of agreement [17][18][19][20][21]. Transpulmonary CI measurements are slightly greater than the corresponding values obtained with a PAC, this method is less sensitive to systematic errors, avoids the risks of PA catheterization, and also measures extravascular lung water volume as well as beat-to-beat SV by pulsed contour analysis of the arterial pressure waveform, even in the context of thoracic surgery [22,23].…”