Clinical validation of a new thermodilution system for the assessment of cardiac output and volumetric parameters

Abstract

IntroductionTranspulmonary thermodilution is used to measure cardiac output (CO), global end-diastolic volume (GEDV) and extravascular lung water (EVLW). A system has been introduced (VolumeView/EV1000™ system, Edwards Lifesciences, Irvine CA, USA) that employs a novel algorithm for the mathematical analysis of the thermodilution curve. Our aim was to evaluate the agreement of this method with the established PiCCO™ method (Pulsion Medical Systems SE, Munich, Germany, clinicaltrials.gov identifier: NCT01405040)MethodsSeventy-two critically ill patients with clinical indication for advanced hemodynamic monitoring were included in this prospective, multicenter, observational study. During a 72-hour observation period, 443 sets of thermodilution measurements were performed with the new system. These measurements were electronically recorded, converted into an analog resistance signal and then re-analyzed by a PiCCO2™ device (Pulsion Medical Systems SE).ResultsFor CO, GEDV, and EVLW, the systems showed a high correlation (r2 = 0.981, 0.926 and 0.971, respectively), minimal bias (0.2 L/minute, 29.4 ml and 36.8 ml), and a low percentage error (9.7%, 11.5% and 12.2%). Changes in CO, GEDV and EVLW were tracked with a high concordance between the two systems, with a traditional concordance for CO, GEDV, and EVLW of 98.5%, 95.1%, and 97.7% and a polar plot concordance of 100%, 99.8% and 99.8% for CO, GEDV, and EVLW, respectively. Radial limits of agreement for CO, GEDV and EVLW were 0.31 ml/minute, 81 ml and 40 ml, respectively. The precision of GEDV measurements was significantly better using the VolumeView™ algorithm compared to the PiCCO™ algorithm (0.033 (0.03) versus 0.040 (0.03; median (interquartile range), P = 0.000049).ConclusionsFor CO, GEDV, and EVLW, the agreement of both the individual measurements as well as measurements of change showed the interchangeability of the two methods. For the VolumeView method, the higher precision may indicate a more robust GEDV algorithm.Trial registrationclinicaltrials.gov NCT01405040.

Impact of misplaced subclavian vein catheter into jugular vein on transpulmonary thermodilution measurement variables

“…MTt means the time that half of the injected cold saline has passed the thermistor, and DSt means the duration of the exponential decrease of the dilution curve (Sakka et al, 1999;Reuter et al, 2005). Cardiac output (CO), global end-diastolic volume (GEDV), intra-thoracic blood volume (ITBV), and extra-vascular lung water (EVLW) are calculated according to the three values described above: both GEDV and ITBV are the preload indicators, and EVLW is a sensitive indicator of pulmonary edema (Katzenelson et al, 2004;Michard et al, 2005;Kuzkov et al, 2006;Khan et al, 2007;Bendjelid et al, 2010;Belda et al, 2011;Eichhorn et al, 2012;Kiefer et al, 2012). The combined measurement of CO, GEDV, and EVLW could provide a synthetic platform for hemodynamic management in critically ill patients.…”

Transcardiopulmonary Thermodilution-Calibrated Arterial Waveform Analysis: A Primer for Anesthesiologists and Intensivists

“…The VolumeView/EV1000 modification uses the maximum upslope and downslope of the thermodilution washout curves; this provides volumes comparable to the PiCCO monitor, but has the putative advantage of avoiding problems with identifying recirculation. 221 After estimating ITTV, PTV can be calculated (Fig 4). While using indocyanine green to estimate CO, Hamilton observed that the dye washout rate was determined not only by CO but also by the sizes of the "mixing chambers" into which the indicator had been injected.…”

Calibrated versus uncalibrated arterial pressure waveform analysis in monitoring cardiac output with transpulmonary thermodilution in patients with severe sepsis and septic shock

“…This method provides CO measurements as well as volumetric indices such as global end-diastolic volume (GEDV), intrathoracic blood volume (ITBV), extravascular lung water (EVLW), global ejection fraction and pulmonary vascular permeability index. 5 The CO is estimated from the bolus TPTD measurements using the StewartHamilton equation. 1 For the CCO measurements, the VolumeView/EV1000 monitor combines the area under the systolic part of the arterial pressure waveform and waveform analysis as used in the FloTrac/Vigileo system.…”