Comparison of the accuracy of the lithium dilution technique with the thermodilution technique for measurement of cardiac output

Abstract

A new indicator dilution technique for measurement of cardiac output is described. Lithium chloride is injected via a central venous catheter and its dilution curve measured in arterial blood using a lithium-selective electrode. We assessed the lithium dilution cardiac output measurement (LiDCO) and a conventional thermodilution cardiac output measurement (ThDCO) by comparing the results of both with cardiac output determined by electromagnetic flowmetry (EMCO) under controlled laboratory conditions in 10 swine. They were monitored with a pulmonary artery catheter, femoral artery catheter and electromagnetic flowmeter placed around the ascending aorta. LiDCO, ThDCO and EMCO measurements were determined at baseline, in a hyperdynamic state produced by administration of dobutamine, at a second baseline and finally in a hypodynamic state induced by propranolol during deep anaesthesia. Data were analysed by linear regression analysis and the comparison method described by Bland and Altman; bias and precision of both LiDCO and ThDCO compared with EMCO were calculated by the method of Sheiner and Beal. The correlation coefficient between LiDCO and EMCO (0.95) was higher than that between ThDCO and EMCO (0.87). The precision value of LiDCO (0.04) was significantly less (i.e. better) than that of ThDCO (0.09). The results of this study indicated that LiDCO was more reliable compared with conventional ThDCO.

Validation of cardiac output measurement with the LiDCOTM pulse contour system in patients with impaired left ventricular function after cardiac surgery*

“…In 10 pigs, Kurita et al also assessed thermodilution and bolus lithium dilution cardiac output and compared them with electromagnetic flowmetry, which probably reflects cardiac output more accurately than thermodilution. They found even better correlation, accuracy and precision between lithium dilution and electromagnetic flowmetry as compared with thermodilution (r = 0.95 and bias = 0.11 (0.18) vs r = 0.87 and bias = 0.03 (0.31)) [9]. Furthermore, strong correlation and minimal bias (r = 0.94; )0.005 l.min…”

“…To allow cardiac output measurement, a peripheral venous and an arterial cannula are required. It has been validated after vascular, urological and thoracic surgery [8] and shows good agreement with the PA catheter in swine [9], in patients with normal left ventricular systolic function [10,11] and in patients with vasodilatation [11]. However, LiDCO has not yet been validated in patients with impaired cardiac function.…”

Continuous cardiac output monitoring via arterial pressure waveform analysis following severe hemorrhagic shock in dogs*

“…The lithium dilution technique produces precise and accurate values of cardiac output and has been validated in multiple species, including dogs (11)(12)(13)(14)(15). Similar to other indicator dilution techniques (cold saline, indocyanine green), CO is determined at a single point in time.…”

Monitorage hémodynamique de l’état de choc septique

“…Cette technique semble bien corrélée aux résultats obtenus par la thermodilution [104,105]. Les doses de lithium injectées sont minimes mais il est recommandé de ne pas eff ectuer plus de dix mesures par jour, surtout chez les patients anuriques, ou encore de ne pas utiliser les curares non dépolarisants qui interfèrent sur les dosages.…”