Measurement of cardiac output by the thermodilution method in rats: The effect of different volumes and temperatures of the indicator solution on cardiac output measurements and on cardiodynamics and hemodynamics of the anesthetized rat

1980 ◽  
Vol 4 (1) ◽  
pp. 11-18 ◽  
Author(s):  
G. Mannesmann ◽  
B. Müller
Keyword(s):  
Cardiac Output ◽  
Indicator Solution ◽  
Thermodilution Method ◽  
Cardiac Output Measurements

Thermodilution method overestimates low cardiac output in humans

1983 ◽  
Vol 245 (4) ◽  
pp. H690-H692 ◽  
Author(s):  
A. van Grondelle ◽  
R. V. Ditchey ◽  
B. M. Groves ◽  
W. W. Wagner ◽  
J. T. Reeves
Keyword(s):  
Cardiac Output ◽  
Heat Loss ◽  
Low Flow ◽  
Clinical Implications ◽  
Low Cardiac Output ◽  
Dye Dilution ◽  
Thermodilution Method ◽  
Cardiac Output Measurements

We compared 57 cardiac output measurements by the thermodilution and Fick methods in 26 patients and found that thermodilution values were higher in all 16 cases in which Fick outputs were less than 3.5 l/min. In 10 cases where Fick values were less than or equal to 2.5 l/min, thermodilution and Fick measurements differed by an average of 35%. When combined with the results of previous studies comparing the thermodilution, dye dilution, and Fick techniques, these findings suggest that the thermodilution method overestimates true cardiac output in the low output range. This overestimation probably is due to heat loss under conditions of low flow. Because the thermodilution method is used widely in patients with low output states, these findings have potentially important clinical implications.

Comparison of continuous with intermittent bolus thermodilution cardiac output measurements

1995 ◽  
Vol 4 (6) ◽  
pp. 460-465 ◽  
Author(s):  
CE Ditmyer ◽  
M Shively ◽  
DB Burns ◽  
RT Reichman
Keyword(s):  
Cardiac Output ◽  
Intraclass Correlation ◽  
Continuous Cardiac Output ◽  
Cardiac Output Monitoring ◽  
Monitoring Method ◽  
Convenience Sample ◽  
Thermodilution Cardiac Output ◽  
Intermittent Bolus ◽  
Thermodilution Method ◽  
Cardiac Output Measurements

BACKGROUND: Few complete studies have been published to validate the agreement between continuous cardiac output and intermittent thermodilution cardiac output. OBJECTIVE: To analyze the agreement between cardiac output measurements by the continuous thermodilution method and the intermittent bolus thermodilution method, using a continuous cardiac output catheter in postoperative cardiothoracic surgery patients. METHODS: A convenience sample of 14 adult cardiothoracic surgical patients with thermodilution pulmonary artery catheters placed preoperatively was used. A total of 214 comparison measurements of cardiac output by both the continuous and intermittent thermodilution methods were taken on patient admission to the critical care unit, every 4 hours, and with any change greater than 10% from baseline readings. RESULTS: The intraclass correlation between continuous cardiac output and intermittent cardiac output was .89. The limits of agreement were -1.34 to 1.18 L/min, indicating that in 95% of readings the difference between continuous cardiac output and intermittent cardiac output were within this range. CONCLUSIONS: The continuous cardiac output monitoring method shows clinically acceptable agreement with the intermittent cardiac output method.

Theoretical and model analysis of the unreliability of cardiac output measurement by means of the thermodilution method

2011 ◽  
Vol 59 (4) ◽  
pp. 435-439 ◽  
Author(s):  
M. Gawlikowski ◽  
T. Pustelny ◽  
B. Przywara-Chowaniec ◽  
J. Nowak-Gawlikowska
Keyword(s):  
Cardiac Output ◽  
Pulmonary Artery ◽  
Salt Solution ◽  
Model Analysis ◽  
Cardiac Output Measurement ◽  
Output Measurement ◽  
Thermodilution Cardiac Output ◽  
Thermal Indicator ◽  
Thermodilution Method ◽  
Cardiac Output Measurements

Theoretical and model analysis of the unreliability of cardiac output measurement by means of the thermodilution methodThermodilution is the clinically most often applied method of cardiac output measurements. This method is based on thermal indicator (iced isotonic salt solution) variation measurements by a Swan-Ganz catheter located inside the pulmonary artery. The unreliability of thermodilution should be estimated theoretically because of the lack of references. In this paper an attempt has been made to estimate theoretically the unreliability of thermodilution cardiac output measurements.

scholarly journals Feasibility of cardiac output measurements in critically ill patients by medical students

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Geert Koster ◽  
Thomas Kaufmann ◽  
Bart Hiemstra ◽  
Renske Wiersema ◽  
Madelon E. Vos ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Critical Care ◽  
Medical Students ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Left Ventricular ◽  
Percentage Error ◽  
Poor Agreement ◽  
Cardiac Output Measurements

Abstract Background Critical care ultrasonography (CCUS) is increasingly applied also in the intensive care unit (ICU) and performed by non-experts, including even medical students. There is limited data on the training efforts necessary for novices to attain images of sufficient quality. There is no data on medical students performing CCUS for the measurement of cardiac output (CO), a hemodynamic variable of importance for daily critical care. Objective The aim of this study was to explore the agreement of cardiac output measurements as well as the quality of images obtained by medical students in critically ill patients compared to the measurements obtained by experts in these images. Methods In a prospective observational cohort study, all acutely admitted adults with an expected ICU stay over 24 h were included. CCUS was performed by students within 24 h of admission. CCUS included the images required to measure the CO, i.e., the left ventricular outflow tract (LVOT) diameter and the velocity time integral (VTI) in the LVOT. Echocardiography experts were involved in the evaluation of the quality of images obtained and the quality of the CO measurements. Results There was an opportunity for a CCUS attempt in 1155 of the 1212 eligible patients (95%) and in 1075 of the 1212 patients (89%) CCUS examination was performed by medical students. In 871 out of 1075 patients (81%) medical students measured CO. Experts measured CO in 783 patients (73%). In 760 patients (71%) CO was measured by both which allowed for comparison; bias of CO was 0.0 L min−1 with limits of agreement of − 2.6 L min−1 to 2.7 L min−1. The percentage error was 50%, reflecting poor agreement of the CO measurement by students compared with the experts CO measurement. Conclusions Medical students seem capable of obtaining sufficient quality CCUS images for CO measurement in the majority of critically ill patients. Measurements of CO by medical students, however, had poor agreement with expert measurements. Experts remain indispensable for reliable CO measurements. Trial registration Clinicaltrials.gov; http://www.clinicaltrials.gov; registration number NCT02912624

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