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.

scholarly journals A Comparison of Methods of Cardiac Output Measurement

1983 ◽  
Vol 11 (2) ◽  
pp. 141-146 ◽  
Author(s):  
R. H. Woog ◽  
D. B. McWilliam
Keyword(s):  
Cardiac Output ◽  
Systematic Error ◽  
Random Error ◽  
Room Temperature ◽  
Comparison Of Methods ◽  
Output Measurement ◽  
Low Cardiac Output ◽  
Dye Dilution ◽  
Output Only ◽  
Cardiac Output Measurements

Cardiac output measurements determined by dye dilution, iced-injectate thermodilution and room temperature thermodilution were compared in man in order to assess the random error of each method and to examine the systematic error of both thermodilution methods in comparison with dye dilution. Results showed that random error was greatest with room temperature thermodilution and least using iced thermodilution. Iced thermodilution correlated well with dye dilution, tending to overestimate cardiac output only at low flows. Room temperature thermodilution, however, overestimated cardiac output by up to 25% in the clinically important range and more so at low cardiac output.

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.

Cardiac output determinations by the dye-dilution method in Squalus acanthias

1965 ◽  
Vol 209 (4) ◽  
pp. 723-726 ◽  
Author(s):  
H. Victor Murdaugh ◽  
Eugene D. Robin ◽  
J. Eugene Millen ◽  
William F. Drewry
Keyword(s):  
Cardiac Output ◽  
Cardiac Index ◽  
Squalus Acanthias ◽  
Physiological Status ◽  
Dilution Method ◽  
Small Fish ◽  
Large Fish ◽  
Dilution Technique ◽  
Dye Dilution ◽  
Cardiac Output Measurements

A dye-dilution technique has been adapted for the measurement of cardiac output in the elasmobranch, Squalus acanthias. Cardiac output averaged 1.60 ± 1.00 liter/kg per hr in 26 fish. Small fish showed a relatively high cardiac index (liters/kg per hr) as compared with large fish. The use of this technique permits sequential cardiac output measurements with the maintenance of an intact physiological status. This technique should permit quantitation of exchange of a variety of substances across the gill membranes.

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.

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