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.

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 Thermodilution Cardiac Output — A Systematic Error

1981 ◽  
Vol 9 (2) ◽  
pp. 135-139 ◽  
Author(s):  
W. B. Runciman ◽  
A. H. Ilsley ◽  
J. G. Roberts
Keyword(s):  
Cardiac Output ◽  
Systematic Error ◽  
Correction Factor ◽  
Cardiac Output Measurement ◽  
Thermodilution Technique ◽  
Output Measurement ◽  
Thermodilution Cardiac Output ◽  
Thermal Indicator ◽  
Wide Range ◽  
Cardiac Output Measurements

The purpose of this study was to examine the mechanism and magnitude of a systematic error in thermodilution cardiac output measurement. One hundred and seventy-one thermodilution cardiac output measurements in dogs using a Swan-Ganz catheter were compared with simultaneously made dye dilution measurements under different conditions over a wide range of cardiac outputs. A systematic error with the thermodilution technique was confirmed and was almost identical to that observed in the literature. It is proposed that its mechanism is loss of thermal indicator between the injectate orifice and detection. Application of a further correction factor for thermal indicator loss is suggested.

Cardiac Output Determination

1993 ◽  
Vol 4 (1) ◽  
pp. 81-97 ◽  
Author(s):  
Susan L. Woods ◽  
Susan Osguthorpe
Keyword(s):  
Cardiac Output ◽  
Critical Care Nurses ◽  
Cardiac Output Measurement ◽  
Nursing Management ◽  
Output Measurement ◽  
Thermodilution Cardiac Output ◽  
Cardiac Output Determination ◽  
Output System ◽  
Cardiac Output Measurements ◽  
Management Issues

Critical care nurses frequently are involved in obtaining cardiac output measurements and in using these data to assess and to plan therapy. This article reviews the physiologic determinants of cardiac output and the clinical factors that influence these determinants. Principles and techniques of common methods of cardiac output measurement are discussed. A thorough presentation of guidelines for troubleshooting problems with thermodilution cardiac output measurement is provided in a table. Nursing management issues are discussed using relevant nursing research. Future considerations in cardiac output measurement are discussed, and suggestions of an ideal cardiac output system are provided

Room-temperature thermodilution cardiac output: proximal injectate lumen vs proximal infusion lumen

1993 ◽  
Vol 2 (2) ◽  
pp. 132-133
Author(s):  
GR Pesola ◽  
B Ayala ◽  
L Plante
Keyword(s):  
Cardiac Output ◽  
Room Temperature ◽  
Central Venous ◽  
Right Heart ◽  
Thermodilution Cardiac Output ◽  
Central Venous Port ◽  
Venous Port ◽  
Port Design ◽  
Venous Infusion ◽  
Cardiac Output Measurements

OBJECTIVE: To assess the accuracy of room-temperature thermodilution cardiac output measurements from the venous infusion port. DESIGN: Central venous port cardiac output measurements were compared with venous infusion port measurements in 48 right-heart catheters. INTERVENTION: Three 10-mL injections of 5% dextrose in water were made through each port. The order of port injection was random. RESULTS: The cardiac outputs were 5.8 +/- 1.8 L/min from both ports, with no difference between ports (paired t test). CONCLUSION: Room-temperature thermodilution cardiac output determinations from the venous infusion port can be used in place of central venous port cardiac outputs if the central venous port becomes nonfunctional.

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.

Consistency between Impedance Technique and Echocardiogram Hemodynamic Measurements in Neonates

2020 ◽  
Author(s):  
Wenshen Wu ◽  
Sulian Lin ◽  
Caixuan Xie ◽  
Jianbo Li ◽  
Jingen Lie ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Prospective Observational Study ◽  
Limits Of Agreement ◽  
Output Measurement ◽  
Accuracy And Precision ◽  
Impedance Technique ◽  
Precision And Accuracy ◽  
Larger Sample ◽  
Hemodynamic Measurements ◽  
Cardiac Output Measurements

Abstract Objective The aim of this study was to validate impedance technique (IT) by investigating the agreement in cardiac output measurements performed by IT and echocardiography (ECHO). Study design This is a prospective observational study, including a total of 30 neonates who underwent hemodynamic measurements by IT and ECHO. To determine the agreement between both methods, we performed IT to measure stroke volume (SV-IT) and cardiac output (CO-IT) immediately before or after ECHO to measure SV (SV-ECHO) and CO (CO-ECHO). The precision and accuracy of the IT relative to ECHO were assessed. Results SV-ECHO and SV-IT were (4.45 ± 0.78) and (4.54 ± 0.81) mL, respectively. The bias and limits of agreement of SV-IT were 0.09 mL and ( –1.92 to 1.73) mL, respectively. The true precision of SV-IT was 27.3%. Furthermore, CO-ECHO and CO-IT were (0.62 ± 0.12) and (0.61 ± 0.12) L/min, respectively. The bias and LoA of CO-IT were 0.01L/min and (–0.33 to 0.31) L/min, respectively. The true precision of CO-IT was 28.3%. Conclusion Agreement between the IT and ECHO in the cardiac output measurement appeared acceptable. However, the accuracy and precision of the IT approach should be further investigated using a larger sample.

scholarly journals The Influence of Limited Dynamic Response of the Indicator Detector in a Swan-Ganz Catheter on the Overestimation of Cardiac Output Measurement By Means of Thermodilution

2012 ◽  
Vol 19 (4) ◽  
pp. 751-758
Author(s):  
Maciej Gawlikowski ◽  
Tadeusz Pustelny
Keyword(s):  
Cardiac Output ◽  
Pulmonary Artery ◽  
Dynamic Response ◽  
Cardiac Output Measurement ◽  
Slew Rate ◽  
Pulmonary Artery Catheterization ◽  
Output Measurement ◽  
The Relationship ◽  
Cardiac Output Measurements

Abstract Nowadays the “gold clinical standard” of hemodynamics diagnostic and cardiac output measurements is pulmonary artery catheterization by means of the Swan-Ganz catheter and thermodilution. The method itself is sensitive to numerous disturbances which cause inaccurate results. One of the well-known disadvantages of thermodilution is the overestimation of results at low values of cardiac output. This effect may concern the limited slew rate of the thermoelement mounted at the tip of the catheter. In this paper the relationship between the dynamic response of the thermoelement and the uncertainty of cardiac output measurements by means of thermodilution has been investigated theoretically and experimentally.

Thermodilution measurement of cardiac output in patients with low output: room-temperature versus iced injectate

1998 ◽  
Vol 7 (6) ◽  
pp. 436-438 ◽  
Author(s):  
M Kiely ◽  
LA Byers ◽  
R Greenwood ◽  
E Carroll ◽  
D Carroll
Keyword(s):  
Cardiac Output ◽  
Cardiac Index ◽  
Room Temperature ◽  
Clinical Decision Making ◽  
Clinical Decision ◽  
Thermodilution Technique ◽  
Convenience Sample ◽  
Low Cardiac Output ◽  
Significant Difference ◽  
Critically Ill Adults

BACKGROUND: Measurements of cardiac output with the thermodilution technique add to data for clinical decision making and therefore must be valid and reliable. However, the results of studies on the accuracy of values obtained with room-temperature and iced injectates, especially in patients with high or low cardiac output, have been conflicting. OBJECTIVE: To determine the effect of the temperature of the injectate (iced or room temperature) on cardiac output values obtained with the thermodilution technique in critically ill adults with known low cardiac output. METHODS: A convenience sample of 50 subjects (41 men and 9 women) who had a cardiac index of less than 2.5 (calculated as cardiac output in liters per minute divided by body surface area in square meters) before the study had cardiac output measured by using a closed system and manual injections of room-temperature and iced injectates. RESULTS: A paired t test indicated no significant difference between iced and room-temperature injectates for cardiac output (iced, 3.62 L/min; room temperature, 3.71 L/min; t = 0.99; P = .327) and cardiac index (iced, 1.95; room temperature, 1.99; t = 0.71; P = .482). CONCLUSION: The findings support the practice of using room-temperature injectate to measure cardiac output in patients with low cardiac output.

Agreement and clinical utility of 2 techniques for measuring cardiac output in patients with low cardiac output

1999 ◽  
Vol 8 (1) ◽  
pp. 464-474 ◽  
Author(s):  
NM Albert ◽  
BT Spear ◽  
J Hammel
Keyword(s):  
Cardiac Output ◽  
Length Of Stay ◽  
Treatment Decisions ◽  
Continuous Cardiac Output ◽  
Hospital Length Of Stay ◽  
Control Group ◽  
Clinical Decisions ◽  
Output Measurement ◽  
Low Cardiac Output ◽  
Experimental Group

BACKGROUND: The reliability of cardiac output obtained with the bolus technique is a problem. OBJECTIVES: To compare measurements of cardiac output measured with bolus and continuous techniques in patients with low cardiac output and to determine if measurements obtained with the continuous technique increased the number of subsequent clinical decisions. METHODS: In 60 intensive care patients, a nurse recorded a single continuous cardiac output measurement and then obtained the mean of 3 consecutive bolus determinations. The medical records of these 60 patients (experimental group) for the next 48 hours and of 60 other patients with regular or mixed venous oximetry catheters (control group) were reviewed to assess the occurrence of cardiac output events and the frequency of clinical decisions based on the events. RESULTS: Mean cardiac output was 4.46 L/min by the continuous technique and 5.20 L/min by the bolus technique (P = .011) for the experimental group. Median bias between the 2 types of measurements was -0.10 L/min (P = .79). Twenty-three of the pairs (38%) had an absolute percent difference greater than 15%. Of these, 18 (78%) had a higher bolus reading. Treatment decisions per 48 hours were 9.9 for the experimental group and 8.6 for the control group (P = .014). Median length of stay was 2 days less in the experimental group (P = .02), and mean highest cardiac output was 0.81 L/min higher (P = .009). CONCLUSIONS: Measurements of cardiac output determined with the continuous technique may be more precise than measurements determined with the bolus technique. Continuous cardiac output information increases the number of treatment decisions and actions that may shorten hospital length of stay.

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