Thermodilution cardiac output values obtained by using a centrally placed introducer sheath and right atrial port of a pulmonary artery catheter

Heat loss from the vascular system could introduce an error in thermodilution cardiac output determinations. Cardiac output measured in the rat via the thermodilution technique following right atrial injection yielded different values (P less than 0.001), depending whether sampling was from the pulmonary artery (460 +/- 31 ml X min-1 X kg-1), right ventricle (311 +/- 19), or thoracic aorta (245 +/- 15). Recirculation errors could not account for the differences. Heat loss from the vascular system was measured from extravascular thermistors within both the thorax and the abdomen. These dilutions were 22-57% in peak height of aortic curves recorded at approximately the same location. Differences in calculated cardiac output between sampling sites could be attributed to rapid heat conduction directly from the right atrium and inferior vena cava to the thoracic aorta with progressive loss of indicator from both the right ventricle and pulmonary artery.

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Erratum to “The Precision of Pulmonary Artery Catheter Bolus Thermodilution Cardiac Output Measurements Varies With the Clinical Situation” J Cardiothorac Vasc Anes 29(2015):881-888

Journal of Cardiothoracic and Vascular Anesthesia ◽

10.1053/j.jvca.2015.10.007 ◽

2016 ◽

Vol 30 (1) ◽

pp. 273

Author(s):

Idar Kirkeby-Garstad ◽

Håkon Trønnes ◽

Roar Stenseth ◽

Olav F.M. Sellevold ◽

Petter Aadahl ◽

...

Keyword(s):

Cardiac Output ◽

Pulmonary Artery ◽

Pulmonary Artery Catheter ◽

Clinical Situation ◽

Thermodilution Cardiac Output ◽

Cardiac Output Measurements

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Injectate port selection affects accuracy and reproducibility of cardiac output measurements with multiport thermodilution pulmonary artery catheters

American Journal of Critical Care ◽

10.4037/ajcc1994.3.1.55 ◽

1994 ◽

Vol 3 (1) ◽

pp. 55-61 ◽

Cited By ~ 2

Author(s):

LE Renner ◽

LT Meyer

Keyword(s):

Cardiac Output ◽

Pulmonary Artery ◽

Inferior Vena Cava ◽

Pulmonary Artery Catheter ◽

Inferior Vena ◽

Vena Cava ◽

Thermodilution Cardiac Output ◽

Electromagnetic Flow ◽

Electromagnetic Flow Meter ◽

Cardiac Output Measurements

OBJECTIVE: To compare the accuracy and reproducibility of thermodilution cardiac output measurements obtained from the injectate and infusion ports of a multilumen pulmonary artery catheter. The thermodilution results were compared with an independent measure of flow obtained from an electromagnetic flow meter. METHODS: In an experimental study conducted at an animal research laboratory of a health sciences university, two virgin western breed ewes were surgically instrumented with an inferior vena cava occluder, which reduced venous return and thus lowered cardiac output, and an ascending aortic electromagnetic flow probe, which provided an independent reference measure of cardiac output. On the day of study, a multilumen pulmonary artery catheter was inserted. Cardiac output was manipulated over a range of 2.9 to 12.1 L/min with i.v. isoproterenol or inferior vena cava occlusion. Approximately 30 simultaneous thermodilution and electromagnetic flow meter measurements of cardiac output were obtained from both the infusion and injectate ports in each of the two subjects. RESULTS: Correlation coefficients were lower and standard error of the estimates was higher for the infusion port (r = .83; SEE = 1.19 L/min) vs the injectate port (r = .94; SEE = .74 L/min), indicating reduced reproducibility with infusion port thermodilution cardiac output determinations. Accuracy was also adversely influenced in the infusion port results. The linear regression for the infusion port data intercepted the Y axis at +2.64 L/min, indicating significant overestimation of cardiac output at flows of less than 5 L/min and underestimation of flow when cardiac output exceeded 8 L/min. CONCLUSIONS: The use of the infusion port for the measurement of thermodilution cardiac output measurements may result in nonreproducible and inaccurate results.

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