Effect of the degree of tricuspid regurgitation on cardiac output measurements by thermodilution.
OBJECTIVE
To determine the relationship between the degree of tricuspid regurgitation (TR) and accuracy of cardiac output measurement by thermodilution in mechanically ventilated patients. DESIGN AND SETTING. Prospective observational study in a 20-bed general intensive care unit in the university hospital.


METHODS
We examined 27 patients (not undergoing cardiac surgery): 8 with no or 1st degree TR, 9 with 2nd degree, and 10 with 3rd degree TR.


METHODS
All patients were measured twice using simultaneously transesophageal echocardiography and pulmonary artery catheter for cardiac output.


RESULTS
Continuous Doppler measurements were taken in the left ventricular outflow tract at the level of the aortic valve. Cardiac output was calculated by multiplying the velocity-time integral by aortic valve area and heart rate. Simultaneous pulmonary artery catheter measurements were taken averaging the results of the three 10-cc boluses of iced saline. The difference between the methods was 0.5+/-1.1 l/min (mean +/-2 SD) in patients with no or 1st degree TR (r=0.96), 0.8+/-2.0 l/min in those with 2nd degree TR (r=0.92), and 1.9+/-2.3 l/min in those with 3rd degree TR (r=0.69).


CONCLUSIONS
A high degree of TR is associated with underestimation of cardiac output measured by thermodilution.
Department of Intensive Care and Anesthesia, University Hospital Kralovske Vinohrody, Srobarova 50, Prague 10, 10034 Czech Republic. balik@fnkv.cz
Martin
M
Balik
Jan
J
Pachl
Jan
J
Hendl
Balik
B
Martin
Pachl
P
Jan
Hendl
H
Jan
D002302:Cardiac Output; D002407:Catheterization, Swan-Ganz; D018153:Czech Republic; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012121:Respiration, Artificial; D013815:Thermodilution / Q000379:methods*; D014262:Tricuspid Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D018608:Ultrasonography, Doppler