Some aspects of determination of the cardiac output by the rebreathing method

1977 ◽  
Vol 83 (2) ◽  
pp. 274-277
Author(s):  
R. S. Vinitskaya ◽  
N. A. Koganova
Keyword(s):  
Cardiac Output ◽  
Rebreathing Method

Evaluation of a modified acetylene rebreathing method for the determination of cardiac output

1986 ◽  
Vol 6 (3) ◽  
pp. 253-268 ◽  
Author(s):  
J. Nyström ◽  
F. Celsing ◽  
P. Carlens ◽  
B. Ekblom ◽  
P. Ring
Keyword(s):  
Cardiac Output ◽  
Rebreathing Method

Comparison of cardiac output during exercise by single-breath and CO2-rebreathing methods

1985 ◽  
Vol 58 (4) ◽  
pp. 1372-1377 ◽  
Author(s):  
M. D. Inman ◽  
R. L. Hughson ◽  
N. L. Jones
Keyword(s):  
Cardiac Output ◽  
Partial Pressure ◽  
Co2 Rebreathing ◽  
Single Breath ◽  
Partial Pressure Of Co2 ◽  
The Difference ◽  
End Tidal ◽  
Rebreathing Method ◽  
Single Breath Method

Cardiac output (Q) was estimated in supine rest and in upright cycling at several work rates up to 200 W in five male and one female subjects. At least four repetitions of both the CO2-rebreathing plateau method (Collier, J. Appl. Physiol. 9:25–29, 1956) and the Kim et al. (J. Appl. Physiol. 21: 1338–1344, 1966) single-breath method were performed at each work rate, in a steady state of O2 consumption and heart rate. At supine rest and low work rates, estimates of Q were similar by the two methods. However, at higher work rates, the single-breath method significantly (P less than 0.05) underestimated the value obtained by CO2 rebreathing. The reason for the difference in estimates of Q by the two methods was traced to the determination of arterial partial pressure of CO2 (PaCO2) and mixed venous partial pressure of CO2 (PvCO2). The estimate of PaCO2 from the single-breath method was approximately 88.5% of the estimate from end-tidal PCO2 used with the rebreathing method (P less than 0.001). The oxygenated PvCO2 calculated from the single-breath Q averaged approximately 92.5% of the PvCO2 from CO2 rebreathing (P less than 0.0001). The difference in estimates of Q was not eliminated by using a logarithmic form of the CO2 dissociation curve with the single-breath method.

Determination of mixed venous O2 and CO2 tensions and cardiac output by a rebreathing method

1966 ◽  
Vol 1 (3) ◽  
pp. 258-264 ◽  
Author(s):  
P. Cerretelli ◽  
J.C. Cruz ◽  
L.E. Farhi ◽  
H. Rahn
Keyword(s):  
Cardiac Output ◽  
Rebreathing Method ◽  
Mixed Venous

Simultaneous determination of the accuracy and precision of closed-circuit cardiac output rebreathing techniques

2007 ◽  
Vol 103 (3) ◽  
pp. 867-874 ◽  
Author(s):  
S. S. Jarvis ◽  
B. D. Levine ◽  
G. K. Prisk ◽  
B. E. Shykoff ◽  
A. R. Elliott ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Simultaneous Determination ◽  
Maximal Exercise ◽  
Single Step ◽  
Accuracy And Precision ◽  
Bartlett’S Test ◽  
Rebreathing Method ◽  
Rebreathing Methods ◽  
Rest And Exercise

Foreign and soluble gas rebreathing methods are attractive for determining cardiac output (Q̇c) because they incur less risk than traditional invasive methods such as direct Fick and thermodilution. We compared simultaneously obtained Q̇c measurements during rest and exercise to assess the accuracy and precision of several rebreathing methods. Q̇c measurements were obtained during rest (supine and standing) and stationary cycling (submaximal and maximal) in 13 men and 1 woman (age: 24 ± 7 yr; height: 178 ± 5 cm; weight: 78 ± 13 kg; V̇o2max: 45.1 ± 9.4 ml·kg−1·min−1; mean ± SD) using one-N2O, four-C2H2, one-CO2 (single-step) rebreathing technique, and two criterion methods (direct Fick and thermodilution). CO2 rebreathing overestimated Q̇c compared with the criterion methods (supine: 8.1 ± 2.0 vs. 6.4 ± 1.6 and 7.2 ± 1.2 l/min, respectively; maximal exercise: 27.0 ± 6.0 vs. 24.0 ± 3.9 and 23.3 ± 3.8 l/min). C2H2 and N2O rebreathing techniques tended to underestimate Q̇c (range: 6.6–7.3 l/min for supine rest; range: 16.0–19.1 l/min for maximal exercise). Bartlett's test indicated variance heterogeneity among the methods ( P < 0.05), where CO2 rebreathing consistently demonstrated larger variance. At rest, most means from the noninvasive techniques were ±10% of direct Fick and thermodilution. During exercise, all methods fell outside the ±10% range, except for CO2 rebreathing. Thus the CO2 rebreathing method was accurate over a wider range (rest through maximal exercise), but was less precise. We conclude that foreign gas rebreathing can provide reasonable Q̇c estimates with fewer repeat trials during resting conditions. During exercise, these methods remain precise but tend to underestimate Q̇c. Single-step CO2 rebreathing may be successfully employed over a wider range but with more measurements needed to overcome the larger variability.

Determination of Cardiac Output and Pressure Gradients at Operation

1958 ◽  
Vol 258 (11) ◽  
pp. 527-530 ◽  
Author(s):  
Herbert L. Tanenbaum ◽  
Eugene Braunwald ◽  
Andrew G. Morrow
Keyword(s):  
Cardiac Output ◽  
Pressure Gradients
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