Day-to-Day Reproducibility of the Single-Breath Method for Estimation of Cardiac Output

1987 ◽  
Vol 1 (3) ◽  
pp. 177-179
Author(s):  
P. Christensen
Keyword(s):  
Cardiac Output ◽  
Single Breath ◽  
Single Breath Method

A modified single breath method for estimation of cardiac output in humans at rest and during exercise

1987 ◽  
Vol 72 (4) ◽  
pp. 437-441 ◽  
Author(s):  
Y. M. H. Al-Shamma ◽  
R. Hainsworth ◽  
N. P. Silverton
Keyword(s):  
Cardiac Output ◽  
Normal Subjects ◽  
Random Errors ◽  
O2 Uptake ◽  
Mean Values ◽  
Single Breath ◽  
Expired Gas ◽  
The Mean ◽  
Rest And Exercise ◽  
Single Breath Method

1. This study was undertaken to determine the accuracy of a modification of a single breath method for estimation of cardiac output. The technique incorporated a single rebreathing stage followed by a prolonged expiration. Cardiac output was determined from the O2 uptake and the instantaneous changes in O2 and CO2 in the expired gas during the prolonged expiration. 2. The mean values and the random errors (determined from the differences between pairs of estimates) of cardiac outputs in normal subjects at rest and exercise were 5.42 and ± 0.60 litres/min (2 sd, 60 pairs) and 14.1 and ±1.8 litres/min (40 pairs). 3. Larger random errors were obtained in a group of cardiac patients but, except in hypoxic patients, the mean values obtained by the single breath and the direct (Fick) methods were almost identical. 4. We conclude that our modification of the single breath method is simple to use and sufficiently reliable for use in humans both at rest and during steady states of light exercise.

Single-breath method of measuring cardiac output--a reevaluation.

1972 ◽  
Vol 33 (6) ◽  
pp. 846-848 ◽  
Author(s):  
M P Hlastala ◽  
B Wranne ◽  
C J Lenfant
Keyword(s):  
Cardiac Output ◽  
Single Breath ◽  
Single Breath Method

Evaluation using dogs of a method for estimating cardiac output from a single breath

1981 ◽  
Vol 50 (1) ◽  
pp. 200-202 ◽  
Author(s):  
M. M. Mohammed ◽  
L. M. Wood ◽  
R. Hainsworth
Keyword(s):  
Cardiac Output ◽  
Pulmonary Blood Flow ◽  
Dilution Method ◽  
Moderate Exercise ◽  
Tolerance Limits ◽  
Dye Dilution ◽  
Single Breath ◽  
Significant Difference ◽  
Anesthetized Dogs ◽  
Single Breath Method

We have evaluated the single-breath method of Kim, Rahn, and Fahri (J. Appl. Physiol. 21: 1338, 1966) using anesthetized dogs (avg wt 26 kg). The systematic error was determined by comparing the single-breath estimates of cardiac output with values obtained by the dye-dilution method. In some dogs the effects of moderate exercise were stimulated by joining the circulations of two dogs. From paired estimates, the random error of the single-breath method was +/- 12% (95% tolerance limits; 23 pairs) over a range of outputs 1.1-5.0 l/min. There was no significant difference between values of cardiac output by the single-breath method and by dye dilution, and in four dogs the dye-dilution values were not significantly different from values of pulmonary blood flow controlled by perfusion. These results indicate that under carefully controlled conditions the single-breath method is capable of providing reliable estimates of cardiac output.

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.

Evaluation of a method for estimating cardiac output from a single breath in humans

1982 ◽  
Vol 53 (4) ◽  
pp. 1034-1038 ◽  
Author(s):  
H. Chen ◽  
N. P. Silverton ◽  
R. Hainsworth
Keyword(s):  
Cardiac Output ◽  
Normal Subjects ◽  
Random Errors ◽  
Tolerance Limits ◽  
Mean Values ◽  
Single Breath ◽  
Significant Difference ◽  
Venous Pco2 ◽  
Mixed Venous ◽  
Single Breath Method

We have modified the single-breath method of Kim et al. (J. Appl. Physiol. 21: 1338–1344, 1966) for estimating cardiac output and arterial and mixed venous carbon dioxide tensions (PCO2). We assessed this using 30 normal subjects and 23 cardiac patients. The procedure was performed satisfactorily in all but two patients. The random errors, from 60 pairs of estimates of cardiac output in normal subjects and 50 pairs in patients, were +/- 12.8 and +/- 19.6% (95% tolerance limits; i.e., coefficient of variation multiplied by 2 for n greater than 50). The systematic error was assessed in 15 patients from comparisons with results obtained by the direct Fick method. There was no significant difference except in two patients with large intracardiac shunts. Mean values of cardiac output by single-breath and direct Fick estimates were 3.80 and 3.83 l/min. Arterial and mixed venous PCO2 were estimated by the single-breath method with random errors of +/- 1.5 and +/- 1.4 Torr, respectively, and no significant systematic errors. We conclude that our modification of the single-breath method is reliable in humans at rest, although the procedures for delivering the breath and processing the data are of critical importance.

Single Breath Method for Cardiac Output in Man

1981 ◽  
Vol 61 (3) ◽  
pp. 31P-31P
Author(s):  
H. Chen ◽  
N.P. Silverton ◽  
R. Hainsworth
Keyword(s):  
Cardiac Output ◽  
Single Breath ◽  
Single Breath Method

Single-Breath Breath Holding Measurement of Pulmonary Blood Flow: Comparison to Direct Fick Cardiac Output

1986 ◽  
Vol 71 (s15) ◽  
pp. 36P-36P ◽  
Author(s):  
A.H. Kendrick ◽  
A. Rozkovec ◽  
M. Papouchado ◽  
J. West ◽  
J.E. Bees ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Pulmonary Blood Flow ◽  
Breath Holding ◽  
Single Breath

Respiratory physiology teaching: determination of residual volume by applying the indicator-dilution technique.

1998 ◽  
Vol 274 (6) ◽  
pp. S53
Author(s):  
H Heller ◽  
K Granitza ◽  
B Eixmann
Keyword(s):  
Indicator Dilution ◽  
Respiratory Physiology ◽  
Successful Outcome ◽  
Residual Volume ◽  
Dilution Technique ◽  
Laboratory Courses ◽  
Single Breath ◽  
Indicator Dilution Technique ◽  
Single Breath Method

Apart from the current teaching of spirometric methods in laboratory courses on respiratory physiology, we have included an experiment in which medical students determine their own residual volume by applying the indicator-dilution technique. For hygienic reasons we used a bag-in-the-box system to dilute helium within alveolar space by performing the single-breath method. Although each participant independently underwent only one single-breath maneuver, we gained a reliable relationship between residual volume and subjects' height and body weight in 68 female (r = 0.6, P < 0.0001) and 99 male (r = 0.42, P < 0.0001) students. From this successful outcome and with the opportunity to discuss the limitations of the single-breath method as well, we inferred that this experiment affords a transparent and instructive approach to interpreting the determination of lung volumes on the basis of the indicator-dilution technique.

Noninvasive determination of cardiac output using single breath CO sub 2 analysis

1996 ◽  
Vol 24 (10) ◽  
pp. 1701-1705 ◽  
Author(s):  
John H. Arnold ◽  
Rudiger I. Stenz ◽  
John E. Thompson ◽  
Lucy W. Arnold
Keyword(s):  
Cardiac Output ◽  
Single Breath
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