Cardiac Output in Healthy Subjects Determined with a CO<sub>2</sub>Rebreathing Method

Jernérus, R.; Lundin, G.; Thomson, D.

doi:10.1111/j.1748-1716.1963.tb02755.x

Cited by 75 publications

(17 citation statements)

References 11 publications

(1 reference statement)

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“…The volume of collected gas was measured by a dry or wet gasometer, and gas analysis was performed with the Scholander micro-gas analyzer. Cardiac output was determined by the CO2 rebreathing technique (JERNERUS et al, 1963): The partial pressure of CO2 in the artery (PaCO2)was estimated from the mean of two partial pressures of CO2 in the alveolar (PACO2) values measured with an Infrared CO2 analyzer (Beckman, LB-1) at the point of maximal expiration. The partial pressure of CO2 in the mixed venous blood (PvCO2)was estimated by rebreathing a CO2 in O2 gas mixture, a method which was devised by KLAUSEN (1965).…”

Section: Methodsmentioning

confidence: 99%

Maximum Cardiac Output Related to Sex and Age

Miyamura

Honda

1973

Jpn.J.Physiol

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Summary Maximum cardiac output (Qmax) was determined for 233 males (aged 9 through 53 years) and 102 females (aged 9 through 20 years) by the carbon dioxide rebreathing technique during bicycle exercise. Maximum cardiac output of the males progressively increased from 12.5 to 22.0 liter/min until age 17 through 18 years and was maintained at this level until age 24 years. From age 25 years a decrease in Qmax to 16.7 liter/min by age 53 years was observed. Qmax of the females increased from a level of 10.5 liter/min at age 9 years to a Qmaximum of 15.5 liter/min at age 18 years, maintaining this level through age 20 years. Male Qmax for comparable ages above 18 years was 30 % higher than female Qmax . Using the average Qmax value of males of 23-24 years as an optimum value, the decrement in Qmax with each year was approximately 0.9 %.The aerobic work capacity (maximum oxygen intake; 102.a.) of humans is known to decrease with increasing years from an optimum age (ROBINSON, 1939;ASTRAND, 1960;. Oxygen intake is strongly related to cardiac output and one of the limitations in oxygen intake must be in the circulatory ability to deliver oxygen to the working muscles. Unfortunately, data regarding the determination of cardiac output at VO2max have previously been reported for only a limited number of subjects representative of a narrow range in ages. Furthermore, data regarding the Qmax of females are limited. Therefore, this study was designed to systematically investigate the effect of increasing age, from 9 through 53 years, on Qmaximum cardiac output for males, and from 9 through 20 years for females. It was anticipated that such a study would define the role played by the cardiac output in the age-related decrease in maximum aerobic capacity and add to knowledge of the progressive increase in aerobic capacity of males and females during the developmental process of puberty.

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Section: Methodsmentioning

confidence: 99%

Maximum Cardiac Output Related to Sex and Age

Miyamura

Honda

1973

Jpn.J.Physiol

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“…In the application of the CO 2 rebreathing method, the partial pressure of mixed venous CO 2 (P V − CO 2 ) was estimated from the exponential rise in CO 2 concentration in the lung-bag system during rebreathing by the graphical extrapolation method (Klausen 1965). The arterial CO 2 pressure (P a CO 2 ) was estimated from the end-tidal CO 2 (Jernérus et al 1963). The P V − CO 2 and P a CO 2 were converted to the content of both arterial (C a CO 2 ) and mixed venous blood (C V − CO 2 ) respectively, through the use of a standard dissociation curve in the oxygenated blood.…”

Section: Measurement Of Cardiac Output By Co 2 Rebreathing Methodsmentioning

confidence: 99%

Validity of the Adaptive Filter for Accurate Measurement of Cardiac Output in Impedance Cardiography

Ono

Yasuda

et al. 2004

Tohoku J. Exp. Med.

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The purpose of this study was to assess the validity of an adaptive filter, the scaled Fourier linear combiner (SFLC), in the impedance cardiography (ICG). Eight healthy males underwent constant-load bicycle exercise at different intensities from unloaded to near maximal intensity. The stroke volume (SV) and cardiac output (Q 4 ) measured by ICG at each condition were compared with those by the CO 2 rebreathing method. We found that the noises were greatly reduced in the impedance waveform and that the inflection points, so-called the B-and X-points, were clearly detected even during strenuous exercise using the SFLC. Although a high correlation was observed between Q 4 s measured by the two methods, the mean values of Q 4 s in each method differed significantly and the regression line also differed significantly from the identity line. Likewise, a significant correlation was observed between SVs obtained by the two methods, but a significant difference in the group mean values and a trend of the regression line were observed. These findings suggest that the use of SFLC in ICG improves the performance in eliminating the noises and in detecting the inflection points in the waveform, thereby contributing to the accurate and beat-to-beat measurements of SV and Q 4 especially during exercise. impedance cardiography; adaptive filter; cardiac output; stroke volume; CO 2 rebreathing

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“…Defares method does not require any technique and is safe even at high exercise intensities. These advantages have stimulated many investigators to test the validity of the cardiac output determined by the Defares method (JERNERUS et al, 1963;KLAUSEN, 1965;LUNDIN and THOMSON, 1965;FERGUSON et al, 1968;KNOWLTON and ADAMS, 1974;HEIGENHAUSER and FAULKNER, 1978). LUNDIN and THOMSON (1965) proved the effect of the lung-bag volume shrinkage on the P'Vc02 estimation by detecting nitrogen concentration.…”

Section: Resultsmentioning

confidence: 99%

Cardiac output determined by the CO2 rebreathing method with correction of lung-bag volume shrinkage.

1984

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The purpose of this study was to elucidate the effect of lungbag volume shrinkage on P'vco2 estimated by the C02 rebreathing method and to correct its effect in calculation of cardiac output. The P'vco2 was extrapolated with the linear relationship between dPAco2 Jdt and PAc o 2 during rebreathing. The P'vc o 2 was higher than real mixed P002 by 0.82 mmHg at rest, by 1.35 mmHg at 50W, 1.57 mmHg at 100W, and 3.06 mmHg at 150W considering the effect of lung-bag volume shrinkage detected by argon concentration. The cardiac output obtained by the C02 rebreathing method with correction of above differences was in good agreement with that determined by the acetylene method (r=0.930, p<0.001). When the cardiac output was plotted against 02 uptake, our results and the regression line were fairly close to the reported regression lines.Key Words: cardiac output, C02 rebreathing method, lung-bag volume shrinkage, mixed venous C02 pressure. DEFARES (1956) not only introduced the rebreathing technique to estimate oxygenated mixed venous C02 pressure (Pvco2), but also was the first to discuss the effect of lung-bag volume shrinkage on the estimation of the Pvco2. The effect of lung-bag volume shrinkage which derived from 02 uptake being higher than C02 elimination during rebreathing was then judged to be negligible.The recent development of a fast responding gas analyzer makes it possible to use the C02 rebreathing method even at high exercise intensities. At the same time, since exercise requires high 02 uptake, the problem of lung-bag volume shrinkage would be revealed. In fact, LUNDIN and THOMSON (1965) proved such effect on the Pvcp2 estimation in detecting the change of nitrogen concentration. Later, FARHI et al. (1976) proposed the equation to estimate the theoretical difference between the real Pvco2 and the Pvco2 determined by the C02 rebreathing

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Cardiac Output in Healthy Subjects Determined with a CO₂Rebreathing Method

Cited by 75 publications

References 11 publications

Maximum Cardiac Output Related to Sex and Age

Maximum Cardiac Output Related to Sex and Age

Validity of the Adaptive Filter for Accurate Measurement of Cardiac Output in Impedance Cardiography

Cardiac output determined by the CO2 rebreathing method with correction of lung-bag volume shrinkage.

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Cardiac Output in Healthy Subjects Determined with a CO2Rebreathing Method

Cited by 75 publications

References 11 publications

Maximum Cardiac Output Related to Sex and Age

Maximum Cardiac Output Related to Sex and Age

Validity of the Adaptive Filter for Accurate Measurement of Cardiac Output in Impedance Cardiography

Cardiac output determined by the CO2 rebreathing method with correction of lung-bag volume shrinkage.

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Cardiac Output in Healthy Subjects Determined with a CO₂Rebreathing Method