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Simultaneous determination of the accuracy and precision of closed-circuit cardiac output rebreathing techniques
被引:72
作者:
Jarvis, S. S.
Levine, B. D.
Prisk, G. K.
Shykoff, B. E.
Elliott, A. R.
Rosow, E.
Blomqvist, C. G.
Pawelczyk, J. A.
机构:
[1] Penn State Univ, Dept Kinesiol, University Pk, PA 16802 USA
[2] Univ Texas, SW Med Ctr, Inst Exercise & Environm Med, Dallas, TX 75230 USA
[3] Presbyterian Med Ctr, Dallas, TX USA
[4] Univ Calif San Diego, Dept Med, La Jolla, CA 92093 USA
[5] SUNY Buffalo, Dept Physiol, Buffalo, NY 14260 USA
[6] Hartford Hosp, Hartford, CT 06115 USA
[7] Premise Dev Corp, Hartford, CT USA
[8] Univ Texas, SW Med Ctr, Dept Internal Med, Div Cardiol, Dallas, TX 75230 USA
关键词:
foreign gas rebreathing;
physiological gas rebreathing;
direct Fick;
thermodilution;
D O I:
10.1152/japplphysiol.01106.2006
中图分类号:
Q4 [生理学];
学科分类号:
071003 ;
摘要:
Foreign and soluble gas rebreathing methods are attractive for determining cardiac output (Q(c)) because they incur less risk than traditional invasive methods such as direct Fick and thermodilution. We compared simultaneously obtained Q(c) measurements during rest and exercise to assess the accuracy and precision of several rebreathing methods. Q(c) 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; Vo(2max): 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 Q(c) 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 Q(c) (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 Q(c) estimates with fewer repeat trials during resting conditions. During exercise, these methods remain precise but tend to underestimate Q(c). Single-step CO2 rebreathing may be successfully employed over a wider range but with more measurements needed to overcome the larger variability.
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页码:867 / 874
页数:8
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