Mixed venous oxygen saturation as a promising parameter for physiologic control of total artificial heart

Citation
M. Nakamura et al., Mixed venous oxygen saturation as a promising parameter for physiologic control of total artificial heart, ASAIO J, 46(6), 2000, pp. 761-766
Citations number
13
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology
Journal title
ASAIO JOURNAL
ISSN journal
1058-2916 → ACNP
Volume
46
Issue
6
Year of publication
2000
Pages
761 - 766
Database
ISI
SICI code
1058-2916(200011/12)46:6<761:MVOSAA>2.0.ZU;2-Y
Abstract
Mixed venous oxygen saturation (SvO(2)) has been proposed as one of the sui table parameters for physiologic control of a total artificial heart (TAH). To establish the practical application of SvO(2), we investigated the resp onse of cardiac output (CO) and SvO(2) to step-loaded exercise. A normal ca lf was surgically equipped with an ultrasonic flowmeter probe and an oximet ry catheter in the pulmonary artery to measure CO and SvO(2), respectively. Three stage step treadmill exercise tests (1, 2, and 4 km/h) were performe d three times. While CO increased from 8.9 L/min at preexercise level to 9. 7, 10.2 and 11.4 L/min at 1, 2, and 4 km/h, respectively, SvO(2) decreased from 59.6% to 56.8, 55.3, and 52.2%, respectively. There existed a linear c orrelation between the magnitude of changes in CO and SvO(2). CO and SvO(2) exhibited a similar course of change, expressing an inverted exponential c urve. The time constant of SvO(2) was from 19 to 35 seconds, whereas that o f CO was from 21 to 39 seconds. We conclude that SvO(2) changes in close as sociation with CO during exercise and has good potential to be a parameter for physiologic control of a TAH, by reflecting the recipient's CO demand w ithout conspicuous time delay.