The Time Course of Mixed Venous Blood Gas Composition following Exercise Onset

1992 ◽  
pp. 263-266
Author(s):  
Richard Casaburi
Keyword(s):  
Time Course ◽  
Venous Blood ◽  
Mixed Venous Blood ◽  
Gas Composition ◽  
Blood Gas ◽  
Exercise Onset ◽  
Venous Blood Gas ◽  
Mixed Venous

Abrupt changes in mixed venous blood gas composition after the onset of exercise

1989 ◽  
Vol 67 (3) ◽  
pp. 1106-1112 ◽  
Author(s):  
R. Casaburi ◽  
J. Daly ◽  
J. E. Hansen ◽  
R. M. Effros
Keyword(s):  
Time Course ◽  
Vena Cava ◽  
Mixed Venous Blood ◽  
Gas Composition ◽  
Blood Gas ◽  
Arterial Blood ◽  
Ergometer Exercise ◽  
Exercise Onset ◽  
Pulmonary Arterial ◽  
Mixed Venous

It has been assumed that increases in both O2 uptake and ventilation occurring within the first few seconds after the onset of exercise cannot be the result of changes in blood gas composition reaching the central circulation because of the circulatory delay from the exercising limbs (A. Krogh and J. Lindhard, J. Physiol. Lond. 42: 112–136, 1913). We sought to validate this assumption by measuring the time course of pulmonary arterial blood gases during the transition from rest to exercise. Six healthy men underwent pulmonary arterial catheterization and then performed transitions from rest to moderate cycle ergometer exercise. An anaerobic sampling manifold withdrew 19 samples of blood during the rest-to-exercise transition; sampling interval was usually 4 s. Blood gas analysis showed that, on average, from rest-to-steady-state exercise, O2 saturation (Svo2) fell from 71 to 41% and mixed venous PCO2 (PvCO2) rose from 42 to 59 Torr. Contrary to our expectations, Svo2 decreased and PvCO2 increased with no discernible latency after exercise onset (by 10% and 2 Torr, respectively, within 6 s). The half time for the Svo2 decrease was 32 s, whereas for the PvCO2 increase it was 80 s. The time course of superior vena cava blood gas composition was determined in several experiments; no rapid changes after exercise onset were found. We conclude that at exercise onset there is a rapid fall in Svo2 and rise in PvCO2 well in advance of arrival of blood produced by exercising legs.(ABSTRACT TRUNCATED AT 250 WORDS)

Mixed venous blood gas sampling is not influenced by the speed of withdrawal in cardiac surgery patients

2004 ◽  
Vol 30 (10) ◽  
pp. 1969-1973 ◽  
Author(s):  
Emmanuel Sirdar ◽  
Jean-Gilles Guimond ◽  
Isabelle Coiteux ◽  
Sylvain B�lisle ◽  
Denis Babin ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Venous Blood ◽  
Mixed Venous Blood ◽  
Blood Gas ◽  
Gas Sampling ◽  
Venous Blood Gas ◽  
Mixed Venous

scholarly journals Arterial and Mixed Venous Blood Gas Tensions in Exercising Ducks

1980 ◽  
Vol 59 (4) ◽  
pp. 914-917 ◽  
Author(s):  
J.P. KILEY ◽  
W.D. KUHLMANN ◽  
M.R. FEDDE
Keyword(s):  
Venous Blood ◽  
Mixed Venous Blood ◽  
Blood Gas ◽  
Venous Blood Gas ◽  
Mixed Venous

Dependence of Middle Ear Gas Composition on Pulmonary Ventilation

1997 ◽  
Vol 106 (4) ◽  
pp. 314-319 ◽  
Author(s):  
Haya Mover-Lev ◽  
Moshe Harell ◽  
Dalia Levy ◽  
Amos Ar ◽  
Michal Luntz ◽  
...  
Keyword(s):  
Steady State ◽  
Middle Ear ◽  
Pulmonary Ventilation ◽  
Venous Blood ◽  
Blood Gases ◽  
Mixed Venous Blood ◽  
Gas Composition ◽  
Blood Gas ◽  
Ventilation Perfusion Ratio ◽  
Mixed Venous

The middle ear (ME) steady state gas composition resembles that of mixed venous blood. We changed arterial and venous blood gases by artificially ventilating anesthetized guinea pigs and measured simultaneous ME gas changes during spontaneous breathing, hyperventilation, and hypoventilation. During hyperventilation, PaCO2 and PvCO2 (a = arterial, v = venous) decreased from 46.0 and 53.0 mm Hg to 17.9 and 37.5 mm Hg, respectively, while PaO2 and PvO2 (85.6 and 38.2 mm Hg) did not change. This was accompanied by an ME PCO2 decrease from 70.4 to 58.8 mm Hg and a PO2 decrease from 36.8 to 25.4 mm Hg. During hypoventilation, PaCO2 and PvCO2 increased to 56.8 and 66.4 mm Hg, while PvO2 decreased to 21.8 mm Hg. The ME PCO2 increased simultaneously to 88.8 mm Hg and the ME PO2 decreased to 25.4 mm Hg. The ME PO2 decrease during hyperventilation may be explained by a 33% decrease in ME mucosa perfusion, calculated from the ME ventilation-perfusion ratio. This study shows that ME gas composition follows fluctuations of blood gas levels and thus may affect total ME pressure.

Blood-gas measurements adjusted for temperature at three sites during incremental exercise in the horse

1998 ◽  
Vol 85 (3) ◽  
pp. 1030-1036 ◽  
Author(s):  
L. E. Taylor ◽  
D. S. Kronfeld ◽  
P. L. Ferrante ◽  
J. A. Wilson ◽  
W. Tiegs
Keyword(s):  
Time Course ◽  
Venous Blood ◽  
Muscle Metabolism ◽  
Blood Gases ◽  
Incremental Exercise ◽  
Strenuous Exercise ◽  
Mixed Venous Blood ◽  
Blood Gas ◽  
Gas Measurements ◽  
Mixed Venous

Rectal temperature (Tre) is often used to adjust measurements of blood gases, but these adjusted measurements may not approximate temperatures during intense exercise at main sites of gas exchange: muscle and lung. To evaluate differences in blood gases between sites, temperatures (T) were measured with thermocouples in the rectum (re), in mixed venous blood (v), in gluteal muscle (mu), and on the skin (sk) in seven Arabian horses as they underwent an incremental exercise test on a treadmill. Blood samples were drawn from the carotid artery and pulmonary artery (mixed venous) 30 s before each increase in speed and during recovery. Blood gases and pH were measured at 37°C, and all variables were adjusted to Tre,[Formula: see text], and Tmu. Adjusted variables during exercise and recovery were significantly different from each other at the three sites. Linear and polynomial equations described the time course of venous temperature and[Formula: see text] from Treand Tskduring exercise and from Tskduring recovery. Interpretation of changes in muscle metabolism and gas exchanges based on blood-gas measurements is improved if they are adjusted appropriately to Tmuor[Formula: see text], which may be predicted from Tskin addition to Treduring strenuous exercise and from Tskduring recovery.

EXTRINSIC ARTIFICIAL HEART CONTROL VIA MIXED VENOUS BLOOD GAS TENSION ANALYSIS

ASAIO Journal ◽  
1973 ◽  
Vol 19 (1) ◽  
pp. 258-268 ◽  
Author(s):  
Theodore H. Stanley ◽  
Jay Volder ◽  
Willem J. Kolff
Keyword(s):  
Artificial Heart ◽  
Venous Blood ◽  
Mixed Venous Blood ◽  
Blood Gas ◽  
Venous Blood Gas ◽  
Tension Analysis ◽  
Mixed Venous
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