A COMPARSION OF CARDIAC OUTPUT, CORONARY BLOOD FLOW, ARTERIAL AND MIXED VENOUS BLOOD GASES, AND ELECTROLYTES IN OPEN-CHEST MANUAL CARDIAC MASSAGE VS. OPEN-CHEST COMPRESSION-ACTIVE-DECOMPRESSION CARDIAC MASSAGE

We have recently demonstrated that changes in the work of breathing during maximal exercise affect leg blood flow and leg vascular conductance (C. A. Harms, M. A. Babcock, S. R. McClaran, D. F. Pegelow, G. A. Nickele, W. B. Nelson, and J. A. Dempsey. J. Appl. Physiol. 82: 1573–1583, 1997). Our present study examined the effects of changes in the work of breathing on cardiac output (CO) during maximal exercise. Eight male cyclists [maximal O2 consumption (V˙o 2 max): 62 ± 5 ml ⋅ kg−1 ⋅ min−1] performed repeated 2.5-min bouts of cycle exercise atV˙o 2 max. Inspiratory muscle work was either 1) at control levels [inspiratory esophageal pressure (Pes): −27.8 ± 0.6 cmH2O], 2) reduced via a proportional-assist ventilator (Pes: −16.3 ± 0.5 cmH2O), or 3) increased via resistive loads (Pes: −35.6 ± 0.8 cmH2O). O2 contents measured in arterial and mixed venous blood were used to calculate CO via the direct Fick method. Stroke volume, CO, and pulmonary O2 consumption (V˙o 2) were not different ( P > 0.05) between control and loaded trials atV˙o 2 max but were lower (−8, −9, and −7%, respectively) than control with inspiratory muscle unloading atV˙o 2 max. The arterial-mixed venous O2difference was unchanged with unloading or loading. We combined these findings with our recent study to show that the respiratory muscle work normally expended during maximal exercise has two significant effects on the cardiovascular system: 1) up to 14–16% of the CO is directed to the respiratory muscles; and 2) local reflex vasoconstriction significantly compromises blood flow to leg locomotor muscles.

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Respiratory measurements of cardiac output: from elegant idea to useful test

Journal of Applied Physiology ◽

10.1152/japplphysiol.01074.2001 ◽

2004 ◽

Vol 96 (2) ◽

pp. 428-437 ◽

Cited By ~ 41

Author(s):

Gabriel Laszlo

Keyword(s):

Cardiac Output ◽

Human Subjects ◽

Venous Blood ◽

The Body ◽

Mixed Venous Blood ◽

Indirect Determination ◽

Arterial Blood ◽

Pulmonary Capillary ◽

Pulmonary Arterial ◽

Mixed Venous

The measurement of cardiac output was first proposed by Fick, who published his equation in 1870. Fick's calculation called for the measurement of the contents of oxygen or CO2 in pulmonary arterial and systemic arterial blood. These values could not be determined directly in human subjects until the acceptance of cardiac catheterization as a clinical procedure in 1940. In the meanwhile, several attempts were made to perfect respiratory methods for the indirect determination of blood-gas contents by respiratory techniques that yielded estimates of the mixed venous and pulmonary capillary gas pressures. The immediate uptake of nonresident gases can be used in a similar way to calculate cardiac output, with the added advantage that they are absent from the mixed venous blood. The fact that these procedures are safe and relatively nonintrusive makes them attractive to physiologists, pharmacologists, and sports scientists as well as to clinicians concerned with the physiopathology of the heart and lung. This paper outlines the development of these techniques, with a discussion of some of the ways in which they stimulated research into the transport of gases in the body through the alveolar membrane.

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Influence of changes in cardiac output on the acid-base status of arterial and mixed venous blood

Pflügers Archiv - European Journal of Physiology ◽

10.1007/bf00580274 ◽

1987 ◽

Vol 410 (3) ◽

pp. 257-262 ◽

Cited By ~ 2

Author(s):

Y. L. Hoogeveen ◽

J. P. Zock ◽

P. Rispens ◽

W. G. Zijlstra

Keyword(s):

Cardiac Output ◽

Venous Blood ◽

Mixed Venous Blood ◽

Acid Base ◽

Acid Base Status ◽

Mixed Venous

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Lactate, pyruvate, glucose, and free fatty acid in mixed venous and arterial blood

Journal of Applied Physiology ◽

10.1152/jappl.1963.18.5.933 ◽

1963 ◽

Vol 18 (5) ◽

pp. 933-936 ◽

Cited By ~ 14

Author(s):

P. Harris ◽

T. Bailey ◽

M. Bateman ◽

M. G. Fitzgerald ◽

J. Gloster ◽

...

Keyword(s):

Fatty Acids ◽

Cardiac Output ◽

Fatty Acid ◽

Free Fatty Acid ◽

Venous Blood ◽

Average Concentration ◽

Mixed Venous Blood ◽

Arterial Blood ◽

Acquired Heart Disease ◽

Mixed Venous

The concentrations of lactic acid, pyruvic acid, glucose, and free fatty acids have been measured simultaneously in the blood from the pulmonary and brachial arteries at rest and during exercise in a group of patients with acquired heart disease. The arteriovenous differences in the concentration of lactate, pyruvate, and free fatty acid were such as could be attributed to chance. The average concentration of glucose was slightly but significantly higher in the brachial arterial blood than in the mixed venous blood. cardiac output; lung metabolism; exercise Submitted on January 15, 1963

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Cardiovascular adjustments to laboratory diving in beavers and nutria

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1982.242.5.r434 ◽

1982 ◽

Vol 242 (5) ◽

pp. R434-R440

Author(s):

T. McKean

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Regional Blood Flow ◽

Castor Canadensis ◽

Venous Blood ◽

Regional Distribution ◽

Blood Gases ◽

Myocastor Coypus ◽

Recovery From Anesthesia ◽

Rate Of Decline

Beavers (Castor canadensis) and nutria (Myocastor coypus) were anesthetized with halothane and catheters placed in the left ventricle, aorta and pulmonary artery, right ventricle or right atrium. The animals were strapped to a board and following recovery from anesthesia the following measurements were taken: regional distribution of blood flow, cardiac output, O2 consumption, arterial and venous blood gases, and pH. The animal was then immersed in 15-20 degrees C water for up to 2.75 min (nutria) or 4 min (beaver) and the measurements repeated. Heart rate and cardiac output decreased by 80 and 75%, respectively. Arterial and venous oxygen partial pressure and content fell as did pH whereas CO2 pressures rose during diving. Oxygen consumption at rest was 124 and 102% of that predicted on the basis of body mass for the beaver and nutria, respectively. Rate of decline of O2 stores during diving decreased by 93% in beavers and 89% in nutria compared to the predive value. Regional blood flow decreased to all organs except the adrenals, heart, and lungs. Blood flow to the brain increased during diving.

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Changes in blood gases and acid-base balance in the exercising dog

Journal of Applied Physiology ◽

10.1152/jappl.1962.17.4.656 ◽

1962 ◽

Vol 17 (4) ◽

pp. 656-660 ◽

Cited By ~ 10

Author(s):

Ronald L. Wathen ◽

Howard H. Rostorfer ◽

Sid Robinson ◽

Jerry L. Newton ◽

Michael D. Bailie

Keyword(s):

Venous Blood ◽

Blood Gases ◽

Respiratory Alkalosis ◽

Hydrogen Ion ◽

Ion Concentration ◽

Mixed Venous Blood ◽

Acid Base Balance ◽

Hydrogen Ion Concentration ◽

Arterial Blood ◽

Mixed Venous

Effects of varying rates of treadmill work on blood gases and hydrogen ion concentrations of four healthy young dogs were determined by analyses of blood for O2 and CO2 contents, Po2, Pco2, and pH. Changes in these parameters were also observed during 30-min recovery periods from hard work. Arterial and mixed venous blood samples were obtained simultaneously during work through a polyethylene catheter in the right ventricle and an indwelling needle in an exteriorized carotid artery. Mixed venous O2 content, Po2 and O2 saturation fell with increased work, whereas arterial values showed little or no change. Mixed venous CO2 content, Pco2, and hydrogen ion concentration exhibited little change from resting levels in two dogs but increased significantly in two others during exercise. These values always decreased in the arterial blood during exercise, indicating the presence of respiratory alkalosis. On cessation of exercise, hyperventilation increased the degree of respiratory alkalosis, causing it to be reflected on the venous side of the circulation. Submitted on January 8, 1962

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Postpneumonectomy alveolar growth does not normalize hemodynamic and mechanical function

Journal of Applied Physiology ◽

10.1152/jappl.1999.87.2.491 ◽

1999 ◽

Vol 87 (2) ◽

pp. 491-497 ◽

Cited By ~ 24

Author(s):

Shin-Ichi Takeda ◽

Murugappan Ramanathan ◽

Aaron S. Estrera ◽

Connie C. W. Hsia

Keyword(s):

Cardiac Output ◽

Minute Ventilation ◽

Lung Resection ◽

Venous Blood ◽

Structural Response ◽

Respiratory Muscles ◽

Blood Gases ◽

Mixed Venous Blood ◽

Power Requirement ◽

Normal Mean

Immature foxhounds underwent 55% lung resection by right pneumonectomy ( n = 5) or thoracotomy without pneumonectomy (Sham, n = 6) at 2 mo of age. Cardiopulmonary function was measured during treadmill exercise on reaching maturity 1 yr later. In pneumonectomized animals compared with Sham animals, maximal oxygen uptake, ventilatory response, and cardiac output during exercise were normal. Arterial and mixed venous blood gases and arteriovenous oxygen extraction during exercise were also normal. Mean pulmonary arterial pressure and resistance were elevated at a given cardiac output. Dynamic ventilatory power requirement was also significantly elevated at a given minute ventilation. These long-term hemodynamic and mechanical abnormalities are in direct contrast to the normal pulmonary gas exchange during exercise in these same pneumonectomized animals reported elsewhere (S. Takeda, C. C. W. Hsia, E. Wagner, M. Ramanathan, A. S. Estrera, and E. R. Weibel. J. Appl. Physiol. 86: 1301–1310, 1999). Functional compensation was superior in animals pneumonectomized as puppies than as adults. These data indicate a limited structural response of conducting airways and extra-alveolar pulmonary blood vessels to pneumonectomy and suggest the development of other sources of adaptation such as those involving the heart and respiratory muscles.

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