Lung diffusion capacity, oxygen uptake, cardiac output and oxygen transport during exercise before and after an Himalayan expedition

1996 ◽  
Vol 74 (1-2) ◽  
pp. 187-193 ◽  
Author(s):  
J. M. Steinacker ◽  
Y. Liu ◽  
A. Halder ◽  
M. Stauch ◽  
D. B�ning ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Oxygen Transport ◽  
Lung Diffusion ◽  
Diffusion Capacity ◽  
Before And After

Appearance of excess lactate in anesthetized dogs during anemic and hypoxic hypoxia

1965 ◽  
Vol 209 (3) ◽  
pp. 604-610 ◽  
Author(s):  
Stephen M. Cain
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Oxygen Transport ◽  
Liver Dysfunction ◽  
Hypoxic Hypoxia ◽  
Blood Gas ◽  
Total Oxygen ◽  
Anesthetized Dogs ◽  
Lactate And Pyruvate ◽  
Mixed Venous

Ten anesthetized, splenectomized dogs were made progressively anemic by replacement of blood with warmed dextran to approximate hematocrits of 30, 20, 15, and 10%. A second group of 10 dogs was made progressively hypoxic by having them inspire 11.4, 9.5, 8.0, and 5.9% O2 in N2. Blood gas contents, pH, and gas tensions were measured in arterial and mixed venous bloods. Cardiac output was calculated from the arteriovenous O2 difference and the O2 uptake. Excess lactate was calculated from measured levels of lactate and pyruvate in blood water. Excess lactate appeared at higher mixed venous Po2 in anemic animals than in hypoxic, 40 mm Hg versus 20 mm Hg. When related to total oxygen transport, however, excess lactate appeared at about the same point (12 ml/kg per min) in both groups. Because liver has been shown to reduce its oxygen uptake with any lowering of perfusate oxygen content, it was suggested that the excess lactate measured during both anemic and hypoxic hypoxia in anesthetized dogs is largely the result of liver dysfunction with respect to lactate.

scholarly journals Ventilation, Oxygen Uptake and Haemolymph Oxygen Transport, Following Enforced Exhausting Activity in the Dungeness Crab Cancer Magister

1979 ◽  
Vol 80 (1) ◽  
pp. 271-285 ◽  
Author(s):  
B. R. McMAHON ◽  
D. G. McDONALD ◽  
C. M. WOOD
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Oxygen Transport ◽  
Lactate Concentration ◽  
Fold Increase ◽  
Oxygen Extraction ◽  
Oxygen Release ◽  
Cancer Magister ◽  
Metabolic Scope ◽  
Dungeness Crabs

Scaphognathite and heart-pumping frequencies, ventilation volume, cardiac output, oxygen uptake and oxygen transport by haemolymph have been studied in unrestrained Dungeness crabs (Cancer magister) before, immediately after, and during recovery from 20 min of enforced exhausting activity. Exercise increased oxygen uptake 4-fold. This increase was achieved by more than 2-fold elevation of both ventilation volume and cardiac output and by greater participation of haemocyanin in oxygen delivery. The elevated ventilation volume resulted entirely from an increase in scaphognathite pumping frequency, while the rise in cardiac output resulted largely from increase in stroke volume. Prior to exercise haemocyanin accounts for less than 50% of the oxygen delivered to the tissues. Following exercise this increases to over 80%, the additional oxygen release being mediated by a depression of prebranchial oxygen tension and a substantial Bohr effect resulting from build up of lactate ion in the haemolymph and subsequent fall in pH. These changes allowed % oxygen extraction from branchial water to be maintained at 28% despite a 2-fold increase in ventilation volume, and allowed an increase in %. oxygen extraction by the tissues. Despite these changes oxygen supply fell below demand during exercise, and considerable anaerobic metabolism resulted, as evidenced by a 9-fold increase in haemolymph lactate concentration. The resulting oxygen debt required 8–24 h for repayment. Aerobic metabolic scope, and mechanisms of increasing oxygen uptake and transport in this crab are compared with those of a range of fish species.

Hemodynamic effects of normovolemic polycythemia in dogs at rest and during exercise

1964 ◽  
Vol 207 (6) ◽  
pp. 1361-1366 ◽  
Author(s):  
Allen B. Weisse ◽  
Farrell M. Calton ◽  
Hiroshi Kuida ◽  
Hans H. Hecht
Keyword(s):  
Cardiac Output ◽  
Pulmonary Artery ◽  
Oxygen Transport ◽  
Peripheral Resistance ◽  
Relative Increase ◽  
Red Cells ◽  
Hemodynamic Effects ◽  
Venous Oxygen Saturation ◽  
Before And After ◽  
Response To Exercise

The hemodynamic effects of acutely induced normovolemic polycythemia were studied in four anesthetized and seven unanesthetized dogs at rest and, in three of the latter, during treadmill exercise. Control observations were made in four other animals. Volume of packed red cells values of 60–79% were produced by exchange transfusion with washed centrifuged red cells. Normovolemic polycythemia in both anesthetized and unanesthetized resting animals was associated with a decrease in cardiac output and oxygen transport; little change in pulmonary artery, carotid artery, right atrium, and pulmonary artery wedge pressures; and increases in calculated total systemic and pulmonary vascular resistances. Mixed venous oxygen saturation was not necessarily reduced. The relative increase in cardiac output and oxygen transport in response to exercise was similar before and after normovolemic polycythemia, but the absolute increments were significantly less after normovolemic polycythemia. Results obtained are consistent with the concept that cardiac output reduction with normovolemic polycythemia is mediated by increased peripheral resistance.

Circulation, oxygen transport, and activity in the crayfish

1981 ◽  
Vol 240 (1) ◽  
pp. R99-R105 ◽  
Author(s):  
P. S. Rutledge
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Stroke Volume ◽  
Oxygen Transport ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Maximum Activity ◽  
Active Oxygen ◽  
Routine Activity ◽  
Fick Principle

Heart and ventilation frequencies, oxygen uptake rate, hemocyanin concentration, and pre- and postbranchial PO2 and pH were measured in unrestrained crayfish (Pacifastacus leniuculus) immediately following routine and forced (maximum) activity. Experiments were performed at 20 degrees C, the temperature of maximum scope for activity in this species, and at 10 and 25 degrees C. A procedure for using N-ethylmaleimide as an anticoagulant in hemolymph sampling is described. Hemocyanin oxygen saturation, oxygen content of pre- and postbranchial hemolymph, cardiac output, and stroke volume were estimated from the measured parameters. PO2 of postbranchial hemolymph sampled immediately after routine activity was low (9-12 Torr), accompanied by hemocyanin oxygen saturations of 55-75%. Maximum forced activity for 10 min caused further reduction in these values. Thus hemocyanin is apparently not usually saturated with oxygen in these crayfish. Cardiac output, as estimated by the Fick principle, was high (at 20 degrees C, 236 ml x kg-1 x min-1 for routine activity and 969 ml x kg-1 x min-1 for forced activity). Evidence is presented that ventilation, rather than circulation, limits active oxygen uptake and scope for activity both above and below 20 degrees C.

scholarly journals Ventilasi dan Perfusi, serta Hubungan antara Ventilasi dan Perfusi

2019 ◽  
Vol 2 (1) ◽  
pp. 29
Author(s):  
Afrita Amalia Laitupa ◽  
Muhammad Amin
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Gas Exchange ◽  
Oxygen Absorption ◽  
Critical Determinant ◽  
Lung Diffusion ◽  
Diffusion Capacity ◽  
Blood Flows ◽  
Functional Factors ◽  
Ventilation And Perfusion

Lung is a place for gas exchange where ventilation and perfusion occurs. Ventilation is the first step where sequential process of inhalation and exhalation take place. Meanwhile perfusion as the other step facilitates the gas exchange and tissue supply need. Blood flows through the lungs are equals as the amount of cardiac output where the factors that control cardiac output are mainly peripheral factors, also control pulmonary blood flow. In general condition, pulmonary blood vessels act as a passive tube, which can be increased with the increasing pressure and narrowed the pressure drop. Oxygen absorption level from lungs into bloodstream is a critical determinant for functional capacity, and an important factor wheter in normal conditions (including exercise) or even in illness state. Lung diffusion capacity is influenced by several geometric and functional factors. Gravitation influence systematic gradient in ventilation and perfusion distribution. Ventilation and blood flow variations at horizontal level also occur due to intrinsic anatomic variations and vascular geometry, as well as the differences in airway and vascular smooth muscle response which modifies the distribution. The change of integrity intrapleural chamber, hydrostatic pressure and osmotic imbalance, malfunction of surfactants, other intrinsic weakness of the branching system in the form of a progressive airway, and all the things that could potentially damage the structure of the lung can cause ventilation and diffusion dysfunction.

Effect of small vs large muscle mass endurance training on maximal oxygen uptake in organ transplanted recipients

2021 ◽  
pp. 1-10
Author(s):  
Alessio del Torto ◽  
Carlo Capelli ◽  
Roberto Peressutti ◽  
Adriana di Silvestre ◽  
Ugolino Livi ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Endurance Training ◽  
Maximal Oxygen Consumption ◽  
Factors Affecting ◽  
Maximal Cardiac Output ◽  
Leg Cycling ◽  
Before And After ◽  
Large Muscle

Maximal oxygen consumption (V̇O2max) is impaired in heart (HTx), kidney (KTx), and liver (LTx) transplanted recipients and the contribution of the cardiovascular, central, and peripheral (muscular) factors in affecting V̇O2max improvement after endurance training (ET) has never been quantified in these patients. ET protocols involving single leg cycling (SL) elicit larger improvements of the peripheral factors affecting O2 diffusion and utilization than the double leg (DL) cycling ET. Therefore, this study aimed to compare the effects of SL-ET vs DL-ET on V̇O2max. We determined the DL-V̇O2max and maximal cardiac output before and after 24 SL-ET vs DL-ET sessions on 33 patients (HTx = 13, KTx = 11 and LTx = 9). The DL-V̇O2max increased by 13.8% ± 8.7 (p < 0.001) following the SL-ET, due to a larger maximal O2 systemic extraction; meanwhile, V̇O2max in DL-ET increased by 18.6% ± 12.7 (p < 0.001) because of concomitant central and peripheral adaptations. We speculate that in transplanted recipients, SL-ET is as effective as DL-ET to improve V̇O2max and that the impaired peripheral O2 extraction and/or utilization play an important role in limiting V̇O2max in these types of patients. Novelty: SL-ET increases V̇O2max in transplanted recipients because of improved peripheral O2 extraction and/or utilization. SL-ET is as successful as DL-ET to improve the cardiorespiratory fitness in transplanted recipients. The model of V̇O2max limitation indicates the peripheral factors as a remarkable limitation to the V̇O2max in these patients.

Circulatory changes in man during mild supine exercise

1961 ◽  
Vol 16 (2) ◽  
pp. 279-282 ◽  
Author(s):  
John T. Reeves ◽  
Robert F. Grover ◽  
Giles F. Filley ◽  
S. Gilbert Blount
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Oxygen Transport ◽  
Oxygen Extraction ◽  
Tissue Oxygen ◽  
Total Blood ◽  
Normal Men ◽  
Total Blood Flow ◽  
Extraction Mechanisms ◽  
Oxygen Difference

Cardiac output and femoral A-V oxygen difference were measured in each of seven normal men at rest and during several stints of supine exercise to investigate the mechanisms of oxygen transport for stepwise increments of oxygen uptake. The femoral A-V oxygen difference increased sharply for mild exercise and showed smaller further increase for heavier exercise stints. The pulmonary A-V oxygen difference followed a similar behavior where the changes were of smaller magnitude. For mild exercise, increasing oxygen transport apparently depends to a greater extent on increasing femoral tissue oxygen extraction and to a lesser extent on increased femoral and total blood flow. For heavier exertion, increasing oxygen transport depends to a greater extent on increasing flow and to a smaller extent on a widening tissue oxygen extraction. Mechanisms which are utilized to meet the increased metabolic demands of exercise depend in part upon the severity of the exertion. Cardiac output appears not to be a simple linear function of oxygen uptake for various metabolic demands ranging from rest to heavy exercise. Submitted on August 8, 1960

Systemic and regional hemodynamics after nitric oxide synthase inhibition: role of a neurogenic mechanism

1994 ◽  
Vol 267 (1) ◽  
pp. R84-R88 ◽  
Author(s):  
M. Huang ◽  
M. L. Leblanc ◽  
R. L. Hester
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Cardiac Output ◽  
No Synthase ◽  
Before And After ◽  
Regional Hemodynamics ◽  
Autonomic Blockade ◽  
Infusion Of Norepinephrine ◽  
Oxide Synthase

The study tested the hypothesis that the increase in blood pressure and decrease in cardiac output after nitric oxide (NO) synthase inhibition with N omega-nitro-L-arginine methyl ester (L-NAME) was partially mediated by a neurogenic mechanism. Rats were anesthetized with Inactin (thiobutabarbital), and a control blood pressure was measured for 30 min. Cardiac output and tissue flows were measured with radioactive microspheres. All measurements of pressure and flows were made before and after NO synthase inhibition (20 mg/kg L-NAME) in a group of control animals and in a second group of animals in which the autonomic nervous system was blocked by 20 mg/kg hexamethonium. In this group of animals, an intravenous infusion of norepinephrine (20-140 ng/min) was used to maintain normal blood pressure. L-NAME treatment resulted in a significant increase in mean arterial pressure in both groups. L-NAME treatment decreased cardiac output approximately 50% in both the intact and autonomic blocked animals (P < 0.05). Autonomic blockade alone had no effect on tissue flows. L-NAME treatment caused a significant decrease in renal, hepatic artery, stomach, intestinal, and testicular blood flow in both groups. These results demonstrate that the increase in blood pressure and decreases in cardiac output and tissue flows after L-NAME treatment are not dependent on a neurogenic mechanism.

scholarly journals Performance of a capnodynamic method estimating cardiac output during respiratory failure - before and after lung recruitment

2019 ◽  
Vol 34 (6) ◽  
pp. 1199-1207
Author(s):  
Thorir Svavar Sigmundsson ◽  
Tomas Öhman ◽  
Magnus Hallbäck ◽  
Eider Redondo ◽  
Fernando Suarez Sipmann ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Respiratory Failure ◽  
Reference Method ◽  
Hemodynamic Instability ◽  
Lung Lavage ◽  
Lung Recruitment ◽  
Recruitment Manoeuvre ◽  
Percentage Error ◽  
Before And After ◽  
The Right

AbstractRespiratory failure may cause hemodynamic instability with strain on the right ventricle. The capnodynamic method continuously calculates cardiac output (CO) based on effective pulmonary blood flow (COEPBF) and could provide CO monitoring complementary to mechanical ventilation during surgery and intensive care. The aim of the current study was to evaluate the ability of a revised capnodynamic method, based on short expiratory holds (COEPBFexp), to estimate CO during acute respiratory failure (LI) with high shunt fractions before and after compliance-based lung recruitment. Ten pigs were submitted to lung lavage and subsequent ventilator-induced lung injury. COEPBFexp, without any shunt correction, was compared to a reference method for CO, an ultrasonic flow probe placed around the pulmonary artery trunk (COTS) at (1) baseline in healthy lungs with PEEP 5 cmH2O (HLP5), (2) LI with PEEP 5 cmH2O (LIP5) and (3) LI after lung recruitment and PEEP adjustment (LIPadj). CO changes were enforced during LIP5 and LIPadj to estimate trending. LI resulted in changes in shunt fraction from 0.1 (0.03) to 0.36 (0.1) and restored to 0.09 (0.04) after recruitment manoeuvre. Bias (levels of agreement) and percentage error between COEPBFexp and COTS changed from 0.5 (− 0.5 to 1.5) L/min and 30% at HLP5 to − 0.6 (− 2.3 to 1.1) L/min and 39% during LIP5 and finally 1.1 (− 0.3 to 2.5) L/min and 38% at LIPadj. Concordance during CO changes improved from 87 to 100% after lung recruitment and PEEP adjustment. COEPBFexp could possibly be used for continuous CO monitoring and trending in hemodynamically unstable patients with increased shunt and after recruitment manoeuvre.

Central and peripheral adaptations of the gas transport system to one-leg training

1981 ◽  
Vol 59 (11) ◽  
pp. 1146-1154 ◽  
Author(s):  
S. G. Thomas ◽  
D. A. Cunningham ◽  
M. J. Plyley ◽  
D. R. Boughner ◽  
R. A. Cook
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Endurance Training ◽  
Maximal Oxygen Uptake ◽  
Enzyme Activities ◽  
Cardiovascular Responses ◽  
Cycle Ergometer ◽  
Left Ventricular ◽  
Enzyme Analysis ◽  
Ergometer Exercise

The role of central and peripheral adaptations in the response to endurance training was examined. Changes in cardiac structure and function, oxygen extraction, and muscle enzyme activities following one-leg training were studied.Eleven subjects (eight females, three males) trained on a cycle ergometer 4 weeks with one leg (leg 1), then 4 weeks with the second leg (leg 2). Cardiovascular responses to exercise with both legs and each leg separately were evaluated at entry (T1), after 4 weeks of training (T2), and after a second 4 weeks of training (T3). Peak oxygen uptake ([Formula: see text] peak) during exercise with leg 1 (T1 to T2 increased 19.8% (P < 0.05) and during exercise with leg 2 (T2 to T3 increased 16.9% (P < 0.05). Maximal oxygen uptake with both legs increased 7.9% from T1 to T2 and 9.4% from T2 to T3 (P < 0.05). During exercise at 60% of [Formula: see text] peak, cardiac output [Formula: see text] was increased significantly only when the trained leg was exercised. [Formula: see text] increased 12.2% for leg 1 between T1 and T2 and 13.0% for leg 2 between T2 and T3 (P < 0.05). M-mode echocardiographic assessment of left ventricular internal diameter at diastole and peak velocity of circumferential fibre shortening at rest or during supine cycle ergometer exercise at T1 and T3 revealed no training induced changes in cardiac dimensions or function. Enzyme analysis of muscle biopsy samples from the vastus lateralis (At T1, T2, T3) revealed no consistent pattern of change in aerobic (malate dehydrogenase and 3-hydroxyacyl-CoA dehydrogenase) or anaerobic (phosphofructokinase, lactate dehydroginase, and creatine kinase) enzyme activities. Increases in cardiac output and maximal oxygen uptake which result from short duration endurance training can be achieved, therefore, without measurable central cardiac adaptation. The absence of echocardio-graphically determined changes in cardiac dimensions and contractility and the absence of an increase in cardiac output during exercise with the nontrained leg following training of the contralateral limb support this conclusion.

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