scholarly journals Impaired systemic oxygen extraction long after mild COVID-19: potential perioperative implications

2021 ◽  
Author(s):  
Paul M. Heerdt ◽  
Ben Shelley ◽  
Inderjit Singh
Keyword(s):  
Oxygen Extraction ◽  
Systemic Oxygen

Arterio-venous gradients of free energy change for assessment of systemic and splanchnic perfusion in cardiac surgery patients

Perfusion ◽  
2006 ◽  
Vol 21 (6) ◽  
pp. 353-360 ◽  
Author(s):  
Jan-Peter Braun ◽  
Stephan M Jakob ◽  
Thomas Volk ◽  
Ulrich R Doepfmer ◽  
Maryam Moshirzadeh ◽  
...  
Keyword(s):  
Blood Flow ◽  
Free Energy ◽  
Cardiac Surgery ◽  
Free Energy Change ◽  
Energy Change ◽  
Splanchnic Blood Flow ◽  
Oxygen Extraction ◽  
Organ Perfusion ◽  
Systemic Oxygen ◽  
Mixed Venous

Objective: Adequacy of organ perfusion depends on sufficient oxygen supply in relation to the metabolic needs. The aim of this study was to evaluate the relationship between gradients of free energy change, and the more commonly used parameter for the evaluation of the adequacy of organ perfusion, such as oxygen-extraction in patients undergoing valve replacement surgery using normothermic cardiopulmonary bypass (CPB). Methods: In 43 cardiac patients, arterial, mixed venous, and hepato-venous blood samples were taken synchronously after induction of anaesthesia (preCPB), during CPB, and 2 and 7 h after admission to the intensive care unit (ICU+2, ICU+7). Blood gas analysis, cardiac output, and hepato-splanchnic blood flow were measured. Free energy change gradients between mixed venous and arterial (-ΔΔG(v-a)) and hepato-venous and arterial (-ΔΔG(hv-a)) compartments were calculated. Measurements and results: Cardiac index (CI) increased from 1.9 (0.7) to 2.8 (1.3) L/min/m (median, inter-quartile range) (p =0.001), and hepato-splanchnic blood flow index (HBFI) from 0.6 (0.22) to 0.8 (0.53) L/min/m (p =0.001). Despite increasing flow, systemic oxygen extraction increased after CPB from 24 (10)% to 35 (10)% at ICU+2 (p =0.002), and splanchnic oxygen extraction increased during CPB from 37 (19)% to 52 (14)% (p =0.001), and remained high thereafter. After CPB, high splanchnic and systemic gradients of free energy change gradients were associated with high splanchnic and systemic oxygen extraction, respectively (p =0.001, 0.033, respectively). Conclusion: Gradients of free energy change may be helpful in characterising adequacy of perfusion in cardiac surgery patients independently from measurements or calculations of data from oxygen transport.

scholarly journals Systemic oxygen extraction during exercise at high altitude

2015 ◽  
Vol 114 (4) ◽  
pp. 677-682 ◽  
Author(s):  
D.S. Martin ◽  
A. Cobb ◽  
P. Meale ◽  
K. Mitchell ◽  
M. Edsell ◽  
...  
Keyword(s):  
High Altitude ◽  
Oxygen Extraction ◽  
Systemic Oxygen

Systemic oxygen extraction during incremental exercise in patients with severe chronic obstructive pulmonary disease

1998 ◽  
Vol 78 (3) ◽  
pp. 201-207 ◽  
Author(s):  
David A. Oelberg ◽  
Benjamin D. Medoff ◽  
Deborah H. Markowitz ◽  
Paul P. Pappagianopoulos ◽  
Leo C. Ginns ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Incremental Exercise ◽  
Oxygen Extraction ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Systemic Oxygen

Systemic vascular distensibility relates to exercise capacity in connective tissue disease

Rheumatology ◽  
2020 ◽  
Author(s):  
Inderjit Singh ◽  
Rudolf K F Oliveira ◽  
Robert Naeije ◽  
William M Oldham ◽  
Mariana Faria-Urbina ◽  
...  
Keyword(s):  
Exercise Capacity ◽  
Cardiopulmonary Exercise Testing ◽  
Exercise Intolerance ◽  
Oxygen Extraction ◽  
Cardiopulmonary Disease ◽  
Aerobic Exercise Capacity ◽  
Systemic Oxygen ◽  
And Gender ◽  
Normal Controls

Abstract Objective Exercise intolerance is a common clinical manifestation of CTD. Frequently, CTD patients have associated cardio-pulmonary disease, including pulmonary hypertension or heart failure that impairs aerobic exercise capacity (pVO2). The contribution of the systemic micro-vasculature to reduced exercise capacity in CTD patients without cardiopulmonary disease has not been fully described. In this study, we sought to examine the role of systemic vascular distensibility, α in reducing exercise capacity (i.e. pVO2) in CTD patients. Methods Systemic and pulmonary vascular distensibility, α (%/mmHg) was determined from multipoint systemic pressure-flow plots during invasive cardiopulmonary exercise testing with pulmonary and radial arterial catheters in place in 42 CTD patients without cardiopulmonary disease and compared with 24 age and gender matched normal controls. Results During exercise, systemic vascular distensibility, α was reduced in CTD patients compared with controls (0.20 ± 0.12%/mmHg vs 0.30 ± 0.13%/mmHg, P =0.01). The reduced systemic vascular distensibility α, was associated with impaired stroke volume augmentation. On multivariate analysis, systemic vascular distensibility, α was associated with a decreased exercise capacity (pVO2) and decreased systemic oxygen extraction. Conclusion Systemic vascular distensibility, α is associated with impaired systemic oxygen extraction and decreased aerobic capacity in patients with CTD without cardiopulmonary disease.

Postnatal changes in critical cardiac output and oxygen transport in conscious lambs

1987 ◽  
Vol 253 (1) ◽  
pp. H100-H106 ◽  
Author(s):  
J. T. Fahey ◽  
G. Lister
Keyword(s):  
Cardiac Output ◽  
Oxygen Consumption ◽  
Oxygen Transport ◽  
Oxygen Extraction ◽  
Base Line ◽  
Arterial Lactate ◽  
Acid Accumulation ◽  
Systemic Oxygen ◽  
The Right ◽  
Lower Cardiac Output

We lowered cardiac output progressively in a controlled, stepwise fashion in conscious, unsedated lambs to determine the critical cardiac output or systemic oxygen delivery (the level at which oxygen consumption decreased abruptly). With the use of incremental inflation of a balloon-tipped catheter placed in the right atrium to lower cardiac output, we examined the response of oxygen consumption, systemic oxygen transport, fractional oxygen extraction, arterial lactate, and blood pressure. We studied lambs at 2 (n = 5), 4 (n = 5), and 8 wk (n = 6) of age and found that the 4-wk-old lambs reached critical values of cardiac output and systemic oxygen transport with the smallest proportional decreases from base-line values. Therefore, the 4-wk-old lambs were the least tolerant of acute decreases in cardiac output. We also found that fractional oxygen extraction was able to increase even after critical systemic oxygen transport was achieved. Furthermore, we found at every age that lactic acid accumulation began when the critical level of cardiac output was reached.

scholarly journals Impaired systemic oxygen extraction in treated exercise pulmonary hypertension: a new engine in an old car?

2018 ◽  
Vol 8 (1) ◽  
pp. 204589321875532 ◽  
Author(s):  
Mariana Faria-Urbina ◽  
Rudolf K.F. Oliveira ◽  
Sergio A. Segrera ◽  
Laurie Lawler ◽  
Aaron B. Waxman ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Pulmonary Hypertension ◽  
Oxygen Uptake ◽  
Maximum Oxygen Uptake ◽  
Oxygen Extraction ◽  
Pulmonary Hemodynamics ◽  
Maximum Exercise ◽  
Systemic Oxygen

Ambrisentan in 22 patients with pulmonary hypertension diagnosed during exercise (ePH) improved pulmonary hemodynamics; however, there was only a trend toward increased maximum oxygen uptake (VO2max) secondary to decreased maximum exercise systemic oxygen extraction (Ca-vO2). We speculate that improved pulmonary hemodynamics at maximum exercise “unmasked” a pre-existing skeletal muscle abnormality.

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