Contribution of Alveolar Ventilation, Pulmonary Blood Flow and Venous Gas Concentrations to Oxygen Uptake and Carbon Dioxide Output

1962 ◽  
Vol 54 ◽  
pp. 5-23
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Oxygen Uptake ◽  
Pulmonary Blood Flow ◽  
Alveolar Ventilation ◽  
Carbon Dioxide Output

PULMONARY FUNCTION, DEDUCED FROM URINARY NITROGEN TENSIONS

PEDIATRICS ◽  
1967 ◽  
Vol 40 (6) ◽  
pp. 937-938
Author(s):  
M. E. A.
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Pulmonary Function ◽  
Partial Pressure ◽  
Urine Sample ◽  
Pulmonary Blood Flow ◽  
Lung Perfusion ◽  
Alveolar Ventilation ◽  
Arterial Oxygen ◽  
Urinary Nitrogen

THE elegant studies reported by Led-better, Homma, and Farhi in this issue are entitled `'Readjustment in Distribution of Alveolar Ventilation and Lung Perfusion in the Newborn." It must come as a great surprise to the reader to discover that the only measurement actually made was the partial pressure of nitrogen in the infants' urine. How could one conclude that there were significant imbalances between the distribution of alveolar ventilation and pulmonary blood flow (VA/Q) in the first days of life in normal infants from a urine sample? It is all the more astounding in the light of previous (and seemingly more direct) studies of alveolar-arterial oxygen and carbon dioxide differences which led others to consider the differences largely explained by anatomical right-to-left shunts.

Breathing in brief exercise

1960 ◽  
Vol 15 (4) ◽  
pp. 583-588 ◽  
Author(s):  
F. N. Craig ◽  
E. G. Cummings
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Metabolic Cost ◽  
Carbon Dioxide Tension ◽  
Minute Volume ◽  
Carbon Dioxide Output ◽  
Respiratory Minute Volume ◽  
Before And After

Two men ran for 20 or 60 seconds while inhaling air, oxygen or 4% carbon dioxide. Inspired respiratory minute volume was determined for each breath. Ventilation increased suddenly in the first breath with minimal changes in end-expiratory carbon dioxide tension and respiratory exchange ratio to a rate that remained constant for 20 seconds before increasing further. The rate of carbon dioxide output was uniform during the first 20 seconds. A 12% grade did not increase ventilation or oxygen uptake during runs of 20 seconds, but in the first minute of recovery, ventilation was 64% greater than after level runs. Inhalation of oxygen inhibited ventilation by 24% in the 20-second periods before and after the end of a 60-second run. Inhalation of carbon dioxide begun at rest produced increments in ventilation and end-expiratory carbon dioxide tension that varied little during running and recovery. In the 20-second runs ventilation varied with speed but appeared independent of ultimate metabolic cost. Submitted on January 21, 1960

Use of respiratory quotients in assessment of aerobic work capacity

1962 ◽  
Vol 17 (1) ◽  
pp. 47-50 ◽  
Author(s):  
B. Issekutz ◽  
N. C. Birkhead ◽  
K. Rodahl
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Work Load ◽  
Work Capacity ◽  
Bicycle Ergometer ◽  
Carbon Dioxide Output ◽  
Ergometer Test ◽  
Aerobic Work Capacity ◽  
Bicycle Ergometer Test ◽  
Better Than

Oxygen uptake and carbon dioxide output were measured in 32 untrained subjects during exercise on the bicycle ergometer. It was shown that the work respiratory quotient (RQ) under standardized conditions can be used as a measure of physical fitness. ΔRQ (work RQ minus 0.75) increases logarithmically with the work load and maximal O2 uptake is reached at a ΔRQ value of 0.40. This observation offered the possibility of predicting the maximal O2 uptake of a person, based on the measurement of RQ during a single bicycle ergometer test at a submaximal load. For each work RQ between 0.95 and 1.15 a factor was presented, together with the aid of a simple equation, which gave a good approximation (generally better than ±10%) of the maximal O2 uptake.

scholarly journals A SYSTEM FOR THE CONTINUOUS MEASUREMENT OF OXYGEN UPTAKE AND CARBON DIOXIDE OUTPUT IN ARTIFICIALLY VENTILATED PATIENTS

1983 ◽  
Vol 55 (8) ◽  
pp. 791-800 ◽  
Author(s):  
A.M. HENDERSON ◽  
P.C. FORRESTER ◽  
R.F. ARMSTRONG ◽  
C.A. MOSSE ◽  
D. HALSALL
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Continuous Measurement ◽  
Carbon Dioxide Output ◽  
Ventilated Patients

Intratest reliability and test–retest reproducibility of the oxygen uptake efficiency slope in healthy participants

2009 ◽  
Vol 16 (4) ◽  
pp. 493-498 ◽  
Author(s):  
Christophe Van Laethem ◽  
Johan De Sutter ◽  
Wim Peersman ◽  
Patrick Calders
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Minute Ventilation ◽  
Exercise Duration ◽  
Peak Oxygen Uptake ◽  
Exercise Tests ◽  
Uptake Efficiency ◽  
Carbon Dioxide Output ◽  
Oxygen Uptake Efficiency Slope ◽  
Healthy Participants

Background The oxygen uptake efficiency slope (OUES) is a newer ventilatory exercise parameter, used in the evaluation of healthy participants and patients with cardiovascular disease. However, few data about the reliability and reproducibility of OUES are available. Our study assessed intratest reliability and test-retest reproducibility of OUES in healthy participants. Design and methods Eighteen participants (age 28 ± 6 years, BMI 22.1 ± 1.9 kg/m2, 10 men) performed two identical maximal exercise tests on a bicycle ergometer. To assess test-retest reproducibility, we performed Bland-Altman analysis and calculated the coefficient of repeatability of the main ventilatory variables. Results OUES remained stable during the second part of the exercise test. Mean values varied 2.4 ± 4.0% between OUES calculated at 70% (OUES70) and at 100% of exercise duration. Mean variation decreased to 1.4 ± 2.3% when OUES was calculated at 90% of exercise duration (OUES90). The Bland-Altman 95% limits of agreement for OUES90 were +3 and –6%, those for OUES70 were +11 and –8%. The coefficient of repeatability for OUES was 597 ml/min or 18.7% of the average value of repeated OUES measurements. These results were similar to those of peak oxygen uptake and minute ventilation/carbon dioxide output. However, the test-retest reproducibility for submaximal-derived values of OUES was lower, as we noted higher coefficients of repeatability for OUES90 and OUES70, increasing up to 27% of the average of repeated values. Conclusion OUES shows excellent intratest reliability and has a test-retest reproducibility that is similar to that of peak oxygen uptake and minute ventilation/carbon dioxide output slope. However, its reproducibility becomes higher when it is calculated from increasing levels of achieved exercise intensity.

Alveolar ventilation and pulmonary blood flow: the V?A/Q? concept

2003 ◽  
Vol 29 (8) ◽  
pp. 1229-1232 ◽  
Author(s):  
Enrico Calzia ◽  
Peter Radermacher
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Alveolar Ventilation

Changes in Ventilation, Oxygen Uptake, and Carbon Dioxide Output during Recovery from Isoflurane Anesthesia

1989 ◽  
Vol 70 (5) ◽  
pp. 737-741 ◽  
Author(s):  
M. J. Clofolo ◽  
F. Clergue ◽  
C. Devillers ◽  
M. Ben Ammar ◽  
P. Viars
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Carbon Dioxide Output ◽  
Isoflurane Anesthesia

Physiological responses and air consumption during simulated firefighting tasks in a subway system

2010 ◽  
Vol 35 (5) ◽  
pp. 671-678 ◽  
Author(s):  
F. Michael Williams-Bell ◽  
Geoff Boisseau ◽  
John McGill ◽  
Andrew Kostiuk ◽  
Richard L. Hughson
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Energy Requirement ◽  
Average Energy ◽  
Peak Oxygen Uptake ◽  
Search And Rescue ◽  
Moderate Intensity ◽  
Physiological Strain ◽  
Carbon Dioxide Output ◽  
Subway System

Professional firefighters (33 men, 3 women), ranging in age from 30 to 53 years, participated in a simulation of a subway system search and rescue while breathing from their self-contained breathing apparatus (SCBA). We tested the hypothesis that during this task, established by expert firefighters to be of moderate intensity, the rate of air consumption would exceed the capacity of a nominal 30-min cylinder. Oxygen uptake, carbon dioxide output, and air consumption were measured with a portable breath-by-breath gas exchange analysis system, which was fully integrated with the expired port of the SCBA. The task involved descending a flight of stairs, walking, performing a search and rescue, retreat walking, then ascending a single flight of stairs to a safe exit. This scenario required between 9:56 and 13:24 min:s (mean, 12:10 ± 1:10 min:s) to complete, with an average oxygen uptake of 24.3 ± 4.5 mL·kg–1·min–1 (47 ± 10 % peak oxygen uptake) and heart rate of 76% ± 7% of maximum. The highest energy requirement was during the final single-flight stair climb (30.4 ± 5.4 mL·kg–1·min–1). The average respiratory exchange ratio (carbon dioxide output/oxygen uptake) throughout the scenario was 0.95 ± 0.08, indicating a high carbon dioxide output for a relatively moderate average energy requirement. Air consumption from the nominal “30-min” cylinder averaged 51% (range, 26%–68%); however, extrapolation of these rates of consumption suggested that the low-air alarm, signalling that only 25% of the air remains, would have occurred as early as 11 min for an individual with the highest rate of air consumption, and at 16 min for the group average. These data suggest that even the moderate physical demands of walking combined with search and rescue while wearing full protective gear and breathing through the SCBA impose considerable physiological strain on professional firefighters. As well, the rate of air consumption in these tasks classed as moderate, compared with high-rise firefighting, would have depleted the air supply well before the nominal time used to describe the cylinders.

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