scholarly journals A convenient form of closed-circuit respiratory apparatus for measuring simultaneously the carbon dioxide output and the oxygen intake over short or long periods

1929 ◽  
Vol 67 (4) ◽  
pp. 423-428 ◽  
Author(s):  
E. P. Poulton ◽  
W. R. Spurrell ◽  
E. C. Warner
Keyword(s):  
Carbon Dioxide ◽  
Closed Circuit ◽  
Oxygen Intake ◽  
Carbon Dioxide Output ◽  
Convenient Form ◽  
Respiratory Apparatus

scholarly journals The duration of the recovery period following strenuous muscular exercise

1933 ◽  
Vol 113 (783) ◽  
pp. 327-344 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Normal Values ◽  
Recovery Period ◽  
Oxygen Intake ◽  
Respiratory Metabolism ◽  
Carbon Dioxide Output ◽  
Steady Level ◽  
Made In

There are a variety of ways in which the duration of the recovery period after exercise can be determined. The method most frequently employed depends upon observations of the respiratory metabolism. This method has been chosen because the respiratory changes due to exercise can be followed with reasonable ease and accuracy, and because these changes are among the last of the more obvious effects of the exercise to disappear during recovery. In addition, interesting data concerning the effects of exercise on respiratory metabolism can be collected during the determination of the duration of the recovery period when this method is used. In determining the duration of the recovery period by observation of the respiratory metabolism, it is necessary to decide when the carbon dioxide output and oxygen intake have returned to their normal values and are no longer affected by the process of recovery from the exercise. This decision has been made in a variety of ways by different investigators. Some have made one or more pre-exercise determinations of the subject's basal oxygen intake and carbon dioxide output. Recovery was said to be complete when the carbon dioxide output and oxygen consumption returned to these values after exercise. Others found that the oxygen consumption did not return to the pre-exercise level within a reasonable length of time, but remained above normal for several hours. They considered that recovery was complete when the carbon dioxide output and oxygen intake returned to a steady level after exercise, even if the level was not the same as that before exercise.

scholarly journals Muscular exercise, lactic acid and the supply and utilisation of oxygen.— Parts VII–VIII

1924 ◽  
Vol 97 (682) ◽  
pp. 155-176 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Body Weight ◽  
Lactic Acid ◽  
The Body ◽  
Muscular Exercise ◽  
Oxygen Intake ◽  
Carbon Dioxide Output ◽  
Long Time ◽  
The Times ◽  
Ventilation Of The Lungs

(A) The relation between oxygen intake and severity of exertion . — When muscular exercise commences, the ventilation of the lungs, the oxygen intake and the carbon dioxide output rise rapidly, in a period of about 2½ minutes, to values characteristic of the severity of the exercise; at these values they remain approximately constant. If the exercise be moderate, i. e ., if the oxygen intake does not approach the maximum for the subject investigated, then the exercise may be continued for a long time: the body is able, so to speak, to provide the energy required “out of income.” If, however, the effort be excessive, the condition of exercise is not stable, the ventilation, the oxygen intake and the carbon dioxide output tend to attain their maximum values, and fatigue and exhaustion gradually or rapidly set in. The relation between these quantities and the magnitude of the effort made is clearly shown in Table I, especially in the series of 14 experiments made on A. V. H. running; at speeds from 2·86 to 4·7 metres per second. These results are plotted as double circles in fig. 1; the other points shown are the results obtained with S., W., and J. (who have approximately the same body-weight and build as A. V. H.), and with C. N. H. L. and H. L. (who are lighter). The observations on the two latter have been “reduced” to the same body-weight as A. V. H. before plotting. The running was on an open-air grass track, about 90 metres round, the speed being kept constant by an observer calling the times of successive laps. In every case the collection of expired gases was preceded by a sufficient foreperiod of exercise (2½ minutes or more) to ensure that a steady condition was reached. The following conclusions may be drawn from these observations:— (1) At low speeds the ventilation is small and the respiratory quotient is low: the oxygen supply is adequate to the needs of the body, lactic acid does not accumulate, and a steady state is soon attained.

scholarly journals THE RESPIRATORY QUOTIENT OF FROG NERVE DURING STIMULATION

1927 ◽  
Vol 11 (2) ◽  
pp. 175-191 ◽  
Author(s):  
Wallace O. Fenn
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Diffusion Coefficients ◽  
Time Course ◽  
Oxygen Intake ◽  
Dissociation Curve ◽  
Similar Time ◽  
High Co2 ◽  
Carbon Dioxide Output ◽  
Carbon Dioxide Dissociation Curve

1. By means of a differential volumeter the increased oxygen consumption and the increased carbon dioxide output of frog nerve during and after stimulation have been observed. 2. Measurements of the R.Q. of nerve by this method are complicated by the retention of carbon dioxide. Attempts were made to avoid this (a) by studying the nerves at high CO2 tensions to make the retention small and (b) by calculating the amount of CO2 retained from the carbon dioxide dissociation curve of nerve and applying this value as a correction. 3. The results of both those methods when averaged together give an R.Q. of the excess metabolism of 1.19 and an R.Q. of the resting nerve of 0.97. 4. Observations on the time course of the gas exchange during stimulation indicate a delay in the appearance of the extra carbon dioxide output relative to the oxygen intake. 5. Very similar time curves can be calculated from the diffusion coefficients and the solubilities of the oxygen and the carbon dioxide.

scholarly journals Muscular exercise, lactic acid, and the supply and utilisation of oxygen.—Parts IV-VI

1924 ◽  
Vol 97 (681) ◽  
pp. 84-138 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Gas Analysis ◽  
Muscular Exercise ◽  
Oxygen Intake ◽  
Left Hand ◽  
Carbon Dioxide Output ◽  
Flat Type ◽  
Wedge Shape ◽  
Douglas Bag ◽  
Prolonged Recovery

The method of studying the respiratory exchanges of man employed throughout our investigation has been that of the Douglas bag. No other method allows the same facility and accuracy in following a rapidly altering oxygen intake and carbon dioxide output. We have found it possible, during and after muscular exercise, to work with periods of collection of half a minute, and even, on occasions when it was necessary, of quarter of a minute. This makes it possible to analyse accurately the rapid alterations of oxygen intake and carbon dioxide output which occur at the beginning and at the end of muscular exercise. The gas analyses have been carried out by the ordinary Haldane’s gas analysis apparatus (large laboratory type) except in certain later experiments, where a modification (in which the gas is bubbled through the pyrogallol) introduced by D. T. Harris was used. The bags employed have been of various types, varying in capacity from 30 to 2,000 litres. They have all—some 25 of them—been made for us specially by Messrs. C. Macintosh & Co., of Cambridge Street, Manchester, and have proved an essential part of our equipment. We are glad to take this opportunity of expressing to the Company, and especially to Mr. J. S. Corker, a director, our most sincere thanks for the courtesy, completeness and expedition with which all our needs have been supplied. Some of these bags especially the smallest, but including two of 500 litres capacity, have been of the ordinary flat type as used by Douglas. Others of 150 to 300 litres capacity, employed for collecting the expired air during running or walking, have been of a truncated wedge shape, carried like a Rücksack on the back, with a sidepipe low down on the left-hand side, to enable the tap to be carried freely the left hand. (See fig. 1.) A third type (400 and 500 litres), roughly cubical in shape, was employed for prolonged collection of expired gases during recovery from muscular exercise. A fourth type (1,000 and 2,000 litres) was used, in experiments to be described later, to contain the inspired gas mixture, which on expiration was collected in bags of the other types. These may be used also to follow very prolonged recovery.

Interaction of Mental Factors with Hypercapnic Ventilatory Drive in Man

1977 ◽  
Vol 52 (3) ◽  
pp. 269-275 ◽  
Author(s):  
J. R. A. Rigg ◽  
E. M. Inman ◽  
N. A. Saunders ◽  
S. R. Leeder ◽  
N. L. Jones
Keyword(s):  
Carbon Dioxide ◽  
Tidal Volume ◽  
Task Performance ◽  
Mental Arithmetic ◽  
Oxygen Intake ◽  
Air Breathing ◽  
Carbon Dioxide Output ◽  
Ventilatory Frequency ◽  
Carbon Dioxide Rebreathing ◽  
Ventilatory Drive

1. The effect of mental arithmetic tasks on ventilation, breathing pattern, oxygen intake and carbon dioxide output was studied during air breathing and carbon dioxide rebreathing in healthy subjects. 2. Ventilation and breathing frequency increased significantly on performance of the task during 4 min air breathing and 4 min rebreathing; tidal volume was unchanged. The slopes of the ventilatory, frequency and tidal volume responses to carbon dioxide changed little during task performance. 3. During 15 min air breathing, oxygen intake was unchanged with task performance. Carbon dioxide output increased significantly with task performance, as a result of wash-out of carbon dioxide from body stores by the increased ventilation. 4. Mental arithmetic had no effect on the coefficients of variation of the slope and position variables of the ventilatory, frequency and tidal volume responses to carbon dioxide. It is concluded that task performance does not improve the reproducibility of these responses.

Global carbon dioxide output of volcanic lakes in the Azores archipelago, Portugal

2021 ◽  
pp. 106835
Author(s):  
César Andrade ◽  
Fátima Viveiros ◽  
J. Virgílio Cruz ◽  
Rui Coutinho
Keyword(s):  
Carbon Dioxide ◽  
Azores Archipelago ◽  
Carbon Dioxide Output ◽  
Volcanic Lakes ◽  
Global Carbon

scholarly journals Investigation and Possibilities of Reuse of Carbon Dioxide Absorbent Used in Anesthesiology

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5052
Author(s):  
Bartłomiej Rogalewicz ◽  
Agnieszka Czylkowska ◽  
Piotr Anielak ◽  
Paweł Samulkiewicz
Keyword(s):  
Carbon Dioxide ◽  
Thermal Properties ◽  
Powder Diffraction ◽  
Soda Lime ◽  
Closed Circuit ◽  
Carbon Dioxide Absorption ◽  
X Ray ◽  
Kinetics Of ◽  
Carbon Dioxide Absorbent

Absorbents used in closed and semi-closed circuit environments play a key role in preventing carbon dioxide poisoning. Here we present an analysis of one of the most common carbon dioxide absorbents—soda lime. In the first step, we analyzed the composition of fresh and used samples. For this purpose, volumetric and photometric analyses were introduced. Thermal properties and decomposition patterns were also studied using thermogravimetric and X-ray powder diffraction (PXRD) analyses. We also investigated the kinetics of carbon dioxide absorption under conditions imitating a closed-circuit environment.

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.

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