A mouthpiece face mask for the exercising dog

1988 ◽  
Vol 64 (5) ◽  
pp. 2240-2244 ◽  
Author(s):  
J. Ampil ◽  
J. I. Carlin ◽  
R. L. Johnson
Keyword(s):  
Cardiac Output ◽  
Lung Volume ◽  
Dead Space ◽  
Face Mask ◽  
Diffusing Capacity ◽  
Lung Volumes ◽  
Fabrication Procedure ◽  
Time Required ◽  
Anesthesia Time ◽  
Rebreathing Method

To develop a rebreathing method for lung volumes, cardiac output with acetylene, and CO diffusing capacity in awake exercising dogs, we have modified and adapted the low-dead-space mask of Montefusco et al. (Angiology 34: 340–354, 1983). We have simplified the fabrication procedure, allowing the physiologist to make the device from parts that can be prefabricated before each dog is custom fitted with the mouthpiece. This decreases the anesthesia time required to custom fit the mouthpiece to each dog. We have also reduced the weight of the mask, making it more tolerable during exercise. We have validated that the mask is leak-free by having the dog rebreathe an inert insoluble gas, He, until equilibration is achieved between the bag and lung. Preliminary measurements of lung volume, cardiac output with acetylene, and CO diffusing capacity have been made during exercise.

Effects of altering ventilation on steady-state diffusing capacity for carbon monoxide

1963 ◽  
Vol 18 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Kaye H. Kilburn ◽  
Harry A. Miller ◽  
John E. Burton ◽  
Ronald Rhodes
Keyword(s):  
Carbon Monoxide ◽  
Steady State ◽  
Tidal Volume ◽  
Lung Volume ◽  
Dead Space ◽  
Control Level ◽  
Alveolar Ventilation ◽  
Positive Pressure ◽  
Diffusing Capacity ◽  
Fixed Rate

Alterations in the steady-state diffusing capacity for carbon monoxide (Dco) by the method of Filley, MacIntosh, and Wright, produced by sequential changes in the pattern of breathing were studied in anesthetized, paralyzed, artificially ventilated dogs. The Dco of paralyzed, artificially ventilated control dogs did not differ significantly during 3 hr from values found in conscious and anesthetized controls. A fivefold increase in tidal volume without changing frequency of breathing raised alveolar ventilation and CO uptake 500% and Dco 186%. A high correlation between tidal volume and Dco was noted during reciprocal alterations of tidal volume and rate which maintained minute volume. The Dco appeared to fall when alveolar ventilation was tripled by increments of rate with a fixed-tidal volume, despite a 63% increase in CO uptake. Doubling end-expiratory lung volume by positive pressure breathing without altering tidal volume or rate did not affect Dco. The addition of 100 ml of external dead space with rate and tidal volume constant decreased Dco to 42% of control level, however, stepwise reduction of dead space from 100 ml to 0 in two dogs failed to change Dco. Added dead space equal to frac12 tidal volume (170 ml) reduced Dco to 25% of control in two dogs with a return to control with removal of dead space. Thus, in paralyzed artificially ventilated dogs, tidal volume appears to be the principal ventilatory determinant of steady-state Dco. Dco is minimally affected by increases in alveolar ventilation with a constant tidal volume effected by increasing the frequency of breathing. Prolonged ventilation, at fixed rate and volume, and increased dead space either did not effect, or they reduced Dco, perhaps by rendering less uniform the distribution of gas, and blood in the lungs. Although lung volume was doubled by positive-pressure breathing, pulmonary capillary blood volume was probably reduced to produce opposing effects on diffusing capacity and no net change. Submitted on March 14, 1962

Regional diffusing capacity in normal lungs during a slow exhalation

1982 ◽  
Vol 52 (6) ◽  
pp. 1487-1492 ◽  
Author(s):  
N. R. MacIntyre ◽  
J. A. Nadel
Keyword(s):  
Carbon Monoxide ◽  
Lung Volume ◽  
Vital Capacity ◽  
Normal Subjects ◽  
Lower Half ◽  
Diffusing Capacity ◽  
Lung Volumes ◽  
Lower Volume ◽  
Xenon 133 ◽  
Normal Lungs

From an analysis of carbon monoxide uptake and xenon-133 distribution after two bolus inhalations of these gases, we calculated regional diffusing capacity in the upper and lower volume halves of the lungs during the middle 60% of an exhaled vital capacity in five seated normal subjects. We found that the regional diffusing capacity of the upper half of the lungs was 11.6 +/- 4.2 (mean +/- SD) ml.min-1.Torr-1 and that the regional diffusing capacity of the lower half of the lungs was 24.4 +/- 2.4 ml.min-1.Torr-1 after 25% of the vital capacity had been exhaled. These values remained relatively constant as lung volume decreased from 25 to 75% of the exhaled vital capacity. Diffusing capacity in the upper half of the lungs ranged from 9.4 to 12.4 ml.min-1.Torr-1 during exhalation, and in the lower half of the lungs from 21.0 to 28.6 ml.min-1.Torr-1 during exhalation. These results suggest that total lung diffusing capacity remains relatively constant over this midrange of lung volumes and that this occurs because the regional diffusing capacities in both the upper and lower halves of the lungs remain relatively constant.

scholarly journals Simultaneous Measurement of Pulmonary Diffusing Capacity for CO and Cardiac Output by a Rebreathing Method in Patients with Pulmonary Diseases.

1995 ◽  
Vol 34 (5) ◽  
pp. 330-338 ◽  
Author(s):  
Hifumi TAKAHASHI ◽  
Katsuyoshi IWABUCHI ◽  
Yukiharu KUDO ◽  
Hitonobu TOMOIKE ◽  
Kyuichi NIIZEKI ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Simultaneous Measurement ◽  
Pulmonary Diseases ◽  
Diffusing Capacity ◽  
Pulmonary Diffusing Capacity ◽  
Rebreathing Method

Hysteresis in the relation between diffusing capacity of the lung and lung volume

1980 ◽  
Vol 49 (4) ◽  
pp. 566-570 ◽  
Author(s):  
S. S. Cassidy ◽  
M. Ramanathan ◽  
G. L. Rose ◽  
R. L. Johnson
Keyword(s):  
Carbon Monoxide ◽  
Functional Residual Capacity ◽  
Lung Volume ◽  
Total Lung Capacity ◽  
Breath Holding ◽  
Residual Volume ◽  
Diffusing Capacity ◽  
Lung Volumes ◽  
Lung Capacity ◽  
Residual Capacity

The diffusing capacity of the lung for carbon monoxide (DLCO) varies directly with lung volume (VA) when measured during a breath-holding interval. DLCO measured during a slow exhalation from total lung capacity (TLC) to functional residual capacity (FRC) does not vary as VA changes. Since VA is reached by inhaling during breath holding and by exhaling during the slow exhalation maneuver, we hypothesized that the variability in the relation between DLCO and VA was due to hysteresis. To test this hypothesis, breath-holding measurements of DLCO were made at three lung volumes, both when VA was reached by inhaling from residual volume (RV) and when Va was reached by exhaling from TLC. At 72% TLC, DLCO was 22% higher when VA was reached by exhalation compared to inhalation (P < 0.02). At 52% TLC, DLCO was 19% higher when VA was reached by exhalation compared to exhalation (P < 0.005). DCLO measured during a slow exhalation fell on the exhalation limb of the CLCO/VA curve. these data indicate that there is hysteresis in DLCO with respect to lung volume.

LUNG VOLUMES OF NORMAL AND ASTHMATIC CHILDREN

PEDIATRICS ◽  
1959 ◽  
Vol 23 (3) ◽  
pp. 507-519
Author(s):  
John F. Andrewes ◽  
Daniel H. Simmons
Keyword(s):  
Allergic Rhinitis ◽  
Functional Residual Capacity ◽  
Lung Volume ◽  
Bronchial Obstruction ◽  
Residual Volume ◽  
Normal Children ◽  
Lung Volumes ◽  
Asthmatic Children ◽  
Residual Capacity ◽  
Time Required

Measurements of the various lung volumes were carried out with 27 normal children, 21 asthmatic children and 4 with allergic rhinitis. The asthmatic children had increases in functional residual capacity and residual volume. There was a significant increase in the time required for intrapulmonary mixing of gas in the asthmatic subjects. A biphasic character to the "wash-out" curves in both normal and asthmatic subjects was shown. It was considered, though not proved, that the increases in lung volume were due to the presence of bronchial obstruction.

Methacholine-induced bronchoconstriction in dogs: effects of lung volume and O3 exposure

1988 ◽  
Vol 65 (6) ◽  
pp. 2679-2686 ◽  
Author(s):  
S. T. Kariya ◽  
S. A. Shore ◽  
W. A. Skornik ◽  
K. Anderson ◽  
R. H. Ingram ◽  
...  
Keyword(s):  
Lung Volume ◽  
Maximal Response ◽  
Maximal Effect ◽  
Response Curves ◽  
Lung Volumes ◽  
Before And After ◽  
Residual Capacity ◽  
Induced Changes ◽  
Conducting Airways ◽  
Concentration Response Curve

The maximal effect induced by methacholine (MCh) aerosols on pulmonary resistance (RL), and the effects of altering lung volume and O3 exposure on these induced changes in RL, was studied in five anesthetized and paralyzed dogs. RL was measured at functional residual capacity (FRC), and lung volumes above and below FRC, after exposure to MCh aerosols generated from solutions of 0.1-300 mg MCh/ml. The relative site of response was examined by magnifying parenchymal [RL with large tidal volume (VT) at fast frequency (RLLS)] or airway effects [RL with small VT at fast frequency (RLSF)]. Measurements were performed on dogs before and after 2 h of exposure to 3 ppm O3. MCh concentration-response curves for both RLLS and RLSF were sigmoid shaped. Alterations in mean lung volume did not alter RLLS; however, RLSF was larger below FRC than at higher lung volumes. Although O3 exposure resulted in small leftward shifts of the concentration-response curve for RLLS, the airway dominated index of RL (RLSF) was not altered by O3 exposure, nor was the maximal response using either index of RL. These data suggest O3 exposure does not affect MCh responses in conducting airways; rather, it affects responses of peripheral contractile elements to MCh, without changing their maximal response.

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