Bronchospirometric studies of lung volumes, ventilation/perfusion ratios and diffusion

1965 ◽  
Vol 20 (1) ◽  
pp. 79-86 ◽  
Author(s):  
E. M. Cree ◽  
H. K. Rasmussen ◽  
F. Wright ◽  
J. K. Curtis
Keyword(s):  
Breath Holding ◽  
Physiological Changes ◽  
Diffusing Capacity ◽  
Lung Volumes ◽  
Nitrogen Washout ◽  
Pulmonary Capillary Blood Flow ◽  
Pulmonary Capillary ◽  
Pulmonary Capillary Blood ◽  
First Time ◽  
And Diffusion

Bilateral bronchospirometric nitrogen washout studies were used for the first time to calculate ventilation/perfusion ratios for the well and poorly ventilated areas in individual lungs. Results were compared with washout studies on both lungs measured together. Data suitable for analysis were obtained from seven patients with chronic lung disease. It was demonstrated that this technique for determining simultaneous ventilation/perfusion ratios for each lung gave accurate and detailed physiological changes. Comparison of the sum of average values for pulmonary capillary blood flow when both lungs were measured together by the same nitrogen washout technique showed a variation within the accepted 10% error for cardiac output. Diffusion for the separate lungs, measured by the carbon monoxide breath-holding method, gave values which correlated with lung volumes. bronchospirometry; nitrogen washout; diffusing capacity Submitted on November 22, 1963

Microvascular injury distal to unilateral pulmonary artery occlusion

1981 ◽  
Vol 51 (4) ◽  
pp. 845-851 ◽  
Author(s):  
R. L. Johnson ◽  
S. S. Cassidy ◽  
M. Haynes ◽  
R. L. Reynolds ◽  
W. Schulz
Keyword(s):  
Pulmonary Artery ◽  
Left Lung ◽  
Left Pulmonary Artery ◽  
Artery Occlusion ◽  
Diffusing Capacity ◽  
Pulmonary Capillary Blood Flow ◽  
Pulmonary Capillary ◽  
Pulmonary Capillary Blood ◽  
Rebreathing Method ◽  
Unilateral Pulmonary Artery Occlusion

We explored three questions: 1) does edema fluid accumulate distal to temporary unilateral pulmonary artery occlusion (TUPAO); 2) if so how rapidly does it accumulate; and 3) how is it affected by positive end-expiratory pressure (PEEP)? Using a tracheal divider we measured pulmonary capillary blood flow (Qc), tissue volume (Vt), and diffusing capacity (DLCO) in each lung with a rebreathing method. After control measurements in 12 dogs, the left pulmonary artery was occluded and measurements were repeated at intervals during 4 h of occlusion and 30 min after release of the occlusion. Six of the dogs were ventilated with 10 cmH2O PEEP. Finally the lungs were removed, weighed, and fixed for histology. TUPAO caused a 29% increase in Vt of the left lung without PEEP and a 59% increase with PEEP. After release of the occlusion, Qc and DLCO in the left lung returned to control levels within 30 min in dogs not on PEEP but remained depressed in dogs ventilated with PEEP even though PEEP was removed. At postmortem the left lung weighed more than expected in both groups of dogs but was significantly heavier in those on PEEP. Histology confirmed bronchovascular cuffing with edema and hemorrhage.

scholarly journals Diffusing capacity and pulmonary capillary blood flow at hyperbaric pressures.

1965 ◽  
Vol 44 (10) ◽  
pp. 1591-1599 ◽  
Author(s):  
J R Nairn ◽  
G G Power ◽  
R W Hyde ◽  
R E Forster ◽  
C J Lambertsen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Capillary Blood ◽  
Capillary Blood Flow ◽  
Diffusing Capacity ◽  
Pulmonary Capillary Blood Flow ◽  
Pulmonary Capillary ◽  
Pulmonary Capillary Blood

Effects of gravity on lung diffusing capacity and cardiac output in prone and supine humans

2003 ◽  
Vol 95 (1) ◽  
pp. 3-10 ◽  
Author(s):  
M. Rohdin ◽  
J. Petersson ◽  
P. Sundblad ◽  
M. Mure ◽  
R. W. Glenny ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Normal Subjects ◽  
Arterial Oxygenation ◽  
Diffusing Capacity ◽  
Alveolar Volume ◽  
Pulmonary Capillary Blood Flow ◽  
Pulmonary Capillary ◽  
Supine Posture ◽  
Pulmonary Capillary Blood ◽  
Residual Capacity

Both in normal subjects exposed to hypergravity and in patients with acute respiratory distress syndrome, there are increased hydrostatic pressure gradients down the lung. Also, both conditions show an impaired arterial oxygenation, which is less severe in the prone than in the supine posture. The aim of this study was to use hypergravity to further investigate the mechanisms behind the differences in arterial oxygenation between the prone and the supine posture. Ten healthy subjects were studied in a human centrifuge while exposed to 1 and 5 times normal gravity (1 G, 5 G) in the anterioposterior (supine) and posterioanterior (prone) direction. They performed one rebreathing maneuver after ∼5 min at each G level and posture. Lung diffusing capacity decreased in hypergravity compared with 1 G (ANOVA, P = 0.002); it decreased by 46% in the supine posture compared with 25% in the prone ( P = 0.01 for supine vs. prone). At the same time, functional residual capacity decreased by 33 and 23%, respectively ( P < 0.001 for supine vs. prone), and cardiac output by 40 and 31% ( P = 0.007 for supine vs. prone), despite an increase in heart rate of 16 and 28% ( P < 0.001 for supine vs. prone), respectively. The finding of a more impaired diffusing capacity in the supine posture compared with the prone at 5 G supports our previous observations of more severe arterial hypoxemia in the supine posture during hypergravity. A reduced pulmonary-capillary blood flow and a reduced estimated alveolar volume can explain most of the reduction in diffusing capacity when supine.

Determination of pulmonary parenchymal tissue volume and pulmonary capillary blood flow in man

1959 ◽  
Vol 14 (4) ◽  
pp. 541-551 ◽  
Author(s):  
Leon Cander ◽  
Robert E. Forster
Keyword(s):  
Blood Flow ◽  
Capillary Blood ◽  
Capillary Blood Flow ◽  
Breath Holding ◽  
Tissue Volume ◽  
Parenchymal Tissue ◽  
Pulmonary Capillary Blood Flow ◽  
Pulmonary Capillary ◽  
Alveolar Level ◽  
Pulmonary Capillary Blood

The rates of disappearance of SF6, N2O, C2H2, diethyl ether and acetone from alveolar air during breath holding, following a single deep inspiration of a mixture containing one of these gases and about 15% helium, was studied in five normal seated subjects. SF6 is so insoluble that no significant change in its concentration relative to helium was found. Ether and acetone are so soluble that they dissolve in the tissues around the respiratory dead space during inspiration and evaporate during expiration, contaminating the expired alveolar gas to such an extent that the exchange of these gases cannot be properly measured at the alveolar level. N2O and C2H2 showed a) a rapid (less than 1.5 sec.) initial fall in relative alveolar concentration and b) a subsequent more gradual decrease; a) presumably results from the solution of the foreign gas in the pulmonary parenchymal tissues and can be used to calculate the pulmonary parenchymal tissue volume (Vt); b) can be used to calculate the pulmonary capillary blood flow (Qc), provided observations are not extended beyond 21 sec. The average values obtained were 3.31 l/min/m2 and 606 ml for Qc and Vt, respectively. Submitted on December 4, 1958

Influence of increased alveolar CO2 tension on pulmonary diffusing capacity for CO in man

1960 ◽  
Vol 15 (4) ◽  
pp. 543-549 ◽  
Author(s):  
J. Rankin ◽  
R. S. McNeill ◽  
R. E. Forster
Keyword(s):  
Systemic Blood Pressure ◽  
Repeated Measurements ◽  
Breath Holding ◽  
Gas Mixture ◽  
Diffusing Capacity ◽  
Pulmonary Diffusing Capacity ◽  
Pulmonary Capillary ◽  
Capillary Blood Volume ◽  
Pulmonary Capillary Blood ◽  
Capillary Bed

Since the pulmonary diffusing capacity for CO theoretically varies with changes in the size of the pulmonary capillary bed, it should be a useful tool for the investigation of the effects of CO2 on the pulmonary capillaries. Dl was measured during hypercapnia in nine normal resting subjects by the CO-helium breath-holding technique. a) When 10% CO2 was simply added to the inspired mixture used in the measurement of Dl, CO disappeared more rapidly from the lung. Dl was increased on the average only 5% after 10 seconds of breath holding. Pulmonary capillary blood volume (Vc) calculated by the method of Roughton and Forster was measured in two subjects and was increased approximately 46.5%. b) After the subject breathed a gas mixture containing 7.5% CO2 for 10 minutes, Dl was increased an average of 24% in all subjects and Vc was increased 112% in one subject studied. In five subjects repeated measurements of Dl, together with measurements of ventilation, systemic blood pressure, pulse rate and pulmonary blood flow in three of them, were made before, during and after a period of hypercapnia. After starting to breath the CO2-enriched gas mixture, Dl rose abruptly, reaching near maximal values in 2–5 minutes, while the other measurements of respiratory and circulatory phenomena continued to rise for 6–10 minutes, suggesting that the presumed increase in the pulmonary capillary bed was not dependent on the systemic respiratory and circulatory changes. Submitted on September 2, 1959

Determination of Pulmonary Tissue volume, Pulmonary Capillary Blood Flow and Diffusing Capacity of the Lung before and after Hemodialysis

1980 ◽  
Vol 3 (5) ◽  
pp. 259-262 ◽  
Author(s):  
J.T. Morrison ◽  
A.F. Wilson ◽  
N.D. Vaziri ◽  
L. Brunsting ◽  
J. Davis
Keyword(s):  
Body Weight ◽  
Capillary Blood ◽  
Diffusing Capacity ◽  
Pulmonary Tissue ◽  
Pulmonary Capillary Blood Flow ◽  
Pulmonary Capillary ◽  
Before And After ◽  
Pulmonary Capillary Blood ◽  
Pulmonary Tissue Volume

In order to better understand changes in lung function before and after dialysis, we studied eight patients with end-stage renal disease undergoing chronic hemodialysis. Pulmonary tissue volume (Vt), pulmonary capillary blood flow (Q̇c), the diffusing capacity for carbon monoxide (DLCO), arterial blood gases and body weight were measured before and after dialysis. A single breath, constant expiratory flow technique for determination of DLCO, Q̇c and Vt was used. DLCO, Q̇c, arterial carbon dioxide, and body weight were reduced post dialysis (P ≤ .01) while Vt failed to change. The alveolar-arterial oxygen difference rose 12 mmHg (P = .01). These results are consistent with pulmonary microembolization during dialysis with deterioration of gas exchange and Q̇c. These changes appear to occur independent of significant changes in Vt. Possible physiologic mechanisms are discussed.

Measurement of pulmonary blood flow during exercise using nitrous oxide

1962 ◽  
Vol 17 (4) ◽  
pp. 579-586 ◽  
Author(s):  
Margaret R. Becklake ◽  
C. J. Varvis ◽  
L. D. Pengelly ◽  
S. Kenning ◽  
M. McGregor ◽  
...  
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
Dilution Technique ◽  
Fick Principle ◽  
Pulmonary Capillary Blood Flow ◽  
Time Period ◽  
Pulmonary Capillary ◽  
Wide Range ◽  
Pulmonary Capillary Blood ◽  
The Difference

Pulmonary capillary blood flow (Qc) in the exercising subject was calculated from the rate of disappearance of N2O during steady state breathing of an N2O-He-O2 mixture. Measurements were made after alveolar rinsing (reciprocal of N2 washout) had occurred, and up to 30 sec, a time period accompanied by minimal recirculation, since FaNN2O during this period did not rise significantly. Repeatability of the method, judged as the difference of a second estimate from a first on the same subject, was comparable to that reported for the direct Fick technique in resting subjects (31 of 33 paired observations agreed within 20%). Results over a wide range agreed with almost simultaneous measurements by a dye dilution technique (24 of 26 paired observations agreed within 20%), and when related to pulse rate and to Vo2, were comparable to those of the other workers whose subjects were studied in a similar posture. Indeed, this technique (using the indirect Fick principle under “steady state” conditions) probably attains its greatest accuracy during exercise when other methods become less easily applicable. Submitted on December 18, 1961

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