Revised Standards for Normal Resting Dead-Space Volume and Venous Admixture in Men and Women

1. Data have been combined from three previous series to provide revised standards for the prediction of physiological dead-space volume (VD), arterial oxygen tension (Pa,o2), alveolar-to-arterial oxygen-tension difference (Pa,o2 - Pa,o2) and venous admixture fraction (Q̇va/Q̇t) in the sitting position. 2. These standards, based on measurements in 96 healthy men and women aged from 20 to 74 years, largely confirm conclusions drawn from the first series of 48 subjects. 3. VD is best predicted on age, height, tidal volume and the reciprocal of respiratory frequency. Pa,o2, (Pa,o2 - Pa,o2) and Q̇va/Q̇t are adequately predicted on age alone.

Download Full-text

Effect of varying inspired O2 tension on alveolar-arterial O2 tension difference in man

Journal of Applied Physiology ◽

10.1152/jappl.1963.18.6.1043 ◽

1963 ◽

Vol 18 (6) ◽

pp. 1043-1048 ◽

Cited By ~ 34

Author(s):

R. B. Cole ◽

J. M. Bishop

Keyword(s):

Oxygen Tension ◽

Dead Space ◽

Interpolation Method ◽

Age Groups ◽

Arterial Oxygen Tension ◽

Carbon Dioxide Tension ◽

Arterial Oxygen ◽

Mean Values ◽

Physiological Dead Space ◽

Alveolar Oxygen

Alveolar-arterial oxygen tension difference (A-aD) and physiological dead space were measured in 16 normal men and women selected equally from the age groups 20–29 and 50–59 years, at mean alveolar oxygen tensions (PaOO2) of 107, 291, and 653 mm Hg. Arterial oxygen tension was measured polarographically and arterial carbon dioxide tension by an interpolation method. Values for A-aD were not related to posture but were significantly greater in the older group. Mean values for A-aD in the younger group were 8.7, 23.5, and 6.1 mm Hg at the three levels of PaOO2, respectively, and 14.1, 44.5, and 21.3 mm Hg, respectively, among the older group. At the two lower levels of PaOO2 results were in general agreement with those of previous workers, but a significant decrease in A-aD was observed when PaOO2 was raised to 653 mm Hg. It is suggested that this finding may be due either to change in the effective size of anatomical shunt while breathing 99.5% oxygen, or to a significant distribution component of total A-aD at the intermediate alveolar oxygen tension. effect of posture, age and sex; physiological dead space; veno-arterial shunt Submitted on April 23, 1963

Download Full-text

Reductions in dead space ventilation with nasal high flow depend on physiological dead space volume: metabolic hood measurements during sleep in patients with COPD and controls

European Respiratory Journal ◽

10.1183/13993003.02251-2017 ◽

2018 ◽

Vol 51 (5) ◽

pp. 1702251 ◽

Cited By ~ 19

Author(s):

Paolo Biselli ◽

Kathrin Fricke ◽

Ludger Grote ◽

Andrew T. Braun ◽

Jason Kirkness ◽

...

Keyword(s):

Respiratory Rate ◽

Dead Space ◽

Minute Ventilation ◽

High Flow ◽

Physiological Dead Space ◽

Copd Patients ◽

Dead Space Volume ◽

Anatomical Dead Space ◽

Dead Space Ventilation ◽

Space Volume

Nasal high flow (NHF) reduces minute ventilation and ventilatory loads during sleep but the mechanisms are not clear. We hypothesised NHF reduces ventilation in proportion to physiological but not anatomical dead space.11 subjects (five controls and six chronic obstructive pulmonary disease (COPD) patients) underwent polysomnography with transcutaneous carbon dioxide (CO2) monitoring under a metabolic hood. During stable non-rapid eye movement stage 2 sleep, subjects received NHF (20 L·min−1) intermittently for periods of 5–10 min. We measured CO2 production and calculated dead space ventilation.Controls and COPD patients responded similarly to NHF. NHF reduced minute ventilation (from 5.6±0.4 to 4.8±0.4 L·min−1; p<0.05) and tidal volume (from 0.34±0.03 to 0.3±0.03 L; p<0.05) without a change in energy expenditure, transcutaneous CO2 or alveolar ventilation. There was a significant decrease in dead space ventilation (from 2.5±0.4 to 1.6±0.4 L·min−1; p<0.05), but not in respiratory rate. The reduction in dead space ventilation correlated with baseline physiological dead space fraction (r2=0.36; p<0.05), but not with respiratory rate or anatomical dead space volume.During sleep, NHF decreases minute ventilation due to an overall reduction in dead space ventilation in proportion to the extent of baseline physiological dead space fraction.

Download Full-text

Hypoxemia due to venous admixture in cirrhosis of the liver

Journal of Applied Physiology ◽

10.1152/jappl.1960.15.2.253 ◽

1960 ◽

Vol 15 (2) ◽

pp. 253-254 ◽

Cited By ~ 30

Author(s):

M. Henry Williams

Keyword(s):

Cardiac Output ◽

Oxygen Tension ◽

Arterial Oxygen Tension ◽

Venous System ◽

Cirrhosis Of The Liver ◽

Portal System ◽

Arterial Oxygen ◽

Venous Admixture ◽

Oxygen Breathing ◽

The Right

The percentage of venous admixture to arterialized blood was measured by two different techniques in two groups of patients with cirrhosis of the liver and, in both groups, averaged 9.7% of the cardiac output. Since one of the techniques was based on measurement of the arterial oxygen tension during oxygen breathing, the venous admixture must have resulted from some type of right-to-left shunt. It was not possible to determine whether the right-to-left shunt resulted from anastamoses between the portal system and the bronchopulmonary venous system or from pulmonary arteriovenous communications. Submitted on March 30, 1959

Download Full-text

Effect of changes in tidal ventilation on physiologic shunting

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1964.206.4.891 ◽

1964 ◽

Vol 206 (4) ◽

pp. 891-897 ◽

Cited By ~ 65

Author(s):

J. Hedley-Whyte ◽

M. B. Laver ◽

H. H. Bendixen

Keyword(s):

Oxygen Tension ◽

Arterial Oxygen Tension ◽

Transpulmonary Pressure ◽

Arterial Oxygen ◽

Venous Admixture ◽

Relative Value ◽

History Of ◽

Alveolar Oxygen ◽

Volume History ◽

Made In

The rate and magnitude of the effects of the pressure-volume history of the lungs on the degree of physiologic shunting (pulmonary venous admixture) were investigated in 20 dogs, anesthetized and curarized. Atelectasis was promoted by decreasing end-expiratory transpulmonary pressure. Ventilation was with 100% oxygen using a constant-volume pump at a frequency of 20 breaths/min. The rates of increase or decrease in the physiologic shunt and of the gradients between derived alveolar oxygen tension and directly measured arterial oxygen tension (A-aD) showed a variation controlled by the pressure-volume history of the lungs. The physiologic shunts produced varied between 0.5% and 80% of the cardiac output. The interrelationships of the components of the shunt equation were studied and their relative value in predicting atelectasis was discussed. The data obtained were related to other observations made in anesthetized man.

Download Full-text

Alveolar to Arterial Oxygen Tension Difference and Venous Admixture in Newly Born Infants with Congenital Diaphragmatic Herniation through the Foramen of Bochdalek

Neonatology ◽

10.1159/000240311 ◽

1971 ◽

Vol 17 (3-4) ◽

pp. 161-172 ◽

Cited By ~ 35

Author(s):

A.I. Murdock ◽

J.B. Burrington ◽

P.R. Swyer

Keyword(s):

Oxygen Tension ◽

Arterial Oxygen Tension ◽

Arterial Oxygen ◽

Venous Admixture ◽

Diaphragmatic Herniation

Download Full-text

Gas Exchange during Exercise in Healthy People: I. the Physiological Dead-Space Volume

Clinical Science ◽

10.1042/cs0510323 ◽

1976 ◽

Vol 51 (4) ◽

pp. 323-333 ◽

Cited By ~ 2

Author(s):

Christine A. Bradley ◽

E. A. Harris ◽

Eve R. Seelye ◽

R. M. L. Whitlock

Keyword(s):

Carbon Dioxide ◽

Dead Space ◽

Confidence Limit ◽

Carbon Dioxide Tension ◽

Physiological Dead Space ◽

Carbon Dioxide Output ◽

Pulmonary Capillary ◽

Dead Space Volume ◽

Capillary Temperature ◽

Space Volume

1. Physiological dead-space volume (VD) was measured in twenty-four healthy men and women aged from 20 to 71 years, at rest and at two rates of work on a treadmill, whilst breathing air and breathing oxygen. 2. The effect of correction of arterial carbon dioxide tension (Pa,co2) to pulmonary capillary temperature on the resulting value for VD was investigated. We find that the effect is substantial and that a correction should be made. 3. Equations have been derived for the prediction of normal VD during exercise. The best prediction was given by a regression on height, age, carbon dioxide output, ventilation and respiratory frequency, with an upper 95% confidence limit of +81 ml.

Download Full-text

Prediction of the Physiological Dead-Space in Resting Normal Subjects

Clinical Science ◽

10.1042/cs0450375 ◽

1973 ◽

Vol 45 (3) ◽

pp. 375-386 ◽

Cited By ~ 6

Author(s):

E. A. Harris ◽

Mary E. Hunter ◽

Eve R. Seelye ◽

Margaret Vedder ◽

R. M. L. Whitlock

Keyword(s):

Tidal Volume ◽

Multiple Regression ◽

Dead Space ◽

Predictive Accuracy ◽

Volume Ratio ◽

Normal Subjects ◽

Physiological Dead Space ◽

Dead Space Volume ◽

Made In ◽

Space Volume

1. Two-hundred and forty duplicate estimations of physiological dead-space volume (VD) were made in forty-eight healthy subjects (twenty-four men and twenty-four women) aged from 20 to 74 years, to assess the predictive accuracy of various standards. 2. The VD/VT (physiological dead-space volume/tidal volume) ratio standard was least precise, but could be improved by allowing for sex and age. 3. The best prediction could be made by multiple regression of VD on age, height, tidal volume (VT) and the reciprocal of respiratory frequency (f), which gave an estimate with a standard deviation of 24·7 ml. 4. Theoretical and practical arguments favour the abandonment of the VD/VT ratio standard. Simple regression of VD on VT also is unsatisfactory, giving a much less precise estimate of VD than a multiple regression on VT and other variables.

Download Full-text

MEASUREMENT OF LUNG DEAD SPACE VOLUME BY CAPNOVOLUMETRY

10.25005/2074-0581-2020-22-3-471-477 ◽

2020 ◽

pp. 471-477

Author(s):

T.A. MIROSHKINA ◽

◽

S.A. SHUSTOVA ◽

Keyword(s):

Dead Space ◽

Alveolar Dead Space ◽

Volumetric Capnography ◽

Equal Area ◽

Physiological Dead Space ◽

Dead Space Volume ◽

Anatomical Dead Space ◽

The Difference ◽

Space Volume

The article provides information on the lung dead space – a part of the respiratory volume that does not participate in gas exchange. The anatomical and alveolar dead spaces jointly together form the physiological dead space. The article describes methods for determining the volume of dead spaces using the capnovolumetry. The volume of physiological dead space is calculated using the C. Bohr equation. The volume of anatomical dead space can be determined using the equal area method proposed by W.S. Fowler. The volume of the alveolar dead space is the difference of volumes of the physiological and anatomical dead spaces. In pathology, the volume of the alveolar space and, consequently, physiological dead space can increase significantly. Determination of the volume of dead space is the significant criterion for diagnostic and predicting the outcome of a number of diseases. Keywords: Physiological dead space , anatomical dead space , alveolar dead space , capnovolumetry, volumetric capnography.

Download Full-text