Determination of Lung Volume in the ICU

Previous work by our group has demonstrated substantial differences in lung volume and morphometric parameters between inbred mice. Specifically, adult C3H/HeJ (C3) have a 50% larger lung volume and 30% greater mean linear intercept than C57BL/6J (B6) mice. Although much of lung development occurs postnatally in rodents, it is uncertain at what age the differences between these strains become manifest. In this study, we performed quasi-static pressure-volume curves and morphometric analysis on neonatal mice. Lungs from anesthetized mice were degassed in vivo using absorption of 100% O2. Pressure-volume curves were then recorded in situ. The lungs were then fixed by instillation of Zenker’s solution at a constant transpulmonary pressure. The left lung from each animal was used for morphometric determination of mean air space chord length ( Lma). We found that the lung volume of C3 mice was substantially greater than that of B6 mice at all ages. In contrast, there was no difference in Lma (62.7 μm in C3 and 58.5 μm in B6) of 3-day-old mice. With increasing age (8 days), there was a progressive decrease in the Lma of both strains, with the magnitude of the decrease in B6 Lma mice exceeding that of C3. C3 lung volume remained 50% larger. The combination of parenchymal architectural similarity with lung air volume differences and different rates of alveolar septation support the hypothesis that lung volume and alveolar dimensions are independently regulated.

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Serial determination of lung volume in small animals by nitrogen washout

Journal of Applied Physiology ◽

10.1152/jappl.1985.59.1.205 ◽

1985 ◽

Vol 59 (1) ◽

pp. 205-210 ◽

Cited By ~ 5

Author(s):

T. A. Standaert ◽

W. A. LaFramboise ◽

R. E. Tuck ◽

D. E. Woodrum

Keyword(s):

Lung Volume ◽

Small Animals ◽

Calibration Data ◽

Water Displacement ◽

Lung Capacity ◽

Serial Determination ◽

Residual Capacity ◽

Volume Measurements

This report describes the design of an apparatus and the procedures used to serially measure the total lung capacity and the functional residual capacity of small animals utilizing the N2-washout technique. The calibration data indicate that the technique is accurate to within 1 ml and has a variance of less than 5%. The in vivo lung volume measurements of rats were validated by comparing them with values obtained with a water-displacement technique; the means were within 0.3 ml. Examples of the precision and changes in lung volume of animals during studies are included to demonstrate the reliability and usefulness of the technique.

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Determination of lung volume: a simple constant volume modification of Christie’s method

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1939.0004 ◽

1939 ◽

Vol 126 (845) ◽

pp. 491-501 ◽

Cited By ~ 16

Keyword(s):

Lung Volume ◽

Vital Capacity ◽

Clinical Investigation ◽

Forced Expiration ◽

Total Lung Volume ◽

Underlying Principle ◽

Gas Dilution ◽

Residual Air ◽

Source Of Error

The total lung volume consists of the vital capacity plus the residual air. Since the vital capacity may be measured directly, determination of the total lung volume depends on the measurement of the residual air. Alternatively, the functional residual air may be measured and the figure added to the complemental air (terminology of Christie 1932). As the volume of reserve air expelled from the lungs in untrained subjects is liable to fortuitous variations, calculations of the residual air based on gas dilution at the end of a forced expiration are open to considerable error; for the same reason, determinations of the functional residual air at the end of an ordinary expiration may be inaccurate. Van Slyke and Binger (1923) and Christie (1932) have shown that this source of error may be avoided by taking graphic spirometer records of respiration during the period of mixing. Since the dilution of the lung gases is achieved by ordinary quiet respiration, this method requires no special respiratory efforts and is thus eminently suitable for clinical investigation. Determination of lung volume by Christie’s method, the underlying principle of which is exceedingly simple, involves only the recording of an ordinary spirometer tracing and the analysis of the oxygen and nitrogen content of the spirometer gas at the end of a period of rebreathing. The essence of the method is as follows:

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DETERMINATION OF LUNG VOLUME BY RESPIRATION OF OXYGEN WITHOUT FORCED BREATHING

Journal of Experimental Medicine ◽

10.1084/jem.55.3.361 ◽

1932 ◽

Vol 55 (3) ◽

pp. 361-375 ◽

Cited By ~ 5

Author(s):

Julius Sendroy ◽

Alma Hiller ◽

Donald D. Van Slyke

Keyword(s):

Carbon Dioxide ◽

Lung Volume ◽

Laboratory Equipment ◽

Forced Breathing ◽

Measured Volume

A method is described for estimating the volume of air in the lungs by the familiar principle of mixing this air with a measured volume of oxygen, and determining the extent to which the nitrogen of the pulmonary air is diluted. By employing a scrubber to remove carbon dioxide, and by measuring the volume of gas in the extrapulmonary part of the system at the end instead of the beginning of the respiratory period, it is possible to prolong the period to as many minutes as are necessary for complete mixture of the gases, and thereby to carry out the estimation without forced breathing. The determination can be carried out with the Roth-Benedict or Krogh spirometer, or, more economically, with the simple spirometer, shown in Fig. 1, assembled from ordinary laboratory equipment. The method gives the same results as the hydrogen method of Van Slyke and Binger (3), and obviates the use and analysis of hydrogen. The relative advantages of the two methods are discussed above. Dr. Ronald V. Christie has informed us that he has encountered considerable differences in the N2 content of the pulmonary air of different individuals. A gain in accuracy would therefore be made if this value were determined for each subject, and substituted for 79.1 in the calculation formulae.

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