| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
University of Washington, Departments of 1 Medicine and 2 Physiology and Biophysics, Seattle, Washington, 98195-6522
High-resolution measurements of pulmonary perfusion reveal substantial spatial heterogeneity that is fractally distributed. This observation led to the hypothesis that the vascular tree is the principal determinant of regional blood flow. Recent studies using aerosol deposition show similar ventilation heterogeneity that is closely correlated with perfusion. We hypothesize that ventilation has fractal characteristics similar to blood flow. We measured regional ventilation and perfusion with aerosolized and injected fluorescent microspheres in six anesthetized, mechanically ventilated pigs in both prone and supine postures. Adjacent regions were clustered into progressively larger groups. Coefficients of variation were calculated for each cluster size to determine fractal dimensions. At the smallest size lung piece, local ventilation and perfusion are highly correlated, with no significant difference between ventilation and perfusion heterogeneity. On average, the fractal dimension of ventilation is 1.16 in the prone posture and 1.09 in the supine posture. Ventilation has fractal properties similar to perfusion. Efficient gas exchange is preserved, despite ventilation and perfusion heterogeneity, through close correlation. One potential explanation is the similar geometry of bronchial and vascular structures.
gas exchange; lung airway; lung mechanics
This article has been cited by other articles:
|
|
 |
|
  Rebuttal from Dr. Glenny J Appl Physiol, May 1, 2008; 104(5): 1535 - 1536. [Full Text] [PDF]
|
|
|
|
 |
|
 A. Kozian, T. Schilling, F. Freden, E. Maripuu, C. Rocken, C. Strang, T. Hachenberg, and G. Hedenstierna One-lung ventilation induces hyperperfusion and alveolar damage in the ventilated lung: an experimental study Br. J. Anaesth., April 1, 2008; 100(4): 549 - 559. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Galvin, G. B. Drummond, and M. Nirmalan Distribution of blood flow and ventilation in the lung: gravity is not the only factor Br. J. Anaesth., April 1, 2007; 98(4): 420 - 428. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. R. Hopkins, D. L. Levin, K. Emami, S. Kadlecek, J. Yu, M. Ishii, and R. R. Rizi Advances in magnetic resonance imaging of lung physiology J Appl Physiol, March 1, 2007; 102(3): 1244 - 1254. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. T. Robertson and M. P. Hlastala Microsphere maps of regional blood flow and regional ventilation J Appl Physiol, March 1, 2007; 102(3): 1265 - 1272. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. J. West, A. Maciejewski, M. Latka, T. Sebzda, Z. Swierczynski, S. Cybulska-Okolow, and E. Baran Wavelet analysis of scaling properties of gastric electrical activity J Appl Physiol, November 1, 2006; 101(5): 1425 - 1431. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Latka, M. Turalska, M. Glaubic-Latka, W. Kolodziej, D. Latka, and B. J. West Phase dynamics in cerebral autoregulation Am J Physiol Heart Circ Physiol, November 1, 2005; 289(5): H2272 - H2279. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J.-C. Richard, M. Janier, F. Lavenne, C. Tourvieille, D. Le Bars, N. Costes, G. Gimenez, and C. Guerin Quantitative Assessment of Regional Alveolar Ventilation and Gas Volume Using 13N-N2 Washout and PET J. Nucl. Med., August 1, 2005; 46(8): 1375 - 1383. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Y. C. Tsang, W. J. E. Lamm, I. R. Starr, and M. P. Hlastala Spatial pattern of ventilation-perfusion mismatch following acute pulmonary thromboembolism in pigs J Appl Physiol, May 1, 2005; 98(5): 1862 - 1868. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. C. Anderson, A. L. Babb, and M. P. Hlastala A fractal analysis of the radial distribution of bronchial capillaries around large airways J Appl Physiol, March 1, 2005; 98(3): 850 - 855. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. A. Altemeier, S. McKinney, M. Krueger, and R. W. Glenny Effect of posture on regional gas exchange in pigs J Appl Physiol, December 1, 2004; 97(6): 2104 - 2111. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Porra, S. Monfraix, G. Berruyer, G. Le Duc, C. Nemoz, W. Thomlinson, P. Suortti, A. R. A. Sovijarvi, and S. Bayat Effect of tidal volume on distribution of ventilation assessed by synchrotron radiation CT in rabbit J Appl Physiol, May 1, 2004; 96(5): 1899 - 1908. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. C. Kreck, M. A. Krueger, W. A. Altemeier, S. E. Sinclair, H. T. Robertson, E. D. Shade, J. Hildebrandt, W. J. E. Lamm, D. A. Frazer, N. L. Polissar, et al. Determination of regional ventilation and perfusion in the lung using xenon and computed tomography J Appl Physiol, October 1, 2001; 91(4): 1741 - 1749. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. C. Beck and T. A. Wilson Variance of ventilation during exercise J Appl Physiol, June 1, 2001; 90(6): 2151 - 2156. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. W. Glenny, H. T. Robertson, and M. P. Hlastala Vasomotor tone does not affect perfusion heterogeneity and gas exchange in normal primate lungs during normoxia J Appl Physiol, December 1, 2000; 89(6): 2263 - 2267. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. W. Glenny, S. L. Bernard, and H. T. Robertson Pulmonary blood flow remains fractal down to the level of gas exchange J Appl Physiol, August 1, 2000; 89(2): 742 - 748. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. Gerbino, S. McKinney, and R. W. Glenny Correlation between ventilation and perfusion determines VA/Q heterogeneity in endotoxemia J Appl Physiol, June 1, 2000; 88(6): 1933 - 1942. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
