Journal of Applied Physiology, Vol 56, Issue 6 1633-1639, Copyright © 1984 by American Physiological Society

ARTICLES

Pleural liquid pressure measured by micropipettes in rabbits

S. J. Lai-Fook, K. C. Beck and P. A. Southorn

Pleural liquid pressure (Ppl) was measured by the micropipette servo-nulling method. In anesthetized, paralyzed, and mechanically ventilated rabbits, windows were made by dissecting away the intercostal muscle layers, exposing the parietal pleura over the right caudal lung lobe. Repeated measurements of Ppl were made at the windows by puncturing the parietal pleura with micropipettes during apnea at functional residual capacity. In five supine rabbits, Ppl relative to atmospheric pressure averaged -3.32 +/- 1.22 (SD) cmH2O at a distance of 5.64 +/- 0.34 (SD) cm above the lung base and -1.64 +/- 0.79 cmH2O at a distance of 2.35 +/- 0.64 cm above the lung base; the vertical Ppl gradient was 0.51 cmH2O/cm height. Ppl interpolated to midlung height was equal in absolute magnitude to mean lung static recoil (Pst) of 2.00 cmH2O. In prone rabbits, Ppl measured near the dorsal surface, 3.9 cm above the lung base, averaged -1.32 +/- 0.46 cmH2O on the costal surface, not statistically different in magnitude from mean Pst of 1.59 +/- 0.09. In contrast, Ppl measured at the same vertical height off the edge of the caudal lung in the costo-diaphragmatic recess was -4.64 +/- 0.65 cmH2O. We concluded from these data that Ppl was equal to pleural surface pressure over the costal surface and that the vertical gradient in Ppl was not hydrostatic, except in large fluid spaces off the sharp edges of the lung.

This article has been cited by other articles:

				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]

				G. R. Washko, C. R. O'Donnell, and S. H. Loring Volume-related and volume-independent effects of posture on esophageal and transpulmonary pressures in healthy subjects J Appl Physiol, March 1, 2006; 100(3): 753 - 758. [Abstract] [Full Text] [PDF]

				S. J. LAI-FOOK Pleural Mechanics and Fluid Exchange Physiol Rev, April 1, 2004; 84(2): 385 - 410. [Abstract] [Full Text] [PDF]

				L. Zocchi Physiology and pathophysiology of pleural fluid turnover Eur. Respir. J., December 1, 2002; 20(6): 1545 - 1558. [Abstract] [Full Text] [PDF]

				A. T. Jones, D. M. Hansell, and T. W. Evans Pulmonary perfusion in supine and prone positions: an electron-beam computed tomography study J Appl Physiol, April 1, 2001; 90(4): 1342 - 1348. [Abstract] [Full Text] [PDF]

				S. E. Sinclair, S. McKinney, R. W. Glenny, S. L. Bernard, and M. P. Hlastala Exercise alters fractal dimension and spatial correlation of pulmonary blood flow in the horse J Appl Physiol, June 1, 2000; 88(6): 2269 - 2278. [Abstract] [Full Text] [PDF]

				M. P. Hlastala, M. A. Chornuk, D. A. Self, H. J. Kallas, J. W. Burns, S. Bernard, N. L. Polissar, and R. W. Glenny Pulmonary blood flow redistribution by increased gravitational force J Appl Physiol, April 1, 1998; 84(4): 1278 - 1288. [Abstract] [Full Text] [PDF]