Accession Number:

AD0777333

Title:

Bulk Elastic Properties of Excised Lungs and the Effect of a Transpulmonary Pressure Gradient,

Descriptive Note:

Corporate Author:

FLYING PERSONNEL RESEARCH COMMITTEE LONDON (ENGLAND)

Report Date:

1973-09-01

Pagination or Media Count:

42.0

Abstract:

Isolated dog lungs and lobes were studied while suspended in air and while immersed in a low density fluidised bed to simulate a pleural pressure gradient. Pressure-volume loops vital capacity, VC were recorded during two minute cycles between transpulmonary pressure of -5 and 30 cm water. Volume history dependent features were investigated by cycling to intermediate pressures from either minimum volume -5 cm H2O, MV or total lung capacity 30 cm H2O, TLC. Cycling to pressures below 2.5 cm water led to closure of lung units and pronounced changes in subsequent inflation curves. Deflation curves were also modified. The points where the lower portions of the curves departed from the exponential curve were considered to represent completion of opening and initial closing of lung units during inflation and deflation respectively. Opening and closing pressures for lower lobes were 2 cm water greater than for upper lobes with the lungs in air, and the difference increased to 4.1 cm water in the fluidised bed. Modified author abstract

Subject Categories:

  • Anatomy and Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE