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In six excised canine lungs, regional alveolar pressures (PA) were measured during small-amplitude high-frequency oscillations applied at the airway opening. Both the regional distribution of PA's and their relationship to pressure excursions at the airway opening (Pao) were assessed in terms of amplitude and phase. PA was sampled in several capsules glued to the pleural surface and communicating with alveolar gas via pleural punctures. Pao and PA were measured over the frequency (f) range 1-60 Hz, at transpulmonary pressures (PL) of 5, 10, and 25 cmH2O. The amplitude of PA excursions substantially exceeded Pao excursions at frequencies near the resonant frequency. At resonance the ratio [PA/Pao] was 1.9, 2.9, and 4.8 at PL's of 5, 10, and 25 cmH2O, respectively. Both spatial homogeneity and temporal synchrony of PA's between sampled lung regions decreased with f and increased with PL. Interregional variability of airway impedance [(Pao - PA)/Vao] and tissue impedance (PA/Vao) tended to be larger than differences due to changing PL but not as large as between-dog variability. These data define the baseline nonhomogeneity of the normal canine lung and also suggest that there may be some advantage in applying high-frequency ventilation at frequencies at least as high as lung resonant frequency.
J J Fredberg, and
D H Keefe, and
G M Glass, and
R G Castile, and
I D Frantz
September 1987,
Der Anaesthesist,
J J Fredberg, and
D H Keefe, and
G M Glass, and
R G Castile, and
I D Frantz
July 1990,
Journal of applied physiology (Bethesda, Md. : 1985),
J J Fredberg, and
D H Keefe, and
G M Glass, and
R G Castile, and
I D Frantz
March 1984,
Journal of applied physiology: respiratory, environmental and exercise physiology,
J J Fredberg, and
D H Keefe, and
G M Glass, and
R G Castile, and
I D Frantz
January 1990,
Intensive care medicine,
J J Fredberg, and
D H Keefe, and
G M Glass, and
R G Castile, and
I D Frantz
January 1989,
Acta anaesthesiologica Scandinavica. Supplementum,
J J Fredberg, and
D H Keefe, and
G M Glass, and
R G Castile, and
I D Frantz
January 1987,
Revista espanola de anestesiologia y reanimacion,
J J Fredberg, and
D H Keefe, and
G M Glass, and
R G Castile, and
I D Frantz
October 1984,
Journal of applied physiology: respiratory, environmental and exercise physiology,
J J Fredberg, and
D H Keefe, and
G M Glass, and
R G Castile, and
I D Frantz
December 2016,
Annals of intensive care,
J J Fredberg, and
D H Keefe, and
G M Glass, and
R G Castile, and
I D Frantz
November 1983,
Critical care medicine,
J J Fredberg, and
D H Keefe, and
G M Glass, and
R G Castile, and
I D Frantz
February 1985,
Pediatric research,
