TY - JOUR
T1 - Human lung pressure-volume relationships
T2 - Alveolar collapse and airway closure
AU - Salmon, R. B.
AU - Primiano, F. P.
AU - Saidel, G. M.
AU - Niewoehner, D. E.
PY - 1981
Y1 - 1981
N2 - We investigated the effect of airway closure and alveolar collapse on the large-volume deflation and inflation transpulmonary pressure-volume (Pty-V) curves of five postmortem excised human lungs. For stepwise static cycles, no inflection occurred on the deflation curve, while either one or two inflections occurred on the inflation curve. These relations were simulated by a multicompartment model, which assumed a bimodal distribution of compartmental collapse-pressure differences. The simulations indicate that alveolar collapse can occur without causing an inflection on the deflation curve and that hysteresis in reopening of collapsed alveoli on inflation can account for a major portion of Ptp-V hysteresis. In contrast, for slow dynamic cycles, an inflection occurred on the experimental deflation Ptp-V curve, and when inflations were begun at sufficiently low volumes, volume did not change until a threshold pressure difference was reached about which Ptp began to oscillate as lung volume increased. These differences in the stepwise static and dynamic Ptp-V curves can result from sustained airway closure on deflation and popping-open on inflation.
AB - We investigated the effect of airway closure and alveolar collapse on the large-volume deflation and inflation transpulmonary pressure-volume (Pty-V) curves of five postmortem excised human lungs. For stepwise static cycles, no inflection occurred on the deflation curve, while either one or two inflections occurred on the inflation curve. These relations were simulated by a multicompartment model, which assumed a bimodal distribution of compartmental collapse-pressure differences. The simulations indicate that alveolar collapse can occur without causing an inflection on the deflation curve and that hysteresis in reopening of collapsed alveoli on inflation can account for a major portion of Ptp-V hysteresis. In contrast, for slow dynamic cycles, an inflection occurred on the experimental deflation Ptp-V curve, and when inflations were begun at sufficiently low volumes, volume did not change until a threshold pressure difference was reached about which Ptp began to oscillate as lung volume increased. These differences in the stepwise static and dynamic Ptp-V curves can result from sustained airway closure on deflation and popping-open on inflation.
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U2 - 10.1152/jappl.1981.51.2.353
DO - 10.1152/jappl.1981.51.2.353
M3 - Article
C2 - 7263442
AN - SCOPUS:0019431433
VL - 51
SP - 353
EP - 362
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 2
ER -