title: Alveolar mechanics studied by in vivo microscopy imaging through intact pleural space.
abstract: In six male anesthetized, tracheotomized, and mechanically ventilated rabbits we derived indications on alveolar mechanics from in vivo imaging, using a "pleural window" technique (pleural space intact) that allows unrestrained movement of the same subpleural alveoli (N=60) on increasing alveolar pressure from 4 to 8 cmH2O. Absolute compliance (C(abs), ratio of change in alveolar surface area to the change in alveolar pressure) was significantly lower in smaller compared to larger alveoli. Specific compliance, C(sp), obtained by normalizing C(abs) to alveolar surface area, was essentially independent of alveolar size. Both C(abs) and C(sp) were affected by large variability likely reflecting the complex matching between elastic and surface forces. We hypothesize that the relative constancy of C(sp) might contribute to reduce interregional differences in parenchymal and surface forces in the lung tissue by contributing to assure a uniform stretching in a model of mechanically inter-dependent alveoli.
authors: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy. Electronic address: caterina.salito@polimi.it.
authors: Caterina
authors: C
authors: Salito
authors: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy.
authors: Andrea
authors: A
authors: Aliverti
authors: Department of Experimental Medicine, University of Milano-Bicocca, Monza, Italy.
authors: Ilaria
authors: I
authors: Rivolta
authors: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy.
authors: Enrico
authors: E
authors: Mazzuca
authors: Department of Experimental Medicine, University of Milano-Bicocca, Monza, Italy.
authors: Giuseppe
authors: G
authors: Miserocchi
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001999:Bronchoscopy; D005110:Extracellular Space / Q000502:physiology; D007091:Image Processing, Computer-Assisted; D008170:Lung Compliance / Q000502:physiology; D008297:Male; D011650:Pulmonary Alveoli / Q000033:anatomy & histology* / Q000502:physiology*; D011817:Rabbits; D015656:Respiratory Mechanics
keywords: Alveolar mechanics; Compliance; In vivo microscopy imaging