Ventilation is frequently used in the treatment of cardiogenic and increased permeability pulmonary edema. The effects of ventilation on the computed tomography (CT) density distribution of pulmonary edema are unclear. We hypothesized that ventilation might open up previously collapsed alveoli with consequent reduced lung density, and that some movement of the alveolar edema fluid might also occur from the alveoli to the interstitium. To address this problem, pulmonary edema was induced in 16 supine dogs by airways instillation of a protein solution similar to serum in each lower lung lobe through a double lumen tracheal tube. The dogs were ventilated only on the left side for 1 min (n = 4), 30 min (n = 6) or 60 min (n = 6). The lower lobes were excised, frozen in liquid nitrogen, and imaged in a CT scanner. Representative regions of interest (ROI) were chosen and tissue sections from corresponding regions were taken for extravascular lung water (Qwl/dQl) and regional blood measurements, and for histology to grade interstitial and alveolar edema. There was a significant (P $<$ 0.05) fall in the CT density of the left lower lobes compared with the right lower lobes in the groups ventilated 30 and 60 min, but no differences in Qwl/dQl or blood content. The histological grading showed a trend (P = 0.054) for more interstitial edema in the left lower lobes in the 60 min ventilation group compared with left lower lobes in the 1 min ventilation group. These data show that in our model of instilled alveolar edema, ventilation acts primarily by increasing aeration by 30 min and that it has a minor role in moving fluid to the interstitium.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.55502 |
| Date | January 1994 |
| Creators | Iancu, Dan M. |
| Contributors | Michel, R. P. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Pathology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001426085, proquestno: AAIMM00029, Theses scanned by UMI/ProQuest. |
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