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Computational pulmonary edema: A microvascular model of alveolar capillary and interstitial flow

We present a microvascular model of fluid transport in the alveolar septa related to pulmonary edema. It consists of a two-dimensional capillary sheet coursing by several alveoli. The alveolar epithelial membrane runs parallel to the capillary endothelial membrane with an interstitial layer in betwe...

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Detalles Bibliográficos
Autores principales: Grotberg, James B., Romanò, Francesco
Formato: Online Artículo Texto
Lenguaje:English
Publicado: AIP Publishing LLC 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9653270/
https://www.ncbi.nlm.nih.gov/pubmed/36389648
http://dx.doi.org/10.1063/5.0109107
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author Grotberg, James B.
Romanò, Francesco
author_facet Grotberg, James B.
Romanò, Francesco
author_sort Grotberg, James B.
collection PubMed
description We present a microvascular model of fluid transport in the alveolar septa related to pulmonary edema. It consists of a two-dimensional capillary sheet coursing by several alveoli. The alveolar epithelial membrane runs parallel to the capillary endothelial membrane with an interstitial layer in between, making one long septal tract. A coupled system of equations is derived using lubrication theory for the capillary blood, Darcy flow for the porous media of the interstitium, a passive alveolus, and the Starling equation at both membranes. Case examples include normal physiology, cardiogenic pulmonary edema, noncardiogenic edema Acute Respiratory Distress Syndrome (ARDS) and hypoalbuminemia, and the effects of positive end expiratory pressure. COVID-19 has dramatically increased ARDS in the world population, raising the urgency for such a model to create an analytical framework. Under normal conditions, the fluid exits the alveolus, crosses the interstitium, and enters the capillary. For edema, this crossflow is reversed with the fluid leaving the capillary and entering the alveolus. Because both the interstitial and capillary pressures decrease downstream, the reversal can occur within a single septal tract, with edema upstream and clearance downstream. Overall, the interstitial pressures are found to be significantly more positive than values used in the traditional physiological literature that creates steep gradients near the upstream and downstream end outlets, driving significant flows toward the distant lymphatics. This new physiological flow may provide a possible explanation to the puzzle, noted since 1896, of how pulmonary lymphatics can function so far from the alveoli: the interstitium can be self-clearing. At the request of the authors, this article is being retracted effective 7 June 2023.
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spelling pubmed-96532702022-11-15 Computational pulmonary edema: A microvascular model of alveolar capillary and interstitial flow Grotberg, James B. Romanò, Francesco APL Bioeng Articles We present a microvascular model of fluid transport in the alveolar septa related to pulmonary edema. It consists of a two-dimensional capillary sheet coursing by several alveoli. The alveolar epithelial membrane runs parallel to the capillary endothelial membrane with an interstitial layer in between, making one long septal tract. A coupled system of equations is derived using lubrication theory for the capillary blood, Darcy flow for the porous media of the interstitium, a passive alveolus, and the Starling equation at both membranes. Case examples include normal physiology, cardiogenic pulmonary edema, noncardiogenic edema Acute Respiratory Distress Syndrome (ARDS) and hypoalbuminemia, and the effects of positive end expiratory pressure. COVID-19 has dramatically increased ARDS in the world population, raising the urgency for such a model to create an analytical framework. Under normal conditions, the fluid exits the alveolus, crosses the interstitium, and enters the capillary. For edema, this crossflow is reversed with the fluid leaving the capillary and entering the alveolus. Because both the interstitial and capillary pressures decrease downstream, the reversal can occur within a single septal tract, with edema upstream and clearance downstream. Overall, the interstitial pressures are found to be significantly more positive than values used in the traditional physiological literature that creates steep gradients near the upstream and downstream end outlets, driving significant flows toward the distant lymphatics. This new physiological flow may provide a possible explanation to the puzzle, noted since 1896, of how pulmonary lymphatics can function so far from the alveoli: the interstitium can be self-clearing. At the request of the authors, this article is being retracted effective 7 June 2023. AIP Publishing LLC 2022-11-11 /pmc/articles/PMC9653270/ /pubmed/36389648 http://dx.doi.org/10.1063/5.0109107 Text en © 2022 Author(s). https://creativecommons.org/licenses/by/4.0/All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) ).
spellingShingle Articles
Grotberg, James B.
Romanò, Francesco
Computational pulmonary edema: A microvascular model of alveolar capillary and interstitial flow
title Computational pulmonary edema: A microvascular model of alveolar capillary and interstitial flow
title_full Computational pulmonary edema: A microvascular model of alveolar capillary and interstitial flow
title_fullStr Computational pulmonary edema: A microvascular model of alveolar capillary and interstitial flow
title_full_unstemmed Computational pulmonary edema: A microvascular model of alveolar capillary and interstitial flow
title_short Computational pulmonary edema: A microvascular model of alveolar capillary and interstitial flow
title_sort computational pulmonary edema: a microvascular model of alveolar capillary and interstitial flow
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9653270/
https://www.ncbi.nlm.nih.gov/pubmed/36389648
http://dx.doi.org/10.1063/5.0109107
work_keys_str_mv AT grotbergjamesb computationalpulmonaryedemaamicrovascularmodelofalveolarcapillaryandinterstitialflow
AT romanofrancesco computationalpulmonaryedemaamicrovascularmodelofalveolarcapillaryandinterstitialflow