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ORIGINAL RESEARCH article

Front. Physiol.
Sec. Respiratory Physiology and Pathophysiology
Volume 15 - 2024 | doi: 10.3389/fphys.2024.1408531

Modelling lung diffusion-perfusion limitation in mechanically ventilated SARS-CoV-2 patients

Provisionally accepted
Giuseppe A. Miserocchi Giuseppe A. Miserocchi 1*Emanuele Rezoagli Emanuele Rezoagli 2,3Agueda Munoz Del Carpio Toia Agueda Munoz Del Carpio Toia 4Pamela Leydi Pamela Leydi 5Natalia Zubieta Natalia Zubieta 6Gustavo Zubieta-Calleja Gustavo Zubieta-Calleja 6Egidio P. Beretta Egidio P. Beretta 2
  • 1 University of Milano-Bicocca, Milan, Italy
  • 2 Department of Medicine and Surgery, University of Milano Bicocca, Monza, Italy
  • 3 IRCCS San Gerardo dei Tintori Foundation, Monza, Italy
  • 4 Catholic University of Santa María, Arequipa, Arequipa, Peru
  • 5 Unidad de Cuidados Intensivos, Hospital Nacional Carlos Alberto Seguin Escobedo,, Arequipa, Peru
  • 6 High Altitude Pulmonary and Pathology Institute (HAPPI-IPPA), La Paz, La Paz, Bolivia

The final, formatted version of the article will be published soon.

    This is the first study to describe the daytime evolution of respiratory parameters in mechanically ventilated COVID-19 patients. The data base refers to patients hospitalised in the intensive care unit (ICU) at Arequipa Hospital (Peru, 2335m) in 2021. In both survivors (S) and non survivors (NS) patients, a remarkable decrease in respiratory compliance was observed, revealing a proportional decrease in inflatable alveolar units. The S and NS patients were all hyperventilated and their SatO2 was maintained at >90%. However, while S remained normocapnic, NS developed progressive hypercapnia. We compared the efficiency of O2 uptake and CO2 removal in the air blood barrier relying on a model allowing to partition between diffusion and perfusion limitations to gas exchange.The decrease in O2 uptake was interpreted as diffusion limitation, while the impairment in CO2 removal was modelled by progressive perfusion limitation. The latter correlated with the increase in positive end-expiratory pressure (PEEP) and plateau pressure (Pplat), leading to capillary compression, increased blood velocity, and considerable shortening of the air-blood contact time.

    Keywords: dead space, Respiratory compliance, Gas exchanges, Diffusion limitation, perfusion limitation, alveolar pressure, Lung distension, mechanical ventilation

    Received: 28 Mar 2024; Accepted: 18 Jun 2024.

    Copyright: © 2024 Miserocchi, Rezoagli, Munoz Del Carpio Toia, Leydi, Zubieta, Zubieta-Calleja and Beretta. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Giuseppe A. Miserocchi, University of Milano-Bicocca, Milan, Italy

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