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03.02.2022 08:39
Study with a model lung: researchers from the TU Freiberg clarify the basics of oxygen transport in the lower respiratory tract
How oxygen is transported from the lungs to the blood and tissues is well known. However, the process cannot be measured with medical devices. In a current specialist publication, researchers from the field of biomedical fluid mechanics at the TU Bergakademie Freiberg present a way of making the oxygen transport between the trachea and the upper bronchial tree precisely visible and measurable with the help of a Plexiglas model of the lung. The results can provide intensive care medicine with important insights into optimizing the oxygen supply of ventilated patients.
The lungs ensure that the blood is supplied with oxygen from the air we breathe and that carbon dioxide is carried away. “While how the lungs work is well known, the vital organ itself is a kind of black box. Important values such as the oxygen concentration can only be measured precisely before inhalation or in the blood. How exactly the oxygen is distributed on its way through the lungs and what that means for intensive care ventilation has not yet been investigated,” says Prof. Rüdiger Schwarze. The expert in the field of fluid mechanics researches how liquids behave physically at the TU Bergakademie Freiberg.
Researchers develop Plexiglas model lungs
As part of a project funded by the German Research Foundation (DFG) from 2015 to 2020 (funding number: 257981040, total funding: 440,000 euros), the researchers developed a simplified model lung made of transparent Plexiglas: “Thanks to the model, we can bring light into the black box bring and visualize the process of gas exchange from the trachea to the upper bronchial tree. In the study, we examined the oxygen transport during so-called liquid ventilation,” explains Dr. Katrin Bauer, research associate and author of the article in the journal Scientific Reports. With this ventilation method, the supply is made with the oxygen-containing liquid perfluorocarbon instead of directly with oxygen. This method has so far been used in clinical studies for acute lung failure and for gentle ventilation of premature babies.
The researchers can make the oxygen in the model liquid visible in the Plexiglas lungs using an oxygen-sensitive and fluorescent dye and thus analyze how exactly the oxygen is distributed from the trachea to the upper bronchi during a simulated breathing cycle. “Specifically, we measured the concentration distribution of the dissolved oxygen during the flow and compared it with the velocity fields known from previous work,” explains co-author Thomas Janke.
Results can be transferred to ventilation with air
Since oxygen transport in the lungs in the upper bronchial tree is dominated by convection and not by diffusion, i.e. transport that is driven by the flow, the results can in principle be transferred from liquid ventilation to oxygen ventilation. “With the help of the lung model, we were able to understand exactly how oxygen is transported in the upper pulmonary branches with the supply of fresh air and the removal of used, oxygen-poor air,” explains Thomas Janke. “The higher the tidal volume, the faster the oxygen is distributed and the faster a higher oxygen concentration can be reached. However, an increased respiratory rate does not affect the oxygen concentration in the lower airways. So if you breathe faster, you don’t achieve a higher oxygen concentration,” says Dr. Katrin Bauer incorporates the results.
Include fundamentals in pre-clinical studies
In order to further validate the results of the basic research of the engineering scientists at the TU Bergakademie Freiberg for ventilation in intensive care units, preclinical studies would have to follow in further steps. “But there is currently no concrete cooperation,” says Prof. Rüdiger Schwarze.
Scientific contacts:
Dr.-Ing. Katrin Bauer, [email protected]
Originalpublikation:
Bauer, K., Janke, T. & Schwarze, R. Oxygen transport during liquid ventilation: an in vitro study. Sci Rep 12, 1244 (2022). https://doi.org/10.1038/s41598-022-05105-1
Features of this press release:
journalists
mechanical engineering, medicine
nationwide
research results
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