Skip to main content

Closed-loop circuit for reduce oxygen waste on hollow-fiber oxygenators during extracorporeal technologies

Closed-loop systems are designed to dynamically regulate a given variable around a desired set point. Examples thereof surround our everyday lives, from cruise control maintaining the correct speed on the highway, to auto-pilot flying modern airplanes safely [1]. Currently, there are two groups of hollow-fiber membrane oxygenator used in practice. The first types are diffusion, plasma-resistant oxygenators that have been increasingly used for extracorporeal life support or extracorporeal membrane oxygenation for patients who can no longer be supported by mechanical ventilation. The second types are hollow-fiber membranes made of microporous poly-propylene that have been widely used for standard cardiopulmonary bypass (CPB) [2]. Microporous hollow-fiber membranes are primarily used for short-term cardiopulmonary bypass application, whereas non-microporous hollow-fiber membranes are primarily used for extracorporeal membrane oxygenation application (ECMO) [3]. During the use of the oxygenator, the lung membrane uses about 30% of the medical oxygen delivered by the gas mixer, and the remainder comes out of the gas exhaust and is dispersed into the environment. In this context, we present a closed system aimed at recovering oxygen from the gas outlet of the oxygenator. First, the system recovers through a disposable polymer tube the gas flow from the oxygenator outlet; second, the condensate and water vapor will be removed with a water separator; third, the CO2 will be removed through a soda lime container; fourth, an electric control unit will decide whether to enrich the% of oxygen recovered through an oxygen source, in relation to the percentage of FiO2 set on the gas mixer (Fig. 1). The closed-loop circuit for oxygenators is a “concept development,” and no data are provided on feasibility in this context. The system should be implemented with continuous monitoring to avoid:

  • the water separator saturation, through excess water evacuation and appropriate filters

  • the risk of increasing pressure in the gas outlet through a safety valve

  • the risk for “rebreathing” and hence CO2 accumulation.

Fig. 1
figure1

Closed-loop circuit for reduce oxygen waste on hollow-fiber oxygenators during extracorporeal technologies

Our proposal has the objective of reducing waste and optimizing the use of medical oxygen; at the same time, this closed system is crucial during the transport phases (mostly airplane), in particular for patients on ECMO, to maximize the use of oxygen, guaranteeing greater autonomy.

Availability of data and materials

Not applicable.

References

  1. 1.

    Platen, PV, Pomprapa A., Lachmann B, et al. The dawn of physiological closed-loop ventilation—a review. Crit Care 24, 121 (2020). https://doi.org/https://doi.org/10.1186/s13054-020-2810-1

  2. 2.

    Berdajs DA, de Stefano E, Delay D, et al. The new advanced membrane gas exchanger. Interact Cardiovasc Thorac Surg. 2011;13(6):591–6. https://doi.org/10.1510/icvts.2011.276873.

    Article  PubMed  Google Scholar 

  3. 3.

    Iwahashi H, Yuri K, Nosé Y. Development of the oxygenator: past, present, and future. J Artif Organs. 2004;7(3):111–20. https://doi.org/10.1007/s10047-004-0268-6.

    Article  PubMed  Google Scholar 

Download references

Acknowledgements

Not applicable.

Funding

None.

Author information

Affiliations

Authors

Contributions

IC designed the work and the conceptualized the idea. RF gave support for the realization of the manuscript. GS gave support for manuscript language. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Ignazio Condello.

Ethics declarations

Ethical approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

None.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Condello, I., Rimmaudo, F. & Speziale, G. Closed-loop circuit for reduce oxygen waste on hollow-fiber oxygenators during extracorporeal technologies. Crit Care 25, 85 (2021). https://doi.org/10.1186/s13054-021-03514-8

Download citation

\