The development and implementation of the extracorporeal membrane oxygenation (ECMO) technique for the treatment of patients in critical conditions make it possible to effectively and safely support gas exchange processes in the blood for a long time. One of the main components of the ECMO unit is a gas permeable membrane which is a barrier separating the blood from the gas phase. Since the 1950s, the development of this technology has been aimed at improving the safety and duration of use of membranes, which led to the creation of oxygenators that provide life support for several weeks. This review is devoted to the development of the extracorporeal membrane oxygenation technology including the choice of materials, methods to improve their hemocompatibility, and approaches to the design of the membrane contactor.

Interaction of certain inorganic and organic compounds with activated carbon and the effect of such interaction on open circuit potential of activated carbon were studied. Open

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Electrochemical methods of redox potential measurements of aqueous solutions and biological media with a platinum electrode were analyzed. Probable reasons of the irreproducibility of open circuit potential measurements were considered. We suggested that accumulation of mixed oxides on the surface of platinum after each measurement may lead to potential shifts of the platinum electrode and therefore to a systematic error in redox potential measurements. Preliminary electrochemical treatment of platinum electrodes by cyclic impulses of externally applied potential was developed from the above considerations. The proposed method of measurement was tested in aqueous solutions of inorganic salts, blood, plasma and blood serum. Time dependencies of platinum electrode potential in the presence of inorganic salts and biological liquids were analyzed. We suggested defining the redox potentials of the tested solutions as potential of the platinum electrode after 10 - 30 min.

Relevance. Acute respiratory infection COVID-19 caused by the SARS-CoV-2 (2019-nCov) coronavirus is severe and extremely severe in 15—20% of cases, which is accompanied by the need for respiratory support. Hyperbaric oxygenation is recognized as an effective therapy for replenishing any form of oxygen debt.Aim of study. To study the safety of HBO use in patients with COVID-19.Material and metods. We examined 32 patients with the diagnosis “Coronavirus infection caused by the virus SARS-CoV-2” (10 — moderately severe patients (CT 1–2), 22 — patients in serious condition (CT 3–4), who received course of hyperbaric oxygenation (HBO). The procedures were carried out in a Sechrist 2800 chamber (USA) at a mode of 1.4–1.6 AT for no more than 60 minutes. In total, the patients received 141 HBO sessions. Before and after each HBO session, the subjective indicators of the patient’s condition were assessed and the blood oxygen saturation was measured.Results. An algorithm for HBO course management was developed, which consists in using “soft” modes (up to 1.4 AT) during the first session, followed by pressure adjustment (not higher than 1.6 AT) during the course to achieve maximum therapeutic effect and comfort for the patient. Against the background of the HBO course, the patients showed an increase in blood oxygen saturation in patients in both surveyed groups, as well as positive dynamics in the form of a decrease in shortness of breath, an improvement in general well-being.Conclusion. The inclusion of daily sessions (at least 4) of hyperbaric oxygenation in “soft” modes (1.4–1.6 ATA) in the complex therapy for COVID-19 has shown its safety and preliminary positive effect on the subjective state of the examined patients and the dynamics of blood oxygen saturation.

According to B. Nordenstrom's concept, homeostasis is controlled by biologically closed electrical circuits in the organism. Therefore, a wide application of implanted platinum electrodes in medicine for diagnostics and treatment is not surprising. Open circuit potentials of platinum electrodes in biological media, termed redox potentials, reflect the level of pro- and antioxidant activities in the organism. The dynamics of redox shifts towards negative potentials in patients with acute cerebral pathology as a result of the treatment by hyperbaric oxygenation was investigated. It was suggested that an increase in antioxidant activity occurs. Thus, redox potential measurements can be used to elucidate certain mechanisms of the effect of hyperbaric oxygenation procedure in patients with acute cerebral pathology. Correlation between redox values and toxicity or quantity of "middle molecule" was found.

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The proposed method is based on the electrochemical measurement of the open-circuit potential of the platinum electrode immersed in blood serum because the measured value reflects the state of equilibrium between prooxidant and antioxidant systems of the organism. Shifts in values of the RPs (open circuit potentials) observed in the course of monitoring are significantly different in patients with transplant dysfunction compared to patients with unremarkable recoveries. The analysis of monitoring allows for the development of certain diagnostic and prognostic criteria of transplant dysfunction. It is important that the proposed method is noninvasive, simple, and inexpensive.