Vol 8, No 1 (2022)

Due to the outbreak of a new coronavirus infection in 2019–2021, the treatment of respiratory system diseases using heated oxygen-helium mixtures has unexpectedly become more urgent. Many publications, messages, interviews appeared in the media, where technologies and designs are called pioneer, and the authors (there were many of them) call themselves pioneers, creators of new innovative technologies, while the essence of the issue was distorted consciously or due to incompetence. This publication attempts to objectively, on the basis of documents, to establish the truth — to name the names of those who really proposed to implement the idea in practice.

The article is devoted to the analysis of literature data on the use of hyperbaric oxygenation (HBO) in patients with COVID-19, complicated by the development of SARS-CoV-2-associated pneumonia to build a hypothesis about possible mechanisms of therapeutic action of hyperbaric oxygen (HBO2) in this pathology. The expediency of using «soft» (1.3–2.0 attacks, 40–60 min) HBO modes in SARS-CoV-2-associated pneumonia is substantiated. Several possible mechanisms of elimination of HBO2 violation of lung gas exchange function in SARS-CoV-2-associated pneumonia are considered. Firstly, hyperoxic stimulation of diaphragm contraction. Secondly, the inhibitory effect of HBO2 on the development of interstitial and alveolar edema in the lungs. Thirdly, elimination of HBO2 stimulating effect of thrombin and fibrinogen on contractility of pulmonary capillary endotheliocytes. Fourth, regulation of HBO2 metabolism of fibronectin, thromboplastin, von Willibrant factors, and platelet activation factor in the wall of pulmonary capillaries. As a result, its thrombogenic activity increases in this pathology.

The aim is to evaluate the effectiveness of hyperoxic and hypoxic argon therapy in the correction of borderline functional states of a person.
Research methods. 16 men (aged 19–42 years) were examined. In group 1 (8 people), courses of normobaric oxygen therapy and hypoxic therapy were conducted: 14 daily procedures of 30 minutes of oxygen respiration, and then (after 30 minutes) 30 minutes of breathing with a gas mixture with an oxygen content in nitrogen of 16–14% vol. Argon therapy was performed in group 2 patients: 8 daily procedures of 20 minutes of breathing with a gas mixture containing 45% oxygen, 35% argon, nitrogen the rest, and then (after 20 minutes) — 20 minutes of breathing with a mixture containing 12–10% oxygen, argon 35% vol., nitrogen the rest.
Results and discussion: it was shown that in group 2 individuals, as a result of the carried-out corrective programs, there was an acceleration of recovery processes, better values of subjective, psychophysiological and somatic status indicators were recorded compared to group 1. Therefore, combined argon therapy is a more effective means of correcting functional conditions compared to standard hyperoxic and hypoxic therapy.

The purpose of the study: to assess the features of microcirculatory blood flow.
Materials and methods. A comparative assessment of microcirculation by laser Doppler flowmetry was carried out in 19 male volunteers aged 20–25 years against the background of breathing heated to 40° C oxygen-nitrogen and helium-oxygen gas mixtures.
Main results. Breathing with a heated oxygen-nitrogen mixture consisted in an increase (by approximately 25–35%) of the values of the integral indicator of microcirculation against the background of a decrease in its efficiency. Switching to breathing with a heated helium-oxygen mixture «HeliOx 25/75» in all examined persons also led to an increase in the volumetric velocity of the peripheral blood flow. However, the degree of increase in the indicator (by 35–45% compared with normal breathing conditions) turned out to be significantly more pronounced than it was during breathing with a heated oxygen-nitrogen mixture. In addition, when breathing «HeliOx 25/75», starting from about the 2^nd minute of breathing, an increase in the efficiency of microcirculation was observed due to an increase in the «contribution» to the blood flow reaction of its «active» (neuromyogenic) components.

The purpose of the scientific article was to study the neurophysiological mechanisms of the occurrence of convulsive activity when breathing oxygen under high pressure under conditions of hyperbaric oxygen and the role of the glutamatergic system in this process.
Research methods: Wistar rats, males, weighing 200–250 g. in the amount of 20 were used in the work. The animals were placed in a pressure chamber and compressed with medical oxygen up to 5 ATА. Behavioral reactions and signs of convulsive activity were recorded in animals during compression and during subsequent exposure. Two experimental groups were previously injected with a glutamine synthetase inhibitor at various concentrations 6 hours before compression.
The main results showed that irreversible inhibition of glutamine synthetase in the rat brain under the action of increased oxygen pressure led to a significant decrease in the latent period of convulsions.

The purpose of the scientific article is to study and analyze the features of medical and sanitary provision of diving operations in the Arctic zone of the Russian Federation.
Materials and methods. The application of theoretical and empirical research methods allowed analyzing the features of medical and sanitary provision of diving operations in the Arctic.
Results and their discussion. Studies have shown that the peculiarities of medical and sanitary provision of diving operations in the Arctic zone of the Russian Federation are associated with the prevention and treatment of hypothermia and decompression sickness in divers, including the use of heated oxygen-helium mixtures for breathing. To solve this problem, evacuation of injured divers with the help of transportation pressure chambers and special mobile diving complexes are also used to provide qualified and specialized assistance in Arctic conditions.

The purpose of the work: to identify the mechanisms of changes in kidney function and water-electrolyte metabolism in divers with different initial resistance to adverse factors of hyperbaria using oral stress renal tests.
Materials and methods. 44 men were examined. Initial resistance to adverse factors of hyperbaria was assessed in all subjects. To determine the state of kidney function, oral stress renal tests were performed under the influence of hypoxia, hyperoxia, toxic nitrogen concentrations and decompression gas formation.
Results and their discussion. Changes in kidney function and water-electrolyte metabolism occurring under the action of hyperbaria factors are largely determined by hormonal mechanisms implemented through the renin — angiotensin-aldosterone system (RAAS). Under the action of hypoxia, hyperoxia, toxic nitrogen concentrations and decompression gas formation on unstable subjects, the vector of changes in the activity of RAAS will mainly be directed towards increasing the secretion of antidiuretic hormone and aldosterone.

The aim of the scientific work was to study the multidirectional effect of hypoxic sessions presented to pregnant rats at different periods of gestation on the manifestation of the ventilatory reaction of their offspring with dosed hypoxic hypoxia.
Materials and methods: a plethysmograph were used to record respiratory volume, respiratory rate and calculate the minute volume of respiration of intact rats (n=77) of the Wistar breed.
Results and discussion: presentation of a hypoxic stimulus to pregnant rats on certain days of gestation did not affect the gestation period, body weight and number of offspring, but changed the ventilatory response to hypoxia in males born and reached three months of age. Prenatal hypoxia, presented in the middle of pregnancy, led to a decrease in the ventilatory response to lack of oxygen in the offspring, and exposure of pregnant rats in hypoxic conditions at the end of the second trimester increased the ventilatory response to hypoxia.

The purpose of the scientific article is to study the new experience of using the hyperbaric oxygenation method in the complex treatment and rehabilitation of patients who have suffered a coronavirus infection when they have postcovid syndrome.
Research methods. During 750 HBO sessions, the dynamics of cardiovascular and respiratory system indicators in patients before and after each session was studied. The data of computed tomography (CT) and external respiration function (FVD) were analyzed before and after the course application of the hyperbaric oxygenation method. The contingent of subjects: 65 patients of different age groups who had suffered a coronavirus infection of varying severity were treated and examined.
Results and their discussion. Hyperbaric oxygenation in the complex treatment and rehabilitation of postcovid syndrome is an effective and promising technique. An algorithm for conducting the HBO course at the outpatient stage of rehabilitation has been developed. The use of the method at an earlier time after hospitalization helps to solve not only medical problems faster — the restoration of functions and structures of damaged organs, but also social problems — the return of able-bodied patients to work and normal daily loads.

As a result of Soviet investigations Russia succeeded for underwater activities and deep-sea diving technologies. The appropriate means and methods were designed and produced. Deep-sea diving is based on advanced diving technique both with medical arrangement. Appropriate regulations determine safety procedures. Progress in diving depends on theoretic investigations, research and design and valid experimental studies. The scheme for deep-diving technologies development is presented.