The purpose of writing the review. Analysis of publications on the role of iron metabolism in the manifestation of the septic process and the dependence of bacterial flora activity on the conditions of their access to iron. Methods. More than 200 publications in pubmed, Medline, EMBASE medical literature databases were analyzed between 2000 and 2018 using the search words: iron and infection, iron and sepsis, iron exchange, iron and bacteria - including and available works in domestic (e-library) literature. Results. The review uses materials from 61 publications that meet the challenges of the search and reflect both the relationship between iron exchange and the development of the septic process and the importance for the medical community of understanding the identified relationships in the search for future therapeutic approaches. Conclusion. The review provides evidence of direct iron involvement in the manifestation of the septic process caused by various bacterial (q/-) and fungal flora. Introduction of iron-hesing agents and ciderophon - conjugate drugs to infected patients today seems to be a biologically acceptable approach as an auxiliary therapy in the treatment of septic process caused by pathogens dependent on iron supply (many bacterial and fungal pathogens), but the problem that is being raised certainly requires further experimental and clinical research.
Oxygen is the main regulator of metabolic processes in the body not only in the context of normal physiology, but also in the development of various critical conditions. In recent years, the problem of pathogenesis of a number organs' and systems' diseases has been enriched by knowledge of the mechanism of damage to cellular structures. Oxygen turned out to be the main factor of damage the very oxygen, due to the lack of which cell death occurs. It turned out that the so-called reactive oxygen species having an unpaired electron have a biological effect, which, depending on the concentration, can be regulatory or, conversely, toxic. Accordingly, interest has also been aroused in compounds that normally prevent the toxic effect of reactive oxygen species antioxidants. Today it is generally recognized that oxidative stress plays an important and possibly a key role in the pathogenesis of critical conditions. Thus, on the one side, excessive production of free radicals is considered as one of the manifestations of the body's protective reaction to the effects of various environmental factors and living conditions (infections, injuries, toxins, ionizing radiation, physical stress, hypothermia, hypoxia, various types of stress), on the other ― increased production of free radicals quickly leads to irreversible damage: destruction of the erythrocytes' membranes with subsequent hemolysis, transformation of hemoglobin into methemoglobin, DNA damage, desensitization of plasma membrane receptors, inactivation of various hormones and enzymes, including antiradical and antiperoxide protection enzymes. The problem of using oxygen in critical conditions is currently widely discussed in the periodical literature with an emphasis on the oxygen concentrations used in patients, both in operating rooms and in intensive care units. Oxygen used in the intensive care of acute respiratory failure and hypoxia should have a certain concentration range. The toxic effects of oxygen can occur with its prolonged use in high concentrations, which causes not only its direct toxic effect on the lungs, but also in the potentiation of the activation of free radical oxidation and excessive production of reactive oxygen species. The review presents current data on the physiological role of oxygen, its participation in metabolic processes against the background of inflammation, hypoxia and under conditions of activation of free radical oxidation processes. The recent approach to oxygen therapy and the research data presented in the review urge to relate to oxygen as a drug in order to avoid manifestations of its toxic effects.
Hypotension is the most common adverse effect of spinal anesthesia (SA). The insidence of SA-induced hypotension in the total population is 15-33%, in patients of older age groups it reaches 80%. At young and middle ages, the main determinant of SA-induced hypotension is considered to be a reduction of postload and venous reflux, due to blood deposition in capacitance vessels of the lower extremities. The aortocaval compressionsyndromeplays a significant role in obstetric practice, cardiac output does not change. In elderly patients, the main prerequisite for the development of hypotension is an enhanced basal sympathetic toneon the background of SA. In patients of this category, in addition to reducing the total peripheral vascular resistance (TPVR), a decline in cardiac output also plays a role. Risk factors for anesthesia-induced hypotension are the followings: (chronic alcohol consumption, history of hypertension, sensory block upper than Th6, and urgency of surgery). To prevent SA-induced hypotension it is advisable to reduce the doses of local anesthetics. Data from the most studies do not confirm the effectiveness of extended infusion therapy in the prevention and correction of hypotension. Vasopressors - phenylephrine in obstetric practice, ephedrine or dopamine in elderly patients are effectiveforpreventinghypotension.
A careful assessment of the risks and benefits should precede each decision to transfusion allogeneic erythrocytes. Currently, a number of important problem in transfusion medicine is very controversial, most importantly the influence of different transfusion thresholds on clinical outcome. The purpose of this article is to highlight some features regarding to effectiveness, outcomes and risks, as well as to present a new trend in the recommendations for blood transfusion. In our days there is a general consensus about the decision to transfuse blood to a specific patient should be based primarily on his/her need for global and regional oxygen delivery and consumption, i.e. on clinical assessment of signs of insufficient global and regional tissue oxygenation, which can vary significantly depending on the individual characteristics of the patient (reactivity features). Evaluation of these signs - physiological triggers of transfusion - requires a deep knowledge of the physiology and pathophysiology of blood transfusions and clinical experience. Actualization of theoretical knowledge and the formation of clinical experience on this problem will permit a physician to make decisions about blood transfusion with the lowest risk for the patient. However, quantitative criteria for individual blood indicators - numerical triggers of transfusion - can be useful in some situations, for example, when monitoring is insufficient or due to the lack of adequate sufficient experience of medical personnel.
Purpose. Search and presentation of data from experimental and clinical studies reflecting the central role of succinate and succinate dehydrogenase in the regulation of adaptation mechanisms in critical conditions. Material and methods. The search for literature sources was carried out using the electronic resources of the Russian scientific electronic library eLIBRARY.ru, with the use of the following keywords: «Krebs cycle, succinate, succinate dehydrogenase, critical conditions», as well as in the English-language text database of medical and biological publications on medical sciences PUBMED, where similar keywords «Krebs cycle, succinate, succinate dehydrogenase, critical conditions» were used. Results. Taking into account the data presented in the review, it can be stated that the complex of succinate and succinate dehydrogenase is the central link in the Krebs cycle and the main structure of the antihypoxic ensemble of all body cells during the adaptation period under critical conditions. Conclusion. The data of experimental and clinical studies reflecting the central role of succinate and succinate dehydrogenase not only in the mechanisms of adaptation to hypoxia, but also in the regulation of inflammation, thermogenesis, hemostasis disorders, acid-base state, electrolyte metabolism, vascular tone and trophism of intestinal tissues, as well as in immunological reactions of the body, allow us to consider the substrate and enzyme as the central link of the Krebs cycle and the main structure of the antihypoxic ensemble of all body cells. The data presented in the review open up new prospects for the use of succinates in critical conditions.
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