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Introduction. The paper deals with relaxation and creep coefficients, long-term ultimate bending deformation under long-term exposure to moisture and chemically active environment (10,000 hours) of sewer pipes.Materials and methods. 400, 1,200 and 1,400 mm diameter sewer pipes made of glass-reinforced polyester. A compressive load was applied to the specimen at a constant rate until a specific annular strain of (3.0 ± 0.5) % was achieved in (60 ± 10) s. The obtained specific annular strain was kept constant for 2 minutes, after this time the compressive load and annular strain were determined and recorded. The essence of the method is to load a test specimen, placed horizontally and immersed in water, at a given temperature, with a diametrically compressive load for a time during which the annular strain remains constant. The load is measured at specified intervals until 10,000 h is reached. According to the test results, the long-term specific annular stiffness and relaxation coefficient under the influence of moisture are determined in accordance with the methodology of GOST R 57008–2016. Two specimens shall be used for testing, unless otherwise specified in the normative document. Long-term specific ring stiffness and relaxation coefficient are the arithmetic mean obtained for two specimens.Results. It was found that the performance characteristics (long-term ultimate bending deformation, relaxation and creep coefficients when exposed to moisture) of the investigated sewer pipes are determined by the specific ring stiffness and their diameter. For polyester pipes with initial ring stiffness of 5,000 N/m2 increasing their diameter from 400 to 1,400 mm leads to linear increase of relaxation coefficient (from 0.79 to 0.96) and decrease of long-term ultimate bending strain (from 0.84 to 0.75 %) when exposed to moisture during 10,000 hours.Conclusions. The durability of the investigated sewer pipes made of glass-reinforced polyester exceeds 50 years.

The OBJECTIVE was to identify prognostic factors of long-term air leak after lobectomies based on the analysis of the main preoperative and surgical clinical and functional indicators.METHODS AND MATERIALS. A retrospective study included 71 patients who underwent lung resection in the volume of lobectomy for lung cancer. The patients were divided into three groups - group 1 (n=42, 59 %) - air leak through the drains stopped within a day after surgery; group 2 (n=10, 14 %) - the duration of air leak from the pleural cavity from 1 to 5 days; group 3 (n=19, 27 %) the duration of air leak more than 5 days after surgery.RESULTS. The average values of the main clinical, surgical and functional indicators, such as the frequency of concomitant COPD, the severity of its course, smoking status, access (thoracotomy / thoracoscopy) in the three groups were almost the same. The difference in the average value of DLCO was characterized by the greatest tendency to reliability: the longer the pulmonary air leak was, the lower the values of this indicator turned out to be. Correlation analysis revealed a noticeable feedback between the long-term pulmonary air leak and the preoperative level of FEV1 (r=-0.59), a direct relationship between the level of FEV1 and DLCO (r=0.51), as well as a noticeable feedback between the long-term pulmonary air leak and the level of DLCO (r=-0.61) and a direct moderate relationship between the pulmonary air leak and the time spent on the stair climbing test (r=0.38).CONCLUSIONS. The combination of a low level of FEV1, a low level of DLCO and a long duration of the stair climbing test makes it possible to assess the risk of prolonged pulmonary air leak as significant and take this into account during the surgical intervention.

The function of the respiratory parenchyma remaining after lung resection is one of the determining factors of the immediate result of the operation and the postoperative quality of life. A number of studies have been conducted to objectify the preoperative prognosis of the functional safety limit of thoracic interventions using a variety of methods and formulas. Unfortunately, until now, there is no convincing data on the correctness of at least one of the proposed methods for predicting respiratory function. The process of rehabilitation of postoperative ventilation function in the lungs is affected not only by the volume of parenchymal resection, but also by the area of resection, the method and trauma of access, the severity of emphysema, intraoperative trauma of mediastinal structures, postoperative progression of pulmonary fibrosis, etc., and video assisted surgery and segmental resections do not provide an obvious functional advantage in the long term after operations. During the first year after anatomical resection of the lung, functional indicators usually improve. Reasons (or reason) of such improvements are not always clear and may be associated with compensatory growth of the pulmonary parenchyma in a number of patients.

The objective was to investigate the efficiency of the preoperative rehabilitation for patients with planned anatomical lung resections.Methods and materials.The study included 92 patients aged 27 to 87 years (mean age (63±10.8) years), 25 women (27.2 %) and 67 men (72.8 %) who underwent anatomical lung resections (79 patients, 85.9 % for lung cancer). Group 1 (39 patients – 42 %) included patients who did not smoke or quitted smoking at least 2 months before the operation. Also, they complied with the recommendations regarding respiratory gymnastics and the use of exercise and induction spirometers in full for at least 14 days. All patients who continued smoking or abandoned it less than 2 weeks before the operation, did not use breathing exercises, were included in group 2 (53 patients – 58 %).Results. Significant difference was found in the number of complications in the studied groups (the average number of complications in one patient in group 1 was (0.46±0.8), in group 2 – (1.47±1.5), p = 0.03). The difference was found in the duration of hospitalization (19.7 days in group 1 and 25.3 days in group 2, p

The objective: basing on published data, to highlight the main issues of preparation of patients with concomitant lung pathology and a high risk of developing postoperative pulmonary complications for planned surgical interventions.Results: changes made to international guidelines over the past 5 years based on evidence-based studies and meta-analyzes have been analyzed. The article presents data on preoperative management of patients with concomitant lung pathologies and a high risk of postoperative pulmonary complications, assessment of the risk of developing these complications based on evaluation of the functional status of patients. It analyzes the contemporary recommendations on the perioperative prevention of pulmonary complications, the use of physical exercises and respiratory gymnastics in the perioperative period in patients with a high risk of postoperative pulmonary complications. It is concluded that the implementation of comprehensive strategy aimed at reducing the risk of pulmonary complications should ensure decrease in their frequency and mortality due to them.

Introduction. Currently, there is a tendency for a number of post-intubation patients to develop post-tracheostomic cicatricial stenosis of the trachea. This dictates a need for the improvement of surgical and anaesthesiologic approaches to intubation management. Objective: Analysis of the specific parameters of anesthesia for cervical tracheal resection in patients with stenosis of the trachea without its intubation.Subjects and methods. We analyzed 12 cases of circular resection of the trachea due to benign stenosis. The degree of anesthetic risk was as follows: 11 patients – ASA 3, 1 patient – ASA 4. Tracheal stenosis persisted for 14±6 months before it was resected (Me 4, Min 1, Max 67). The length of the resected part of the trachea was 27±3 mm (Me 25, Min 15, Max 40), duration of surgery – 159±9 min (Me 160, Min 65, Max 240). The anesthesia strategy included the insertion of the I-Gel supraglottic airway device with a jet ventilation catheter put through the I-Gel. Temporary stenting of the stenosis zone of the trachea before surgery (if necessary) instead of bougienate was an important component of the anesthesia strategy. Mandatory use of sedation (dexmedetomidine) is suggested before and within 12 hours after surgery.Results. This strategy can be successfully implemented if the minimum diameter of the tracheal stenosis exceeds 7 mm (the jet ventilation catheter is necessary to be applied through this lumen and a fine bronchoscope used to monitor the state of the catheter tip). Preliminary stenting with metal stents was performed in 5 patients. The I-Gel lumen was wide enough to manipulate a flexible endoscope, a catheter guide was inserted for jet ventilation, and then the catheter itself was placed. The use of high-frequency ventilation mask it advisable to ensure adequate gas exchange at all stages of the surgery. Sedation with dexmedetomidine reduced the patient’s discomfort after the surgery due to the fixation of the patient’s head with stitches in a “nodding” position, which reduced anastomosis tension. In all 12 patients, this anesthesia strategy was successful and provided a more favorable environment for surgeons compared to the classical approach with the use of an endotracheal tube. In all patients, anastomosis healed by primary tension with no complications.Conclusion. The use of a supraglottic airway device, dexmedetomidine, and temporary stenting of the stenotic part of the trachea allow the surgeon to avoid tracheal intubation during circular resection and expand the range of anesthesiological tools during tracheal surgery.

The analysis of literature on the possibility of performing anatomical pulmonary resections in patients with concomitant COPD was performed. According to most researchers, FEV1 and DL (CO) more than 80 % indicated a high probability of an uncomplicated postoperative period after any anatomical resection of the lung. If the specified parameters were less than 80 %, additional studies were required: functional tests (6-minute walk test, staircase test), stress testing, calculation of predicted postoperative values of respiratory function, and, if necessary, lung scintigraphy could be performed to study regional respiratory function. The decision about the possibility and need for surgical treatment should have been made individually at the threshold values of these parameters. At the same time, there is currently no system for assessing the risk of postoperative complications for a particular patient, based on all the information about it, which represents the potential for further research.The authors declare no conflict of interest.The authors confirm that they respect the rights of the people participated in the study, including obtaining informed consent when it is necessary, and the rules of treatment of animals when they are used in the study. Author Guidelines contains the detailed information.

Goal of the study: to evaluate the possibility of using dexmedetomidine for drug sedation when performing intraluminal endoscopic surgery (ILES). Materials and methods. 136 cases of dexmedetomidine used were analyzed in 100 patients at the age of 58.0 ± 1.5 years old (Me = 59, Min = 22, Max = 87) during the first and repeated video-assisted bronchoscopies, esophagogastroscopies, duodenoscopies and colonoscopies lasting for 73 ± 3 min. (Me = 65, Min = 15, Max = 330). Results. Sole use of dexmedetomidine was effective only in short-term ILES causing minimal trauma. If ILES lasts longer and causes bigger trauma dexmedetomidine is to be combined with nefopam, fentanyl, trimeperidin, propofol, and ketamine. Combined use of dexmedetomidine resulted in the reduction of doses of the drugs, provided opportunity to manage the depth of sedation without depression of spontaneous respiration, post-operative and post-procedure agitation, algidity, nausea and vomit. Conclusion. Dexmedetomidine can be considered as the drug of choice for sedation in ILES.

OBJECTIVE. The research showed the possibility of operative treatment of patients with terminal stage of respiratory failure who underwent long-term oxygen therapy. MATERIAL AND METHODS. Surgical correction of respiratory failure was performed for two patients after clinical, functional and radio studies. RESULTS. The degree of arterial hypoxemia significantly decreased after operation due to improved ventilation of maximally saved pulmonary tissue areas. This allowed doctors to apply a situational oxygen therapy. Tolerance of physical activity reliably improved and value of BODE-index decreased. CONCLUSIONS. The terminal stage of respiratory failure couldn’t be a contraindication to surgical treatment.

The influence of anesthetics, namelydexmeditomidine (Dexdor®, «Orion PharmaLtd.») and propofol (Propofol®, «Fresenius Kabi Ltd.»), on a photoinduced lysis of human red blood cells was under study in conditions close to the physiological ones (pH 7,4, 37 oC) using radachlorin (Radachlorin® «Radapharma Ltd.») as a photosensitizer. The «red» diode served as a source of light (658 nm). After irradiation (1.15 J/sm2.s) the process of haemolysis was monitored by a photometry, and a value T50 was measured, that is a period of time from the irradiation ending to the 50 % lysis of red blood cells in an incubation mixture. Dexmeditomidine in all concentrations tested, including the therapeutic range, failed to influence the T50 value. Propofol in the therapeutic range of its concentrations caused significant but doseindependent increase of T50 that is an evidence of the preparation antioxidant action. The absence of the dexmeditomidine «interference» into the mechanism of a photo dynamic effect can be considered as an advantage of thisanesthetic properly for the medical support of a photodynamic therapy.

The results of investigations of multi-component nanostructured coatings of (TiAlSiY)N/CrN type are presented. The influence of different variants of substrate surface pretreatment on adhesive strength and hardness of coatings was studied. Pre-treatment of samples was carried out in plasma of two-stage gas discharge according to various technological schemes. Except for ion-plasma purification, some samples were pretreated with a sublayer of chromium within 5 minutes. The coatings were formed by a vacuum-arc deposition method at simultaneous spraying of two cathode targets. The first cathode is made of chromium, and the second cathode is made of multicomponent Ti - Al - Si - Y alloy obtained by vacuum-arc remelting of powder mixture of the mentioned elements. The coatings were deposited on polished stainless-steel substrates at negative 280 V bias potential. The geometry of the unit and its elements, as well as technological characteristics of the processes of evaporation-condensation were selected so that at a speed of rotation of samples 8 revolutions per minute the formation of the coating with a total thickness of about 9.0 microns occurred in approximately 60 minutes. The analysis of the composition of the coatings shows that the content of elements in the coating differs greatly from the content of elements in the sprayed cathodes. The X-ray diffractometry has shown that all deposition modes are characterized by the formation of phases with cubic (fcc) crystal lattice in both phase layers of multilayer coatings. In the layers formed at spraying of TiAlSiY alloy, a multi-element disordered solid solution (TiAlSiY)N with a crystal lattice of NaCl type and a lattice parameter of 0.4241 nm, as well as chromium mononitride CrN with a lattice parameter of 0.4161 nm, is determined. It has been established that preliminary formation of a chromium sublayer on the substrate leads to significant changes in adhesive strength of multi-component coatings compared to coatings without a sublayer.