Suction System Research Articles

Intensive Care Nurses' Evidence-based Knowledge and Experiences Regarding Closed Suctioning System

Endotracheal suctioning is a vital procedure performed by intensive care nurses to maintain airway patency and optimal gas exchange in critically ill patients under mechanical ventilation. As the procedure can cause several complications, intensive care nurses should have adequate evidence-based knowledge on how to perform the procedure. This study aimed at examining intensive care nurses' knowledge and experience of the closed suctioning system. This study was a prospective, cross-sectional, descriptive, and multi-centered study conducted with 195 nurses working in the tertiary intensive care units in five Turkish hospitals. The data were collected with a questionnaire developed by the researchers in light of the literature. The data were evaluated with Kruskal-Wallis and Mann-Whitney U tests. The mean age of the nurses was 30.58 ± 6.28 years. The mean knowledge score of the nurses for the closed system was 27.35 ± 12.05 (range = 0-80) and 80.5% of them obtained scores ranging between 0 and 40. Also, 71.8% stated that they did not have any difficulty performing suctioning with the closed system catheter, and 85% said that they saved time with the closed system. However, 50.8% of the nurses said they were not able to suction viscous and sticky secretions efficiently, 44.6% stated they did not need to irrigate the inside of the catheter, and 45.1% of them were undecided whether the coude tip catheter led to hemorrhagic secretion more than straight tip catheter. Almost one-fifth of the nurses had good scores on evidence-based knowledge of suctioning. Most of the nurses' experiences regarding the use and manipulation of the closed system were positive. However, almost half of the nurses pointed out that the closed system was not effective enough to suction viscous and sticky secretions. Regular in-service training sessions may help to improve nurses' current knowledge and experiences.

Hybrid Laminar Flow Control on A320 Fin: Retrofit Design and Sample Results

A flight test with a simplified hybrid laminar flow control (HLFC) system on the vertical tail plane (VTP) of an A320 aircraft was performed in April/May 2018. This HLFC system was a prototype for a simplified system that might be attractive for drag reduction of commercial long-range aircraft. The paper presents the design principles of a simplified HLFC system, including passive suction, and shows their application to aerodynamic and suction system design for the retrofit of an A320 VTP. Furthermore, sample flight test results will be presented and discussed.

Airway gas temperature within endotracheal tube can be monitored using rapid response thermometer

Inappropriate preparation of respiratory gases is associated with serious complications during mechanical ventilation. To develop a temperature monitoring system of respiratory gases within the endotracheal tube, four newborn piglets were studied using an ultra-rapid-response thermometer attached to the closed endotracheal tube suction system. Respiratory gas temperatures were monitored at the mouth-corner level of the endotracheal tube using three thermocouples (Tairway, inserted into the endotracheal tube via the closed suction system; Ttube_centre and Ttube_wall, embedded within the endotracheal tube 0.5 mm and 1.6 mm from the tube wall, respectively). Univariate analysis showed that inspiratory Ttube_centre and inspiratory Ttube_wall were positively correlated with inspiratory Tairway (both p < 0.001). Multivariate analysis showed the dependence of inspiratory Tairway on inspiratory Ttube_centre and Ttube_wall and deflation of endotracheal tube cuff (p < 0.001, p = 0.001 and p = 0.046, respectively). Inspiratory gas temperature within the endotracheal tube can be monitored using a thermometer attached to the closed endotracheal tube suction system. Our system, with further validation, might help optimise respiratory gas humidification during mechanical ventilation.

Influence of suction and collar on reducing local scouring in cylindrical pier

Bridges are among the most important structures in river engineering. One of the significant causes of the destruction of bridges is local scouring around the piers. In the present research, collar and suction system both employed the upstream of the pier against local scouring. In separate experiments, the collar models were examined in different dimensions and the suction system was considered at different depth levels. Then, the combined collar-suction model was tested. The results showed that the suction system at the bed level (Z/h = 0) with the suction rate of (Qs/Q = 1.7%) had 51% efficiency; the 3D-length, 2D-width collar yielded 59% efficiency; and the combined suction-collar model had 94% efficiency in reducing local scouring of the pier by decreasing down-flow velocity, as well as the Reynolds Shear Stresses (RSSs) and Turbulence Kinetic Energy (TKE).

Potential sources of operating room air contamination: a preliminary study

The Neptune® surgical suction system (NSSS) and the Bair Hugger® (BH) forced-air warmer both discharge filtered exhaust or heated air into the operating room (OR), often in close proximity to a surgical site. To assess the effectiveness of this filtration, we examined the quantity and identity of microbial colonies emitted from their output ports compared with those obtained from circulating air entering the OR. Air samples were collected from each device using industry-standard sampling devices in which a measured volume of air is impacted on to a blood agar plate at a controlled flow rate. Twelve ORs were studied. Sample plates were incubated for one week per study protocol, then interpreted for colony counts and sent for species identification. The average colony count from the NSSS exhaust was not significantly different from that obtained from room air samples, however the average count from the BH output was significantly higher (P=0.0086) than room air. Genetic identification profiles revealed the presence of environmental or commensal organisms that differed depending on the source. High variability in colony counts from both devices suggests that certain NSSS and BH devices could be significant sources of OR air contamination. Our study showed that the BH patient warming device could be a source of airborne microbial contamination in the OR and that individual BH and NSSS units exhibit a higher output of microbial cfu than would be expected compared with incoming room air. We make simple suggestions on ways to mitigate these risks.

Optimizing effects on airway pressure and minute volume during closed endotracheal suctioning: a simulated lung model

A closed suction system is used to remove endotracheal secretions without interrupting the patient’s ventilation. Closed suctioning may reduce adverse effects associated with suctioning with, for example, decreased clinical signs of hypoxemia and limited environmental, personnel, and patient contamination. However, it is not clear whether ventilation is maintained during the procedure. We aimed to determine the effects of endotracheal tube (ETT) size, suction catheter (SC) size, and SC length in the ETT on ventilation parameters measured during suction. Suction was performed on a test lung, ventilated with either volume-controlled continuous mandatory ventilation (VC-CMV) or pressure-controlled continuous mandatory ventilation (PC-CMV) using ETT sizes of 6.0–8.5 mm paired with SC sizes of 8–16 French gauge (Fr = 0.33 mm). Airway resistance ( Raw), peak inspiratory pressure (PIP), positive end-expiratory pressure (PEEP), and expiratory minute volume ( Vexp) were recorded for each ventilation episode by a HAMILTON-G5 ventilator. Here, Raw was considerably increased by insertion of the SC into the ETT. This Raw effect altered the PIP and Vexp. PIP was increased in VC-CMV because the ventilation area of the ETT was reduced, and Vexp was decreased in PC-CMV in relation to the size of the SC. PEEP decreased with application of the 16 Fr SC and 30 L/min flow rate in VC-CMV. We conclude that airway pressure and minute volume are not maintained during closed endotracheal suctioning with VC-CMV and PC-CMV, respectively. The degree of interference to ventilation is affected through selection of appropriate SC size and ventilation settings.

리니어 압축기 흡입계 형상에 따른 EER 변화 예측

Refrigerators are comprised of compressors, condensers, expansion valves, and evaporators. Among these parts, a compressor accounts for the majority of power consumed by a refrigerator. Therefore, it is important to improve the efficiency of a compressor to save the electrical energy consumed in a household. In this study, the variation in energy efficiency ratio (EER) with respect to muffler shape was examined for a linear compressor suction system. Furthermore, two cases, namely the baseline model and modified model, were considered. For numerical analysis, a one-dimensional lumped model and CFD coupled model were adopted. The numerical analysis results indicated that the modified model improved EER by approximately 0.49% in comparison with the baseline model. Hence, the modified model was more effective in energy saving. Additionally, the experimental results were qualitatively consistent with the numerical analysis results.

Expert consensus statements for the management of COVID-19-related acute respiratory failure using a Delphi method

BackgroundCoronavirus disease 2019 (COVID-19) pandemic has caused unprecedented pressure on healthcare system globally. Lack of high-quality evidence on the respiratory management of COVID-19-related acute respiratory failure (C-ARF) has resulted in wide variation in clinical practice.MethodsUsing a Delphi process, an international panel of 39 experts developed clinical practice statements on the respiratory management of C-ARF in areas where evidence is absent or limited. Agreement was defined as achieved when > 70% experts voted for a given option on the Likert scale statement or > 80% voted for a particular option in multiple-choice questions. Stability was assessed between the two concluding rounds for each statement, using the non-parametric Chi-square (χ2) test (p < 0·05 was considered as unstable).ResultsAgreement was achieved for 27 (73%) management strategies which were then used to develop expert clinical practice statements. Experts agreed that COVID-19-related acute respiratory distress syndrome (ARDS) is clinically similar to other forms of ARDS. The Delphi process yielded strong suggestions for use of systemic corticosteroids for critical COVID-19; awake self-proning to improve oxygenation and high flow nasal oxygen to potentially reduce tracheal intubation; non-invasive ventilation for patients with mixed hypoxemic-hypercapnic respiratory failure; tracheal intubation for poor mentation, hemodynamic instability or severe hypoxemia; closed suction systems; lung protective ventilation; prone ventilation (for 16–24 h per day) to improve oxygenation; neuromuscular blocking agents for patient-ventilator dyssynchrony; avoiding delay in extubation for the risk of reintubation; and similar timing of tracheostomy as in non-COVID-19 patients. There was no agreement on positive end expiratory pressure titration or the choice of personal protective equipment.ConclusionUsing a Delphi method, an agreement among experts was reached for 27 statements from which 20 expert clinical practice statements were derived on the respiratory management of C-ARF, addressing important decisions for patient management in areas where evidence is either absent or limited.Trial registration: The study was registered with Clinical trials.gov Identifier: NCT04534569.

Open and Closed Endotracheal Suction Systems Divergently Affect Pulmonary Function in Mechanically Ventilated Subjects.

In mechanically ventilated subjects, intra-tracheal secretions can be aspirated with either open suction systems (OSS) or closed suction systems (CSS). In contrast to CSS, conventional OSS require temporarily disconnecting the patient from the ventilator, which briefly diminishes PEEP and oxygen supply. On the other hand, CSS are more expensive and less effective at aspirating secretions. Thus, it was hypothesized that the 2 procedures differentially affect pulmonary and cardiovascular parameters after suction. Subjects in the ICU (N = 66) were quasi-randomized for initial treatment with OSS or CSS in a crossover design. To compare the potential for these suction systems to compromise cardiorespiratory stability, changes in cardiopulmonary physiology were assessed from before to just after use of each suction system (three 10-s aspirations). For most pulmonary and cardiovascular parameters (ie, peak inspiratory pressure, airway resistance, pressure plateau, heart rate, and arterial pressures), the effects of aspiration inversely correlated with baseline values for that parameter, with a similar regression slope between suction systems. However, when controlling for baseline values, OSS caused significantly greater increases in airway resistance and peak inspiratory pressure (P < .001 and < .01 vs CSS, respectively). Elevated airway resistance prior to endotracheal suction may justify use of a CSS and contraindicate a conventional OSS in mechanically ventilated subjects. Adoption of this approach into clinical guidelines may prevent suction-induced pulmonary injury in subjects, especially for those with underlying diseases involving increased airway resistance or increased alveolar pressure. (ClinicalTrials.gov registration: NCT03256214.).

Closed endotracheal suction catheter system related complications in mechanically ventilated COVID-19 patients.

Sir, In the current coronavirus disease 2019 (COVID-19) pandemic, about 15% of patients may develop severe disease and 5% critical disease requiring admission to an intensive care unit (ICU) and mechanical ventilation.[1] In mechanically ventilated patients, closed endotracheal suctioning system is used to prevent disconnection of circuit and consequent de-recruitment of alveoli and to prevent aerosolisation of droplets and potential contamination of surroundings.[23] However, in times of sudden surge in cases, trained ICU staff may not be always available. Moreover, efficiency is reduced after wearing personal protective equipment (PPE) and visibility may turn poor due to fogging of goggles. Therefore, inadvertent human errors may occur. We report two such cases involving the use of in-line closed suction catheter system (DAR™ closed suction system, Covidien Ireland Limited). In the first case, we noticed that the closed suction catheter was not completely withdrawn outside after suctioning was complete and the rotatory access knob was closed. Presence of part of the suction catheter inside the endotracheal tube led to increase in the peak airway pressures and frequent ventilator alarms that was initially interpreted as bronchospasm [Figure 1a]. However, a very close inspection revealed the actual problem. In another case, although the suction catheter was completely withdrawn, the rotating access knob was not closed, which led to significant leak in the circuit and activation of ventilator alarms [Figure 1b]. Inflated plastic sheath covering of the closed suction system revealed this problem. These kinds of problem may lead to unnecessary troubleshooting warranting treatment/interventions (like treating with bronchodilators in case of misdiagnosed bronchospasm or inflating the pilot balloon further in case of leak), which may even harm the patient (like barotrauma or alveolar de-recruitment). Fortunately, in both our cases, the actual problems were identified and no adverse events were seen. Problems like blocked tip of closed suction catheter leading to inadequate suctioning[4] and migration of piece of closed suction catheter leading to bronchial obstruction have been already reported.[5]Figure 1: (a) Closed suction catheter (black arrow) partially kept inside endotracheal tube and difficult to detect due to transparent colour of distal part of the catheter; (b) rotating access knob was not closed causing leak and overinflated plastic sheathing (white arrow)While the nursing staff were aware of the standard operating procedures for the closed suction system in ICU, impaired visibility due to fogging of goggles was the reason reported behind such inadvertent mistakes in both the cases. The fogging issue has been addressed by regular use of antifogging markers.[6] However, we would like to suggest two design modifications of the closed suction system. First, the colour of the in-line catheter may be made more conspicuous throughout the length of the catheter. The suction catheter of DAR™ closed suction system (Covidien Ireland Limited) is blue in the advancing end while being transparent towards the tail end [Figure 1b] and may evade detection if left inside the ventilator circuit with suboptimal visibility while working with PPEs. Second, an in-line self-sealing valve/diaphragm may be placed at the rotatory access knob to eliminate the risk of circuit leak in case the rotating access knob is inadvertently left open. To conclude, impaired visibility due to fogging of goggles may lead to inadvertent errors while operating equipment like closed suction catheter system in COVID-19 ICUs. Heightened vigilance and appropriate troubleshooting interventions might avoid and resolve such unintentional mistakes. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Laser dentistry in daily practice during the COVID-19 pandemic: Benefits, risks and recommendations for safe treatments.

The COVID-19 pandemic forced dental professionals to cope with an unexpected challenge and caused an abrupt cessation of conventional care practices. The high degree of contagiousness as well as the diffusion of the virus through the air and droplets via respiratory transmission placed dental professionals at top-level risk of contracting and spreading the disease. General recommendations were announced in different countries, including patient distancing, air ventilation, surface and instrument sanitization, and the wearing of suitable masks and shields. However, many dental treatments are performed using lasers, and some specific precautions must be added to conventional procedures to ensure the advantages of this technology to patients because of the particular tissue–matter interaction effects of laser wavelengths. Based on the literature, the authors evaluated all of using laser wavelengths to analyze the risk and the benefits of using lasers in daily dental practice, and to provide safety recommendations during pandemic. An unrestricted search of indexed databases was performed. Laser use effects were categorized into: 1) explosive processes that produce tissue ablation and aerosol formation; 2) thermal actions that create vaporization and smoke plume; 3) photobiomodulation of the cells; and 4) enhanced chemical activity. Knowledge of the device functions and choice of adequate parameters will reduce aerosol and plume formation, and the application of suction systems with high flow volume and good filtration close to the surgical site will avoid virus dissemination during laser use. In the categories that involve low energy, the beneficial effects of lasers are available and sometimes preferable during this pandemic because only conventional precautions are required. Lasers maintain the potential to add benefits to dental practice even in the COVID-19 era, but it is necessary to know how lasers work to utilize these advantages. The great potential of laser light, with undiscovered limits, may provide a different path to face the severe health challenges of this pandemic.

Clinical application of a digital thoracic drainage system for objectifying and quantifying air leak versus the traditional vacuum system: a retrospective observational study.

BackgroundDigital thoracic drainage systems have recently been introduced and widely used in clinical practices in developed countries. These systems can monitor intrathoracic pressure changes and air leaks in real time, and also allow for objective and quantitative analyses, which aid in managing patients with a prolonged persistent air leak into the pleural space. We investigated the feasibility and effectiveness of such a new device versus the traditional vacuum system for treating patients with pneumothorax.MethodsClosed thoracostomy drainage was carried out on 100 adult patients with primary or secondary pneumothorax between January 2017 and December 2018. All the patients were aged ≥18 years and treated with a chest tube at a single medical center by the same cardiothoracic surgeons and intensivists. Patients who underwent closed thoracostomy drainage using an indwelling 24-French chest tube were divided into 2 groups immediately before closed thoracostomy: the digital thoracic drainage group (digital group, n=50) and the traditional analogue thoracic drainage group (analogue group, n=50). The detailed information about demographic data, treatment outcome, duration of indwelling catheterization., hospital days, cost-effectiveness and patient satisfaction was evaluated. We also evaluated whether digitally recorded intrapleural pressure changes and air leaks would predict chest tube removal timing and outcome.ResultsThe baseline parameters of the 2 groups were comparable with no significant differences in sex, age, weight or body mass index. The mean hospital day was shorter in the digital group than in the analogue group (17.96±12.23 vs. 18.32±16.64, P=0.902), and there was no statistically significant difference in the hospital length of stay between the 2 groups. Air leaks through the chest tube and duration of chest tube indwelling hours showed no significant statistical differences between the digital and analogue groups (213.47±219.80 vs. 261.94±184.47, P=0.235 and 223.44±218.75 vs 275.29±186.06, P=0.205, respectively). Total drainage amount and ambulation time per day were significantly higher in the digital group than in the analogue group [209.62±139.63 vs. 162.48±80.42 (P=0.042) and 6.42±3.62 vs.3.94±1.74 (P<0.001), respectively]. Hours of full expansion were significantly shorter and sleep disturbance caused by the noise of chest tube drainage was less in the digital group than in the analogue group [25.64±14.55 vs. 46.52±25.53 (P<0.001) and 2.38±1.03 vs. 5.70±2.87 (P<0.001), respectively].ConclusionsTo date, there is no definite consensus and guidelines on the standardized digital suction system in pneumothorax. This study proposed the guidelines for the application of digital thoracic drainage systems in pneumothorax and also suggested that digital thoracic drainage systems might be a valuable tool to determine chest tube removal timing and reducing the length of hospital stay in patients with pneumothorax.

Laboratory and numerical investigations of the effect of geometric parameters on the buckling capacity of thin-walled composite cylindrical shells under external pressure loading.

Buckling is one of the important issues in determining the mechanical behavior of cylindrical shells, especially composite shells. What makes the buckling matter important in composite cylindrical shells is the complexity of the behavior of these structures under the influence of a variety of special loads such as buckling under external pressure load. Uniform lateral loading in tanks occurs when tanks are in the state of liquid discharge. Moreover, if special contrivances such as the drainage valves do not work or properly, then buckling phenomenon and will cause an overall failure in the tank. In this research, the air suction system is used in order to apply external pressure and study the buckling behavior of specimens. As the buckling occurs, tiny cracks are created with a mild sound in the shell wall and in the extreme stage the loading process stops when it collapses. In this paper, the effect of geometric parameters, such as the R/t and L/R of a composite tank under external pressure, on buckling behavior is investigated. Obtained results are compared with software and theoretical results. The results showed in specimen of the same length, by increasing the geometric parameter R / t, the buckling capacity of the shells decreases and the number of buckling modes increases and by increasing the geometric parameter L / R, the buckling capacity of the shells increases and the number of buckling modes decreases.

Driving endotracheal sputum position by automatic positioning for an automatic endotracheal suction system

This study aims to secure the free time of nursing care providers and to ensure safe and sustainable nursing by partially automating endotracheal suction. As an elemental technique, an attempt is made to move the sputum position in a trachea by using change of position by an automated roll over support bed.

Notions regarding the design of suction systems for industrial ventilation

Air flow in ducts is one of the basic processes of ventilation and air conditioning. Knowledge of this phenomenon and the laws according to it is indispensable for drawing up the sizing calculations of the duct networks, for determining the energy needed to move the air as well as for determining the aerodynamic parameters related to the ventilation ducts. Industrial buildings include large spaces with various sources of releases of harmful substances. Type of these sources and their location depends on the technological process in each section or room.The main role of industrial ventilation systems is to provide a continuous source of fresh air supply from the outside, to keep the temperature and humidity at comfortable levels, to maintain an adequate supply of oxygen in the work area, to control concentrations of hazardous explosive and / or toxic gases in the air and at work, to remove unwanted odors from a particular area and to remove and dilute airborne contaminants. The paper presents the design of exhaust systems, the calculation of suction ventilation systems and the choice of ducts with higher aerodynamic parameters in the choice of fans, using nomograms.

2-Dimensional Investigations of In-Cyclinder Flow and Turbulence at Suction Stroke in Internal Combustion 4-Stroke Engines

Studies and experiments conducted for the performance enhancement of internal combustion engines are of great importance. Today, challenges encountered in securing energy resources, the incremental costs and environmental factors constantly remind us that we should not ignore fuel economy in motor vehicles. Studies conducted in this framework focus on lower fuel consumption and less exhaust emissions while improving performance. Undoubtedly, combustion chamber designs and charge systems have a great effect on exhaust emissions and performance. For this reason, a suction stroke was modeled in two dimensions using the fluent software to better understand the charge systems in internal combustion engines. The design was based on 1600 cc Fiat engine measurements and engine geometry was defined. CFD (Computational Fluid Dynamics) software was used to investigate the valve opening and cylinder and combustion chamber air motion at 900, 3000, 5000 rev-1 RPM and the results were discussed in detail. CFD results will assist engine designers in understanding the effects of suction system and its components on various parameters.

Hybrid physical–numerical study on the performance of clear-water flow through vertical multi-holes suction (VMHS) systems

ABSTRACT Different features of the hydro-suction systems were used for reservoir sediment removal so far. The Vertical Multi-Hole Suction (VMHS) system, investigated during the last decade, indicated promising results as an environmentally friendly method since it: (i) uses the available head difference between reservoir and downstream river, (ii) do not interfere with the regular dam operation, and (iii) is regarded as cost-effective method. Many aspects of such system need in-depth investigation and, in this research, the performance of the VMHS system was experimentally and numerically investigated with clear water flow to evaluate the whole system and individual hole efficiencies. The numerical model was calibrated against experimental data and used to determine discharge through holes, flow pattern and pressure distribution along the suction pipe. Different arrangements of hole sizes, numbers, and locations, on the hydro-suction pipe were thoroughly studied by this method. Some efficiency indicators were proposed and based on the compiled experimental data and numerical results the most efficient hole diameter and arrangements were determined.

Dental Aerosol as a Hazard Risk for Dental Workers.

Standard dental procedures, when using a water coolant and rotary instruments, generate aerosols with a significantly higher number of various dangerous pathogens (viruses, bacteria, and fungi). Reducing the amount of aerosols to a minimum is mandatory, especially during the new coronavirus disease, COVID-19. The study aimed to evaluate the amount of aerosol generated during standard dental procedures such as caries removal (using dental bur on a high and low-speed handpiece and Er:YAG laser), ultrasonic scaling, and tooth polishing (using silicon rubber on low-speed handpiece) combined with various suction systems. The airborne aerosols containing particles in a range of 0.3–10.0 μm were measured using the PC200 laser particle counter (Trotec GmbH, Schwerin, Germany) at three following sites, manikin, operator, and assistant mouth, respectively. The following suction systems were used to remove aerosols: saliva ejector, high volume evacuator, saliva ejector with extraoral vacuum, high volume evacuator with extraoral vacuum, Zirc® evacuator (Mr.Thirsty One-Step®), and two customized high volume evacuators (white and black). The study results showed that caries removal with a high-speed handpiece and saliva ejector generates the highest amount of spray particles at each measured site. The aerosol measurement at the manikin mouth showed the highest particle amount during caries removal with the low and high-speed handpiece. The results for the new high volume evacuator (black) and the Zirc® evacuator showed the lowest increase in aerosol level during caries removal with a high-speed handpiece. The Er:YAG laser used for caries removal produced the lowest aerosol amount at the manikin mouth level compared to conventional dental handpieces. Furthermore, ultrasonic scaling caused a minimal aerosol rise in terms of the caries removal with bur. The Er:YAG laser and the new wider high volume evacuators improved significantly suction efficiency during dental treatment. The use of new suction systems and the Er:YAG laser allows for the improvement of biological safety in the dental office, which is especially crucial during the COVID-19 pandemic.

Simulation and Measurement of Aerosolisation in Different Chest Drainage Systems

The aim of the study was to assess the degree of aerosolisation in different chest drainage systems according to different air leak volumes, in a simulated environment. This novel simulation model was designed to produce an air leak by passing air through and agitating a fluorescent fluid. The air leak volume and amount of fluorescent fluid were tested in various combinations and aerosolisation was assessed at 10-minute intervals using the ultraviolet light. The following chest drainage systems were compared: (1) single-chamber chest drainage system, (2) 3-compartment wet-dry suction chest drainage system, (3) digital drainage and monitoring system. The impact of suction (−2 and −4 kPa) in generating aerosolised particles was tested as well. A total number of 187 of 10-minute interval measurements were performed. The single-chamber chest drainage system generated the largest number of aerosolised particles at different air leak volumes and drainage output. The 3-compartment wet-dry suction system and the digital drainage and monitoring system did not generate any identifiable aerosolised particles at any of the air leak or drain output volumes considered. Suction applied to the chest drainage systems did not have an effect on aerosolisation. Aerosol generation in the simulated air-leak model demonstrated the potential risk of SARS-CoV-2 spread in the clinical setting. Full personal protective equipment must be used in patients with an air leak. Single-chamber chest drainage system generates the highest rate of aerosolised particles and it should not be used as an open system in patients with an air leak.

ОПРЕДЕЛЕНИЕ ОСНОВНЫХ СВОЙСТВ ПЫЛЕВЫХ ЧАСТИЦ ЗАТОЧНОГО УЧАСТКА

The abrasive processing of metal products is accompanied by harmful dust emissions into the work area. Exceeding the MPC of dust particles in the work area has a negative impact on the health of working personnel-it leads to occupational diseases of dust etiology. To localize harmful dust emissions when working on grinding machines, there are various dust collectors and their modifications, which allow to deal with harmful dust emissions with different efficiency. The design of the dust collector shrouds may involve connecting to an aspiration system that creates a low-pressure zone in the housing of the shroud, and thereby helps to remove harmful particles released during work. To correctly calculate the costs of air removed by local suction systems, it is necessary to analyze the dust situation and determine the properties of dust aerosols at a specific enterprise. In this work, the analysis of samples of dust particles selected at the grinding site of the plant for the manufacture of metal-cutting and metal tools, as well as technological equipment of LLC Production Company "Russian tool". Obtaining correct and up-to-date data on the size and chemical analysis of dust particles is necessary for the development of an energy-efficient aspiration system, as well as a mathematical model of the movement of dust particles.