Tracheal Research Articles

Electrical energy saving analysis based on solar power collector’s thermal system

This article analyzed the processes of new types of solar collector water heating systems designed to form solar collector thermal energy, air movement mode, including boundary layers of air flow, based on solar energy due to the abundance of sunny days in Uzbekistan. Additional parts in the interior, pipes, structures of the heating surface, methods for calculating basic physics were indicated. Also, the issues of forming the boundary layers of air flow, determining the elongation of the boundary layers and forming the air movement of the air flow, which occur under conditions of laminar or turbulent flow, are determined by changes in the patterns of air flow movement. A mathematical and immersion model was developed based on the results obtained directly in Reynolds number (Re) in the range 1000-5000 of these thermal and hydrodynamic processes. In the research work, the concave dimensions of the air pipe, including the length of the concave step, were determined taking into account the relationship between t and the concave height h, the formation of air flow movements and the breakpoints of the boundary points. Based on this system, traditional fuel resources were saved as well as energy saving problems in the electric power system.

Prevention of cuff injury of the intubation tube by blunt window opening in tracheostomy.

One of the intraoperative complications of tracheostomy under general anesthesia is cuff injury of the intubation tube. In the present study, we investigated whether a blunt tracheal opening is a useful method to avoid cuff injury. A retrospective cohort study was conducted to examine patients who underwent tracheostomy under general anesthesia at a single institution from January 1, 2017 to July 31, 2021. Electrocautery was used to thin the connective tissue between the tracheal rings, and bluntly open the trachea with mosquito forceps or similar instruments. Primary outcomes included cuff injury rate, number of surgeons involved, and career as otolaryngologist at the time of surgery. The secondary outcome was perioperative complications. Of the 64 cases, 3 had cuff injuries. 2 of the 3 had cuff injuries during the creation of an anteriorly based flap. 16 surgeons were involved ranging from the first to sixth year as an otolaryngologist, with the third year of otolaryngologist being the most common. The median physician year for instructors was 18 years. The most common postoperative complication was granulation in 9 cases. There were no cases of incorrect cannula insertion or difficulty in cannula insertion. A blunt tracheal opening was considered useful as a method to prevent cuff injury.

Experimental analysis and biaxial biomechanical behaviour of ex-vivo sheep trachea

Besides surgery, there are currently no other established methods for routine treatment of tracheal pathologies such a tracheal stenosis or tracheal and airway tumors. Even with several attempts to repair the infected trachea with artificial and natural prostheses, there is a need for the fundamental understanding of the tissue’s mechanical behaviour. The purpose of this study was to investigate the mechanical behaviour of the tracheal tissue under biaxial tensile loading. Furthermore, the study examines the material properties of the tissue through a study of the model parameters for six constitutive models. Materials and methods: The fourteen (n = 14) specimens of sheep trachea (Vleis Merino) measured to be ∼30 × 20 mm where only the effective area of ∼25 × 16 mm was subjected to engineering strain. In this study, we assume that the tracheal tissue is anisotropic and incom-pressible, therefore we apply and study the material parameters from six different constitutive material models. Results: The results show that the tracheal tissue is twice as stiff along the circumferential direction as it is along the longitudinal direction. It is also observed that the material properties are different (non-homogeneous) along the trachea. Conclusion: The findings of this study will benefit computational models for the study of tracheal diseases or injuries. Furthermore, these findings will assist in the development of regenerative medicine for different tracheal pathologies and in the bioengineering of replacement tissue in cases of damage.

Implementation and Results of a Dedicated Telemedicine Program (TeleTrachea) for Patients with Tracheal Diseases.

Background: Central airway diseases requiring frequent outpatient visits to a specialized medical center due to tracheal devices. Many of these patients have mobility and cognition restrictions or require specialized transport due to the need for supplemental oxygen. This study describes the implementation and results of a telemedicine program dedicated to patients with central airway diseases based in a Brazilian public health system. Methods: A retrospective study of telemedicine consultation for patients with central airway diseases referred to a public academic hospital between August 1, 2020 and August 1, 2022. The consultations occurred in a telemedicine department using the hospital's proprietary platform. Data retrieved consisted of demographics, disease characteristics, and the treatment modalities of the patients. The analysis included the savings in kilometers not traveled, the carbon footprint based on reducing CO2 emissions, and the cost savings in transportation. Results: A total of 1,153 telemedicine visits conducted in 516 patients (median age of 31.5 years). Two hundred ninety patients (56.2%) had a tracheal device (129 silicone T-Tube, 128 tracheostomy, and 33 endoprosthesis) and 159 patients (30.8%) had difficulties in transportation to the specialized medical center. Patients were served from 147 Brazilian cities from 22 states. The savings in kilometers traveled was 1,224,108.54 km, corresponding to a 250.14 ton reduction in CO2 emissions. The costs savings in transportation for the municipalities was BRL$ 1,272,283.78. Conclusions: Telemedicine consultations for patients with central airway diseases are feasible and safe. Cost savings and the possibility of disseminating specialized care make telemedicine a fundamental tool in current medical practice.

New phosphodiesterase-4 inhibitors present airways relaxant activity in a guinea pig acute asthma model.

Asthma is a disease characterized by chronic inflammation and hyper responsiveness of airways. We aimed to assess the relaxant potential of phosphodiesterase-4 (PDE4) inhibitors N-sulfonilhidrazonic derivatives on non-asthmatic and asthmatic guinea pig trachea. Firstly, guinea pigs were sensitized and challenged with ovalbumin, and then morphological, and contractile changes were evaluated resulting from asthma, followed by evaluation of relaxant effect of derivatives on guinea pig trachea and the cAMP levels measurement by ELISA. It has been evidenced hypertrophy of airway smooth muscle, inflammatory infiltrate, and vascular abnormalities. Moreover, only sensitized tracheal rings were responsive to OVA. Contractile response to histamine, but not to carbachol, was greater in sensitized animals, however the relaxant response to aminophylline and isoprenaline were the same in non-asthmatics and asthmatics. N-sulfonilhidrazonic derivatives presented equipotent relaxant action independent of epithelium, with exception of LASSBio-1850 that presented a low efficacy (< 50%) and LASSBio-1847 with a 4-fold higher potency on asthmatics. LASSBio-1847 relaxant curve was impaired in the presence of propranolol and potentiated by isoprenaline in both groups. Furthermore, relaxation was potentiated 54- and 4-fold by forskolin in non-asthmatics and asthmatics, respectively. Likewise, LASSBio-1847 potentiated relaxant curve of aminophylline 147- and 4-fold in both groups. The PKA inhibitor H-89 impaired the relaxant potency of the derivative. Finally, LASSBio-1847 increased tracheal intracellular cAMP levels similarly to rolipram, selective PDE4 inhibitor, in both animals. LASSBio-1847 showed to be promising to relax guinea pig trachea from non-sensitized and sensitized guinea pigs by activation of β2-adrenergic receptors/AC/cAMP pathway.

Photothermal-Controllable Microneedles with Antitumor, Antioxidant, Angiogenic, and Chondrogenic Activities to Sequential Eliminate Tracheal Neoplasm and Reconstruct Tracheal Cartilage.

The optimal treatment for tracheal tumors necessitates sequential tumor elimination and tracheal cartilage reconstruction. This study introduces an innovative inorganic nanosheet, MnO2 /PDA@Cu, comprising manganese dioxide (MnO2 ) loaded with copper ions (Cu) through in situ polymerization using polydopamine (PDA) as an intermediary. Additionally, a specialized methacrylic anhydride modified decellularized cartilage matrix (MDC) hydrogel with chondrogenic effects is developed by modifying a decellularized cartilage matrix with methacrylic anhydride. The MnO2 /PDA@Cu nanosheet is encapsulated within MDC-derived microneedles, creating a photothermal-controllable MnO2 /PDA@Cu-MDC microneedle. Effectiveness evaluation involved deep insertion of the MnO2 /PDA@Cu-MDC microneedle into tracheal orthotopic tumor in a murine model. Under 808nm near-infrared irradiation, facilitated by PDA, the microneedle exhibited rapid overheating, efficiently eliminating tumors. PDA's photothermal effects triggered controlled MnO2 and Cu release. The MnO2 nanosheet acted as a potent inorganic nanoenzyme, scavenging reactive oxygen species for an antioxidant effect, while Cu facilitated angiogenesis. This intervention enhanced blood supply at the tumor excision site, promoting stem cell enrichment and nutrient provision. The MDC hydrogel played a pivotal role in creating a chondrogenic niche, fostering stem cells to secrete cartilaginous matrix. In conclusion, the MnO2 /PDA@Cu-MDC microneedle is a versatile platform with photothermal control, sequentially combining antitumor, antioxidant, pro-angiogenic, and chondrogenic activities to orchestrate precise tracheal tumor eradication and cartilage regeneration.

Comparative analysis of the degree of hydrolysis of biopolymers in hyaline cartilage homogenates in the presence of proteolytic enzymes

Investigating the degree of hydrolysis in the presence of different proteolytic enzymes is one of the tasks regarding further development of nutraceuticals obtained from connective tissues for biomedicine. Hydrolysis of biopolymers in cattle and swine tracheal hyaline cartilage homogenates was carried out in the presence of the following enzymes: pancreatin, chymopsin, papain and karipazim, a drug that contains papain, a proteolytic enzyme. This study shows that karipazim manufactured by MedFlorina LLC has better efficacy than karipazim manufactured by ZAO Vifiteh, and the greatest degree of hydrolysis for collagen occurrs at 60°C and karipazim concentration of 10%. More complete hydrolysis of proteoglycans was performed in the cattle hyaline cartilage homogenates, because the analysis of NMR spectra revealed the glucose, the final product of glycosaminoglycan hydrolysis.

Voice Restoration after Traumatic Subglottic Tracheal Stenosis.

Tracheal stenosis post intubation is one of the most common complication for which resection and anastomosis is done.Here we present a 21 year male patient who was intubated post organophosphorous poisoning. Diagnosed with tracheal stenosis post intubation and managed with tracheal resection and anastomosis with uneventful recovery.Post intubation tracheal stenosis is one of the serious complications and requires a multidisciplinary team and high volume centre for adequate management. Considering the fact that this case report has tracheal stenosis of grade IV type with resected length of tracheal cartilage of more than 3 cm and trachea- tracheal anastomosis makes this a rare case report.

Determination of active concentrations and velocities of phases in airlift three-phase flows

A one-dimensional ascending steady flow of a mixture of air, water, and solids in a vertical lift lift pipe is considered. As a physical model, this three-phase flow is represented as the compatible movement of the pulp (a mixture of liquid and solid particles) and compressed air in the form of shells. It is assumed that the lifting of solid material is carried out by liquid plugs that move in the intervals between the air shells. The purpose of the work is to determine the actual concentrations and velocities of the phases as one of the important hydrodynamic characteristics of the flow. The method of statistical averaging of these characteristics is used, similar to the theoretical-probabilistic method of averaging in the theory of turbulence, the basis of which is the transition from consideration of a single flow to consideration of a statistical set of similar flows carried out under almost identical conditions. The actual phase concentrations in any given live current section are considered in terms of the unconditional probability of one or another phase passing through the section. To determine the true velocities of the phases, hydraulic continuity equations are used, containing probability-averaged hydrodynamic quantities and describing each phase individually as some continuum in the statistical sense. In this case, the true velocity of a phase in any given live section is defined as the statistical average of the velocity, provided that this phase clearly intersects the section. The expressions obtained for the real concentrations and velocities of the phases form the theoretical basis for the construction of a hydraulic mathematical model of the three-phase flow with respect to the problem of airlift calculation.

MECHANICAL CHARACTERISATION OF FIBER-REINFORCED GLASS POLYMER COMPOSITE PIPES

This paper presents the details of experimental testing for the suitability of glass fibre-reinforced polymer (GFRP) pipes for gas transmission lines. Hydrostatic bursting pressure and split ring tests were performed on 150 mm (6 in.) and 250 mm (10 in.) diameter pipes made by both the pultruded and filament wound processes. The filament wound pipes were tested to evaluate the butt joint failure strengths. The classical lamination theory (CLT) was used to predict the elastic behaviour of these pipes. It was found that filament wound pipes offer superior resistance to internal pressures compared to pultruded pipes. Furthermore, the joints were found to be the most limiting component in terms of pipeline burst pressure capacity. The observed elastic behaviour by the employed hydrostatic pressure test method showed strong agreement with the CLT predictions which confirms its applicability for testing GFRP pipes for bursting pressure. Failure predictions between the experimental data and theory had minor discrepancies.

Radical Surgical Treatment of Idiopathic Tracheal Stenosis. A Clinical Observation

Introduction. Idiopathic cicatricial tracheal stenosis (ICTS) comprises a rare and dangerous disease of unknown etiology. Its morphological substrate consists in the formation of circular fibrotic stenosis, usually at the level of the cricoid cartilage and the first two С-shaped rings of the trachea. The first cases of the disease were described by Brandenburg only in 1972. Progression of the disease is slow, right up to severe respiratory failure and asphyxia. Treatment methods for idiopathic cicatricial tracheal stenosis include both endoscopic and open surgical techniques. However, endoscopic treatment fails to produce the desired effect. Materials and methods. The authors of the present paper performed tracheo-laryngeal resection as a radical method for treating idiopathic tracheal stenosis in a 54-year-old patient against the background of prolonged unsuccessful endoscopic treatment. The follow-up period accounted for 45 days. Examinations in the postoperative period showed complete epithelialization of the anastomosis line without inflammation. Results and discussion. Idiopathic cicatricial tracheal stenosis is considered to be a dangerous disease without significant causes of development. However, it is claimed to be a potentially curable disease, though its treatment is a difficult task. Some authors report satisfactory results of endoscopic treatment of ICTS, but most publications on this issue consider a single tracheo-laryngeal resection with anastomosis as the most optimal method of treatment, thereby correlating with the results of the present study. Conclusion. The present observation characterizes the peculiarity and possibility of radical treatment of ICTS, since the endoscopic method of treatment produces only a temporary effect. Small number of observations and lack of a coherent pathogenetic theory necessitate further research into this problem.

Functional, Radiological and Endoscopic Diagnostic of Tracheal Diseases

Diseases of the trachea are rare, while other diseases associated with shortness of breath and pulmonary symptoms are common, which is why the necessary diagnosis and therapy are regularly delayed. At the same time, diseases range from simple scarring stenosis to extensive tumour disease. Patients may be otherwise healthy, suffer from autoimmune disease, or have severe general illnesses, as in tracheotomised patients. Therefore, history and clinical examination provide very important clues to a disease of the trachea. Subsequent diagnostics should be ordered in a reasonable manner and lead to the correct diagnosis and subsequent therapy in a timely manner. Functional, radiological and endoscopic examinations, each with a special focus in experienced hands, avoid duplicate examinations or misinterpretations. Patients are grateful because diseases of the trachea - a central airway that cannot be bypassed - are experienced as life-threatening or at least as severely limiting the quality of life.

Dual‐Stroke Soft Peltier Pouch Motor Based on Pipeless Thermo‐Pneumatic Actuation

Soft pneumatic actuators are made of flexible materials that deform in response to pressure changes. Due to their reliability, safety, and flexibility, such actuators enable diverse hardware design and become indispensable for soft robots. However, bulky air compressors and pipes constrain their further integration and lightweight. The liquid–vapor phase transition can produce significant encapsulated volume changes and achieve pipeless thermo‐pneumatic actuation. Herein, a novel soft thermoelectric‐based actuator, named Peltier pouch motor (PPM), is presented with modular and dual‐stroke characteristics enabled by active phase transition of low‐boiling‐point liquid. Furthermore, its lightweight and stretchable compliance contributes to assembly‐induced hyper‐modularity to create diverse degrees‐of‐freedom hybrid systems. Finally, the various forms of PPM units are exploited and versatile locomotion is facilitated for five different applications under multi‐medium scenarios, including thermo‐responsive land locomotion, submersible noise‐free hovering, smart curtains control, body‐temperature‐driven wrist rehabilitation, and adaptive hybrid gripper. In these results, it is indicated that the proposed PPM unit advances in hyper‐modularity with excellent performance in high load rate (around 400%), heat transfer efficiency (heating boost, 425%; cooling boost, 138%), and thermal response performance (heating, 0.57° s−1; cooling, 0.29° s−1; 4.5 V), inspiring widely innovative soft robots through the pipeless thermo‐pneumatic actuation.

Performance of an Air-Cooled Heat Exchanger in a Separation Unit Based on Fouling Factor and Pressure Drop

Heat exchangers transfer heat from a high temperature to a low temperature in a fluid. Air-cooled heat exchangers are one of the most widely used types of heat exchangers, after shell and tube heat exchangers. Its performance is determined by calculating the fouling factor value and the pressure drop. The purpose of this case study is to evaluate the performance of a water-cooled heat exchanger in a plant that produces a thickening agent (CMC, or carboxymethylcellulose), which affects the amount of ethanol produced. Ethanol will cool from 79.347 to 54.133 oC, and air will cool from 31.333 to 59.667 oC as the cold fluid. The calculation results show that both reviews exceed the design threshold of 0.007056 h.ft2.oF/Btu. These heat exchangers require maintenance and repair. These results differ from the pressure drop values on the air side and pipe section, which are 1.2.10-3 inH2O and 0.647 psia, respectively. Both values remain outside the allowable limits. The performance evaluation of process equipment in the separation unit was aided by field data. The review of the data was able to predict a plant shut-down. This action was able to effect a partial or total plant shut-down due to fouling and scale exceeding design data thresholds.

Industrial scale testing on the combustion and NOx emission characteristics of ammonia cofiring in a 40 MWth coal-fired boiler

This paper reports the first industrial scale testing on ammonia (NH3) cofiring in a 40 MWth coal-fired boiler under high ammonia cofiring ratio (ENH3, percent of thermal input) ranging from 0 % to 25 %. A full-scale cofiring swirl burner is designed to inject NH3 gas with pulverized coal through the primary air pipe of the burner. The effects of ammonia cofiring ratio and key boiler operating parameters on boiler NOx emission and fuel burnout are examined. The results show that the boiler can establish stable ignition and combustion under all ammonia cofiring conditions in this study. The burnout of coal under ammonia cofiring conditions are better than those of coal combustion cases. Overfire air (SOFA) has significant influences on boiler NOx emission and burnout of coal and NH3. It is found that there exists optimal SOFA ratio in the range of 15–20 % within which both boiler NOx emission and NH3 slip can be well controlled. Under 20 % SOFA ratio, boiler NOx emission tends to increase and then decrease with the increase of ENH3 reaching the peak value under ENH3 = 5 %. As a result, the NOx emission can be reduced to the level lower than that of coal combustion case under ENH3 > 20 %. Boiler excess O2 also shows significant influences on boiler NOx emission and NH3 slip. With the decrease of boiler O2, boiler NOx emission decreases significantly while NH3 slip increases rapidly. It is found that there exists optimal boiler O2 in the range of 3.0–3.7 % within which both boiler NOx emission and NH3 slip can be kept at relatively low levels. Injection of NH3 from the side wall of furnace is also tested in this study. The NOx emission shows similar trends with the change of ENH3 in the range of 0–20 %. However, above this range the NOx emission tends to increase with further increase of ENH3. The results of this paper demonstrate the technical feasibility of NH3 cofiring in large-scale coal-fired boilers under high cofiring ratios and provide important guidance to the operation of boilers.

Biomechanical Evaluation of Tracheal Needle Puncture Forces: Comparative Analysis of Annular Ligaments and Tracheal Cartilage.

Percutaneous tracheotomies (PCT) are commonly performed minimally invasive procedures involving the creation of an airway opening through an incision or puncture of the tracheal wall. While the medical intervention is crucial for critical care and the management of acute respiratory failure, tracheostomy complications can lead to severe clinical symptoms due to the alterations of the airways biomechanical properties/structures. The causes and mechanisms underlaying the development of these post-tracheotomy complications remain largely unknown. In this study, we aimed to investigate the needle puncture process and its biomechanical characteristics by using a well establish porcine ex vivo trachea to simulate the forces involved in accessing airways during PCT at varying angular approaches. Given that many procedures involve inserting a needle into the trachea without direct visualization of the tracheal wall, concerns have been raised over the needle punctures through the cartilaginous rings as compared to the space between them may result in fractured cartilage and post-tracheostomy airway complications. We report a difference in puncture force between piercing the cartilage and the annular ligaments and observe that the angle of puncture does not significantly alter the puncture forces. The data collected in this study can guide the design of relevant biomechanical feedback system during airway access procedures and ultimately help refine and optimize PCT.

Tracheal ulcer development from high volume, low-pressure cuffed endotracheal tubes

IntroductionIatrogenic injury to the larynx, particularly the vocal cords from prolonged intubation, has been well-studied; however, tracheal injuries are rarely reported. This study investigates the effectiveness of cuffed, high-volume, low-pressure endotracheal tubes in preventing the development of tracheal ulcers in intubated subjects. MethodsA retrospective, IRB-approved review was performed on 1355 subjects who underwent percutaneous tracheostomy from 2002 to 2018. The presence and severity of tracheal ulcers were collected using documentation and photos during percutaneous tracheostomy placement. Primary outcome measures included: the length of time on a ventilator until tracheostomy (LOVT), length of hospitalization (LOH), and mortality in relationship to the severity of the tracheal injury. Data was reported as n (%) and median (IQR). The differences in means between groups were analyzed by ANOVA and Chi-square test with an alpha of 0.05. Results206 subjects met the inclusion criteria; 65 subjects had an absence of tracheal injury, and 141 subjects developed tracheal ulcers. Subjects with tracheal ulcers were grouped by the following severity scale: no ulcer; mild ulcer (minimal mucosal erosion with exudate); moderate ulcer (mucosal erosion); and severe (tracheal ring exposure). There were no statistically significant differences in age (p = 0.99), gender (p = 0.83), BMI (p = 0.44), LOH (p = 0.88), LOVT (p = 0.93), and mortality (p = 0.306) between subjects with differing severity of ulcers. The average annual incidence of clinically significant ulcers (moderate and severe) was 2.2 %. ConclusionsThe lack of statistical correlation between the duration of intubation and tracheal ulcer severity, along with a low annual incidence of tracheal ulcers, supports the improved safety of high-volume, low-pressure cylindrical, cuffed endotracheal tubes. This study is among the first to specifically focus on injuries at the level of the cuff and tip of endotracheal tubes with implications in preventive measures and potential product design changes.

Emergency front-of-neck access in infants: A pragmatic crossover randomized control trial comparing two approaches on a simulated rabbit model.

Rapid-sequence tracheotomy and scalpel-bougie tracheotomy are two published approaches for establishing emergency front-of-neck access in infants. It is unknown whether there is a difference in performance times and success rates between the two approaches. The aim of this cross-over randomized control trial study was to investigate whether the two approaches were equivalent for establishing tracheal access in rabbit cadavers. The underlying hypothesis was that the time to achieve the tracheal access is the same with both techniques. Between May and September 2022, thirty physicians (pediatric anesthesiologists and intensivists) were randomized to perform front-of-neck access using one and then the other technique: rapid-sequence tracheotomy and scalpel-bougie tracheotomy. After watching training videos, each technique was practiced four times followed by a final tracheotomy during which study measurements were obtained. Based on existing data, an equivalence margin was set at ∆ = ±10 s for the duration of the procedure. The primary outcome was defined as the duration until tracheal tube placement was achieved successfully. Secondary outcomes included success rate, structural injuries, and subjective participant self-evaluation. The median duration of the scalpel-bougie tracheotomy was 48 s (95% CI: 37-57), while the duration of the rapid-sequence tracheotomy was 59 s (95% CI: 49-66, p = .07). The difference in the median duration between the two approaches was 11 s (95% CI: -4.9 to 29). The overall success rate was 93.3% (95% CI: 83.8%-98.2%). The scalpel-bougie tracheotomy resulted in significantly fewer damaged tracheal rings and was preferred among participants. The scalpel-bougie tracheotomy was slightly faster than the rapid-sequence tracheotomy and favored by participants, with fewer tracheal injuries. Therefore, we propose the scalpel-bougie tracheostomy as a rescue approach favoring the similarity to the adult approach for small children. The use of a comparable equipment kit for both children and adults facilitates standardization, performance, and logistics. ClinicalTrials.gov identifier: NCT05499273.

Brazilian airway surgery survey indicates low overall numbers and need for improved teaching skills.

The Brazilian Society of Thoracic Surgeons (BSTS) conducted an on-line survey to determine the number of surgeons that perform adult and paediatric airway surgery, and to understand the practice patterns along the country. Active members were electronically invited to complete the questionnaire through the REDCapR platform. Invitations were sent from January to April 2020. The survey encompassed 40 questions that explored 4 different topics in the assessment of tracheal diseases: (1) Surgeon`s Demography; (2) Institutional profile, (3) Education and training in laryngo-tracheal surgery, (4) Preoperative and post operative evaluation. Eighty-nine % of the responders declared to perform tracheal surgery with a median of 5 tracheal resection procedures per year(IQR 3-12). Interaction with other specialties occurs in 37.3% of cases. Access to technology and devices is highly variable across the country. Resident training in airway surgery consists in traditional lectures in 97% of the cases. Training in animals(15.2%), cadavers(12.1%) and simulators(6.1%) are rare. Pre-operatory evaluation encompasses flexible bronchoscopy (97.8%) and/or CT scan of the airways (90.6%). Swallowing(20.1%) and voice(14.4%) disorders are rarely evaluated. Eighty nine % of the surgeons consider bronchoscopy to be the pre-operatory gold-standard exam, followed by CT scan (38.8%) and CT-3D reconstruction (37.4%). Brazilian surgeons refer that airway resection and reconstruction is part of their current practice, but the total number of procedures per surgeon per year is low. Access to high-end technology and equipment is heterogenous. Training offered to residents in most academic institutions relies on traditional lectures.

Does Cuff Design Impact Insertion andRemoval Force ofTracheostomy Tubes? A Bench Model.

Percutaneous dilatational tracheostomy is a commonly performed procedure in intensive care units. Unrecognized tracheal ring fracture has been suggested as a possible factor for tracheal stenosis. The degree of tracheal compression relates to the amount of force required to cannulate the trachea. The objective of this study was to determine the force required to insert two types of tracheostomy tubes with different cuff designs. This bench model measured the insertion and removal force of two tracheostomy tubes; one with a barrel-shaped, high-volume, low-pressure cuff (traditional Shiley tracheostomy tube) and another with a taper-shaped, low-volume, low-pressure cuff (Shiley flexible tracheostomy tube). Three sizes of tracheostomy tubes either with a barrel- or taper-shaped cuff were tested (Jackson sizes 4, 6, and 10, corresponding to 6.5-, 7.5-, and 10-mm ISO sizes, respectively). A model representing the tissue that the tube traverses to enter the tracheal lumen was designed, and the tracheostomy tube was mounted on a universal testing machine to measure the force necessary to insert and remove the tube. Across all tracheostomy tubes' sizes tested, significantly less force was required to insert the Shiley flexible tracheostomy tube compared to the traditional Shiley tracheostomy tube. Significantly less force was also required to remove the flexible tracheostomy tube compared to the traditional tracheostomy tube. This model suggests that less force is required to insert the Shiley flexible tracheostomy tube, which could result in less tracheal compression. This may be because of the smaller taper-shaped cuff that, when deflated, occupies less volume compared to the barrel-shaped cuff. As a result, less tracheal injury may occur when using the Shiley flexible tracheostomy tube during percutaneous tracheostomy procedures.