ABSTRACT

Bronchoscopy is an important procedure to examine the airways. It is traditionally taught by having trainees perform it in humans. This carries risks, albeit rarely, and causes stress to trainees. The objective of this study was to review bronchoscopy simulators, as well as their use in and impact on medical education, presenting perspectives on the use of simulators in the post-pandemic world. This review was based on articles published in English in 2000-2021 and retrieved from any of the following databases: MEDLINE (PubMed), Embase, SciELO, and Google Scholar. Bronchoscopy simulators have improved markedly over time, allowing the teaching/learning process to take place in a risk-free environment. Bronchoscopy simulation training is an interesting option for the evaluation of the airways, especially in the coming years, with the COVID-19 pandemic highlighting the need for continuing medical education.

Keywords: Bronchoscopy; Learning; Teaching; Students; Coronavirus.

RESUMO

A broncoscopia é um procedimento importante para examinar as vias aéreas. O treinamento tradicional consiste em realizar o procedimento em humanos. Isso traz riscos, embora apenas raramente, e causa estresse nos broncoscopistas em formação. O objetivo deste estudo foi realizar uma revisão da literatura a respeito de simuladores de broncoscopia e seu uso e impacto na educação médica, apresentando perspectivas acerca do uso de simuladores no mundo pós-pandemia. A revisão baseou-se em artigos publicados em inglês em 2000-2021 e recuperados a partir de buscas realizadas nos seguintes bancos de dados: MEDLINE (PubMed), Embase, SciELO e Google Acadêmico. Os simuladores de broncoscopia melhoraram muito ao longo dos anos, permitindo que o processo de ensino e aprendizagem ocorra em um ambiente livre de riscos. O treinamento com simuladores de broncoscopia é uma opção interessante para a avaliação das vias aéreas, principalmente nos próximos anos, já que a pandemia de COVID-19 ressaltou a necessidade de educação médica continuada.

Palavras-chave: Broncoscopia; Aprendizagem; Ensino; Estudantes; Coronavirus.

INTRODUCTION
 
Bronchoscopy is an extremely important procedure performed by specialists such as pulmonologists, otolaryngologists, and surgeons. Appropriate training in performing bronchoscopy is essential because it is a complex procedure that requires mastery of cognitive and motor skills.(1) It is traditionally taught by the “see one, do one, teach one” approach, in which professionals in training perform the procedure directly in humans, under the guidance of experienced professionals.(1) This has long been an effective method for training bronchoscopists. However, complications may require repeated examinations, causing high levels of stress to learners.(2)
 
Technological advances have allowed the use of simulators, which have become an interesting alternative tool. Furthermore, the COVID-19 pandemic has posed numerous challenges. Given the reduction in the number of trainees in surgical procedures and the need to ration personal protective equipment (PPE), the use of simulators to train professionals in techniques such as bronchoscopy has become especially important.(3)
 
The objective of this study was to review the development of bronchoscopy simulators, as well as their use in and impact on medical education, presenting perspectives on the use of simulators in the post-pandemic world.
 
STUDY SELECTION PROCESS
 
We searched the MEDLINE (PubMed), Embase, SciELO and Google Scholar databases for articles published in English between 2000 and 2021. Articles were initially selected by title, then by abstract review prior to complete article review.
 
BRONCHOSCOPY SIMULATORS
 
The first study on simulation in bronchoscopy was conducted in 1999 in a swine model.(1) In that same year, a virtual reality simulator was developed, namely the PreOp Endoscopic Simulator® (HT Medical Systems; Rockville, MD, USA). In 2001, a study was conducted on simulator effectiveness in bronchoscopy training. (4) The AccuTouch® simulator (Immersion Medical; Gaithersburg, MD, USA) was developed and validated during this period.(5)
 
Several tools are currently being used. Bronchoscopy training in animal models is known as a wet lab simulation. Some advantages of this method are the similarity of the anatomy and the possibility of using a real bronchoscope. The disadvantages include ethical issues in the use of animals for human training, the cost of raising them, and the potential damage to the bronchoscopy equipment.(1)
 
Low-fidelity simulation consists of the use of inanimate airway models—which do not simulate resistance to scope or breathing movements and which and are not very realistic in anatomy—into which real bronchoscopes are inserted. There is a range of models, from simple, non-anatomical labyrinths to more modern simulators.(1,2) The non-anatomical labyrinth models provide training in the movement of the wrist and hands, and even bronchial tree models made of newsprint and vinyl glue are available. The most up-to-date models in this category, made of silicone and plastic-based materials, consist of a mannequin composed of a head, a larynx, a tracheobronchial tree, and a thorax, to which a panel is attached to visualize the procedure externally, like the Laerdal Airway Management Trainer® (Laerdal; Stavanger, Norway; Figure 1) and the Airway Larry® (Nasco; Fort Atkinson, WI, USA).(1) There is also the CLA Broncho Boy® model (CLA; Coburg, Germany), which has a detailed tracheobronchial tree at the level of the first segmental bronchi.(1)

 
Another class of low-fidelity simulators is produced by three-dimensional (3D) printers.(6) One study evaluated their performance in bronchoscopy training and found a significant improvement in examination speed and performance after training.(7) These are low-cost alternatives that allow the use of a real bronchoscope. However, the equipment can be damaged, and these systems do not provide much realism.
 
High-fidelity simulation is based on the use of computers for virtual projection of the airways, also known as virtual simulators. The first simulator is the PreOp Endoscopy Simulator® (HT Medical Systems; Rockville, MD, USA).(1) There is currently a new version of this simulator, designated the AccuTouch Endoscopy Simulator® (Figure 2) and consisting of a flexible scope and a computer with a monitor and software for simulating the procedure. The interface is a replica of the human face, with an access area in the nasal region for insertion of the scope. There is also hardware for detecting the movements performed by the machine operator, capable of simulating the mechanical resistance of a real examination, as well as coughing and the respiratory movements of the patient.(2) At the end of the examination, the equipment provides metrics related to the performance of the trainee, including procedure time, “red out” time, number of contacts with the bronchial walls, bronchial segments inspected, and use of the suction button, thus ensuring feedback.(2) In addition, it is possible to identify the anatomical structures explored because the device projects the location of the bronchoscope, injects aliquots of lidocaine, performs biopsies, and reproduces multiple clinical scenarios. This simulator was used in most of the studies reviewed here, with positive results.
 



 
Other available models include the Gi-Bronch Mentor® (Simbionix USA Corp; Cleveland, OH, USA) and Orsim® (Airway Limited; Auckland, New Zealand).(1) These are simulators that reproduce extreme anatomical reality, ensuring learners an environment conducive to their learning. However, despite the complexity of the imaging system, even the most up-to-date models reproduce the tactile sensitivity of the examination in a rudimentary way, and tactile sensitivity is important when learning how to perform a bronchoscopy.
 
With the improvement of virtual simulators, it has become possible to train skills with a high degree of realism, allowing beginners to learn from their mistakes before having direct contact with patients. Therefore, students can improve their performance in challenging situations, such as gaining access to the pediatric airway and performing a bronchoscopy in patients with COVID-19.(8)
 
Since bronchoscopy is an aerosol-generating procedure, it is necessary to implement strategies to mitigate contamination risks during the procedure, such as an acrylic casing during intubation and the use of disposable curtains to create a tent around the patient.(8) Thus, training with simulators eliminates the risk of infection in a pandemic environment.
 
VIRTUAL SIMULATORS IN THE EVALUATION OF BRONCHOSCOPISTS
 
Bronchoscopy teaching has not yet been standardized. At least 100 supervised procedures are recommended for the acquisition of basic competence.(9) However, this method has been questioned.
 
In a study conducted by Crawford & Colt,(9) pulmonology residents were asked to identify the bronchial segments using a virtual simulator. The bronchoscopists in training identified 71% of the segments; 50% of the experienced bronchoscopists identified all segments; and beginners were not able to identify all necessary segments. This great variability indicated the need to review the assessment methods in the teaching of bronchoscopy.
 
Guidelines were updated, and it was recommended that the assessment of individual trainee improvement be performed with simulators. It was initially shown that the metrics provided by simulators allow the differentiation between beginners and experienced bronchoscopists.(4) However, it was later proposed that these metrics should not be used as the only assessment method, the accuracy of the software being questioned.(10)
 
In this context, two instruments were developed, namely the Bronchoscopy Skills and Tasks Assessment Tool (BSTAT) and the Bronchoscopy Step-by-Step Evaluation Tool (BSET).(11) The BSTAT provides a numerical score based on posture and knowledge of anatomy, as well as on tasks such as transbronchial biopsy and bronchoalveolar lavage. The BSET evaluates the handling of the bronchoscope at increasing levels of difficulty. A high correlation was found between the two instruments (0.86 for the BSTAT and 0.85 for the BSET), with clear differences between beginners and experts. However, there were no significant differences among intermediate-level trainees.(11)
 
In another study, based on video footage of trainees performing simulated bronchoscopy and evaluated by a checklist, it was possible to distinguish among beginners, intermediate users, and experts.(10) In yet another study, an automatic motion analysis system was used in order to analyze scope movements.(12) Deviations were found to be greatest for beginners and smallest for experienced operators, the motion analysis system therefore being able to distinguish among beginners, intermediate operators, and experts.(12) Table 1 summarizes the studies examining the role of virtual simulators in the evaluation of bronchoscopists in training.

 
The use of virtual simulators in bronchoscopy has become an important option for evaluating professionals in training because virtual simulators allow the assessment of objective metrics and individual improvement in a risk-free environment. This becomes relevant in the context of the COVID-19 pandemic, with virtual simulators allowing the assessment of the performance of learners without any risk of exposure to the coronavirus.
 
TRAINING ON VIRTUAL SIMULATORS
 
Virtual simulators allow the evaluation of bronchoscopy training by the equipment’s own metrics. One study found evident improvement after training, both in dexterity, with fewer contacts with the bronchial walls (p = 0.022), and in efficiency, with a higher percentage of analyzed bronchi (p = 0.029).(4) Even a short introductory course with simulators showed significant improvement in resident performance (p = 0.017).(13) In another study, similar results were obtained, with a significant reduction in procedure time (p = 0.002) and improvement in general performance (p = 0.002).(14)
 
The effects of previous simulator training on performance in real patients have also been investigated. The use of simulated bronchoscopy has been found to increase the speed of skill acquisition, with improved BSTAT scores (p < 0.05).(15) Ost et al. found similar results; specifically, a reduction in the time needed to perform the procedure (p = 0.001) and an increased percentage of identified bronchi (p = 0.03).(5) Even a short training session with a bronchoscopy simulator has been found to improve pediatric endotracheal intubation, with reduced time needed for intubation (p < 0.001) and increased percentage of airway visualization (p = 0.004).(16)
 
In a meta-analysis published in 2017,(17) virtual bronchoscopy simulator training was evaluated by examining original articles published between 2000 and 2016. Eight studies were included, and the authors concluded that bronchoscopy simulator training improves technical skills and that simulators can be an important learning tool.(17) In a systematic review,(18) the structure of simulation training in bronchoscopy and assessment of competence in bronchoscopy training were investigated. The review showed that simulation in bronchoscopy is effective, as well as showing that the training must be structured, that practice in pairs contributes to increasing the use of simulators, and that it is important to assess learners through validated tools.(18) Table 2 summarizes the studies evaluating the impact of virtual simulators on bronchoscopy training.

 
The effectiveness of simulator training is a fact of recognized relevance in the post-COVID-19 era because it assures continuing education regardless of the stage of the pandemic, which is still ongoing. Thus, more evidence on the effectiveness of simulation bronchoscopy training helps educators make decisions, highlighting the need for further studies on the subject.
 
TEACHING METHODS IN BRONCHOSCOPY TRAINING
 
Given the relevance of bronchoscopy training on virtual simulators, new teaching methods have emerged in the past few years.
 
The effectiveness of bronchoscopy simulation training on a single day has been reported to be the same as that of training over one week (p > 0.36), a finding that suggests that bronchoscopy simulation training can be conducted in a format that best suits trainees and training centers.(19)
 
Self-training can also be considered, wherein learners follow the manufacturer instructions to train themselves. One study showed a significant improvement in BSTAT scores after four self-driven training sessions on a virtual simulator (p < 0,0001). (2) Veaudor et al.(14) obtained similar results with self-training residents, who acquired basic skills similar to those of experienced bronchoscopists (p = 0,002).
 
Evidence on the use of bronchoscopy simulators for training residents has increased. However, little is known about the impact of bronchoscopy simulation training on medical students, although some recent studies have investigated this issue.
 
One study found no difference in effectiveness between bronchoscopy simulation training of medical students in pairs and individually (p < 0.16).(20) Training in pairs was considered more effective because the same resources used individually can be used in pairs.(20)
 
Intubation using fiberoptic bronchoscopy simulators has been evaluated in medical students, with no significant difference in technical skills between beginners and experts after training.(21) The modeling example, in which trainees observe the procedure performed by the instructor during bronchoscopy simulation training, has also been evaluated.(22) After training, the modeling example group was found to be significantly better than the control group (p < 0.0001), a finding that demonstrates the effectiveness of this method.(22) Table 3 summarizes the studies examining bronchoscopy simulation training methods.

 
Thus, several studies have provided a well-established basis for the use of simulators in bronchoscopy training.
 
BRONCHOSCOPY SIMULATION AND COVID-19
 
Medical education has been profoundly affected by COVID-19. The number of professionals allowed in the examination room had to be reduced, thus limiting the training of residents. In addition, because of the need to manage medications and beds, many procedures were suspended, thereby affecting the learning process.(23)
 
Bronchoscopy is a procedure that generates aerosols, leading to potential exposure to the virus. Furthermore, in cases of medical emergencies, such as foreign body removal, airway obstruction, or atelectasis caused by mucus plugging, there may not be enough time to perform COVID-19 diagnostic tests on the patient. Such situations impel bronchoscopists to perform the procedure quickly and efficiently, minimizing the time of exposure to the virus and, consequently, the probability of infection.(24,25)
 
Recent studies have evaluated the transmissibility of SARS-CoV-2 among bronchoscopists and found a low risk of transmission.(26,27) However, it should be noted that strict adherence to the guidelines recommended by the WHO and other organizations was reported, with most procedures being performed in negative pressure rooms, with all professionals wearing PPE, with neuromuscular blockade to prevent coughing, with bronchoscopy under apnea, with the use of disposable bronchoscopes, and with a reduced number of health professionals.(28) These situations require experienced professionals who are able to perform the procedure quickly.
 
Koehler et al. developed a simulation model to visualize aerosol, droplet generation, and surface contamination using a fluorescent solution during a bronchoscopy simulation.(29) The authors found evidence of aerosol generation, droplet dispersion, and surface contamination; however, the proper use of PPE and safety strategies mitigated contamination risks.(29)
 
The changes imposed by COVID-19 require prior preparation from professionals performing bronchoscopy. Simulation allows professionals to state their concerns, discuss perceptions about the safety and comfort of both the team and the patient, and practice technical modifications to the procedure. The benefits of simulations are more clearly noted in emergency bronchoscopy situations, when previous training sessions have been reported to provide better communication and operational planning.(24)
 
In the COVID-19 era, simulation laboratories have gained importance in health sectors.(3) Bronchoscopy simulation allows the improvement of basic skills such as knowledge of anatomy, 3D spatial orientation, and motor coordination without putting patients at risk, as well as ensuring the continuation of the learning process regardless of the state of the pandemic. Lower levels of stress result in more efficient learning, ensuring effective performance in real situations.(2)
 
LIMITATIONS AND PERSPECTIVES
 
One of the difficulties in using virtual simulations is related to the cost. Low-fidelity simulator models cost between USD 2,000.00 and USD 3,000.00. The cost of developing and producing a simulator from 3D printing can range from USD 5.00 to USD 100.00. (6) On the other hand, virtual simulators can cost as much as USD 100,000.00. This problem can be solved by acquiring a single piece of equipment to be shared among different institutions.(9)
 
Another limitation is the absence or limited availability of pediatric simulators. Future simulators should incorporate multiple scenarios, allowing trainees to acquire decision-making ability and new skills, as well as basic proficiency.(17) However, because of the impact of the COVID-19 pandemic in 2020 and the uncertainty regarding how long the COVID-19 pandemic will last, simulation laboratories have become a necessity. Simulators guarantee the continuation of learning regardless of the state of the pandemic, providing training in daily clinical situations and in more difficult situations.
 
FINAL CONSIDERATIONS
 
Simulators in bronchoscopy training are useful and interesting tools to complement the conventional method of training. They allow trainees to practice in a risk-free environment and allow mistakes to be made. Bronchoscopy simulation training meets the growing medical needs to ensure an effective teaching/learning process while ensuring patient safety. In addition, the COVID-19 pandemic has highlighted the importance of continuing education in a safe environment regardless of the state of the pandemic, allowing materials and supplies to be used in order to fight the virus.
 
Further studies on bronchoscopy simulation are needed in order to make this promising teaching tool more accessible. Its increased use in training centers by physicians and students alike will encourage other medical professionals to perform this procedure during and even after the COVID-19 pandemic.
 
AUTHOR CONTRIBUTIONS
 
LMNV: literature review and drafting of the manuscript; PAMC and CCI: drafting of the manuscript and critical revision of the manuscript for important intellectual content; LMNV, PAMC, and CCI: final approval of the version to be published.
 
CONFLICTS OF INTEREST
 
None declared.
 
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