- Email: [email protected]
Simulation of the airway
Operative Techniques in Otolaryngology (2007) 18, 134-139
Simulation of the airway Ayesha N. Khalid, MD,a W. Bosseau Murray, MDb From the aDepartment of Surgery, Division of Otolaryngology–Head and Neck Surgery, Penn State College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania; and the b Department of Anesthesiology, Penn State College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania. KEYWORDS Medical education; Residents; Otolaryngology; Virtual reality; Simulation; Surgical skills; Crisis resource management
Simulation can be used to prepare the surgical and other skills of otolaryngology residents prior to performing the procedures and actions in the clinical environment. Virtual reality environments, including haptic devices, which recreate the sense of touch have made such training possible. Airway emergencies are challenging and life-threatening medical crises that can be repeatedly practiced in a simulated environment until a specified level of competency has been attained. During an airway crisis with rapidly developing hypoxia and asphyxia, where time is of the essence, interpersonal and communication skills are essential for efficient teamwork. These teamwork skills can be practiced in a high fidelity, realistically simulated clinical environment under the rubric of crisis resource management. With the availability of virtual reality machines, it has become an ethical imperative to train residents prior to patient contact. © 2007 Elsevier Inc. All rights reserved.
Simulation is a technique—not a technology—to amplify real patient experiences with guided experiences, artificially contrived, that evoke or replicate substantial aspects of the real world in fully interactive manner. —David Gaba, MD, 2004 Otolaryngology residents and practitioners currently are taught through a variety of continuing-education methods, including didactic lectures, videotapes, cadaver dissections, and direct observation of procedures. With the major determinant of a patient’s safety and eventual outcome being determined by the skill and judgment of the trained surgeon, surgical simulator tools may provide an additional method of teaching as well as assessing surgical skill.1,2 The acquisition of new skills in surgery requires prior factual knowledge as well as greater levels of knowledge (Table 1) followed by supervised training and opportunity for sufficient practice in the necessary surgical techniques. Classical teaching regarding education includes a discussion of Bloom’s classification of knowledge and a taxonomy of educational objectives, as shown in Table 1, that aid in defining observable and measurable behaviors that are exAddress reprint requests and correspondence: W. Bosseau Murray, MD, Department of Anesthesiology, H-187, Penn State Milton S. Hershey Medical Center, 500 University Drive, Hershey, PA 17033. E-mail address: [email protected]. 1043-1810/$ -see front matter © 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.otot.2007.07.001
pected to be learned through an exercise. Bloom’s work centered on presenting these behaviors in terms of the type of knowledge that is being acquired and relating them to a set of cognitive processing skills that are required to learn a specific set of objectives. Surgical simulation offers a means of achieving such a specified group of objectives with the overall goal of competency in performing surgical procedures, without placing patients at risk.3-5 Specific to the field of otorhinolaryngology, where the airway may be compromised, multiple types of procedures pose significant risk to the patient when an inexperienced trainee attempts the procedure for the first time. For instance, airway emergencies are challenging and life-threatening medical crises that require a diverse set of technical skills along with good communication, professional conduct, and teamwork, in addition to a sound foundation of medical knowledge.6 Simulation is a useful tool to teach both the psychomotor aspects, as well as the attitudinal principles required when working in a team. Simulation training has existed as a core technology for aviation training for a long time. Similarly, virtual reality (VR) simulations are an innovative approach to add to the teaching tools for residents in surgical training. In the aviation industry, flight simulation was pioneered more than 50 years ago to aid in pilot training, and now this industry has multiple standardized tools for training, evaluating, and certifying
Khalid and Murray Table 1
Simulation of the Airway
135
Bloom’s Taxonomy of Educational Objectives and Educational Activities Example: Mastoidectomy
Factual knowledge Facts Understanding Application Analysis
Synthesis Evaluation/comparison Psychomotor skills Attitudinal skills
The resident knows the anatomical relationship of mastoid to the facial nerve The resident understands that mastoid drilling could damage the facial nerve The resident drills carefully, slowly, and monitors with a nerve stimulator The resident uses the previous levels of knowledge in an advanced case to think about bone destruction and the fact that there might be no bone left between the mastoid and the facial nerve The resident comes up with a plan to search for the nerve before even starting to drill The resident compares different ways of identifying the facial nerve, and selects the most optimal method in this case The resident has practiced drilling skills in hard and in soft bone The resident can control the drill when perforation of bone unexpectedly occurs The resident communicates with the anesthesiologist about the need for nerve stimulation and appropriate use of muscle relaxants The resident discusses with the team to minimize interruption at a critical stage of the surgery
pilots.1,7 Studies of air flight scenarios that were aimed at testing accuracy demonstrate a transfer effectiveness ratio of 0.48, which means that 1 hour of teaching via simulation saves half an hour of teaching time in the air.1 Because of its success in the aviation industry, computer-based simulators are now increasingly being used in a variety of medical learning domains. At present, VR simulation plays a role in training of multiple disciplines, including ophthalmologic, gastrointestinal, and plastic and anesthetic procedures.8-11 Although the efficacy of VR simulation has been proven in many studies, a comparison of its efficacy with conventional teaching methods remains to be answered.7,11 In 1999, the American College of Graduate Medical Education (ACGME) endorsed 6 general competencies required by all residents before completion of their training.12 The first of these competencies is centered on providing patient care, and one of the tenets of providing appropriate patient care is the ability to “perform competently all medical and invasive procedures considered essential for the area of practice.” There has been a dramatic shift in the educational paradigm for residents, as surgical training programs are increasingly not only responsible for providing adequate teaching but also developing assessment and evaluation tools to assess surgical competency before graduation. The use of surgical simulation allows programs to develop basic technical skills and enables evaluation at various resident training levels before completion of training. Traditional otolaryngology residency training has addressed these vital technical and nontechnical skills primarily by individual clinical experience and by studying clinical protocols and the literature. Unlike the well-established tradition of temporal bone dissection in the cadaver before live surgery, training programs do not currently provide a uniform airway emergency experience to trainees. The aim of surgical simulation is to familiarize the trainee with the procedure in question while it is performed in an environment that does not place patients or trainees at risk. Completion of such a program familiarizes the trainee with the surgical instruments and their proper usage. Participation in surgical simulation should therefore allow trainees to be better equipped to correctly and safely perform the
procedure under supervision before any complicating factors related to patient anatomy or disease in the operating room.
Usage of simulation in surgical airway training Traditional otolaryngology programs have focused on animal models and inanimate objects for teaching procedural skills. Acquisition of new skills such as percutaneous endoscopic tracheotomy requires supervised training and the opportunity for sufficient practice. It is an airway procedure that affords little room for poor surgical skill and carries significant morbidity and mortality with an unskilled surgeon. Several studies have shown the utility of surgical simulation in training surgical residents to obtain a minimum level of skill.13 A study by Gardinier’s group incorporates usage of an animal model to allow practice inserting the bronchoscope under visualization on a monitor followed by examination of the trachea and direct visualization of the second and third tracheal rings where the insertion of the seeker needle is then confirmed endoscopically before proceeding.13 This model is based on the Ciaglia technique and is followed by the same sequence of steps as in a human model involving insertion of the guidewire, followed by bougie, followed by the tracheotomy tube. This animal model is rudimentary compared with the newer models of surgical simulation discussed below; however, it provides an example of practice with an endoscope as well as the monitoring of skill acquisition. Use of simulation technology is based on the use of VR to augment procedural teaching. VR is a computer-based environment that teaches users new skills through a variety of interactions with visual, tactile, and auditory feedback (Figure 1). The aim is to simulate a real-life environment. Advantages of such simulated training experiments allow trainees to train at their own pace, any time of the day, and allows them to return to practice scenarios until they are deemed proficient at the exercise. In the aerospace industry, VR has been used for a long time, and pilots have manda-
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Figure 1
Schematic set-up of virtual reality simulator interface in laboratory.
tory flight simulation training at biannual intervals to continue assuming flight responsibilities.7 Simulation technology has added the feedback to the participant through the usage of haptic technology, which is based on the sensation of tactile stimulation and feedback while performing a task under surgical simulation.14 The word haptic originates from the Greek word, “haptere,” to touch (Figure 2). Multiple companies are developing these haptic, or force-feedback, devices to use in training for surgical techniques such as laparoscopy, and with relation to the tracheobronchial tree, bronchoscopies. As demonstrated in Figures 1 to 3, these devices are based on the principle that they provide a reaction to the trainee’s movement, by producing resistive forces simulating those generated in an actual environment, and allow the trainee to gain a real
Figure 2 Haptic device that provides visual and tactile forcefeedback during a scenario. (Photo courtesy of W. Bosseau Murray, MD.) (Color version of figure is available online.)
“feel” for the technique while viewing a 3-dimensional, computer-generated display.15 In training users on bronchoscopies, these devices have proven to be effective not only at improving skill rapidly on the device itself but also when measuring a transfer of skill from the device to the patients themselves.16 Simulation training for surgeons as well as anesthesiologists has gained acceptance as a teaching tool and, as discussed in this article, various types of simulators are under development and commercially available.2,14,17 Figure 4 is an example of such a teaching tool that is available. The need for surgical simulation is even more evident when considering procedures such as rigid bronchoscopy, which are encountered and practiced even less frequently. The advent of fiberoptic technology and the flexible bronchoscope has meant that rigid bronchoscopy has become an increasingly specialized procedure with limited indications.3 This has meant that otorhinolaryngologist trainees are not exposed to the same number of procedures as they were in previous years. If skill competence in airway management and bronchial foreign body removal are to be attained, new ways of training using simulators need to be considered. For these simulators to be credible, it is important that operative simulations demonstrate proven training and educational benefit. Multiple studies demonstrate that surgical simulation-based training is an effective means of improving bronchoscopic skills.3,16 One example of a surgical procedure is the examination of the tracheobronchial tree in cases involving removal of a foreign body. A study by Hilmi and coworkers3 demonstrated a significant improvement in both task time and in the overall quality of task performance following a 6-hour period of intensive training.
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Figure 3 Photograph of haptic feedback device in our simulation laboratory. (Photo courtesy of W. Bosseau Murray, MD.) (Color version of figure is available online.)
Several models of translating these manual skills to bronchoscopy simulators have been described.4 A study by Colt and colleagues describes a study using a VR skill center consisting of a simulated flexible bronchoscope, a robotic interface device, and a personal computer with monitor and simulation software (Figure 1).18 The bronchoscope is modeled after a conventional flexible fiberoptic bronchoscope providing realistic images as the user navigates through the virtual anatomy, and the exercises consist of an initial introduction to the full bronchoscopic examination with the robotic interface tracking the motions of the flexible bronchoscope and reproducing via tactile feedback all the forces felt during an actual bronchoscopic examination. Further
Figure 4 A commercially available laryngeal simulator device provided by Reach In technology. (Color version of figure is available online.)
feedback is provided with the virtual patient breathing, coughing, bleeding, and exhibiting changes in vital signs, and the user is provided with usage of virtual topical anesthetic or saline solutions that are delivered through a foot pedal. With this basic set-up, trainees are provided with training scenarios that range from inspection of abnormalities of the airway to assessment of endobronchial tumors, performing endobronchial biopsy, and bronchoalveolar lavage. Similar to other studies, Colt’s group found that in this group of trainees dexterity and accuracy were improved by subjects who used the VR bronchscopy simulator before and after VR training.18 Dexterity was measured as the number of contacts with the tracheobroncial wall per minute whereas accuracy was the thoroughness of examination as measured by the number of bronchial segments missed. VR technology removes some of the limitations imposed by animal models, such as the simulation of real-life events such as respiratory movements, vocal cord closure, obstructing airway secretions, and/or procedure-related hemodynamic compromise. The results of these studies demonstrate that even a short, focused course of instruction and unsupervised practice using the simulator enabled novice trainees to attain a basic level of manual and technical skill to perform a diagnostic inspection of the tracheobronchial tree. Flexible fiberoptic bronchoscopy is a common procedure performed by anesthesiologists, pulmonologists, and otorhinolaryngologists, and the use of simulation has demonstrated proven benefits to augment clinical training.8,16,18 There are a few airway surgery simulators with the focus on using haptic technology to allow surgical trainees to perform laryngeal operations.2 One such company, Reachin Technology, provides an interface whereby trainees can visualize the anatomy as they make incisions and assess
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their proximity to nearby structures. In addition, on the frontier are some teaching tools whereby one group is interested in teaching more complex surgical procedures such as a laryngectomy via surgical simulation and has published a book on this topic; in the future, perhaps more complex surgeries can all be previewed and practiced in a simulation environment.
Crisis resource management Another concept recently introduced by the Accreditation Council for Graduate Medical Education as a required curricular component is teamwork whereby residents are supposed to develop their interpersonal and communication skills and work effectively within a health care team (www. acgme.org). Optimizing teamwork and cooperation is a concept first developed, once again, in the airline and aeronautics industry as cockpit or crew resource management. The terminology was changed to crisis resource management (CRM) for use in the health care industry.6,19-22 CRM is a conceptual framework that allows groups of people to train in responding effectively in emergency scenarios and has been applied to various medical training programs, most notable in anesthesiology though the work of Gaba and colleagues, as well as in emergency medicine.19,20 A pilot program has been developed to bring the principles of CRM to the field of otorhinolaryngology, and a study by Zirkle’s group6 used the simulation laboratory to create complex airway emergency scenarios with a curriculum focused on teamwork in carrying out the airway evaluation and securing a stable airway. Interestingly, the curriculum also involved a “debriefing” after each scenario whereby trained facilitators viewed a videotape reenactment and discussed how each participant responded during the crisis. All the participants then evaluated the program as a whole and provided constructive criticism on how to make the scenarios more relevant to cases seen in the trauma bay.
Conclusion Currently, otolaryngology residency training programs are focused on knowledge and skills acquisition and, as such, developing competent surgical otoalryngologists is an important part of residency training. However, we agree with the notion that optimal care of a patient requires additional attributes that may be needed such as the ability to work well within a team and be able to rely on other members of the health care team in times of crisis. The literature on CRM focuses on 5 key principles that require attention during medical emergencies: communication, clarity of one’s role within the health care team, technical issues, adequate usage of support personnel and, most importantly, global assessment of the emergency. Proponents of simulation in health care state there is much to be learned from these role-playing and technically challenging scenarios. Limitations of such a system, however, include the common concern that a simulated emergency is still, in essence, “obviously fake” and that participants may not take it seri-
ously. Zirkle and colleagues respond to this assertion with the claim that a carefully conducted debriefing of the scenario with trainees sharing their enthusiasm in a risk-free environment allows for measurable learning to take place.6 Their goal was focused on teaching team-building skills using CRM principles in typical otolaryngic emergencies and as such, the objectives were met in the pilot study. Simulation has been an exciting addition to the armamentarium of clinical skills training. Through refinements in the technical aspects of VR and the further development of haptic technology, surgical simulation can provide a muchneeded bridge between bench-top and blackboard learning skills and overall surgical competence. Furthermore, surgical simulation environments may serve effective evaluation tools of individual team members, teams themselves, and the effect of external stressors and environmental factors on the functioning of an effective team.4 Ultimately, surgical simulation may also prove to be a valuable tool in identifying, isolating, and reduction of errors within the operating room as well as within the larger context of our health care system.
Websites of interest This is by no means an exhaustive list nor are any of these website or products endorsed by the authors of editors of this text.
Societies interested in simulation technology ●
Society for simulation in health care: www.ssih.org
Commercial websites ● ●
www.immersion.com (endoscopy VR surgical simulator) www.lockheedmartin.com (endoscopic sinus surgery simulator)
References 1. Kuppersmith RB, Johnston R, Jones SB, et al: Virtual reality surgical simulation and otolaryngology. Arch Otolaryngol Head Neck Surg 122:1297-1298, 1996 2. Liu A, Bhasin Y, Bowyer M: A haptic-enabled simulator for cricothyroidotomy. Stud Health Technol Inform 111:308-313, 2005 3. Hilmi OJ, White PS, McGurty DW, et al: Bronchoscopy training: is simulated surgery effective? Clin Otolaryngol Allied Sci 27:267-269, 2002 4. Abrahamson S, Denson JS, Wolf RM: Effectiveness of a simulator in training anesthesiology residents. 1969. Qual Saf Health Care 13:395397, 2004 5. Goldmann K, Steinfeldt T: Acquisition of basic fiberoptic intubation skills with a virtual reality airway simulator. J Clin Anesth 18:173-178, 2006 6. Zirkle M, Blum R, Raemer DB, et al: Teaching emergency airway management using medical simulation: a pilot program. Laryngoscope 115:495-500, 2005 7. Fried MP, Gallagher AG, Satava RM: Training to proficiency: aircraft to OR. Arch Otolaryngol Head Neck Surg 130:1145-1146, 2004 8. Schaefer JJ 3rd: Simulators and difficult airway management skills. Paediatr Anaesth 14:28-37, 2004
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9. Stringer KR, Bajenov S, Yentis SM: Training in airway management. Anaesthesia 57:967-983, 2002 10. Peugnet F, Dubois P, Rouland JF: Virtual reality versus conventional training in retinal photocoagulation: a first clinical assessment. Comput Aided Surg 3:20-26, 1998 11. Baillie J: Endoscopic retrograde cholangiopancreatography simulation. Gastrointest Endosc Clin N Am 16:529-542, viii, 2006. 12. Carr MM: Program directors’ opinions about surgical competency in otolaryngology residents. Laryngoscope 115:1208-1211, 2005 13. Gardiner Q, White PS, Carson D, et al: Technique training: endoscopic percutaneous tracheostomy. Br J Anaesth 81:401-403, 1998 14. Moody L, Baber C, Arvanitis TN: Objective surgical performance evaluation based on haptic feedback. Stud Health Technol Inform 85:304-310, 2002 15. Riener R, Burgkart R: A new haptic interface for VR medical training. Stud Health Technol Inform 85:388-394, 2002 16. Ost D, DeRosiers A, Britt EJ, et al: Assessment of a bronchoscopy simulator. Am J Respir Crit Care Med 15 164:2248-2255, 2001
139 17. Rolfsson G, Nordgren A, Bindzau S, et al: Training and assessment of laparoscopic skills using a haptic simulator. Stud Health Technol Inform 85:409-411, 2002 18. Colt HG, Crawford SW, Galbraith O 3rd: Virtual reality bronchoscopy simulation: a revolution in procedural training. Chest 120:1333-1339, 2001 19. Gaba DM: The future vision of simulation in health care. Qual Saf Health Care 13:i2-i10, 2004 (suppl 1) 20. Reznek M, Smith-Coggins R, Howard S, et al: Emergency medicine crisis resource management (EMCRM): pilot study of a simulationbased crisis management course for emergency medicine. Acad Emerg Med 10:386-389, 2003 21. Holzman RS, Cooper JB, Gaba DM, et al: Anesthesia crisis resource management: real-life simulation training in operating room crises. J Clin Anesth 7:675-687, 1995 22. Aggarwal R, Undre S, Moorthy K, et al: The simulated operating theatre: comprehensive training for surgical teams. Qual Saf Health Care 13:i27-132, 2004 (suppl 1)
Simulation of the airway Ayesha N. Khalid, MD,a W. Bosseau Murray, MDb From the aDepartment of Surgery, Division of Otolaryngology–Head and Neck Surgery, Penn State College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania; and the b Department of Anesthesiology, Penn State College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania. KEYWORDS Medical education; Residents; Otolaryngology; Virtual reality; Simulation; Surgical skills; Crisis resource management
Simulation can be used to prepare the surgical and other skills of otolaryngology residents prior to performing the procedures and actions in the clinical environment. Virtual reality environments, including haptic devices, which recreate the sense of touch have made such training possible. Airway emergencies are challenging and life-threatening medical crises that can be repeatedly practiced in a simulated environment until a specified level of competency has been attained. During an airway crisis with rapidly developing hypoxia and asphyxia, where time is of the essence, interpersonal and communication skills are essential for efficient teamwork. These teamwork skills can be practiced in a high fidelity, realistically simulated clinical environment under the rubric of crisis resource management. With the availability of virtual reality machines, it has become an ethical imperative to train residents prior to patient contact. © 2007 Elsevier Inc. All rights reserved.
Simulation is a technique—not a technology—to amplify real patient experiences with guided experiences, artificially contrived, that evoke or replicate substantial aspects of the real world in fully interactive manner. —David Gaba, MD, 2004 Otolaryngology residents and practitioners currently are taught through a variety of continuing-education methods, including didactic lectures, videotapes, cadaver dissections, and direct observation of procedures. With the major determinant of a patient’s safety and eventual outcome being determined by the skill and judgment of the trained surgeon, surgical simulator tools may provide an additional method of teaching as well as assessing surgical skill.1,2 The acquisition of new skills in surgery requires prior factual knowledge as well as greater levels of knowledge (Table 1) followed by supervised training and opportunity for sufficient practice in the necessary surgical techniques. Classical teaching regarding education includes a discussion of Bloom’s classification of knowledge and a taxonomy of educational objectives, as shown in Table 1, that aid in defining observable and measurable behaviors that are exAddress reprint requests and correspondence: W. Bosseau Murray, MD, Department of Anesthesiology, H-187, Penn State Milton S. Hershey Medical Center, 500 University Drive, Hershey, PA 17033. E-mail address: [email protected]. 1043-1810/$ -see front matter © 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.otot.2007.07.001
pected to be learned through an exercise. Bloom’s work centered on presenting these behaviors in terms of the type of knowledge that is being acquired and relating them to a set of cognitive processing skills that are required to learn a specific set of objectives. Surgical simulation offers a means of achieving such a specified group of objectives with the overall goal of competency in performing surgical procedures, without placing patients at risk.3-5 Specific to the field of otorhinolaryngology, where the airway may be compromised, multiple types of procedures pose significant risk to the patient when an inexperienced trainee attempts the procedure for the first time. For instance, airway emergencies are challenging and life-threatening medical crises that require a diverse set of technical skills along with good communication, professional conduct, and teamwork, in addition to a sound foundation of medical knowledge.6 Simulation is a useful tool to teach both the psychomotor aspects, as well as the attitudinal principles required when working in a team. Simulation training has existed as a core technology for aviation training for a long time. Similarly, virtual reality (VR) simulations are an innovative approach to add to the teaching tools for residents in surgical training. In the aviation industry, flight simulation was pioneered more than 50 years ago to aid in pilot training, and now this industry has multiple standardized tools for training, evaluating, and certifying
Khalid and Murray Table 1
Simulation of the Airway
135
Bloom’s Taxonomy of Educational Objectives and Educational Activities Example: Mastoidectomy
Factual knowledge Facts Understanding Application Analysis
Synthesis Evaluation/comparison Psychomotor skills Attitudinal skills
The resident knows the anatomical relationship of mastoid to the facial nerve The resident understands that mastoid drilling could damage the facial nerve The resident drills carefully, slowly, and monitors with a nerve stimulator The resident uses the previous levels of knowledge in an advanced case to think about bone destruction and the fact that there might be no bone left between the mastoid and the facial nerve The resident comes up with a plan to search for the nerve before even starting to drill The resident compares different ways of identifying the facial nerve, and selects the most optimal method in this case The resident has practiced drilling skills in hard and in soft bone The resident can control the drill when perforation of bone unexpectedly occurs The resident communicates with the anesthesiologist about the need for nerve stimulation and appropriate use of muscle relaxants The resident discusses with the team to minimize interruption at a critical stage of the surgery
pilots.1,7 Studies of air flight scenarios that were aimed at testing accuracy demonstrate a transfer effectiveness ratio of 0.48, which means that 1 hour of teaching via simulation saves half an hour of teaching time in the air.1 Because of its success in the aviation industry, computer-based simulators are now increasingly being used in a variety of medical learning domains. At present, VR simulation plays a role in training of multiple disciplines, including ophthalmologic, gastrointestinal, and plastic and anesthetic procedures.8-11 Although the efficacy of VR simulation has been proven in many studies, a comparison of its efficacy with conventional teaching methods remains to be answered.7,11 In 1999, the American College of Graduate Medical Education (ACGME) endorsed 6 general competencies required by all residents before completion of their training.12 The first of these competencies is centered on providing patient care, and one of the tenets of providing appropriate patient care is the ability to “perform competently all medical and invasive procedures considered essential for the area of practice.” There has been a dramatic shift in the educational paradigm for residents, as surgical training programs are increasingly not only responsible for providing adequate teaching but also developing assessment and evaluation tools to assess surgical competency before graduation. The use of surgical simulation allows programs to develop basic technical skills and enables evaluation at various resident training levels before completion of training. Traditional otolaryngology residency training has addressed these vital technical and nontechnical skills primarily by individual clinical experience and by studying clinical protocols and the literature. Unlike the well-established tradition of temporal bone dissection in the cadaver before live surgery, training programs do not currently provide a uniform airway emergency experience to trainees. The aim of surgical simulation is to familiarize the trainee with the procedure in question while it is performed in an environment that does not place patients or trainees at risk. Completion of such a program familiarizes the trainee with the surgical instruments and their proper usage. Participation in surgical simulation should therefore allow trainees to be better equipped to correctly and safely perform the
procedure under supervision before any complicating factors related to patient anatomy or disease in the operating room.
Usage of simulation in surgical airway training Traditional otolaryngology programs have focused on animal models and inanimate objects for teaching procedural skills. Acquisition of new skills such as percutaneous endoscopic tracheotomy requires supervised training and the opportunity for sufficient practice. It is an airway procedure that affords little room for poor surgical skill and carries significant morbidity and mortality with an unskilled surgeon. Several studies have shown the utility of surgical simulation in training surgical residents to obtain a minimum level of skill.13 A study by Gardinier’s group incorporates usage of an animal model to allow practice inserting the bronchoscope under visualization on a monitor followed by examination of the trachea and direct visualization of the second and third tracheal rings where the insertion of the seeker needle is then confirmed endoscopically before proceeding.13 This model is based on the Ciaglia technique and is followed by the same sequence of steps as in a human model involving insertion of the guidewire, followed by bougie, followed by the tracheotomy tube. This animal model is rudimentary compared with the newer models of surgical simulation discussed below; however, it provides an example of practice with an endoscope as well as the monitoring of skill acquisition. Use of simulation technology is based on the use of VR to augment procedural teaching. VR is a computer-based environment that teaches users new skills through a variety of interactions with visual, tactile, and auditory feedback (Figure 1). The aim is to simulate a real-life environment. Advantages of such simulated training experiments allow trainees to train at their own pace, any time of the day, and allows them to return to practice scenarios until they are deemed proficient at the exercise. In the aerospace industry, VR has been used for a long time, and pilots have manda-
136
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Figure 1
Schematic set-up of virtual reality simulator interface in laboratory.
tory flight simulation training at biannual intervals to continue assuming flight responsibilities.7 Simulation technology has added the feedback to the participant through the usage of haptic technology, which is based on the sensation of tactile stimulation and feedback while performing a task under surgical simulation.14 The word haptic originates from the Greek word, “haptere,” to touch (Figure 2). Multiple companies are developing these haptic, or force-feedback, devices to use in training for surgical techniques such as laparoscopy, and with relation to the tracheobronchial tree, bronchoscopies. As demonstrated in Figures 1 to 3, these devices are based on the principle that they provide a reaction to the trainee’s movement, by producing resistive forces simulating those generated in an actual environment, and allow the trainee to gain a real
Figure 2 Haptic device that provides visual and tactile forcefeedback during a scenario. (Photo courtesy of W. Bosseau Murray, MD.) (Color version of figure is available online.)
“feel” for the technique while viewing a 3-dimensional, computer-generated display.15 In training users on bronchoscopies, these devices have proven to be effective not only at improving skill rapidly on the device itself but also when measuring a transfer of skill from the device to the patients themselves.16 Simulation training for surgeons as well as anesthesiologists has gained acceptance as a teaching tool and, as discussed in this article, various types of simulators are under development and commercially available.2,14,17 Figure 4 is an example of such a teaching tool that is available. The need for surgical simulation is even more evident when considering procedures such as rigid bronchoscopy, which are encountered and practiced even less frequently. The advent of fiberoptic technology and the flexible bronchoscope has meant that rigid bronchoscopy has become an increasingly specialized procedure with limited indications.3 This has meant that otorhinolaryngologist trainees are not exposed to the same number of procedures as they were in previous years. If skill competence in airway management and bronchial foreign body removal are to be attained, new ways of training using simulators need to be considered. For these simulators to be credible, it is important that operative simulations demonstrate proven training and educational benefit. Multiple studies demonstrate that surgical simulation-based training is an effective means of improving bronchoscopic skills.3,16 One example of a surgical procedure is the examination of the tracheobronchial tree in cases involving removal of a foreign body. A study by Hilmi and coworkers3 demonstrated a significant improvement in both task time and in the overall quality of task performance following a 6-hour period of intensive training.
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Figure 3 Photograph of haptic feedback device in our simulation laboratory. (Photo courtesy of W. Bosseau Murray, MD.) (Color version of figure is available online.)
Several models of translating these manual skills to bronchoscopy simulators have been described.4 A study by Colt and colleagues describes a study using a VR skill center consisting of a simulated flexible bronchoscope, a robotic interface device, and a personal computer with monitor and simulation software (Figure 1).18 The bronchoscope is modeled after a conventional flexible fiberoptic bronchoscope providing realistic images as the user navigates through the virtual anatomy, and the exercises consist of an initial introduction to the full bronchoscopic examination with the robotic interface tracking the motions of the flexible bronchoscope and reproducing via tactile feedback all the forces felt during an actual bronchoscopic examination. Further
Figure 4 A commercially available laryngeal simulator device provided by Reach In technology. (Color version of figure is available online.)
feedback is provided with the virtual patient breathing, coughing, bleeding, and exhibiting changes in vital signs, and the user is provided with usage of virtual topical anesthetic or saline solutions that are delivered through a foot pedal. With this basic set-up, trainees are provided with training scenarios that range from inspection of abnormalities of the airway to assessment of endobronchial tumors, performing endobronchial biopsy, and bronchoalveolar lavage. Similar to other studies, Colt’s group found that in this group of trainees dexterity and accuracy were improved by subjects who used the VR bronchscopy simulator before and after VR training.18 Dexterity was measured as the number of contacts with the tracheobroncial wall per minute whereas accuracy was the thoroughness of examination as measured by the number of bronchial segments missed. VR technology removes some of the limitations imposed by animal models, such as the simulation of real-life events such as respiratory movements, vocal cord closure, obstructing airway secretions, and/or procedure-related hemodynamic compromise. The results of these studies demonstrate that even a short, focused course of instruction and unsupervised practice using the simulator enabled novice trainees to attain a basic level of manual and technical skill to perform a diagnostic inspection of the tracheobronchial tree. Flexible fiberoptic bronchoscopy is a common procedure performed by anesthesiologists, pulmonologists, and otorhinolaryngologists, and the use of simulation has demonstrated proven benefits to augment clinical training.8,16,18 There are a few airway surgery simulators with the focus on using haptic technology to allow surgical trainees to perform laryngeal operations.2 One such company, Reachin Technology, provides an interface whereby trainees can visualize the anatomy as they make incisions and assess
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Operative Techniques in Otolaryngology, Vol 18, No 2, June 2007
their proximity to nearby structures. In addition, on the frontier are some teaching tools whereby one group is interested in teaching more complex surgical procedures such as a laryngectomy via surgical simulation and has published a book on this topic; in the future, perhaps more complex surgeries can all be previewed and practiced in a simulation environment.
Crisis resource management Another concept recently introduced by the Accreditation Council for Graduate Medical Education as a required curricular component is teamwork whereby residents are supposed to develop their interpersonal and communication skills and work effectively within a health care team (www. acgme.org). Optimizing teamwork and cooperation is a concept first developed, once again, in the airline and aeronautics industry as cockpit or crew resource management. The terminology was changed to crisis resource management (CRM) for use in the health care industry.6,19-22 CRM is a conceptual framework that allows groups of people to train in responding effectively in emergency scenarios and has been applied to various medical training programs, most notable in anesthesiology though the work of Gaba and colleagues, as well as in emergency medicine.19,20 A pilot program has been developed to bring the principles of CRM to the field of otorhinolaryngology, and a study by Zirkle’s group6 used the simulation laboratory to create complex airway emergency scenarios with a curriculum focused on teamwork in carrying out the airway evaluation and securing a stable airway. Interestingly, the curriculum also involved a “debriefing” after each scenario whereby trained facilitators viewed a videotape reenactment and discussed how each participant responded during the crisis. All the participants then evaluated the program as a whole and provided constructive criticism on how to make the scenarios more relevant to cases seen in the trauma bay.
Conclusion Currently, otolaryngology residency training programs are focused on knowledge and skills acquisition and, as such, developing competent surgical otoalryngologists is an important part of residency training. However, we agree with the notion that optimal care of a patient requires additional attributes that may be needed such as the ability to work well within a team and be able to rely on other members of the health care team in times of crisis. The literature on CRM focuses on 5 key principles that require attention during medical emergencies: communication, clarity of one’s role within the health care team, technical issues, adequate usage of support personnel and, most importantly, global assessment of the emergency. Proponents of simulation in health care state there is much to be learned from these role-playing and technically challenging scenarios. Limitations of such a system, however, include the common concern that a simulated emergency is still, in essence, “obviously fake” and that participants may not take it seri-
ously. Zirkle and colleagues respond to this assertion with the claim that a carefully conducted debriefing of the scenario with trainees sharing their enthusiasm in a risk-free environment allows for measurable learning to take place.6 Their goal was focused on teaching team-building skills using CRM principles in typical otolaryngic emergencies and as such, the objectives were met in the pilot study. Simulation has been an exciting addition to the armamentarium of clinical skills training. Through refinements in the technical aspects of VR and the further development of haptic technology, surgical simulation can provide a muchneeded bridge between bench-top and blackboard learning skills and overall surgical competence. Furthermore, surgical simulation environments may serve effective evaluation tools of individual team members, teams themselves, and the effect of external stressors and environmental factors on the functioning of an effective team.4 Ultimately, surgical simulation may also prove to be a valuable tool in identifying, isolating, and reduction of errors within the operating room as well as within the larger context of our health care system.
Websites of interest This is by no means an exhaustive list nor are any of these website or products endorsed by the authors of editors of this text.
Societies interested in simulation technology ●
Society for simulation in health care: www.ssih.org
Commercial websites ● ●
www.immersion.com (endoscopy VR surgical simulator) www.lockheedmartin.com (endoscopic sinus surgery simulator)
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