Dexter plays a central role in the Introduction to Bronchoscopic Airway Management Course run by Dr Colin Marsland at Wellington Hospital in New Zealand. The course uses mastery learning concepts and deliberate practice to achieve a uniform standard of proficiency in bronchoscopic manipulation prior to first clinical exposure. Proficiency is defined and training includes performance measurement culminating in anaesthesia trainees receiving a ‘Bronchoscopic Drivers Licence’ that is required prior to them using bronchoscopes in the clinical environment under staged supervision.
The Wellington course is outlined below to help inform instructional design elsewhere. Discussion is very welcome via the contacts page.
The course is bookended by two lectures:
1. Introduction to Driving (based on information in the Dexter training manual)
Structure and function of bronchoscopes, optical and mechanical skills, the importance of rotation, fine movement, how to drive smoothly, control of the bronchoscope without a conduit, common mistakes, defining and demonstrating proficiency, components of assessment.
2. Bronchoscopic Intubation - Clinical Aspects
Indications and contra-indications for AFOI. Equipment and preparation. Positioning, sedation, analgesia, topicalisation and the patient experience. Endotracheal tubes, conduits, combination techniques including LMAs and videolaryngoscopes. Performance, teamwork and assessment.
These didactic sessions bookend a period of several weeks during which the trainees have access to the bronchoscopy training lab for the purposes of practice. They can use the lab whenever they have time, including nights and weekends. They are told to perform at least 6 half hour practice sessions during this period if they want to perform at a proficient standard in their assessment and gain their ‘driver’s licence’.
Key Teaching Points for Development of Bronchoscopic Dexterity
The Dexter teaching modules systematically cover the core information required for the development of bronchoscopic dexterity. After a decade of teaching these skills and observing their development in trainees, the following aspects are worth emphasizing (CM) :
1. Understand the implications of restricted field of view
Anticipating, identifying and centring targets early assists smooth navigation.
If you don’t know what you are looking at or can’t see where to go, withdraw into the airspace, identify a landmark, get it into the centre of the field of view and start again.
Objects outside the field of view will be missed unless looked for.
2. Moving obliquely (zero degree video-bronchoscope)
Rotate target into the12 o’clock-6 o’clock axis (imagine a vertical line in the centre of the screen)
Flex to Centre the target in the middle of the screen (the bronchoscope is always heading to the centre of the screen.
Advance to target
Have a look at the video. Remember you can rotate the target to either 12 o’clock or 6 o’clock and then flex it back into the centre.
3. Efficient Rotation
Top hand rotates, lower hand supports
Hold the handpiece towards the fingers of the top hand not the fist (rotate in fingertips if necessary).
Top and bottom hands connected by slight tension in insertion cord
Avoid lower hand pinching the insertion cord as this prevents rotation
Have a look at the extent of rotation of the tropical scene in this video. It is severely reduced if the scope is held in the upper fist, if loops are formed and if the lower hand pinches the insertion cord and prevents it rotating. These are common technical errors that have a profound effect on your ability to manipulate the bronchoscope accurately.
4. Fine movement and accuracy
Rotate precisely. When moving obliquely, ensure that target is rotated fully into the 12-6 axis before centring. Otherwise, when flexed, the target will be off-centre and the bronchoscope will move across rather than directly to the target. Remember that the bronchoscope is always heading to the centre of the screen.
Support the insertion cord gently with your lower hand. Allow it to rotate.
5. Control without a conduit.
Over-reliance on conduits is bad for driving skills. Conduits include intubating oro-pharyngeal airways, LMAs, ETTs and anatomic structures such as the nose and tracheo-bronchial tree. Driving proficiently in the large unsupported airspace from mouth to larynx is an important skill. A good anatomic part-task trainer is the best model to develop this.
Hold insertion cord at about 12 cm
Connect hands via slight tension in insertion cord and let the lower hand pull the upper hand toward the larynx as the sequential anatomical targets are centred and passed.
Start with centred view on screen so that you can see teeth and uvula
Move upper and lower hands together
Move smoothly between sequential anatomic targets to glottis
Maintain lower hand support on insertion cord by resting fingers on teeth as reach glottis and then finger walk the scope into the trachea.
Have a look at the accompanying video. The lower hand holds the bronchoscope at about 12 cm from the tip. Both hands stay connected and the same distance apart until the bronchoscope approaches the glottic aperture and the lower hand reaches the teeth. The insertion cord is stabilised against the teeth with the ring finger while the index finger and thumb walk up the scope and support its advance between the vocal cords. (The ‘finger walk’) Once in the tracheo-bronchial tree, the bronchoscope is essentially supported in a biological conduit.
Performance Goals and Measurement
To be awarded their drivers licence, trainees must successfully complete 3 tasks:
1) Accurately complete a directed navigation exercise in Dexter that includes demonstration of extensive rotation in the image pod, a challenging level of fine manipulation in the navigation pod and a distance measurement. Trainees must accurately identify/complete 4 out of 5 images/tasks in less than 8 minutes to pass.
2) Proficient score in 2 out of 3 endoscopic passes from mouth to carina using the Global Rating Scale for Fibreoptic Bronchoscope Manipulation (GRS).
A video example of GRS 3 (Proficient) is available here.
3) Accurate completion of a directed navigation exercise in the bronchial tree of the anatomic manikin e.g move smoothly into RUL and LUL bronchi.
Global Rating Scale of Fibreoptic Bronchoscope Manipulation (GRS) (PDF)
Hardware in the Bronchoscopy Lab at Wellington
Part Task Trainers
Dexter Endoscopic Dexterity Training System (2)
Trucorp Medsim (1)
Bronchoscopes and Camera Systems
Storz Telepac camera and bronchoscope (1)
Olympus Bronchoscope (eyepiece)
Ambu a-scope screen and bronchoscope (1)
Logistical Requirements for Distributed Practice
85% of novices achieve GRS 3 (Proficient) by3 hrs of distributed practice and this increases to 96% by 4 hrs of practice. While novices with high aptitude may achieve proficiency in a workshop setting, most will require more practice time than can be achieved in the typical half day workshop. Large numbers of novices can achieve proficiency if they have access to the models and equipment for a period of several days or weeks. This is best suited to training in local departments or potentially during multi-day conferences or workshops.
Data shown in blue are from a study we published in the BJA where novices (n = 29) were assessed after every hour of practice with Dexter and an anatomic manikin until they could achieve a proficient score. Data in red are from a submitted study (n = 33) looking at outcome from a novice bronchoscopy workshop that allowed 1.5 hrs of hands on practice prior to assessment. Basic principles of mastery learning and dedicated practice can result in a uniform outcome independent of individual aptitude. A uniform standard of proficiency is achievable for all anaesthetic trainees if this approach is applied.
Audit data from the teaching program in Anaesthesia at Wellington Hospital (2010 – 2013). 85% of trainees who have taken part gained their driver’s licence. Of the people who did not achieve proficiency on the first assessment, no-one has failed to achieve their licence if they have kept practicing. None of the people who failed to achieve their licence practiced after their initial assessment.
Local departmental champions are important to set up the training environment, teach didactic information, demonstrate technique and performance goals and undertake performance measurement. A departmental champion can recruit support for the concept of the “drivers licence” including the clinical benefit to trainees of this mark of proficiency. This may include encouraging subsequent clinical use and involvement in bronchoscopy clinics etc. In Wellington this approach has created an enthusiastic demand for the training and an appreciation for its value.
Integration of Psychomotor Proficiency into Bronchoscopic Competence
Developing proficiency in manipulation of a bronchoscope is an essential part of bronchoscopic competence. The other components, notably patient selection, preparation and management are equally important but the skills required are more knowledge based and can be developed with didactic teaching and clinical demonstration followed by supervised clinical experience. The development of psychomotor skills requires a different approach and that’s where Dexter comes in.