It is the fundamental responsibility of an anaesthesiologist to maintain adequate gas exchange by securing the airway, and tracheal intubation is an essential skill in both elective and emergency anaesthesia. Recent guidelines for dealing with both anticipated and unanticipated difficult airways incorporate the use of flexible fibreoptic intubation (FOI).1,2 FOI is a crucial skill for anaesthesiologists to master, but junior anaesthesiologists have reported their perceived level of competence in FOI as insufficient and a recent study found that anaesthesia residents performing FOI on manikins failed to intubate in 55% of cases.3,4 Lack of experience and training has been found to be a central reason for avoiding the use of FOI in airway management and difficulty in learning to manoeuvre the flexible scope has been suggested as the hardest part of learning FOI.5,6
Training in complex motor skills can be achieved effectively outside the operating room. The training of FOI in a simulated environment has been thoroughly investigated on both sophisticated high fidelity simulators and simple ‘bench models’.7–11
A recent comparison of three different simulator modalities of varying fidelity found overall improvement in performance, inviting the exploration of the best way to structure the simulation training of airway management.12 Research into which training modality would prove the most effective has been conducted by Chandra et al.,9 who found no added benefit from training on a costly simulator compared with a simple bench model. Boet et al.13 responded to these findings by suggesting that training modalities can be differentiated in accordance with part-task training theory, in which the simple bench model can be seen as a part-task trainer and the virtual reality simulator as an integrated whole-task trainer. They hypothesised that part-task training could be the most effective way to structure a training programme in FOI. However, the introduction of mandatory multimodality part-task training programmes could be impractical as well as costly, and should be evidence-based.
The aims of the present study were to compare the effect of training the motor skills of FOI as part-task training or as whole-task training and to relate the performance levels achieved by the novices to the standard of performance of experienced FOI practitioners.
Materials and methods
Ethical approval from the local research ethics committee was sought, and the Research Ethics Committee of the Capital Region of Denmark waived the need for full ethical approval (Julie Dahl Larsen, protocol H-2-2012-156) on 30 November 2012. All participants gave informed consent to participate in the study.
Our study population consisted of residents in the first year of training in anaesthesiology, from eight different hospitals in Denmark. At this level of anaesthesiology training, the residents have general experience in airway management, but very little, if any, experience of FOI. Demographic data collection consisted of age, sex and number of FOIs performed. The study design is depicted as a flowchart in Fig. 1.
The participants first watched a short film on scope manipulation (4 min) to ensure a uniform basic level of knowledge and were then allocated to the intervention (part-task training as well as whole-task training) or control group (whole-task training only) by a computerised random number generator with unbalanced randomisation.
The part-task group first trained for 25 min on the Simbionix GI-Bronch Mentor (Simbionix, Cleveland, Ohio, USA, approx. €100 000). This simulator provided a simple programme to train basic hand-eye coordination needed for manoeuvring a flexible scope as part-task training. The part-task exercise consisted of repetitions of a single module in the GI-Bronch Mentor simulator. This module consists of an artificial (nonanatomical) environment and allows the trainee to focus on efficient scope manoeuvring. The Simbionix simulator logs a performance score and the time to completion, and these metrics were collected. The performance score and time to completion were provided to the trainee after each repetition, for direct feedback on performance.
Subsequently, the part-task group trained for 25 min on the AccuTouch Flexible Bronchoscopy Simulator (CAE Healthcare, Montreal, Canada, approx. €110 000). This simulator gave the trainee a whole-task experience of performing FOI on a patient up until insertion of the tube (whole-task training). The AccuTouch simulator logs a path efficiency score and the time to completion, and these metrics were collected. The path efficiency score and time to completion were provided to the trainee after each repetition, for direct feedback on performance.
The whole-task group trained for 50 min on the AccuTouch simulator.
This training regimen ensured that participants in both groups spent the same amount of time training in the manoeuvring of flexible scopes.
After simulator training, insertion of a tracheal tube using FOI was practised on manikins. This practice was instructed by an experienced anaesthesiologist. The manikins in use were the BronchoBoy II (CLA, Coburg, Germany) and the AirSim Bronchi (TruCorp, Belfast, UK). The scopes used for performing FOI were Ambu aScope 3 (Ambu, Ballerup, Denmark) and Olympus Portaview-LF (Olympus, Shinkuku, Japan). The combination of these four devices ensured varied training and assessment of participants.
The transfer of skills to performing on a manikin after simulator training was assessed by an experienced anaesthesiologist (L.R.) blinded to the prior simulator-training regimen. The participants performed 12 different intubation scenarios (Fig. 2). Data on the first three and last three procedures were collected for analysis of initial and final performance. After each scenario, feedback was provided, apart from the last three intubations (final test), when no verbal feedback on performance was given.
Ten anaesthesiologists with experience in FOI from the Intensive Care Department of Rigshospitalet, University Hospital of Copenhagen, were given the same final test and assessed on manikin performance, and data on their experience level in FOI were collected.
To reduce intercase variability, all procedures were combined in blocks of three and the mean scores of each block were used for analysis. To explore the learning effect of each of the three training modalities (the part-task simulator, the whole-task simulator and the manikins), the first three attempts were compared with the last three attempts using the Wilcoxon signed-rank test. The part-task group was compared with the whole-task group with regard to initial and final performance on the whole-task simulator and the manikins. Finally, the initial and the final performances by the trainees on the manikins were compared with the performance of the experienced anaesthesiologists. These comparisons were made using the Mann–Whitney U test.
Statistical analysis was performed using a statistical software package (PASW, version 18.0; SPSS Inc., Chicago, Illinois, USA). Differences were considered to be statistically significant when the P value was less than 0.05.
Twenty-three junior anaesthetists participated in the study. The mean age was 33.9 (SD 4.3) years. All had less than 1 year of experience in anaesthesiology and no prior experience in performing FOI. Thirteen physicians were randomised to the part-task group and 10 to the whole-task group.
During training on all three simulation modalities, the scores improved significantly and the duration of the procedures was reduced significantly (Table 1). There were no significant differences between the part-task group and the whole-task group regarding score or procedure time for the whole-task simulator or the manikins (Table 2). When comparing the first three manikin performances of the novices with the performance of the 10 experienced anaesthesiologists, the latter performed significantly better than the novices. However, the novices improved their skill level significantly, and by the end of manikin training, their performance was at a level comparable with that of the experienced anaesthesiologists (Fig. 3).
There was a significant positive learning effect of short training sessions (25 to 50 min) for all three simulation modalities used in this study (virtual-reality part-task training, virtual-reality whole-task training and training with real scopes on manikins). However, this study demonstrated no significant difference between the effects of part-task and whole-task training regimens. Dividing the training into two different modalities did not prove superior to training on a single modality when training time was kept similar in the two groups. This corresponds to the finding by Chandra et al.,9 who demonstrated no added benefit from training on high-fidelity simulators compared with low-fidelity training. However, our results do not support the hypothesis made by Boet et al.13 that dividing the training in a part-task manner would have an impact on performance.
When comparing novice performances with experienced anaesthesiologists, we found that the novices’ quality of performance at the onset of manikin training was significantly lower than that of experienced anaesthesiologists. This ability to differentiate between novices and experienced FOI performers indicates construct validity of the measurements. The initial performance of the novices on the manikin indicates that 50 min of virtual-reality training is not enough to ensure basic competency. Manipulation of the flexible scope can be practised in virtual-reality simulators, but correct handling of the intubation tube needs to be practised in a physical environment.
After practising 12 different intubations on manikins in less than 1 h, the novices were performing at the same level as the experienced anaesthesiologists. This is consistent with findings by Naik et al.,11 who demonstrated that 45 min of training on a simple bench model improved FOI performance. Another study has shown that competence in performing FOI was achievable within 10 performed intubations.14 However, we only explored the basic motor learning skills necessary to perform FOI. The procedure is more challenging in a real-life setting and the clinical learning curve will be longer.
By training first-year residents in anaesthesiology, we were able to assemble a group of individuals with the ideal potential to benefit from FOI training. With knowledge of airway anatomy and prior experience in intubation by direct laryngoscopy, but no experience of FOI, they were at a stage in their education at which a course in FOI would fit appropriately. The number of first-year anaesthesiologists available at the eight hospitals that participated restricted the size of our study population. This is true for most training studies, and respiratory therapists have previously been used in investigations with study populations of 28 and 30 individuals.9,15 The fact that we did not find any significant differences between the groups in either training modality might be due to our sample size (type II error). A larger sample could possibly show a statistical difference, but we believe that a difference with clinical importance would have been detected using our sample size.
We did not investigate the transfer of the learned skills to a clinical setting. This is an essential argument for simulation-based training and has already been explored several times. Rowe and Cohen7 found that a virtual-reality simulator was effective as an instructional tool before the first attempt at FOI in the operating room. Simple ‘bench models’ have also been found more effective than didactic teaching when examined for transfer of skills to the operating room.11 This is in accordance with the recent recommendations by Hamstra et al.16 that focus should be on functional correspondence between the simulator and the applied context.
However, it is important to acknowledge the fact that performance on a static manikin in the laboratory cannot be directly equated with clinical competence. The use of manikins instead of clinical investigations on patients has been met with criticism and is mostly aimed at assessment of novel airway devices.17 When investigating skill proficiency by performance measures, we believe it is possible to achieve valid results in a simulator setting. A great advantage of simulation training is the capability to standardise the training and the assessment of its effects. However, the feedback provided during the training was individually tailored to each participant, addressing what he or she should focus on. Real-time feedback on performance is an important part of simulation training, in accordance with the theory of variable priority training.18 The feedback provided during the manikin training may have been a contributing factor to our finding of no significant difference between the two groups. A systematic review of medical simulation training found that the provision of feedback and repetitive practice are key features of efficiency in simulation training. 19
In conclusion, simulation-based training is very effective for novices to learn the motor skills necessary to perform FOI. However, dividing the training in a part-task manner poses no additional benefits compared with a whole-task training regimen. We propose that simple whole-task training programmes should be established locally with the available resources.
Acknowledgements relating to this article
Assistance with the study: none.
Financial support and sponsorship: departmental funding only.
Conflicts of interest: none.
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