A virtual reality simulator (ORSIM, Airway Simulation Ltd.) may be more effective than conventional teaching methods in improving performance of fiber-optic bronchoscopy (FOB)-guided intubation in patients under general anesthesia. According to a recent study, post-training performance of FOB-guided intubation, as measured by intubation time and Global Rating Scale, improved in operators who received 60 minutes of virtual reality training, whereas intubation performance was unchanged in the control group.
“These results suggest that fiber-optic bronchoscopy simulation using a high-fidelity virtual reality simulator is a useful adjunct in acquiring fiber-optic bronchoscopy intubation skill,” said David Wong, MD, professor of anesthesiology at the University of Toronto.
As Dr. Wong reported, although bronchoscopic intubation is a core skill, aptitude varies at centers around the world because of limited practice with the technique. According to Dr. Wong, it takes approximately 50 intubations to learn the skill, but many more repetitions are required to retain the skill over time.
“FOB intubations are commonly taught using a ‘see one, do one’ method,” he explained, “but when I visit different centers nationally and internationally, I find that this skill is eroding because they’re not being done frequently enough.”
Although virtual reality bronchoscopic simulators have been in existence for nearly 15 years, said Dr. Wong, these machines are very large and prohibitively expensive. Recently, however, high-fidelity virtual reality FOB simulators like ORSIM—consisting of a virtual bronchoscope, an interface and a laptop computer—have become available. Although the ORSIM has been shown to improve bronchoscopy performance in nonpatient studies, it had never been tested in patients, the authors noted.
Residents or anesthesia assistants with fewer than five FOB intubations viewed a 15-minute presentation featuring anatomy lessons, teaching materials and several demonstration videos. After the presentation, the participants performed the first FOB intubation in the operating room (OR) on a patient under general anesthesia receiving low-flow nasal oxygen. The participants were recorded by camera and timed from insertion of the fiber-optic bronchoscope orally to visualization of end-tidal carbon dioxide.
After performing the first intubation, participants in the control group received no additional training. Those in the intervention group, however, received up to 60 minutes of training with the ORSIM simulator. Finally, participants in both groups performed a second FOB-guided intubation within one week of the first FOB intubation. These intubations were also recorded and timed. The recordings of both intubations were subsequently evaluated using an eight-item Global Rating Scale and 11-item checklist by judges blinded to the intubation order.
As Dr. Wong reported at the Society of Airway Management 2017 annual meeting, of the 34 patients enrolled in the study, three failed to complete both intubations due to staff intervention. For those who completed the study, demographic characteristics were similar in both the control (n=15) and intervention (n=16) groups (Table).
|Table. Study Outcomes|
|Intubation Time (seconds)||Global Rating Scale||Checklist Score|
|CON (n=15)||SIM (n=16)||CON (n=15)||SIM (n=16)||CON (n=15)||SIM (n=16)|
a Denotes P<0.05 between pre- and post-training values.
CON, control group; SIM, simulation group
Simulation Practice Improves Intubation Time And Performance
Within the control group, there was no significant difference between pre- and post-training intubation time or Global Rating Scale, Dr. Wong noted. Within the simulation group, however, there was significant improvement between pre- and post-training intubation time, with times improving from 178 to 119 seconds (P=0.01). Moreover, Global Rating Scale scores improved from 23 to 28 after practice with the ORSIM simulator (P=0.04). Pre- and post-training checklist scores remained similar in both the control and simulation groups, the authors noted.
Given the improvement in performance with the simulator compared with didactic teaching alone, Dr. Wong advocated the use of simulation even earlier in the training process, but acknowledged that the price may be a limiting factor—ORSIM costs “upwards of $15,000,” he said.
“Based on these results, I think there is a role for simulators as a training tool before people undergo their first intubation, but the decision to use them may ultimately be determined by practical and economic concerns,” he said.
Nevertheless, for hospitals reluctant to invest in high-fidelity virtual reality simulators, lower fidelity simulators could offer similar results at a significant discount. Studies comparing training with lower cost simulators with high-fidelity simulators have shown very little difference in performance in patients undergoing bronchoscopy, Dr. Wong reported.
“The interval between first and second FOB intubation was one week,” said session moderator Narasimhan Jagannathan, MD. “If you repeated this study with a longer interval, do you think you’d find a difference? The concern is that we seldom do fiber optics, so a week seems like a short period to truly assess a difference.”
“That’s a good point,” Dr. Wong responded. “The main purpose of this study is to assess whether simulation affects the acquisition of fiber-optic intubation skill. We chose a one-week interval because we didn’t want the experience to be diluted or for our subjects to do an additional intubation between assessments.
“That being said, many different studies have addressed the question of how long skills are retained,” Dr. Wong added. “We’ve been involved in cricothyroidotomy studies, for example, that have demonstrated skill retention within the first few weeks of acquisition, but after three months, that skill is frequently forgotten. Regarding FOB intubation, though, I cannot speculate what time frame would make a difference.”