Recent literature has shown that video laryngoscopy performed by a number of methods can be useful for teaching endotracheal intubation (ETI) to learners at many levels of medical specialization [1] . However, these video laryngoscopes are expensive and provide images of an inconsistent quality [2] . Recently, an attempt was made to combine Glide Scope™ and iPhone™ to record ETI with learners. This involved a cumbersome mounting of the iPhone™ on the Glide Scope™ with an acceptable quality of the images [3] . Subsequent attempts have been made to use Google Glass™ (GG) to visualize and teach ETI among medical students and other learners [4] [5] . Not stated in the publications is that GG, when worn, does not allow visualization of the cords unless the learner stoops to a position where there is direct line of sight between the eyes and the cords. This is due to the narrow field of view offered by GG. Likewise, the GoPro™ (GP), which has excellent resolution, does not allow reasonable visualization of the cords because of its wide and fish-eye (warped) field of view. This results in a distant view of the structures distal to the hypopharynx. The problem concerning line of sight with a narrow field of view that prohibits direct visualization of the cords is not cited in the literature regarding the utilization of GG as a teaching tool for ETI [4] [5] . In addition, the ability of GP to accurately visualize the cords has not been confirmed [6] .

This is an educational proof of concept feasibility convenience sample pilot study to compare the ability of GG with Vuzix™ camera adaptor and GP-wearing anesthesiologists and emergency physicians from both Haiti and the United States, to use video recorded ETI for teaching purposes in the austere medical environment. In addition, we compare the connectivity of the two systems for live stream broadcasting. The video could be then used locally or remotely as an educational tool. The efficacy of each method is calculated using a five-point Likert Scale determined by the user regarding a checklist derived from preexisting literature concerning the basic markers for the preparation of ETI, cord visualization, and subsequent passage of the endotracheal cords.

Therefore, we have compared these two systems and describe the simple adaptation of the GG that allows for excellent visualization of the hypopharynx and the cords. We propose a system of the utilization of both the GG and GP to teach the basic steps of ETI.

A case series of twenty-five patients, five in the United States (US) at Memorial Hospital in South Bend, IN and twenty at Saint Luc’s Hospital in Port Au Prince, Haiti, is presented. These patients were collected from November 1^st 2015 through February 1^st of 2016. The cohort studied was comprised of sixteen males and nine females ranging in age from eighteen to sixty years old. Institutional Review Board (IRB) approval was obtained and granted from the Memorial Hospital IRB. Informed consent was obtained for each patient. Consents were written in English and Creole and obtained by one of the authors who spoke Creole and English (DZ). In the US, the anesthesiologist and the emergency physicians utilized the GG to intubate five patients. This was the preliminary phase where the anesthesiologist and emergency physicians gained familiarity with the GG with and without various prototype adaptors (Figure 1 and Figure 2). These five patients demonstrated the above-mentioned limitations of GG. Subsequently, adaptations were made based on two separate trips to Haiti which resulted in the final collection of twenty patients. The adapted GG system and GP allowed for the visualization of the vocal cords with varied success which were documented using the Likert-Scale assessment of the ETI parameters [7] .

The group of physicians studied includes one US anesthesiologist, two US

emergency physicians, one Haitian anesthesiologist, and two Haitian critical care physician learners. The standard parameters for preparation and for monitoring successful ETI were the following: LEMON airway assessment method, the scissors maneuver, blade insertion, hypopharynx visualization Cormack-Lehane difficulty of intubation criteria, visualization of the cords and visualization of the endotracheal tube passing the vocal cords [8] . The LEMON scoring system is a mnemonic which stands for Look, Evaluate the 3-3-2 rule, Mallampati score, Obstruction, and Neck mobility [7] . The Cormack-Lehane system, based on grades 1 - 4 with 1 signifying full view of the glottis and 4 signifying neither glottis nor epiglottis seen, classifies the view seen by direct laryngoscopy based on the structures seen during endotracheal intubation [7] . The US anesthesiologist utilized the GP and GG while the two US emergency physicians only utilized GG. All three Haitian physicians utilized the GP and GG. Scoring and graphical data reflect the Likert-Scale scoring system and not the scoring systems inherent in the original Cormack-Lehane classification.

The results depicted in Table 1 and Figures 3-5 represent each physician and learner’s best score during all attempts made during ETI with GP and GG. These results show that the GP is superior to GG for assessing the LEMON scoring system until visualization of the oropharynx. The GG is inferior for those previous parameters, but is markedly superior for calculation of Cormack-Lehane score (cord visualization) and passing of the endotracheal tube (Figures 1-3). This pattern is reflected whether in the US by an anesthesiologist teacher or in Haiti by US physicians or Haitian learners. The previous expertise in ETI by US emergency medicine physicians provided a significant advantage in vocal cord visualization and visualization of tube passing. Review of videos is easier on the GP because of the following reasons: 1) videos can be visualized on the GPs built-in screen, 2) the GP can transmit its own Wi-Fi signal allowing it to connect to larger mobile devices for real-time viewing. While the review of GG can

US 1―United States anesthesiologist, US 2 and US 3―United States emergency physicians, H1―Haitian anesthesiologist, H2 and H3―Haitian critical care physician learners.

also be done in real time, it is made complicated by the need to remove and adjust headwear to the teacher’s sight as well as its dependence on a wireless network rather than local connection. Both video files could be loaded on the portable computer and provided an educational opportunity with both methodologies for teacher and learner to evaluate the approaches for LEMON scoring. Visualization was unequal between GG and GP for the calculation of the Cormack-Lehane score. When viewed on a laptop, there were clear differences in the resolution of the GP vs. GG, with GP having much higher resolution capabilities with the tradeoff of decreased frame-rate and distant view of the cords due to its wide-angle fish eye lens. The GG was able to visualize the cords due to the zoom that was offered at the cost of narrower vision, reduced resolution but stable frame-rate, while being unable to completely capture the intubators’ field of view.

Previous studies have demonstrated that telemedicine may be used for teaching critical care skills to physicians as well as non-physicians [9] [10] . Recently, telemedicine has been used to assist in the teaching of ETI and the monitoring of patients in the austere medical environment of low income countries [11] .

This proof of concept feasibility study demonstrates that with further advancements in video quality, and adjustment of the GG scope, it would be possible to have video as well as real-time transmission of the entire process of ETI. Currently, GG when worn, does not allow visualization of the cords unless the learner stoops to a position where there is direct line of sight between the eyes and the cords (Figure 6(a)). However, the GG system, when modified so that the camera was placed below the eyes and above the superior labial margin, allowed for excellent visualization of the cords and passage of the endotracheal tube through the cords (Figure 6(b), Figure 7, and Figure 8). Future use of telemedicine to transmit real-time images to a remote site has been described with the Glide-Scope™ and iPhone™ compatible visualization system [3] . This term, known as “Telebation” has been previously described, however its use required the highly technical and expensive Glide-Scope™ within a special adaptor. The technology reviewed here is portable and inexpensive. The advantages are that it can be used in the austere environment and allow for remote monitoring. GG can serve as an educational and consulting intervention in the ICU for physicians in the austere environment who can intubate as well as monitor ventilated patients in a setting where this would not be possible without on-site instruction. The use of this telemedicine technique was not available on either of our two

trips due to lack of sufficient bandwidth. We plan future studies using the GG as a template for calculation of Cormack-Lehane scores and for documentation of passage of endotracheal tubes through cords. This will be dependent on our ability to fashion the previously mentioned adaptor to the headset that would allow simultaneous video recording as well as visualization of all phases of intubation. In addition, we hope to expand the bandwidth available at St. Luc’s hospital such that we can trial remote video monitoring of ETI and, as such, apply the principles of “Telebation” previously mentioned [3] .

Previous studies have presented either case reports or abstracts which describe in generic fashion the ability of GG to assist in teaching ETI, without describing the quality of visualization of the vocal cords or of the endotracheal tube passing the cords [4] [5] [12] . This is the first study of its kind to actually demonstrate in a quantitative fashion the ability of the GG to measure standard parameters of successful pre-intubation scoring, cord visualization, and endotracheal tube passage through the cords. A major technical limitation of GG is the narrow field of view that requires that the learner establishes a direct line of sight while doing ETI. Therefore, the only way that the GG can be used to visualize the vocal cords is for the learner to crouch and to establish a line of sight that does not reflect the natural posture of the learner who is performing ETI (Figure 6(a)). We have described, for the first time, a very simple and rudimentary harness system that allows the wearer of GG to effectively assess all the parameters of successful intubation (Figure 6(b), Figure 7, and Figure 8). Future ergonometric adaptations should allow for a much more robust study of using this very inexpensive tool as a teaching aid in the austere medical environment such as Haiti. Table 2 and Table 3 reveal the benefits and disadvantages of the GP and GG with lens adaptor for viewing ETI for the Haitian and US anesthesiologists. In addition, similar contrasts can be seen with US emergency physicians and Haitian critical care physician learners. In summary, the GP allows for better visualization for the parameters that require a wider view of the patient prior to visualization of the hypopharynx. However, the GG with adaptor allows superior visualization in the parameters that require more focused view of the cords (Figure 8).

This study has shown the feasibility of using the modified GP and GG technologies to instruct critical care physicians in ETI with the provision of excellent vocal cord visualization and accurate calculation of Cormack-Lehane scores.

Multiple studies have revealed an increased need for hands on training and improved simulations for learners during their initial attempts at ETI, especially in the prehospital setting [13] [14] . We have proposed an inexpensive yet effective system utilizing GP and modified GG technologies which can be used to teach ETI to learners of any level of medical expertise. This wearable technology could be expanded to instruct ETI to prehospital personnel in austere environments, medical students, far forward military medical providers, and other learners in resource limited settings.

Manuscript was written and prepared by Michael Son BS, David Zimmer DVM, Ross McCauley MS, Joseph Dynako BS, NuhaZackariya, Faadil Shariff, and Mark Walsh MD. Editing was performed by Bhavesh Patel MD, Michael T. McCurdy MD, and Shane Kappler MD. Physicians performing intubation and adjusting equipment included Mark Walsh MD, Donald Zimmer MD, Richard Skupski MD, Lovely Nathalie Colas MD, Gerson Pyram MD, Marc Edson Augustin MD, Carmeline Mathurin MD, Stanley Louis MD, Patricia Saint Louis MD, Stanley Loriston MD, and Bhavesh Patel MD. Study idea and conception performed by Dan Herbstman BS, Mark Walsh MD, Donald Zimmer MD, Richard Skupski MD, Marc Edson Augustin MD, Bhavesh Patel MD, Lucio Cervantes BS, and Sarah Greve BS.

All authors reviewed and edited the paper.

This study was supported in part by an educational research grant by Third Eye Health and by the support of the family of Stefan Randjelovic.

Dan Herbstman is the CEO of Third Eye Health. The other authors declare no conflicts of interest regarding the publication of this paper.

Son, M., Zimmer, D., McCauley, R., Zimmer, D., Dynako, J., Skupski, R., Patel, B., Zackariya, N., Shariff, F., Colas, L.N., Pyram, G., Augustin, M.E., Mathurin, C., Louis, S., Louis, P.S., Loriston, S., Herbstman, D., Cervantes, L., Kappler, S., McCurdy, M.T., Thachil, J., Greve, S. and Walsh, M. (2018) Evaluation of Google Glass™ with Camera Adaptor and GoPro™ as Teaching Tools for Endotracheal Intubation in the Austere Medical Environment. Open Journal of Anesthesiology, 8, 229-239. https://doi.org/10.4236/ojanes.2018.88024