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Bougie-Integrated Endotracheal Intubation Stylet


OBJECTIVE: Design and build a bougie-integrated endotracheal intubation (ETI) stylet that improves operator first pass success rates by resolving anatomic challenges associated with indirect and direct laryngoscopy. The technology should provide enhanced ETI performance and autonomy for providers of varying skill levels operating in austere and remote environments. DESCRIPTION: Each year millions of patients will have a breathing tube, known as an endotracheal tube (ETT) inserted into their windpipe in order to assist with ventilation or to protect their airway. The procedure is called endotracheal intubation (ETI), and thousands who undergo ETI will experience serious complications as a result of operator difficulty during the process. ETI is a complex procedure that requires considerable skill. An improperly placed tube can deprive a patient of oxygen and can rapidly lead to death. Emergency circumstances, such as trauma and austere conditions make ETI riskier and more difficult. In the combat prehospital environment where airway loss and ventilatory compromise represents one of the leading causes of death, ETI encompasses over 80% of airway securement. It is also in this setting where airway interventions, specifically ETI, is one of the most common incorrectly performed life-saving interventions. A significant number of casualties arrive at Combat Support Hospitals in need of an immediate ETT, suggesting that many prehospital operators lack either the technology or skill to confidently provide definitive airway management. Although anatomic, skill, and circumstantial issues all contribute this capability gap, there also exists an ETI technology gap. Rapid, first-pass ETI success is critical in order to save lives, decrease complications and minimize downstream casualty acuity. ETI needs to be more accessible to a broader range of operators, particularly those with lower skill and experience levels. This is particularly relevant in the context of future Multi Domain Operational (MDO) environments where small, widely dispersed units will require levels of self- sufficiency that are higher than what is currently demanded. In the MDO, endotracheal intubation will become more necessary due to evacuation constraints and prolonged transit times. The MDO environment is also where resource-consuming complications must be avoided. These challenges effectively widen the current ETI capability gap. ETI is a three-step process that involves: 1) viewing the vocal cords with a device called a laryngoscope (visualization), 2) delivering the tip of the ETT to the vocal cords (insertion), and 3) advancing the tube into the trachea (cannulation). For over 120 years the visualization step with direct laryngoscopy (DL) has been the main procedural pain-point. With this in mind, video-assisted laryngoscopy (VL) was introduced into clinical practice relatively recently. Despite VL’s ability to provide easier views, it has not resulted in a consistent improvement in airway management success. Therefore, a stylet technology that could resolve the anatomic and technical ETI challenges associated with both contemporary DL and traditional VL could be disruptive in terms of closing the deadly skill gap. Such a stylet technology would ideally incorporate 1) an intubating “bougie” that can be easily and atraumatically guided into the trachea, 2) a minimal gap between the bougie and the ETT, 3) a feature that allows advancement of the ETT into the airway to enhance operator autonomy, and 4) a feature that allows adjustments for ETT’s of different lengths. PHASE I: The main goal of Phase I is to develop an innovative design for an advanced bougie-integrated ETI stylet and to exhibit its feasibility by conducting a demonstration of a prototype in a manikin model by end users. One example of a manikin model is the Advanced Modular Manikin (AMM) for healthcare simulation which is open source platform (see reference 6 below). The technology should provide a leveraging advantage over existing devices in overcoming operator skill-level issues and the anatomic impediments that vex operators during DL and VL. A first deliverable should be a detailed description of the proposed trechnology for sponsoring end-users including its principle of operation.The technology should be able to deploy a flexible bougie into the trachea that will serve as guide for the ETT, thereby easing glottic insertion and preventing ETT hang-up on glottic and subglottic structures during ETT cannulation. The outer diameter of the bougie should be as close as possible to the inner diameter of the ETT, which may necessitate different size ranges in terms of length and diameter. The amount of collision between the tip of the bougie during advancement and the anterior trachea should be minimized. The tip of the bougie should be atraumatic. The bougie should be able to be retracted and redirected if necessary. The resting position of the ETT on the device should be adjustable. There should be a feature that allows the operator to advance the ETT off of the device and into the airway in order to provide more autonomous operation. The physical design must have an anthropometric form factor that will accommodate a wide range of hand sizes. The device should be designed to be entirely or partly disposable for space saving purposes. It should not require any electrical power. Innovation is encouraged in each design aspect to prompt intuitive ease of use. A second deliverable is a computer-aided design (CAD) model of the stylet. A third deliverable is the demonstration of low fidelity protype in a manikin model performed by sponsoring end-users at San Antonio Military Medical Center. The exhibit should validate that the conceptual design will be capable of achieving longer-term goals. PHASE II: The overall objective of Phase II is to produce a fully operational bougie-integrated ETI stylet that aligns with the specified goals, form factor, and functional characteristics outlined in Phase I. The first goal of Phase II is to produce an intermediate-fidelity prototype. The emphasis should be on form, function, and component interaction. Contractors are encouraged to perform a failure mode and effects analysis (FMEA) at this stage as a means to analyze the risk factors associated with a device. A first deliverable is a description of the prototype and a report detailing an interim formative user study of the intermediate-fidelity prototype performed by ETI operators on manikin and/or cadaver models. Testing of improvements and changes is then encouraged in order to take advantage of data obtained from user feedback. The next goal is to produce a higher fidelity prototype based upon usability study findings, additional user requirements, and other observations. Focus areas for this stage include material selections for the final product (e.g., biocompatibility, frictional interactions, bougie characteristics), design for manufacturing, and minimizing cost of goods. The aim of this stage is to produce a second deliverable that is a modified form of the first prototype, except more closely functioning and performing as the final intended device. Design innovations resulting in an intuitive ease of use are strongly encouraged. A second deliverable is a description of the updated prototype and a report detailing modifications made based upon prior user testing and risk analysis. A third deliverable will be the report of another interim formative user study. This assessment should also evaluate labels and the comprehension of instructions for use (IFU). The final stage of development serves to finalize and validate component system design and interaction and to fabricate a completed device. Here again, testing of improvements and changes are encouraged in order to take advantage of data obtained from usability studies and risk analysis. The presentation and demonstration of a fully functional device to sponsoring end-users at San Antonio Military Medical Center will constitute the fourth and final deliverable, accompanied by a Food and Drug Administration (FDA) regulatory plan to illustrate the pathway to clearance, and any other relevant reports and designs. PHASE III DUAL USE APPLICATIONS: A novel tracheal intubation stylet should be designed for dual-use purpose. In addition to meeting DoD needs, the technology should also appeal to the broader civilian healthcare market including prehospital EMS, critical care transport, the hospital emergency department, intensive care units, and anesthesiology. The small business concern is encouraged to obtain funding from non-SBIR/STTR government sources and/or the private sector to develop or transition their device into viable product or service for sale to the DoD or private sector markets. Phase III funding should aim towards the adaptation of a bougie-integrated stylet technology for DoD field use, which should include formative usability testing by DoD end -users. Weight should be minimized and the device should be suitable for storage and transport in medical field packs. Contractors are also encouraged to adapt aspects of their research or technology into other related technologies that could be potentially inserted into defense systems as a result of this particular SBIR project. Utility may be enhanced if the technology incorporated optional visualization technology. The contractor should refine and implement their regulatory strategy for obtaining FDA approval of their technology for use as an airway device based on their initial FDA feedback. Phase III funding should also aim towards the development of training software and other training tools. This phase should culminate in a clear path to FDA approval. In conjunction with FDA submission, the contractor should develop scaled up manufacturing of the technology that follows FDA quality regulations. In addition, the work may result in technology transition to a DoD Acquisition Program likely through USAMMDA or a SOCOM/AFSOC unit with planned expansion to the military at large after initial entry into the government purchase pathways. The ability to provide a simple to use ETI stylet system that decreases required skill levels and improves ETI success rates will result in lives saved and enhanced casualty flow in MDO environments. REFERENCES: 1. Schauer SG, Naylor JF, Maddry JK, Beaumont DM, Cunningham CW, Blackburn MB, April MD. Prehospital Airway Management in Iraq and Afghanistan: A Descriptive Analysis. South Med J. 2018 Dec;111(12):707- 713 2. Adams BD, Cuniowski PA, Muck A, De Lorenzo RA. Registry of emergency airways arriving at combat hospitals. Journal of Trauma and Acute Care Surgery. 2008;64(6):1548-1554. 3. Levitan RM, Heitz JW, Sweeney M, Cooper RM. The complexities of tracheal intubation with direct laryngoscopy and alternative intubation devices. Ann Emerg Med. 2011 Mar;57(3):240-7. 4. Lascarrou JB, Boisrame-Helms J, Bailly A, Le Thuaut A, Kamel T, et al. Video Laryngoscopy vs Direct Laryngoscopy on Successful First-Pass Orotracheal Intubation Among ICU Patients: A Randomized Clinical Trial. JAMA. 2017 Feb 7;317(5):483-493 5. Maples, SL. Sustainment Considerations for the Multi-Domain Battle. School of Advanced Military Studies US Army Command and General Staff College, Fort Leavenworth, KS 2018 (accessed 31 May, 2021) 6. David Hananel, BSEE, BACS, Dan Silverglate, BAFA, BSCS, Dan Burke, A.S, Benjamin Riggs, Jack Norfleet, PhD, Robert M Sweet, MD, FACS, The Advanced Modular Manikin Open Source Platform for Healthcare Simulation, Military Medicine, Volume 186, Issue Supplement_1, January-February 2021, Pages 49–57, KEYWORDS: Intubation, endotracheal, airway, stylet, bougie, laryngoscopy, video, direct
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