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Advanced Nasopharyngeal Airway


OBJECTIVE: Design and produce an advanced nasopharyngeal airway (NPA) that provides more effective and reliable upper airway patency in unconscious patients than existing NPAs, which can be easily inserted and removed by medics/first responders such as combat life savers with varying skill levels. DESCRIPTION: Airway compromise continues to account for approximately one in ten preventable battlefield deaths. Combat medics often provide care in no or low-light conditions, surrounded by the chaos of combat, and with the limited dexterity that accompanies bulky body armor, gloves, and heavy equipment. Therefore, a critical procedure such as airway management requires very simple tools that are highly effective. The purpose of this research and development effort is to revolutionize one of the most basic lifesaving airway management tools, the NPA. The NPA is a 140-year-old technology that was designed to open an obstructed airway in a patient who is unconscious or deeply sedated, and still factors prominently within Tactical Combat Casualty Care (TCCC) guidelines and civilian acute care. Although NPAs are easy to insert by medics, they are not universally effective in relieving airway obstruction, they are underutilized in the TCCC environment, and they are in need of an innovative overhaul. A review of the Department of Defense Trauma Registry (DODTR) showed that only 2% of non-head and neck-injured in-theater trauma patients who had a prehospital airway intervention had a prehospital NPA placed by combat medics, yet 6% had a cricothyroidotomy (a hole cut in their neck to allow breathing). Similarly, the Prehospital Trauma Registry (PHTR) which is module of the DODTR capturing data during the Role 1 phase of care, found that only 19.5% of casualties requiring airway interventions had NPAs placed, which was closely followed by a 12% cricothyroidotomy rate, suggesting that NPAs are underutilized. This is further supported by observations that combat medics have been performing surgical airways on a number of occasions for casualties who were unconscious from hemorrhagic shock or traumatic brain injury (TBI) but who had no direct maxillofacial injuries or documented airway problems. This is troubling, because the failure rate for combat medic-performed cricothyroidotomy is as high as 33%. Recently, the TCCC Airway Working Group raised concerns about the effectiveness of current NPAs especially in battlefield applications. Despite the presence of a traditional NPA, airway obstruction can still occur in up to 42% of heavily sedated patients. The pathophysiology of upper airway obstruction during depressed levels of consciousness is highly complex and is not fully addressed by the traditional NPA. Contemporary sleep apnea science has provided substantial insight regarding the locations, mechanisms, and forces associated with upper airway collapse. A novel NPA founded upon this new knowledge will potentially be more effective in relieving upper airway obstruction resulting in lives saved, greater operator confidence, and the avoidance of unnecessary and risky medic-performed surgical airways. A novel NPA technology should 1) be easy to insert and removed by low-skilled operators, 2) be no more traumatic than traditional NPAs, 3) demonstrate greater efficacy than traditional NPAs, and 4) have a relatively low cost of manufacturing to enhance dual-purpose utilization. PHASE I: The main goal of Phase I is to design an innovative concept for a novel NPA and to exhibit its feasibility by conducting a demonstration of a prototype to Department of Defense (DoD) end users. A first deliverable is a concept paper that describes how the new technology will function and why it will theoretically perform better than existing NPAs in relieving airway obstruction associated with depressed levels of consciousness. A physical description of the device along with its features should be included, as well as a description of the proposed manufacturing process. Contractors are encouraged to develop innovate designs to address the stated problem. The technology should be able to be inserted through the nasopharynx with the no greater force or mucosal trauma than traditional NPAs. Once inserted into the airway, the NPA should provide relief of obstruction at multiple pharyngeal levels. Ideally, the technology should be a one-size-fits-all solution in order to minimize operator equipment burden. The device should allow for nasal as well as oral ventilation and should facilitate effective spontaneous breathing as well as positive pressure ventilation via face mask. The physical design must have an anthropometric form factor and material characteristics that will accommodate ease of insertion. Weight should be minimized. The device should be approximately the same size of the standard NPA and should be able to withstand the crushing forces within medic backpacks. The device should be designed to be entirely disposable. Innovation is strongly encouraged in each design aspect in order to prompt intuitive ease of use. A second deliverable is a computer-aided design (CAD) model of the concept NPA. A third and final deliverable is an in-person demonstration of a low fidelity prototype (e.g., 3D printed model) to end users in order to demonstrate the principle of operation. The exhibit should demonstrate that the conceptual design will be capable of achieving the long-term goals. PHASE II: The overall objective of Phase II is to produce an operational advanced NPA 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 subcomponent interaction. Performers are encouraged to initiate 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 a small, interim formative user study of the intermediate-fidelity prototype performed by users in manikin and/or cadaver models. One example of a manikin model is the Advanced Modular Manikin (AMM) for healthcare simulation which is open source platform (see reference 6 below). 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 (e.g., biocompatibility, hardness and flexibility, frictional interactions), 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 last stage of development serves to finalize and validate component system design and interaction and to fabricate a final prototype. 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 DoD end-users 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 NPA should be designed with 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. 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 served the additional purpose of serving as an airway adjunct during procedural deep sedation. 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 novel NPA that reliably prevents upper airway obstruction will result in lives saved and the avoidance of unnecessary emergency surgical airways. REFERENCES: 1. Blackburn MB, April MD, Brown DJ, et al. Prehospital airway procedures performed in trauma patients by ground forces in Afghanistan. J Trauma Acute Care Surg. 2018;85(1S Suppl 2) 2. Schauer SG, Naylor JF, Maddry JK, Kobylarz FC, April MD. Outcomes of Casualties Without Airway Trauma Undergoing Prehospital Airway Interventions: A Department of Defense Trauma Registry Study. Mil Med. 2020;185(3-4) 2. Otten EJ, Montgomery HR, Butler FK Jr. Extraglottic Airways in Tactical Combat Casualty Care: TCCC Guidelines Change 17-01 28 August 2017. J Spec Oper Med. 2017 Winter;17(4):19-28. PMID: 29256190. 3. Mabry RL. An analysis of battlefield cricothyrotomy in Iraq and Afghanistan. J Spec Oper Med. 2012;12(1):17-23. 4. Stoneham MD. The nasopharyngeal airway. Assessment of position by fibreoptic laryngoscopy. Anaesthesia. 1993 Jul;48(7):575-80. 5. 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: Nasopharyngeal, nasal, airway, obstruction, cricothyroidotomy
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