One project presented at TATRC's field airway management review this fall was a universal cricothyrotomy device. This can be operated safely with one hand to surgically create an open airway. One button extends the depth-limited scalpel blade, and another button retracts the blade and extends hooks to hold the airway open. Photo courtesy of Pyng Medical Corporation.
Many lives have been saved since the U.S. military examined the number of battlefield deaths due to blood loss and added modern tourniquets to all medical kits in 2005. The military recently convened a national panel to see if it could do the same for another preventable cause of death on the battlefield: airway obstruction.
To find out what more could be done to reduce the number of deaths from airway injuries, the U.S. Army Medical Research and Materiel Command's Telemedicine and Advanced Technology Research Center and Combat Casualty Care Research Program organized a national review in November. TATRC Trauma Portfolio manager Dr. Thomas Knuth and CCCRP director Col. Dallas Hack chaired the meeting. They invited field medics, those who train them, medical and technology experts from all branches of the military and civilian institutions, and the investigators on several projects the military is funding related to field airway management.
Said Knuth, "We brought everyone together to compare what we're researching with what is currently available and what is truly needed. TATRC regularly organizes national panels such as this to shape federally funded research throughout the country to ensure it most effectively improves the medical care of our warfighters."
While TATRC focuses on technology, just as important is the collaboration and results-focused perspective it brings. "TATRC's role is to steward taxpayer money responsibly, to identify research gaps and redundancies so we can move toward evidence-based solutions to save lives," Knuth noted.
A major need identified by the group was a simple, safe way to surgically create an open airway on the battlefield, a procedure called a cricothyrotomy. This is particularly important due to the nature of airway injury deaths from OEF/OIF, most of which resulted from direct injuries, usually due to gunshots to the face or neck. According to emergency physician Lt. Col. Robert Mabry, who directs the Pre Hospital Care Division of the Joint Trauma System, one third of battlefield cricothyrotomies fail.
Better equipment is one key. Medics currently carry an emergency cricothyrotomy kit that includes five separate pieces. To simplify the kit, Pyng Medical Corporation has developed a universal cricothyrotomy device that incorporates the scalpel and tissue spreading hooks into one unit. The design protects from cutting too deeply or letting go of the opening before inserting a breathing tube.
Other critical needs revolve around training. While the first responder medic in the field is not often called upon to perform a cricothyrotomy, he or she has to know when to do one and how. Yet it's difficult to provide adequate decision-making and technical skills for this life-or-death operation in the current one-week predeployment trauma course. In addition, there is currently no standard method of assessing whether an individual has gained the skills to perform the procedure.
"Medical modeling and simulation is a major TATRC focus, particularly for education in trauma and emergency medicine," said TATRC assistant director Col. Ron Poropatich. "We could support projects that develop creative ways for medics to practice enough to gain the necessary judgment and technical skills."
Added Knuth, "We can incorporate ways to measure the outcomes of the training as well, so we can assess whether someone is proficient."
The panel explored demonstrations of new training technologies, including the National Capital Area Medical Simulation Center's virtual cricothyrotomy teaching tool, which uses 3D glasses and two joystick "hands" to enable users to see and feel their way through a simulated airway surgery. The SimCenter is part of the Uniformed Services University of the Health Sciences.
Most airway management procedures are performed in or en route to aid stations and hospitals. This is where the expert panel suggested the greatest improvement in clinical outcomes could be realized through harnessing enhanced technologies such as video laryngoscopy to visualize airways and telemedicine to provide access to expert guidance from military anesthesiologists.
According to Maj. (Dr.) Christopher V. Maani, chief of anesthesia and principal investigator at the U.S. Army Institute of Surgical Research and Army Burn Center, despite the current technology, intubation errors occurred in 23 percent of attempts during a prospective observational study of almost 2,000 civilian prehospital intubations (Wang et al). The need for refining airway management was further shown by a study of 492 trauma patients intubated in the prehospital setting without the use of anesthesia or muscle relaxants, where only one patient survived (Lockey et al).
The panelists reviewed several projects aimed at bringing new technology to airway procedures, including an Android-based wireless telemedicine system being developed by the University of Nebraska, and a portable airway system from AI Medical Devices that replaces an entire cart full of equipment with a universal handle that can hold a series of interchangeable tools.
Said Knuth, "The way forward is much clearer because of TATRC's review process. Our efforts in airway management are an excellent example of the collaboration that can help improve outcomes in both military and civilian trauma care."
David Lockey, Gareth Davies, Tim Coats: Survival of trauma patients who have prehospital tracheal intubation without anaesthesia or muscle relaxants: observational study. BMJ VOLUME 323:141.
Henry E. Wang, Judith R. Lave, Carl A. Sirio and Donald M. Yealy: Paramedic Intubation Errors: Isolated Events Or Symptoms Of Larger Problems? Health Affairs, 25, no.2 (2006): 501-509.