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Device aims to create airway after battlefield injury

A low-cost, low-tech device may soon help combat medics quickly and accurately open an airway through the throat to restore breathing for badly injured soldiers.

When a battlefield explosion injures a soldier’s face or neck, the critical air passage between the head and lungs often ends up blocked, which can lead to brain damage and death within minutes.

Student engineers at Johns Hopkins University designed a gadget they call CricSpike to try to boost medics’ success rate in creating the artificial airways needed to bypass such injuries. The goal is to keep wounded soldiers alive until more advanced treatment can take place at a hospital.

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The invention focuses on the emergency neck-incision tactic called a cricothyrotomy. This procedure shows up on TV and in movies as a relatively simple series of steps, such as stabbing a ballpoint pen into the neck, that saves the life of a crucial character. But in a real-life combat setting, this tricky treatment must be done very quickly under less than ideal conditions—and it does not always work.

Combat medics who attempt a cricothyrotomy in the field are unsuccessful about a third of the time, the biomedical engineering students found. Even physicians and physician assistants failed about 15 percent of the time in hospital settings.

More soldiers could be saved if the battlefield cricothyrotomy success rate improved. In Iraq and Afghanistan, 10 to 15 percent of preventable battlefield deaths were due to airway obstructions or respiratory failure. Many of these injuries were blamed on the growing use of IEDs, improvised explosive devices.

Preventing deaths became the group’s goal. “We were all excited by the emergency life-saving aspects of this project,” said Antonio Spina, the student who was team leader during his recently completed senior year.

More work to be done

The students designed their prototype with an eye toward simplifying and speeding up the procedure and improving the accuracy of the insertion.

One of the main problems, the students discovered, was that the tools typically used in battle zones often do not manage to connect to the patient’s trachea, commonly called the windpipe. Instead, these tools become lodged just under the patient’s skin or bypass the trachea and instead strike the esophagus, which leads to the stomach, not the lungs.

The students devised an improved intratracheal tip carefully crafted to extend beyond the skin layers to the windpipe, but not far enough to reach the esophagus. To insert this tip into the neck, the students devised a two-piece handle that easily breaks away once the tip is connected to the trachea.

The student inventors packaged the CricSpike tip and its handle into a kit that also includes a scalpel and an endotracheal tube to channel air to the windpipe. The kit also contains a bag valve mask that the medic can attach and squeeze to push air through the tip or tube and into the wounded soldier’s lungs.

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In demonstrations with a medical mannequin and animal tissue, the students have shown that their prototype components can work. Although more development and testing are needed, the prototype earned awards at two recent medical device competitions. The undergraduates worked with the staff of Johns Hopkins Technology Ventures to obtain a provisional patent.

“The students did a great job,” says retired military physician James K. Gilman, the project’s sponsor. “But the final prototype was still pretty rough. Relying on 3D printing techniques could only get them to a certain level. The next step in the development process would have to involve production of a more professional prototype.”

Team member Qiuyin Ren, a rising senior, says she and the other team members who return to Johns Hopkins in the fall intend to build a more polished prototype. The student inventors hope a health care device maker eventually will license their design and incorporate it into an improved cricothyrotomy kit for combat areas.

Gilman, a former major general who until recently was executive director of the Johns Hopkins Military and Veterans Health Institute, offered the challenge to the students through the university’s Center for Bioengineering Innovation and Design. He was team medical adviser. Emergency physician Steven Tropello also provided assistance and is included on the provisional patent.

Source: Johns Hopkins University