USAF School of Aerospace Medicine provides trained medical professionals; research on the stresses of flight

WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- Researchers, educators and trainers from the 711th Human Performance Wing's U.S. Air Force School of Aerospace Medicine are teaming up to capture and understand lessons learned from more than 15 years of wartime aeromedical evacuation missions. Their efforts are aimed at conducting research that will help guide future training and patient care practices.

Eight classes a year complete the rigorous training curriculum of the Aerospace Medicine Flight Nurse and Aeromedical Evacuation Technician Course at the school while being exposed to various types of wartime injuries and the realism of flying on Air Force cargo aircraft during an aeromedical evacuation mission. Some 300 aeromedical evacuation nurses and technicians and 120 Critical Care Air Transport Teams receive initial skill training at USAFSAM each year.

USAFSAM provides integrated teams of educators and trainers to conduct Air Force combat medical training and en route care through academic instruction, state-of-the-art medical simulation, and direct patient care to prepare Air Force medics for contingency operations and rapid aeromedical evacuation anywhere in the world.

Students going through aeromedical evacuation and critical care air transport training at the school benefit from realistic ground training on a C-17 mockup and a previously airworthy C-130. The C-17 mockup, a $6.8 million investment over the six year period since it was purchased, can simulate the lighting, sounds (including an explosion, rapid decompression and crash landing) and heating and cooling conditions that can be experienced onboard aeromedical evacuation missions using operational aircraft.

"We have all the mannequins and stanchions to outfit the plane to simulate a true patient load," said Col. Annette Gablehouse, a certified nurse anesthetist and Department Chair of Aeromedical Evacuation Training. "With this, we have an invaluable training asset that provides that realism and transferrable training so our students can leave here with their check-rides and a basic qualification."

Students must complete 40 hours of missions on the mockups as part of their ground training check-rides. High fidelity mannequins used by students can blink their eyes, their tongues can swell and they can bleed from a hemorrhage.

Aeromedical evacuation crew member muscle skeletal injuries studied

"One recent study we conducted analyzes a concern about the work that nurses and technicians do on aeromedical missions which can produce muscle skeletal injuries," said Col. Susan Dukes, a nurse scientist and chief of the En Route Research Division - part of the school's Aeromedical Research Department. The study examined the lifting, moving and different work positions medical crewmembers experience during the course of their duty.

Flight Simulation

"It's expensive to fly planes and there aren't always real patients available, but our nurses, doctors and technicians need to train to know how to do their jobs during flight, so when they actually need to fly and take care of real patients, they'll be ready. Our research is trying to determine what the best mix of real patients and simulated patients is," said Dukes.

The aircraft mockups allow for what's called crew resource management research. According to Gablehouse, this allows researchers and instructors to watch how students and simulated patients communicate with each other. Because of the unique positioning of USAFSAM and the Human Effectiveness Directorate both within the 711th Human Performance
Wing, personnel are able to work side by side during this study to finely tune what kind of communication is most effective during flight.

"It's interesting, because what they're finding in that particular study is that in certain simulated noisy aircraft environments, there is much less input by the patient to the nurse, so they might get very short answers rather than an explanation that would be helpful to the nurse or technician in order to understand the patient's needs," said Dukes.

With the loud noise of the aircraft, in-flight headsets with microphones are used by crew members to communicate.

"Improved methods of communicating with patients can help decrease the potential for errors," Dukes said.

Stresses of Flight
 
The stresses of flight are another area of research being led by the En Route Care Research Division. There are nine classic stresses of flight that exist: hypoxia, barometric pressure, thermal, gravitational forces, noise, vibration, third-spacing, dehydration, and fatigue. Vibration is not simulated in the C-130 and C-17 trainers-students must actually get on a plane and fly to experience aircraft flight vibration.

"One of the concerns is what does that vibration on planes over a period of time do to a patient with a traumatic brain injury, internal injuries - especially lung injuries, or for patients on a ventilator?" said Dukes.

Other stresses of flight that can't be assessed in the C-130 and C-17 trainers include cabin pressurization and high altitude which causes low oxygen levels. Currently, studies on hypoxia are being led by the Naval Medical Research Unit - Dayton, with members of the En Route Care Research Division supporting.

"We want to know how a prolonged period of time at lower oxygen levels affects the decisions that nurses, doctors, or whoever has to make," Gablehouse said. "On the ground, we're at 21 percent room oxygen. If you're at a cabin altitude of 8,000 feet for five hours, that's going to be like being on top of a mountain. You'll get tired, sometimes dizzy and short of breath. We want to know how this affects a person's cognitive function in this decreased oxygen environment."

The En Route Care Research Division currently has about 82 studies in progress with 20 of those studies within the Impact of Transport Program of Research, according to Dukes.

Effect of flight on medical equipment

The effects on people during flight are not the only thing being studied at the USAFSAM. Another area of en route care research that's being conducted is the equipment that is utilized for patient care in flight.

"Ventilators and pneumatic tourniquets are approved by the Food and Drug Administration, they're on the market and used by hospitals across the board, but sometimes there is concern whether the equipment works the same way at altitude because of pressure and hypoxia. This effort is to make sure the equipment works the same way at altitude, and if it doesn't, what needs to be changed," Gablehouse said.

Cabin Altitude Restrictions

Exactly when the best time to transport a patient is and the use of cabin altitude restrictions - an intervention that can be used for patients that shouldn't be traveling at high altitudes is also a key area of research.

"A doctor can order that a plane fly lower where the pressurization and oxygen levels are closer to normal," said Dukes. The study shows that those patients that have flown with a cabin altitude restriction have fewer required post-flight procedures as compared to similar patients that were not flown with cabin altitude restrictions, Dukes said.

Turning Toward the Future of Aeromedical Evacuation Training

With years of combat aeromedical evacuation data now available, the focus of research now turns toward the future of aeromedical training.

"We got really good at providing care the last 15 years in the Iraq and Afghanistan environments so we're now looking forward to see whether care is going to be different or the same," said Dukes. "We're asking questions such as 'How is patient care going to be changed if flight times are much longer? How does patient care need to change if we're not able to fly a patient out of an austere environment right away? How many crew members do we need on the aircraft so some can be in a rest cycle and some can be in an active cycle?'"

According to Dukes, during the wars in Iraq and Afghanistan, much of the clinical care experience flight nurses and technicians received was from their deployments.

"Our military inpatient facilities are much more clinic-based in garrison. At home, we don't see the same kinds of injuries that you see in a deployed environment. So I think that is one of the reasons why the simulation and training emphasis is so great right now because we have to have an effective way to maintain those skills when there aren't those deployments taking care of those critical patients," said Dukes.

Importance of a Realistic Training Environment

"That's why it's so important to me to have this realistic training environment here -to simulate those injuries with mannequins because they're usually some sort of blast injury, some sort of a gunshot wound, or blunt trauma," Gablehouse said.

"Those injuries don't go to clinics. That's where we use our mannequins so they see those injuries that they would have and then the realism that we get from these aircraft using that real-world equipment. Hopefully doing that, it's keeping those skills fresh, and teaching our new folks that are coming in that don't have that 10 years of experience that our seasoned crew members have. Injuries that they would see out there during real-world missions are recreated here in a training environment for students to hone their skills."

Taking a Look Back for an Informed Move Forward with Training

"In order for practice to change, there has to be a lot of retrospective looks to come up with true evidence-based reasoning to change procedures," Gablehouse said.

"Throughout the wars in Iraq and Afghanistan, our crews have taken phenomenal care of their patients, but we haven't had a system in place to really capture that information," said Dukes.

Dukes said it has been difficult to go back and look at patients and see what kinds of interventions they had right before a flight, in-flight, right after flight, and what the outcomes were from the care that was provided during the En Route care system.

"We are in the process right now of creating a registry to try to go back and capture that valuable information because it can be used to look at processes and improve care moving forward," Dukes said.

Started just within the last year, the registry includes aeromedical flight data from 2001-2014 and is projected to include 160,000 patients covering 350,000 patient movements.

"The goal is to cull through the information and ask a great variety of questions to make care during the aeromedical evacuation process even better in the future," said Dukes.