April 12, 2017

Mars astronauts would be "on their own" for medical care

Astronauts on a mission to Mars would essentially be on their own for medical care, according to NASA flight surgeon Dr. David Reyes. With resupply or mission evacuation impossible, and with difficulty in communicating with the ground, astronauts would have to be trained and equipped to provide their own care.

Reyes gave an interesting talk about the history of space medicine last weekend at the Museum of Flight. He noted that being a flight surgeon is the opposite of being a typical doctor.

NASA flight surgeon Dr. David Reyes
 gave a talk about the history of
aerospace medicine April 8, 2017 at
the Museum of Flight.
Photo: Greg Scheiderer.
“Regular medicine is taking care of sick people in a normal environment,” Reyes said. “Aerospace medicine is taking care of healthy people in an abnormal or unusual environment.” He added that the astronauts are usually super healthy, but the environments they deal with are challenging to say the least.

Much of the job of the flight surgeon is to help determine the medical risks of space travel, to help come up with and test gear to avert those risks, and to help astronauts learn about symptoms of conditions they may encounter.

For example, astronauts in training are put into an altitude chamber, and the air is pumped out of the chamber to simulate the atmosphere at 21,000 feet above sea level. Then they take off their oxygen masks. Reyes said this makes them “goofy” with hypoxia.

“The reason we put them in this chamber is so that they can recognize those symptoms for themselves,” Reyes said. “Everyone has a unique response to low oxygen.” If they’ve experienced it they can recognize it in the event oxygen problems occur in flight.

Mission medical kits

It was fascinating to look at the evolution of medical kits for various missions. In the days of Mercury, the kit was essentially a few bandaids, aspirin, motion sickness pills, and a couple of other remedies. It was not much more than a prudent backpacker would take on a day hike. Mercury missions were short and the astronauts, strapped into a small capsule, didn’t have to do much physical activity.

A Mercury medical kit. Photo: NASA
With Gemini and Apollo the kits were expanded as the missions became longer and more active, but they still weren’t all that extensive.

“This is like everything you might have in your medicine cabinet at home,” Reyes noted of the kits.
By the time of Skylab each crew received 80 hours of paramedic training. The medical kit was huge and even included a dental kit. The space shuttle went far beyond the home medicine cabinet. The International Space Station has a Crew Medical Officer who is an astronaut with additional medical training. It carries an extensive medical kit with nine different packs. It also employs a Crew Health Care System or CHCS—pronounced “checks”—that is the first robust medical system for space missions.
Given all of that, Reyes pointed out that, “Nothing really serious has happened in space flight.” Astronauts on longer missions suffer bumps and bruises and rashes, and insomnia, but the most serious condition has been a urinary tract infection on one Apollo flight.

Bones and eyes

These days the two problems they’re studying the most are bone mass loss and visual impairment. They’ve known about the bone mass challenge for a while, and it’s why the astronauts spend at least two hours per day exercising. Without it, “We’d send a 40- or 50-year-old astronaut up and they’d come back looking like an 80-year-old after six months in the space station,” Reyes said.

The vision issues only became apparent in the last seven years or so, and Reyes said they’re still researching those. A couple of things happen to some astronauts: fluid buildup in the eye because of zero gravity, and change of eye shape. They’ve developed adjustable eyeglasses should astronauts develop vision problems in flight.

Mars poses challenges

Missions to Mars would provide medical as well as ethical challenges. On all space missions so far, flight surgeons on the ground have been able to offer advice and counsel. For Mars, the long lag for radio signals, up to 22 minutes for transmission, would make conversation difficult, and during the time Mars is on the other side of the Sun from Earth there would be no communication at all.

“When you go to Mars, basically you’re on your own,” Reyes said of the astronauts.

There is debate about how much medical equipment and medicine to take on a Mars mission. Every item launched on a mission represents a tradeoff in mass and cost and whatever might not go along. An even bigger, ethical question involves what happens if an astronaut suffers a serious injury.

“If you have a limited set of supplies, and somebody gets severely injured and will require a lot of care, how much care are you going to give them?” Reyes asked. “If you use up your whole med kit, that puts everybody else at risk. So you have to think, ‘Is there some point that we’re going to withdraw care because we’re jeopardizing the rest of the mission?’”

It’s an on-going area of discussion.

Why be a flight surgeon?

Like many of us who are interested in space and astronomy, Reyes caught the bug from television.

“When I was a kid I watched the Moon landing on TV,” he said. “A black and white TV at my parents’ house.” He thought it was the coolest thing ever.

“I’ve always had an interest in space,” he added. His undergraduate major was in geology, and he studied some planetary science. He then went into the Air Force and medicine. He filled a free month during his residency with an introduction to aerospace medicine course at the University of Texas. He was drawn in by the lectures from real flight surgeons.

“This is what I want to do,” he learned.

No comments:

Post a Comment