Travel medicine for the zero-gravity set

Virgin Galactic is already offering $200,000 tickets to intrepid tourists who want to take a suborbital flight on a craft called SpaceShipTwo. Start-up Golden Spike announced earlier this month that it would offer round trips to the moon for two starting at $1.4 billion.

But having a couple of hundred of thousand (or million) lying around might not be the only requirement for folks wanting to take a jaunt in outer space. A team of researchers and physicians, led by University of California, San Francisco, surgeon Dr. S. Marlene Grenon, suggested Thursday that would-be space travelers also will need permission slips from their doctors.

That means doctors will have to figure out what kind of advice to give, the authors wrote in a study published in the journal BMJ. “We all have questions from patients related to air travel. In the short future, we may be getting questions from our patients about space travel,” Grenon said in a statement.

The study, published as part of a special Christmas issue, detailed some of the physiological changes that people undergo outside of Earth’s gravity and atmosphere. “Volume shifts” can cause cardiovascular deconditioning, bone loss and suppression of the immune system. Space travelers can experience vision troubles because of changes in pressure in the cranium. They can suffer motion sickness, appetite loss, dehydration, back pain and skin problems. Cancer risk may be heightened as well because of radiation exposure.

Most physicians in general practice don’t know much about how space travel affects health, the team wrote. They offered suggestions on getting up to speed — within reason.

Just as most doctors aren’t expert on the physiology of airplane flight, they probably don’t need to become expert in the physiology of space flight. But they do need to start thinking about space flight a little bit, recognizing that there are specific risks associated with space flight for healthy and unhealthy people alike. Standards governing medical advice for casual space passengers are in the works, the authors wrote.

Two tables included in the paper offered additional, if breezy, details. The first, a summary of the medical conditions associated with spaceflight and potential countermeasures, informs physicians that motion sickness in space orbit can be treated with anti-nauseant drugs; bone loss with exercise and vitamin supplementation; the bends with the appropriate use of a spacesuit.

The second table described the considerations doctors might keep in mind as patients with common medical problems travel beyond Earth. Those with asthma and cardiovascular disease should make sure they’re managing their conditions optimally though drugs and other interventions. People with a history of deep vein thrombosis might get heparin injections during flight. Pregnant women and those with cancer should “consider postponing flight.”

“You must check with your doctor to see if your heart and other vital organs are up for this type of adventure,” said Millie Hughes-Fulford, a professor of biochemistry and biophysics at UCSF who flew into space on the shuttle Columbia in 1991.

“It feels like you’re on the top of a roller coaster while you’re in outer space. That feeling, in the pit of your stomach, is what you’ll experience the entire time” you’re on your space vacation, she said, in a statement.

And on that note: Bon voyage.