Bed Rest in the name of science? Do you really want to sign up?
On a recent trip to the University of Texas in Galveston, I visited a laboratory focused on studying the effects of spaceflight on humans. This laboratory, which looks like a typical hospital floor with beds and nurses stations is at the University of Texas Medical Branch (UTMB). Most of us who have followed the space program, and even those who don’t follow it closely, know NASA does medical research on the astronauts. What I did not know, is how extensive the research programs are on volunteers who want to help the space program. In fact, the program I describe below is recruiting volunteers. After reading this article, if you want to volunteer, I suggest you go to the website and read about the study and what you would have to do to apply.
This NASA research project made me aware of how much I don’t know about this area of space science. Yet, it made sense, that the scientists and doctors who will never be astronauts, can still design studies to help future astronauts stay healthy.
Picture it: you are in a bed for 3 months laying flat on your back, with your head at a slight tilt down – 6 degrees down to be exact. I am still trying to figure out which would be worse; having my head tilted down for 3 month in bed, or regardless of the tilt, having to spend 3 months in bed.
The reason the volunteers are tilted is to mimic on Earth one of the effects of zero gravity on the body. When astronauts go to space, very quickly, the lack of gravity sends blood and fluid to the upper part of the body. A typical stay for an astronaut on the space station is 3 months. At the end of three months, astronauts lose about 2 quarts of blood volume, and up to 15% of bone mass. They also lose muscle mass and strength. Many of us know these statistics. But the other effects on astronauts that are still being researched, hence the need for study volunteers, include inter cranial pressure (pressure inside the head) and increased pressure in the eye.
Astronauts are reporting even 2 years after flight, pressure inside the head persists. Others report the increased eye pressure years after flight and even more severe vascular problems in the eye. We had an astronaut with us on the tour Sam Durrance. He has flown twice. He never experienced the head or eye symptoms, but did experience 15% strength loss in his arms, but not his legs.
When Sam mentioned his loss of strength experience, the physician leading the tour took us over to a piece of equipment that NASA has just finished developing. It is a leg press machine – but it’s configured so the volunteer uses the machine while laying in a horizontal position. The tour guide explained that NASA is trying to determine whether the leg press will keep the volunteer from losing muscle mass during the 3 months of bed rest.
It was about this point in the tour all of us started to get it. The volunteer never leaves the bed or the 6 degree down position. Not to go to the bathroom, not to eat, not to exercise, not even to watch tv. Just to make sure we asked our tour guide about showering. That’s when he told us, they roll the volunteers into a special shower where the volunteers can roll over on their stomachs during the shower, but the rest of the three months they are lying on their backs. Complete bed rest is the best way we can mimic conditions in space on Earth.
Researcher topics explore the body’s ability to adapt to the head-down tilt in the same manner that the astronauts’ bodies change in space. As the studies continue, the researchers hope to learn novel and effective ways to rehabilitate patients who have had to endure long term bed rest.
We were taken to the rehabilitation units where the doctors use a suspended harness to rehabilitate the volunteers once they are allowed up from the 3 months of bed rest. Most are not able to stand without being supported by the harness as they begin to rehabilitate their bodies. The obvious connection with research on aging was mentioned as an ongoing project at UTMB.
The Spaceflight Simulation Study project website can be found at: http://clinicaltrials.gov/ct2/show/NCT00891449