NASA Study Reveals Blood Clots, Reverse Blood Flow in Astronauts
NASA scientists have discovered an important risk to human health in spaceflight: stagnant or reverse blood flow and blood clots.
Karina Marshall-Goebel, a senior scientist at NASA, authored the study, “Assessment of Jugular Venous Blood Flow Stasis and Thrombosis During Spaceflight,” which appeared last week in the Journal of the American Medical Association.
She found, of 11 crew members on the International Space Station, six demonstrated “stagnant or retrograde flow in the internal jugular vein,” a major blood vessel on the side of the neck, due to weightlessness. One crew member developed a blood clot and another was found to have a potential partial blood clot.
It is the first time researchers have observed these conditions in astronauts.
“Reverse flow is really interesting, and we’re uncertain if it’s harmful,” Michael Stenger, the head of the Cardiovascular and Vision Laboratory at NASA’s Johnson Space Center and one of the study’s co-authors, told CNN.
“Reverse flow in the jugular vein could be completely harmless as the blood is simply leaving the head via one of the other venous pathways. However, reverse flow implies altered venous pressure dynamics, which could impact the ability of the brain to drain cerebral spinal fluid and possibly increase pressure in the brain. This is something we’re continuing to investigate.”
The astronaut with the blood clot was treated with anticoagulants for the remainder of the space flight.