The National Aeronautics and Space Administration (NASA) scientists have discovered new risk for humans in spaceflight after they observed backwards blood flow in astronauts’ veins. Researchers performed the assessment to find out the impact of long-term exposure to a weightless environment during spaceflight as it can result in a chronic headward blood and tissue fluid shift compared with the upright posture on Earth. However, the risks vanishes as soon as astronauts come bck to earth.
Speaking to an American magazine, a senior NASA scientist Karina Marshall-Goebel said that they were not expecting such a result since it was never reported before. The findings showed a strange phenomenon where the blood in the jugular vein began moving in the opposite direction. Marshall-Goebel, who authored the research paper, said that though it was sloshing back and forth a bit, there was no net-forward movement.
As a part of the research, six out the 11 International Space Station crew members, demonstrated a stagnant or retrograde flow in the internal jugular vein, one of the most important parts of the body. The jugular vein drains deoxygenated blood from the brain which is essential to reduce pressure and stalled blood flow can cause severe damage to internal organs. One of the crew members even developed a clump of blood during spaceflight. The astronauts without any clot-related symptoms were also given blood-thinning drugs for the rest of their time in orbit.
According to the report, in-flight IJV measurements were acquired at approximately 50 days and 150 days into spaceflight during normal spaceflight conditions as well as during the use of lower body negative pressure. “Lower body negative pressure may be a promising countermeasure to enhance venous blood flow in the upper body during spaceflight,” read the report. NASA scientists also said that the blood may have switched directions citing similar phenomenon in patients with tumours where blood tries to find a different root to the heart. They said that the condition vanished after astronauts returned to earth.