- Joined
- 21 January 2015
- Messages
- 10,664
- Reaction score
- 12,291
Via NSF.
Related press release from LSU Health Sciences Center:
Related press release from UNC School of Medicine:
Published NEJM case study:
Related press release from LSU Health Sciences Center:
1st Reported Occurrence & Treatment of Spaceflight Medical Risk 200+ Miles Above Earth
Serena Auñón-Chancellor, M.D., M.P.H., Clinical Associate Professor of Medicine at LSU Health New Orleans School of Medicine’s branch campus in Baton Rouge, is the lead author of a paper describing a previously unrecognized risk of spaceflight discovered during a study of astronauts involved in long-duration missions. The paper details a case of stagnant blood flow resulting in a clot in the internal jugular vein of an astronaut stationed on the International Space Station. The paper is published in the January 2, 2020 issue of the New England Journal of Medicine, available here.
“These new findings demonstrate that the human body still surprises us in space,” notes Dr. Auñón-Chancellor, who also remains a member of NASA’s Astronaut Corps and is board certified in both internal and aerospace medicine. “We still haven’t learned everything about Aerospace Medicine or Space Physiology.”
Eleven astronauts were involved in the vascular study, which sought to help close gaps in knowledge about circulatory physiology that will not only benefit patients on Earth, but could be critical for the health of astronauts during future space exploration missions to the moon and Mars. The study measured the structure and function of the internal jugular vein in long-duration spaceflight where astronauts are exposed to sustained headward blood and tissue fluid shifts.
Ultrasound examinations of the astronauts’ internal jugular veins were performed at scheduled times in different positions during the mission. Results of the ultrasound performed about two months into the mission revealed a suspected obstructive left internal jugular venous thrombosis (blood clot) in one astronaut. The astronaut, guided in real time and interpreted by two independent radiologists on earth, performed a follow-up ultrasound, which confirmed the suspicion.
Since NASA had not encountered this condition in space before, multiple specialty discussions weighed the unknown risks of the clot traveling and blocking a vessel against anticoagulation therapy in microgravity. The space station pharmacy had 20 vials containing 300 mg of injectable enoxaparin (a heparin-like blood thinner), but no anticoagulation-reversal drug. The injections posed their own challenges – syringes are a limited commodity, and drawing liquids from vials is a significant challenge because of surface-tension effects.
The astronaut began treatment with the enoxaparin, initially at a higher dose that was reduced after 33 days to make it last until an oral anticoagulant (apixaban) could arrive via a supply spacecraft. Anticoagulation-reversing agents were also sent.
Although the size of the clot progressively shrank and blood flow through the affected internal jugular segment could be induced at day 47, spontaneous blood flow was still absent after 90 days of anticoagulation treatment. The astronaut took apixaban until four days before the return to Earth.
On landing, an ultrasound showed the remaining clot flattened to the vessel walls with no need for further anticoagulation. It was present for 24 hours after landing and gone 10 days later. Six months after returning to Earth, the astronaut remained asymptomatic.
The astronaut had no personal or family history of blood clots and had not experienced headaches or the florid complexion common in weightless conditions. The changes in blood organization and flow, along with the prothrombotic risk uncovered in the study show the need for further research.
Concludes Auñón-Chancellor, “The biggest question that remains is how would we deal with this on an exploration class mission to Mars? How would we prepare ourselves medically? More research must be performed to further elucidate clot formation in this environment and possible countermeasures.”
Internal jugular venous thrombosis has most often been associated with cancer, a central venous catheter, or ovarian hyperstimulation. Recently, it has been found in a growing number of IV drug abusers who inject drugs directly into the internal jugular vein. The condition can have potentially life-threatening complications, including systemic sepsis and pulmonary embolism.
Other members of the research team included James M. Pattarini, M.D., M.P.H., National Aeronautics and Space Administration Johnson Space Center, Houston, TX; Stephan Moll, M.D., University of North Carolina School of Medicine, Chapel Hill, NC; and Ashot Sargsyan, M.D., KBR, Houston, TX.
The study was funded by the National Aeronautics and Space Administration under the Human Research Program (grant NNJ11ZSA002NA).
______________________________________________________________________________________________________________
LSU Health Sciences Center New Orleans (LSU Health New Orleans) educates Louisiana's health care professionals. The state's health sciences university leader, LSU Health New Orleans includes a School of Medicine, the state's only School of Dentistry, Louisiana's only public School of Public Health, and Schools of Allied Health Professions, Nursing, and Graduate Studies. LSU Health New Orleans faculty take care of patients in public and private hospitals and clinics throughout the region. In the vanguard of biosciences research, the LSU Health New Orleans research enterprise generates jobs and enormous annual economic impact. LSU Health New Orleans faculty have made lifesaving discoveries and continue to work to prevent, advance treatment, or cure disease. To learn more, visit http://www.lsuhsc.edu, http://www.twitter.com/LSUHealthNO, or http://www.facebook.com/LSUHSC.
Media Contact
Leslie Capo
Office: 504-568-4806
Cell: 504-452-9166
Related press release from UNC School of Medicine:
The Ultimate Telemedicine: UNC Expert Helps Treat Astronaut’s Blood Clot During NASA Mission
Blood clot expert Stephan Moll, MD, professor of medicine in the UNC School of Medicine, consulted NASA on how to treat a U.S. astronaut’s deep vein thrombosis during a mission on the International Space Station. Moll co-wrote a case study on the successful treatment that has been published in the New England Journal of Medicine.
Contact: Carleigh Gabryel, 919-864-0580, carleigh.gabryel@unchealth.unc.edu
January 2, 2020
CHAPEL HILL, NC – “My first reaction when NASA reached out to me was to ask if I could visit the International Space Station (ISS) to examine the patient myself,” said Stephan Moll, MD, UNC School of Medicine blood clot expert and long-time NASA enthusiast. “NASA told me they couldn’t get me up to space quickly enough, so I proceeded with the evaluation and treatment process from here in Chapel Hill.”
Moll was the only non-NASA physician NASA consulted when it was discovered that an astronaut aboard the ISS had a deep vein thrombosis (DVT) – or blood clot – in the jugular vein of their neck. The astronaut’s identity is being kept anonymous for privacy reasons, so identifying information such as when this event happened is being omitted from the case study. We do know that the astronaut was two months into a six-month mission on the ISS when the DVT was discovered.
This was the first time a blood clot had been found in an astronaut in space, so there was no established method of treatment for DVT in zero gravity. Moll, a member of the UNC Blood Research Center, was called upon for his vast knowledge and treatment experience of DVT on Earth.
“Normally the protocol for treating a patient with DVT would be to start them on blood thinners for at least three months to prevent the clot from getting bigger and to lessen the harm it could cause if it moved to a different part of the body such as the lungs,” Moll said. “There is some risk when taking blood thinners that if an injury occurs, it could cause internal bleeding that is difficult to stop. In either case, emergency medical attention could be needed. Knowing there are no emergency rooms in space, we had to weigh our options very carefully.”
Moll and a team of NASA doctors decided blood thinners would be the best course of treatment for the astronaut. They were limited in their pharmaceutical options, however. The ISS keeps only a small supply of various medicines on board, and there was a limited amount of the blood thinner Enoxaparin (Lovenox®) available. Moll advised NASA on what dosage of Enoxaparin would effectively treat the DVT while also lasting long enough, until NASA could get a new shipment of drugs – which Moll helped select – to the ISS.
The course of treatment with Enoxaparin – a drug delivered by an injection into the skin – lasted for around 40 days. On day 43 of the astronaut’s treatment, a supply of Apixaban (Eliquis®) – a pill taken orally– was delivered to the ISS by a supply spacecraft.
Throughout the treatment process, which lasted more than 90 days, the astronaut performed ultrasounds on their own neck with guidance from a radiology team on Earth in order to monitor the blood clot. Moll was also able to speak to the astronaut during this period through email and phone calls.
“When the astronaut called my home phone, my wife answered and then passed the phone to me with the comment, ‘Stephan, a phone call for you from space.’ That was pretty amazing,” said Moll. “It was incredible to get a call from an astronaut in space. They just wanted to talk to me as if they were one of my other patients. And amazingly the call connection was better than when I call my family in Germany, even though the ISS zips around Earth at 17,000 miles per hour.”
Four days before the astronaut’s journey home to Earth, they stopped taking Apixaban. Moll and his NASA counterparts made that decision because of how physically demanding and potentially dangerous the re-entry process can be for astronauts, and they did not want an injury to be exacerbated by the use of blood thinners. The astronaut landed safely on Earth and the blood clot required no more treatment.
This astronaut’s blood clot was asymptomatic – they didn’t have any symptoms that would have otherwise made them aware of the clot. The DVT was discovered when the astronaut was taking ultrasounds of their neck for a research study on how body fluid is redistributed in zero gravity. If it wasn’t for the study, there’s no telling what the outcome could have been. That’s why Moll continues to work with NASA and says there’s a need for more research of how blood and blood clots behave in space.
“Is this something that is more common in space?” posed Moll. “How do you minimize risk for DVT? Should there be more medications for it kept on the ISS? All of these questions need answering, especially with the plan that astronauts will embark on longer missions to the moon and Mars.”
Published NEJM case study:
