Zero-G Blood and the Many Horrors of Space Surgery
MATTHIEU KOMOROWSKI WANTED to be an astronaut. Still does. The French-born anesthesiologist, currently getting a PhD at Imperial College London, applied to the European Space Agency in 2008. But he knows his chances are limited. “Being basically a medical resident I didn’t get very far in the selection,” Komorowski says. “But I’ve been working on building up my skills.”
Among those skills: administering anesthesia for surgery. And as Komorowski found when he started looking at the literature on space medicine, that might be more helpful than it sounds. Of all the concerns about astronaut safety and health, traumatic injury is the one that worries people the most. It has the biggest potential impact on a mission and, worse, it’s the one people know least about.
In part that’s because it has never happened. Over decades of Apollo, Mir, Skylab, space shuttle, and International Space Station missions, astronauts have had medical concerns and problems—and, of course, there have been deadly catastrophes. But no astronaut has ever had a major injury or needed surgery in space. If humans ever again venture past low Earth orbit and outward toward, say, Mars, someone is going to get hurt. A 2002 ESA report1 put the chances of a bad medical problem on a space mission at 0.06 per person-year. As Komorowski wrote in a journal articlelast year, for a crew of six on a 900-day mission to Mars, that’s pretty much one major emergency all but guaranteed.
Worst case: Someone goes outside the spacecraft to fix something heavy and it gets away from them, crushing an arm or a leg. The astronaut gets exposed to vacuum, but makes it back inside the vehicle—dehydrated, partially frozen, bleeding heavily, in shock. What happens next will depend on whether the crew is in orbit around Earth, or in interplanetary space—and on what kind of gear is on board.
NASA doesn’t seem headed for Mars any time soon, but people like Elon Musk are making noises about missions as early as the end of this decade. At the International Astronomical Conference in Guadalajara last September, Musk described plans for a Mars mission that seem to now be delayed or scaled back. But he still says SpaceX is going. Speaking to the ISS Research and Development Conference in Washington DC on July 19, Musk also said: “If safety is your top goal, I would not go to Mars.”
Yes, sure, space is unsafe. Even if you manage to stave off killer radiation, you still have to worry about muscles atrophying and bones getting less dense—and more breakable—in weightlessness. Not to mention the ever-present danger, thanks to long-term isolation in a confined space, of “psychiatric decompensation.” That’s NASA-talk for catastrophic marbles-losing.
Spend a long time in space, though, and your body starts to change in all sorts of other ways, too, and they all make traumatic injuries even worse. Your total amount of circulating blood and red cell mass goes down. Your blood vessels don’t constrict and dilate as well. That suite of cardiovascular problems adds up to what on Earth would look like the result of significant blood loss—and this is before you get injured. Your hormones go kind of wonky, and your immune system and wound healing get sluggish. Your bones break more easily and heal more slowly, if at all. Meanwhile, infectious bacteria become more resistant to antibiotics, and, oh, hey, you know how you always get sick after a “long” airplane flight? Imagine if the flight lasted two years.
Thanks to a freedom-of-information request from Vice, the medical gear on board the ISS is public knowledge. The crew has access to a small but professional pharmacy, including some serious drugs and EpiPens. They have an automated emergency defibrillator, gear to administer intravenous fluids, and diagnostic equipment like blood pressure cuffs. The ISS also carries an ultrasound device, for example—the only sophisticated imaging device on board, but one that’s great at finding internal bleeding and monitoring fluid levels in eyeballs, a thing astronauts have to worry about so they don’t go blind. It might also have therapeutic uses. Oh, and they have some dental equipment, which, nope, hard pass. “When it boils down to it, there’s a few things we train to handle right away,” says Steve Swanson, who commanded the ISS for six months in 2014. “Anything besides that, we were going to be calling the ground.”
Swanson learned to insert a chest tube and do a tracheotomy on a goat during training, and spent some time assisting in an emergency room. But even with that experience behind him, he and his fellow astronauts wondered how a real emergency would actually play out. “We always think about worst-case scenarios. What would you do if there was a little hole? A big hole? What would you really do?” he says. “If someone is really bad, we’ll throw them in a Soyuz and come down. But that’s not an easy trip.”
Essentially, ISS crews learn to mostly stabilize and restrain an injured astronaut, and then call the ground to talk to a flight surgeon. Anil Menon, one of about 20 NASA flight surgeons, wouldn’t tell any specific stories about astronauts’ medical problems—doctor-patient confidentiality applies even in space. But over the years he has done everything from answering a slightly worried email from the ISS to a full-blown team meeting with specialists teleconferencing in.
That’s all possible if you’re in low Earth orbit, where the ISS is. The communications delay from Johnson Space Center to the floating lab is basically nil, and in the event of a serious injury, an astronaut could nominally get into a Soyuz capsule docked at the ISS and come home.
On the other hand, “de-orbiting” is the kind of decision that goes all the way to the flight director and head of NASA—and it might not even work. “If someone breaks a leg, how would you get them in the suit?” Swanson asks. The Soyuz capsule is a cramped fit. “They’re really bent up in there.” If the patient is intubated, on a ventilator with oxygen tanks, they won’t fit into the Soyuz at all, much less into a pressure suit.
So NASA is sponsoring all kinds of research to try to figure this stuff out. Researchers on parabolic “vomit comet” airplane flights with brief periods of weightlessness have performed intubations, opened and closed wounds, repaired blood vessels, and done all kinds of other gory stuff in animals. One team even cut a benign tumor off a human man’s arm.
Some of the biggest challenges remain the messiest. In space, blood can splatter even more than it usually does on Earth, unconstrained by gravity. Or it can pool into a kind of dome around a wound or incision, making it hard to see the actual trauma. (Fun fact: If you are bleeding more than 100 milliliters per minute, you are probably doomed. An amazing 2009 paper in the Journal of Trauma Management & Outcomes called “Severe Traumatic Injury During Long Duration Spaceflight” suggests that an onboard computer monitoring hemorrhage rate could see that and ping the Chief Medical Officer to say, yeah, don’t use any more fancy anti-coagulant bandages on that guy—he’s a goner.)
One cool idea for dealing with the spurting/pooling blood problem in space is to seal a wound or incision site in a kind of bubble filled with fluid, like saline, and then operate laparoscopically, with tiny instruments on extended arms. A team led by James Antaki, a biomedical engineer at Carnegie Mellon, actually tried it on a simulated bleeding arm on a vomit comet mission four years ago. “I wimped out on going,” Antaki says. His first version had a flexible collar with gaskets for instruments and a transparent top, almost like a diver’s mask. “I’ve evolved it into a flexible, blister-like enclosure that’s puncturable,” he says. “It’s transparent so you can see what’s bleeding, the vessels and vasculature, and you poke through with an instrument, make stitches or retract and resect, cauterize, and go.” It’s made of a thick elastomer reinforced with a fiber mesh that stays closed almost like a self-sealing tire; Antaki hopes to send the latest version on a SpaceX mission to the ISS this autumn for testing—on a simulator, not an astronaut.
And Komorowski, the would-be astronaut anesthesiologist? It turns out all that cardiovascular “reconditioning”—the loss of blood volume and overall slowdown—can be catastrophic for anesthesia. “The drugs we use to put people to sleep during general anesthesia are actually quite dangerous. They lower blood pressure. They dilate blood vessels,” he says. Administering them requires really finicky training to tailor dosages to different people’s metabolisms even on Earth, and that ignores the problem of how to get complicated, often flammable gases on board a spacecraft.
Komorowski suggests adding something new to the space exploration pharmacopeia: the hardcore dissociative anesthetic ketamine. “It’s used throughout the world in hostile environments,” he says. “It doesn’t impair hemodynamic systems. The cardiovascular system is preserved, so it’s suitable for patients after blood loss, in shock, or severely dehydrated.” And it’s safe. “Even if you get it wrong and give five times too much, most likely not much is going to happen.” (Except, you know, a certain kind of party might break out.)
NASA, meanwhile, has awarded dozens of grants to researchers trying to better understand the physiology of space travel and possible medical interventions. Menon says they might be able to get around the signal-delay problem with interplanetary telemedicine by sending multimedia tutorials on a long duration mission, or by having procedures with hard stops built in after certain steps. That way, astronauts doing the meatball surgery could stop, stabilize their colleague, and await evaluation and further instructions.
If people are going to leave orbit, though, that research is going to have to head for the final frontier, too. “I think something that would be ethically acceptable would be to try a sedation in space, because the risk is really moderate, and we could learn a lot,” Komorowski says. “It’d have to be done by an anesthesiologist to start with, so I volunteer to go.” See, now he’s working the angles.