Space Sta­tion ER

NASA astro­nauts are paragons of fit­ness. Good thing.

Air & Space Smithsonian - - Front Page - BY TIM WRIGHT

ABOARD AN AN­CIENT BOE­ING KC-135 nick­named the “Vomit Comet,” a med­i­cal re­search team goes to work as the NASA air­craft flies a par­a­bolic curve, en­ter­ing a 25-sec­ond pe­riod of zero grav­ity. To avoid float­ing away, sur­geon Mark R. Camp­bell wedges his feet be­neath a bar at the base of a pro­to­type sur­gi­cal ta­ble. Atop the ta­ble lies an anes­thetized and rigidly re­strained rab­bit, Camp­bell’s re­search sub­ject. This test is the cul­mi­na­tion of six months of plan­ning.

Camp­bell ig­nores the sen­sa­tion of weight­less­ness as he takes a scalpel and care­fully opens the rab­bit’s carotid artery, then pulls back to watch. Ini­tially, Camp­bell sees ex­actly what he ex­pects. In zero grav­ity, bright red globes of blood streak out of the wound like paint balls fired from a gun. But within sec­onds, the steady flow of globes di­min­ishes and then stops while a dome of blood grows over the in­ci­sion. Dis­mayed, Camp­bell makes his carotid in­ci­sion larger to in­crease blood flow but the re­sults are un­changed, and a cut into a ma­jor artery in the rab­bit’s ab­domen has the same re­sult. “Fi­nally we just fig­ured out that that’s the way blood acts in weight­less­ness,” he says. “It didn’t act the way we thought it would.”

In five decades of hu­man space­flight and 15 years of con­tin­u­ous oc­cu­pa­tion of the In­ter­na­tional Space Sta­tion, no hu­man has ever un­der­gone a sur­gi­cal pro­ce­dure in or­bit. Given the in­tent of na­tional space agen­cies, pri­vate com­pa­nies, and even some in­di­vid­u­als to launch long-range space mis­sions, it seems in­evitable that at some point some­one will have a bad day, and surgery will be needed to save a life. When that day comes, the pa­tient may want

to send Camp­bell a thank-you note.

Camp­bell’s 1991 rab­bit experiment took place dur­ing the buildup for Space Sta­tion Free­dom, which was to have been a gi­gan­tic out­post, with a 1,200-pound, X-ray–equipped mod­ule that could ad­dress al­most any med­i­cal emer­gency. The well­stocked space ER was a ne­ces­sity be­cause of the space shut­tle’s ex­pected launch sched­ule—once ev­ery 45 days. Though a pa­tient on the ground could be brought to a hos­pi­tal within min­utes, in space it was con­ceiv­able that for 45 days, an in­ca­pac­i­tated or badly hurt as­tro­naut would have to suf­fer with­out sup­port from Earth­bound doc­tors and equip­ment. “That was a re­ally long time,” says Camp­bell.

A re­tired NASA flight sur­geon, Camp­bell is a mem­ber of the FAA’S Com­mer­cial Space Trans­porta­tion Ad­vi­sory Com­mit­tee and a prac­tic­ing gen­eral sur­geon in Paris, Texas. Be­cause no one was sure if surgery in zero grav­ity was pos­si­ble, his experiment on bleed­ing be­hav­ior was an early step in a new world. By the time the par­a­bolic flights con­cluded, in 2000, Camp­bell had at­tempted pro­ce­dures rang­ing from sim­ple su­tures and CPR to la­paroscopy while float­ing in brief pe­ri­ods of zero grav­ity. By that time NASA faced the re­al­ity of far fewer shut­tle launches with much more time be­tween, and Free­dom mor­phed into the smaller In­ter­na­tional Space Sta­tion, and most of the planned med­i­cal ca­pa­bil­i­ties were shelved.

Aboard the In­ter­na­tional Space Sta­tion, the care avail­able to the per­ma­nent crew of six is min­i­mal. There are ven­ti­la­tion de­vices to as­sist breath­ing, a de­fib­ril­la­tor for heart prob­lems, a fold­ing pa­tient re­straint ta­ble that dou­bles as a trans­port de­vice. An ul­tra­sound-imag­ing de­vice, meant for sci­en­tific re­search, could in a pinch be used for di­ag­nos­tics. The med­i­cal kit can han­dle rel­a­tively mi­nor ail­ments but sim­ply can­not cope with dis­as­ter. No mat­ter the equip­ment, the crew may be un­able to han­dle the sit­u­a­tion. Even qual­i­fied doc­tors that fly may be too out of prac­tice to per­form.

“They are trained to treat some­one who is chok­ing; we have a pro­ce­dure where they re­spond to toxic ex­po­sure; we can treat a seizure, chest pain…. Most of these things do not re­quire any sur­gi­cal-type in­ter­ven­tion—it’s a sim­ple pro­ce­dure like putting in an air­way,” says Terry Tad­deo, NASA’S cur­rent chief of space medicine. “If they re­ported some­thing they didn’t feel com­fort­able with, we would get the peo­ple in [mis­sion con­trol] that could as­sist, talk them through it.” Rather than a so­phis­ti­cated med­i­cal suite, the ISS keeps a spare Rus­sian Soyuz capsule for use as a lifeboat, with the treat­ment plan be­ing a ride home within 24 hours. Strapped into the Soyuz’s con­fines, astro­nauts ex­pe­ri­ence up to 8 Gs dur­ing a reen­try, which makes it one of the rough­est am­bu­lance rides any­one is likely to ex­pe­ri­ence.

In the eco­nom­ics of space re­search, the cold fact is that any med­i­cal ca­pa­bil­ity launched comes at the ex­pense of some­thing else, so agen­cies launch only as much as they feel they can get away with. Prospec­tive astro­nauts are sub­jected to an in­tense se­lec­tion process, and those at risk for even mi­nor med­i­cal con­di­tions are weeded out, min­i­miz­ing the chances that weighty med­i­cal equip­ment is needed.

“If we’re go­ing to or­bit, that’s like go­ing on a camp­ing trip,” says Linda Plush, a nurse prac­ti­tioner and co-founder of the Space Nurs­ing So­ci­ety. “So I’m not go­ing to take the kitchen sink. I’m go­ing to look at what’s com­mon, what’s likely to oc­cur, and pre­pare for that.”

But a deep-space mis­sion, like to Mars or be­yond, changes the cal­cu­la­tions. An ex­plo­ration space­craft will end up so far away that evac­u­a­tion will be all but im­pos­si­ble. “If you have sur­gi­cal ca­pa­bil­i­ties, the ques­tion is where do you draw the line?” asks as­tro­naut Mike Bar­ratt, a physi­cian who has been on two ISS mis­sions. “Are you go­ing to al­ways have a doc­tor on board? That means that one-sixth of the as­tro­naut of­fice has to be a clin­i­cally cur­rent sur­geon.”

Be­cause the astro­nauts have no dis­cernible med­i­cal prob­lems, Bar­ratt be­lieves the most likely rea­son for surgery will be a wound. “When you think about

what brings peo­ple to the ER on the ground, it’s trau­matic forces. It’s falls, it’s mo­tor ve­hi­cle ac­ci­dents, it’s gun­shot wounds and in­dus­trial ac­ci­dents. [In space] we don’t have mo­tor ve­hi­cles. We don’t have falls be­cause there’s no grav­ity. We don’t have gun­shots. So then you’re down to in­dus­trial ac­ci­dent-type things and shrap­nel.”

But would you even want to per­form a med­i­cal pro­ce­dure aboard the ISS? “If you sneeze, if you go to the bath­room and you have bad tech­nique, or if eat­ing and you’re a messy eater—all that stuff goes into the at­mos­phere for your com­padres to breathe,” ex­plains ISS vet­eran Bar­ratt. “And ev­ery­body sheds dead skin at a high rate in space, and that one’s of the things we see a lot in the fan fil­ters and the fil­ter in­takes…. So we aren’t any­where near as clean as an op­er­at­ing room.”

“If you do an op­er­a­tion,” says sur­geon Mark Camp­bell, “wouldn’t that mean your risk of in­fec­tion would be higher be­cause you’ve got all these nasty par­ti­cles float­ing around? Well, no one knows.”

Tinier par­ti­cles are a risk too. In the closed en­vi­ron­ment of a space­craft, ex­haled mol­e­cules of anes­thetic would be­come a per­ma­nent part of the air the crew breathes, so there is no way they wouldn’t in­hale mol­e­cules of anes­thetic gas. When an anes­thetic is needed, the in­hab­i­tants are lim­ited to drugs that can be in­jected or swal­lowed.

Not that we un­der­stand quite how medicines work in space. On Earth some med­i­ca­tions are sen­si­tive to light or tem­per­a­ture; with ex­tra ra­di­a­tion and changes to the hu­man body, much re­mains un­known. For that mat­ter, some germs and bac­te­ria don’t act like they do on Earth. In low Earth or­bit some or­gan­isms seem less vir­u­lent and oth­ers more so, and we don’t re­ally un­der­stand why. Even less is known about their be­hav­iors in the ra­di­a­tion-filled en­vi­ron­ment of deep space. “The drugs we use in space, we use at dosages we use on Earth,” says

In a med­i­cal emer­gency, the Soyuz capsule docked to the ISS (op­po­site) can be­come an am­bu­lance. Ex­per­i­ments with sur­gi­cal con­tain­ment mea­sures on air­craft showed an OR in mi­cro-g to be a poor op­tion.

Neu­ro­lab on the shut­tle Columbia mea­sured as­tro­naut ner­vous sys­tems in space (and showed surgery on rats can be done safely).

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